Comparative Evaluation of the Antioxidant Capacities

Research ArticleComparative Evaluation of the Antioxidant CapacitiesOrganic Acids and Volatiles of Papaya Juices Fermented byLactobacillus acidophilus and Lactobacillus plantarum

Ronghao Chen Wenxue Chen Haiming Chen Guanfei Zhang and Weijun Chen

College of Food Science and Technology Hainan University Haikou Hainan 570228 China

Correspondence should be addressed to Weijun Chen chenwjhainueducn

Received 30 July 2017 Revised 7 November 2017 Accepted 13 December 2017 Published 3 January 2018

Academic Editor Jorge Barros-Velazquez

Copyright copy 2018 Ronghao Chen et alThis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Fermentation of foods by lactic acid bacteria is a useful way to improve the nutritional value of foods In this study thehealth-promoting effects of fermented papaya juices by two species Lactobacillus acidophilus and Lactobacillus plantarum weredetermined Changes in pH reducing sugar organic acids and volatile compounds were determined and the vitamin C totalphenolic content and flavonoid and antioxidant capacities during the fermentation process were investigated Juices fermentedby Lactobacillus acidophilus and Lactobacillus plantarum had similar changes in pH and reducing sugar content during the 48 hfermentation period Large amounts of aroma-associated compounds and organic acids were produced especially lactic acidwhich increased significantly (119901 lt 005) (54318mg100mL and 57129mg100mL resp) improving the quality of the beverageIn contrast the production of four antioxidant capacities in the fermented papaya juices showed different trends after 48 hoursrsquofermentation by two bacteria Lactobacillus plantarum generated better antioxidant activities compared to Lactobacillus acidophilusafter 48 h of fermentationThese results indicate that fermentation of papaya juice can improve its utilization and nutritional effect

1 Introduction

Lactic acid fermentation is one of the oldest and mosteconomical methods used in food preservation especiallyas a ldquonaturalrdquo process that enhances the efficacy and qualityof foods while improving the organoleptic qualities of theproduct [1ndash3] In fact at the end of the twentieth centurythe Food and Agriculture Organization (FAO) of the UnitedNations recognized the importance of fermented productshighlighting their economic importance for local commu-nities in developing countries [4] Probiotic foods are animportant and dominating part of the functional food mar-ket accounting for 60 to 70 of the total functional foodmarket [5] withmore than 370 products launchedworldwidein Japan and Europe in 2005 [6] A number of studies havereported that the development of fruit juice-based fermentedbeverages would be the next food category in which health-promoting probiotic bacteria will make their mark [7 8]Many countries have conducted extensive research and devel-opment on probiotic-fermented fruit and vegetable beverages

in recent years especially in Korea India and Brazil Thesestudies have used watermelons tomatoes apples and so onas raw materials for fermentation by lactic acid bacteria [9ndash11] An important aspect of lactic acid bacteria (LAB) fer-mentation is the production of organic acids sugar polymersaromatic compounds vitamins polyphenolic compoundsand some useful enzymes which enrich the human diet[12 13] The fermentation products generated by differentlactic acid bacteria are not the same Lee et al [14] showedvariations among the respective LAB strains from kimchiand Kumar et al [15] showed that L plantarum Lp91 has abetter effect than Lp21 in the management of hypercholes-terolaemia Thus significant differences in the antioxidantactivity and composition of fermented products can begenerated by specific probiotic strains [16]

Papaya (Carica papaya L) a member of the Caricaceaefamily is widely cultivated in tropical and subtropical regionsand ismarketed around the world for its great taste and nutri-ents [17 18] Papaya has been identified as a valuable sourceof nutrients and antioxidants and is also used for traditional

HindawiJournal of Food QualityVolume 2018 Article ID 9490435 12 pageshttpsdoiorg10115520189490435

2 Journal of Food Quality

medicine Its fruits stems leaves and roots are used in awide range of medical applications including the productionof two important bioactive compounds (chymopapain andpapain) which are widely used for digestive diseases [19ndash21] However postharvest losses of papaya occur throughoutthe value chain due to rapid deterioration of its chemicalcomponents and pulp softening which results in a short shelflife of the fresh fruit [22 23]Many studies have demonstratedthe feasibility of using fruits such as oranges pineapplesbananas and cranberries to produce probiotic beverages[24] However other fruits such as papaya have not beenadequately studiedThus far only a small amount of researchhas been conducted on fermented papaya beverages Amongthese most have studied the use of papaya for wine-making[25 26] Di Cagno et al [27] demonstrated the growthand survival of L plantarum and L pentosus in a papayajuice-based medium All of these studies have demonstratedthat papaya beverages are suitable for microbial growth Toexplore the feasibility of LAB fermentation of papaya bev-erages to improve the utilization value of papaya this studyassessed two lactic acid bacteria for fermentation

2 Materials and Methods

21 Materials

Samples and Bacteria Papaya puree skim milk powder andedible glucose were purchased from the Nanguo Supermar-ket and Hainan Dachuan Food Co Ltd (Haikou China)Lactobacillus acidophilusGIM1731 (L acidophilus) andLacto-bacillus plantarum GIM1140 (L plantarum) were purchasedfrom GuangdongMicrobiology Culture Center (GuangzhouChina)

Preparation of Papaya Juices and Fermentation Each samplewas formulated to 200 g for fermentation According tomass45 papaya puree 45 distilled water 5 edible glucose and5 skim milk powder (10-fold diluted skim milk powder)were added to a conical flask heat sterilized at 90∘C for10min and then cooled in a water bath Each LAB strain wasinoculated at 5 of the mass ratio of the fermentation brothand the mixture was incubated at 37∘C for 48 h under staticconditions Samples were stored at minus80∘C Fermentationprocesses were repeated three times

22 Methods

221 Determination of pH The pH of the samples wasmeasured by a digital pH meter (FE20 laboratory pHmeter)

222 Determination of Reducing Sugars The reducing sugarscontent of fermented juice was analyzed as glucose equiva-lents by the 35-dinitrosalicylic acid (DNS) method of Saqib[28] with somemodification In this application 2mL of 250-fold diluted sample and 4mL DNS reagent were added to the10-mL graduated tube and heated in a boiling water bath for5 minutes When removed the tube was immediately placedin cold water cooled to room temperature supplementedwith water to 10mL and shaken well The absorbance was

measured at 540 nmThe results were expressed asmilligramsof glucose equivalents

223 Determination of Vitamin C The 26-dichloropheno-lindophenol titrimetric method was used to measure thelevels of reduced ascorbic acid [29]

224 Determination of Total Phenolic Content Extracts wereprepared by mixing 5 g of sample with 25mL of 50 ethanolThe mixture was placed in a thermostat oscillator set at100 rmin for 1 h and was then centrifuged at 4000 rminfor 10min Extracts were transferred into test conical flasksand stored at 4∘C before analysis Total phenolic content wasdetermined using the Folin-Ciocalteu method described byde Sa et al [30] with some modifications A 1mL aliquotof each fermented papaya beverage extract was mixed with02mL of Folin-Ciocalteursquos reagent and was incubated atroom temperature for 3minThen themixture was dissolvedin 75 Na2CO3 and adjusted to a volume of 10mL After30min the absorbance was measured at 765 nm The resultswere expressed asmilligrams of gallic acid equivalents (GAE)

225 Determination of Total Flavonoids Content The totalflavonoids content of samples was measured according tothe method of Wu et al [31] with some modifications A06mL aliquot of each sample was mixed with 12mL of 80methanol then 018mL of 20 NaNO2 was added After6min 036mL of 8 Al(NO3)3 was added followed by theaddition of 12mL of 1molL NaOH after 5min After 15minthe absorbance was measured at 510 nm The results wereexpressed as milligrams of rutin equivalents (RE)

226 Determination of Total Carotenoid Content The totalcarotenoid content was measured according to the methodof Carbonell-Capella et al [32] with some modification A1mL aliquot of each sample was homogenized with 5mLof extraction solvent (hexaneacetonemethanol 50 25 25VV) The mixture was placed in a thermostat oscillator set at100 rmin for 30min and then was centrifuged at 6000 rminat 4∘C for 10minThe top colored hexane layer was recoveredand transferred to a 25mL volumetric flask and the volumewas then adjusted to 25mL with hexane The absorbanceof the samples was measured at 450 nm The results werecalculated as described by Ritter and Purcell (1981) using theextinction coefficient of 120573-carotene 1198641 = 2505

227 Determination of the Total Antioxidant Capacity In Vitro

(1) 22-Diphenyl-1-Picrylhydrazyl (DPPH) Radical ScavengingAssay The DPPH∙+ assay was performed according to Liet al [33] with some modifications Briefly 002 g of DPPHwas transferred to a 25 mL volumetric flask the volume wasadjusted to 25mLwithmethanol and after the flask was fullyoscillated the solution was subjected to ultrasound for 5minThe 08mgmL solution of DPPH in methanol was dilutedwith methanol until the solution had an absorbance of 12ndash13at 517 nm A 012mL aliquot of sample was added to 4mL ofthe DPPH radical solutionThemixture was incubated in the

Journal of Food Quality 3

dark for 45min after which the absorbance was measured at517 nmThe DPPH radical scavenging activity ( inhibition)was calculated using the formula (1 minus 11986011198600) times 100 where1198600 is the absorbance of the reagent blank and 1198601 is theabsorbance of the sample

(2) 221015840-Azinobis-(3-Ethylbenzothiazoline-6-Sulfonate) (ABTS)Radical Scavenging Assay The ABTS∙+ assay was performedaccording to Um et al [34] with some modification First0192 g of ABTS and 0067 g of K2S2O8 were dissolved inphosphate buffered saline (PBS pH = 7) transferred to a 50mL volumetric flask and the volume was adjusted to 50mLThe working solution of ABTS+∙ was obtained by diluting thestock solution in PBS to give an absorption of 070 plusmn 002 at734 nm A 50 120583L aliquot of each sample was added to 4mL ofthe ABTS+∙ solution and absorbance readings at 734 nmweretaken at every 10min

The ABTS radical scavenging activity ( inhibition) wascalculated using the formula (1 minus 11986011198600) times 100 where 1198600 isthe absorbance of the reagent blank and1198601 is the absorbanceof the sample

(3) Ferric Reducing Antioxidant Power (FRAP) Assay Theantioxidant capacity was determined using the FRAP assaywhich was performed according to Morales-Soto et al [35]with some modification The freshly prepared FRAP solu-tion contained 25mL of 03molL acetate buffer (pH 36)25mL of 10mmolL 246-tripyridyl-135-triazine (TPTZ)(dissolved in 40mmolL HCl) and 25mL of 20mmolL fer-ric chloride A 02mL aliquot of each 10-fold diluted samplewasmixedwith 4mL of FRAP solution andwas incubated for50min at room temperature The ferric reducing ability wasmeasured by monitoring the absorbance at 593 nm using aspectrophotometer (TU-1810 Puxi Beijing China) and theFRAP solution was used as a blank FeSO4 was used as acontrol to obtain the standard curve The FRAP values werecalculated relative to the activity of FeSO4 and expressed asFeSO4 equivalents

(4) Cupric Ion Reducing Antioxidant Capacity (CUPRAC)Assay The typical CUPRAC method as described byKondakci et al [36] was performed as follows A solutioncomprised of 1mL of 5mmolL copper sulfate 1mL of375mmolL neocuproine (dissolved in methanol) and 1mLof ammonium acetate buffer at pH 70 was prepared Then01mL of sample solution and 09mL of distilled water wereadded and well mixed This final mixture was incubatedat room temperature for 30min in a stoppered test tubeafter which the absorbance at 450 nm was measured againsta reagent blank Trolox solution was used as a control toobtain the standard curveTheCUPRACvaluewas calculatedrelative to the activity of trolox and was expressed as troloxequivalents

228 Liquid Chromatography Analysis of Organic Acids Toavoid affecting the determination of the organic acid contentthe supernatant was obtained by centrifugation before themeasurement to remove the protein [37] In brief 2mL ofsample was added to 2mL of a solution in 18 Ba(OH)2

adding 2mL of a solution of 2 ZnSO4 The mixture wasvortex shaken allowed to settle for 15min and centrifugedat 8000 rmin for 10min Measurements of organic acidcontents were performed according to the method describedby Zhao et al [38] The sample was filtered through a022120583m pore size membrane filter before injection AnHPLC system (Agilent 1260 Agilent Technologies Inc USA)equipped with a pump system and a UV-visible detectorwas used to monitor the absorbance at 210 nm for theanalysis of organic acids Organic acids were simultane-ously analyzed on a ZORBAX SB-Aq column (250mm times46mm 5120583m) (Agilent Agilent Technologies Inc USA)which was kept at 30∘C The assay conditions used wereas follows the flow was set at 08mLmin and the eluentconsisted of 002molL ammonium dihydrogen phosphate(pH 266 adjust pH by phosphate) with 3 methanol Theflow ratio was isocratic elution of Solvent A (ammoniumdihydrogen phosphate) Solvent B (methanol) (97 3) Thechromatographic peaks corresponding to each organic acidwere identified by comparing the retention times with thoseof standards For each compound a calibration curve wasprepared using standards to determine the relationshipbetween the peak area and organic acid concentration

229 Analysis of Volatile Compounds The volatile com-pound analysis was performed according to the methoddescribed by Fuggate et al [39] with some modificationVolatile components in the headspace were trapped by solidphase microextraction (SPME) The dioctanol was used asan internal standard For each sample a 1mL aliquot wastaken from a 20 mL sealed headspace bottle A CTC TrinityAutosampler was used for all assays with a SPME fibreof 5030 120583m DVBCARPDMS The following extractionconditions were used temperature 50∘C equilibration ofthe fibre 15min extraction time 30min agitation speed250 rmin injection time 4min

AUSAAgilent 7890A-5975CGas Chromatography-MassSpectrometer (GC-MS) equipped with a DB-wax (30m longtimes 025mmID times 025 120583mdf) columnwas used for all analysesThe chromatographic conditions included a flow rate of1mLmin using helium (99999) as a carrier gas and aninjection temperature of 260∘C The column temperaturewas maintained at 40∘C for 5min was ramped at 5∘Cminto 250∘C and then was held for 5min The power supplymode was set to electronic ionization (EI) The interfaceion source and quadrupole temperatures were 260 230 and150∘C respectively the electron energy used was 70 eV andthe detector voltage was 2235V the scan mode was set at fullscan with a mass range of 20ndash400 amu using the NIST 2011library

2210 Statistical Analysis The statistical analysis was con-ductedwithDPS ver 1510 software and SPSS ver 170 software(Chicago IL USA) Results were recorded as the means plusmnstandard deviation (SD) of triplicate experiments Analysisof variance (ANOVA) was performed on data sets andsignificant differences (119901 lt 001 and 119901 lt 005) between themeans were determined by Duncanrsquos multiple range test


0 6 12 18 24 30 36 42 48Time (h)

L acidophilusL plantarum

35

40

45

50

55pH

5

6

7

8

9

6 12 18 24 30 36 42 480Time (h)


The c

onte

nt o

f red

ucin

g su

gar (

g10

0g)

Figure 1 Changes in pH and reducing sugar content of the fermented papaya juices

3 Results and Discussion

31 FermentationCharacteristics of the Papaya Juice during the48 h Fermentation The pH value is an important parameterto gauge the progress and end point of lactic acid fermen-tation influencing the flavor of the fermented product [40]The two cultures showed similar characteristics with respectto changes in pH values and in the content of reducing sugarsThe changes in pH values of the two probiotic cultures areshown in Figure 1 with the pH of both cultures decreasingsignificantly during the fermentation process (119901 lt 005)For example after 48 h fermentation the pH of fermentedpapaya juice with L acidophilus (FPJA) decreased from 536to 360 and the pH of fermented papaya juice with Lplantarum (FPJP) decreased from 534 to 355 Klupsaiteet al [41] reported that the fermentation of narrow-leavedlupine resulted in similar changes in pH values Changes inreducing sugar content of the fermented papaya juices areshown in Figure 1 and the content of reducing sugar of bothFPJA and FPJP decreased significantly during fermentation(119901 lt 005) The reducing sugar content of FPJA decreasedfrom 886 g100 g to 560 g100 g and the reducing sugarcontent of FPJP decreased from 880 g100 g to 576 g100 gHowever the fermented papaya juices still had a high contentof reducing sugar retaining enough sweetness

32 The Relationship between Antioxidative Components andAntioxidant Capacities

321 Antioxidative Components of the Fermented PapayaJuices after the 48 h Fermentation Period A large number ofstudies analyzing the bioactive composition of papaya havebeen reported Papaya is rich in total phenols carotenoidsflavonoids vitamin C and other bioactive substances [42]The total phenolic content of FPJA decreased more signifi-cantly than that of FPJP as shown in Table 1 (119901 lt 005) The

Table 1 Changes in total phenolic content of the fermented papayajuices

Fermentation time (h)Total phenolic content of the fermented

papaya juices (mg100 g)L acidophilus L plantarum

0 319 plusmn 06a 321 plusmn 08ab

6 288 plusmn 05cd 319 plusmn 04ab

12 302 plusmn 03bc 298 plusmn 04c

18 307 plusmn 07ab 325 plusmn 18a

24 311 plusmn 08ab 307 plusmn 08bc

30 321 plusmn 08a 330 plusmn 15a

36 291 plusmn 197c 317 plusmn 16ab

42 274 plusmn 04de 305 plusmn 05bc

48 272 plusmn 09e 295 plusmn 06c

Values are expressed as the mean plusmn SD Values with different letters (a sim e)in the same column are significantly different at 119901 lt 005

total phenolic content of FPJA decreased from 3189mg100 gto 2716mg100 g a decrease of 1483 while the totalphenolic content of FPJP decreased from 3209mg100 gto 2953mg100 g representing a decrease of 798 Thetotal flavonoids content of both FPJA and FPJP increasedsignificantly after fermentation as shown in Table 2 (119901 lt005) The total flavonoids content of FPJA increased from050mg100 g to 111mg100 g and the total flavonoidscontent of FPJP increased to 145mg100 g The totalcarotenoid content of FPJA decreased from 1547mg100 gto 1148mg100 g and vitamin C content decreased from2111mg100 g to 1756mg100 g The total carotenoid contentof FPJP decreased from 1547mg100 g to 1115mg100 gand the vitamin C content decreased from 2111mg100 g to1822mg100 g


Table 2 Changes in others antioxidative components of the fer-mented papaya juices

Antioxidativecomponents

Papaya juice(mg100mL)

L acidophilus48 h

(mg100mL)

L plantarum48 h

(mg100mL)Total flavonoidscontent 050 plusmn 006c 111 plusmn 017b 145 plusmn 013a

Total carotenoidcontent 155 plusmn 13a 115 plusmn 13b 111 plusmn 10b

Vitamin Ccontent 211 plusmn 10a 176 plusmn 10b 1822 plusmn 10b

Values are expressed as the mean plusmn SD Values with different letters (a sim c)in the same column are significantly different at 119901 lt 005

322 Antioxidative Activity of the Fermented Papaya Juicesafter the 48 h Fermentation Period Different antioxidantcompoundsmay act against oxidizing agents through distinctmechanisms so that a single isolation method cannot com-pletely evaluate the antioxidant capacity of samples [43] Forthis reason fourmethods of assessing antioxidants were usedto study the antioxidant capacity of FPJ (Table 1)

The antioxidant activity of FPJ determined by the DDPHradical scavenging assay is shown in Table 3 The DPPHradical scavenging activities of FPJA decreased significantlyafter the fermentation process (119901 lt 005) and the inhibitiondecreased from 8190 to 5560 The DPPH radical scav-enging activity of FPJP ranged from7739 to 8625 and theinhibition increased by 463 A similar change in the DPPHradical scavenging has been reported in other studies [44 45]The inhibition of FPJ showed that for both cultures there wasgt50of radical scavenging activity after 48 h of fermentation

The results of the ABTS radical scavenging assays areshown in Table 3 The ABTS radical scavenging activity ofFPJA decreased significantly after 48 h fermentation (119901 lt005) In contrast the ABTS radical scavenging activity ofFPJP tended to increase after fermentation although nosignificant difference was observed In both samples theinhibition remained gt80 after the fermentation Kim et al[46] reported that fermented potato juices with Lactobacilluscasei have a similar change in ABTS radical scavengingactivity

Similarly the FRAP and CUPRAC values in FPJAdecreased significantly after the 48 h fermentation period(119901 lt 005) (Table 3) Hence FRAP decreased by 2060(decrease from 568 to 451mM FeSO4) and CUPRACdecreased by 645 (decreasing from 124 to 116mM trolox)The FRAP and CUPRAC values of FPJP increased slightlyafter the 48 h fermentation period (119901 lt 005) (Table 3)Hence FRAP increased from 554 to 574mM FeSO4 (ns)and CUPRAC increased from 126 to 157mM trolox (119901 lt005)

Both strains have the same pattern for the content ofantioxidant compounds We observed that the total phenoliccontent of both strains had maximal values at 30 hoursand then decreased (Table 1) The reasons for the decreasein the phenolic compounds in the papaya juices duringprobiotics fermentation likely include their precipitation oroxidation during the process the combination or adsorption

of phenolic compounds with solids proteins or even yeastsand polymerization all of which results in important lossesof these compounds [47] In contrast the total flavonoidscontent of both strains increased This could be explainedby enzymatic degradation and by acids produced by thestrain facilitating the release of phenolics and flavanones fromtheir complexed forms in dietary fibre into freely solubleforms by the fermenting microorganism [12 48] Similarresults were observed in the study of Kantachote et al [49]who fermented coconut water with Lactobacillus plantarumDW12Therewas a significant decrease in the total carotenoidcontent and vitamin C of papaya juices after fermentation bythe two cultures (119901 lt 005) The reason for the decreasedtotal carotenoid content and vitamin C is that carotenoidsand vitamin C are easily oxidized at high fermentationtemperatures [50 51]

In recent years many scholars have become concernedabout the antioxidant activity of fermented foods Ohata etal [52] studied fermented meat sauce observing an increasein the DPPH radical scavenging activity Simsek et al [53]studied fermented vegetable juices but found no significantdifference between the DPPH radical scavenging activity offermented and unfermented vegetable juices Nazzaro et al[54] showed a decrease in the DPPH radical scavengingactivity of fermented carrot juices with L rhamnosus and alsoshowed an increase in the DPPH radical scavenging activityof fermented carrot juices with L bulgaricus after 48 h Inaddition Gan et al [55] reported that there is no change intheABTS free radical scavenging capacity of fermentedmungbean with L plantarumWCFS1

Overall the two probiotic cultures showed differenttrends of antioxidant capacities Li et al [56] studied the effectof onion juice on the fermentation of milk by L acidophilusdemonstrating that the antioxidant activity decreased signif-icantly during the fermentation process confirming that itwas necessary to scavenge radicals for L acidophilus growthHervert-Hernandez et al [57] studied the stimulatory roleof grape pomace polyphenols on L acidophilus growth andinferred that L acidophilus may be able to use polyphenolspossessing antioxidant functions as substrates Our resultsare supported by the research of Ankolekar et al [58] whoobserved a decrease in total phenolic content and antioxidantcapacities throughout fermentation by L acidophilus Dasand Goyal [59] reported that L plantarum shows betterantioxidant activity compared to L acidophilus and can act asan antioxidative probiotic L plantarum fermentation brothhas a strong reducing ability Fe2+ chelating ability and avariety of free radical scavenging abilities as demonstratedby the work of Tang et al [60] All of these studies help tofurther illustrate our experimental results

33 The Organic Acid Contents of the Fermented PapayaJuices Lactic acid bacteria catabolize sugars via fermenta-tion leading to the formation of organic acids (includinglactic acid acetic acid) with ethanol as the final products [6162] L acidophilus is an obligately homofermentative bacteria(produces lactic acid as main metabolic product) while Lplantarum belongs to the facultatively homofermentative


Table 3 Change in antioxidant activity of the fermented papaya juices

Fermentation time (h) DPPH ( InhA) ABTS ( Inh)L acidophilus L plantarum L acidophilus L plantarum

0 819 plusmn 12a 795 plusmn 07c 905 plusmn 20a 885 plusmn 10a

6 771 plusmn 29a 774 plusmn 04d 868 plusmn 31bc 849 plusmn 09d

12 788 plusmn 04a 785 plusmn 04cd 869 plusmn 26bc 862 plusmn 04c

18 780 plusmn 04a 814 plusmn 05b 875 plusmn 08ab 876 plusmn 06abc

24 706 plusmn 01b 830 plusmn 12b 881 plusmn 07ab 869 plusmn 11bc

30 669 plusmn 396b 863 plusmn 11a 898 plusmn 09ab 876 plusmn 07ab

36 777 plusmn 22a 827 plusmn 09b 906 plusmn 13a 879 plusmn 06ab

42 608 plusmn 57c 835 plusmn 17b 869 plusmn 07c 888 plusmn 07a

48 556 plusmn 15d 831 plusmn 19b 842 plusmn 10c 888 plusmn 046a

Fermentation time (h) FRAP (mM FeSO4) CUPRAC (mM trolox)L acidophilus L plantarum L acidophilus L plantarum

0 568 plusmn 008a 554 plusmn 006cd 124 plusmn 004de 126 plusmn 002d

6 523 plusmn 008bc 530 plusmn 011e 129 plusmn 0012bc 123 plusmn 008d

12 571 plusmn 006a 554 plusmn 016cd 158 plusmn 004a 137 plusmn 005c

18 524 plusmn 016bc 573 plusmn 007abc 134 plusmn 003c 144 plusmn 002c

24 500 plusmn 008cd 587 plusmn 007a 127 plusmn 003d 161 plusmn 001ab

30 481 plusmn 015d 580 plusmn 009ab 121 plusmn 003de 143 plusmn 003c

36 533 plusmn 017b 563 plusmn 014bc 152 plusmn 004b 155 plusmn 001b

42 511 plusmn 012bc 538 plusmn 013de 127 plusmn 003d 168 plusmn 016a

48 451 plusmn 016e 574 plusmn 017abc 116 plusmn 006f 157 plusmn 002ab

Values are expressed as the mean plusmn SD Values with different letters (a sim f) in the same column are significantly different at 119901 lt 005 A inhibition

Table 4 Changes in organic acid of the fermented papaya juices

Organic acids Papaya juice (mg100mL) Fermented 48 h with L acidophilus(mg100mL) Fermented 48 h with L plantarum (mg100mL)

Lactic acid 266 plusmn 3b 543 plusmn 68a 571 plusmn 32a

Oxalic acid 857 plusmn 56a 785 plusmn 72a 809 plusmn 76a

Tartaric acid 036 plusmn 003a 010 plusmn 002c 016 plusmn 002b

Formic acid 881 plusmn 041b 2094 plusmn 410a 1842 plusmn 208a

Pyruvic acid 055 plusmn 005b 113 plusmn 015a 120 plusmn 011a

Malic acid 532 plusmn 28b 776 plusmn 35a 742 plusmn 20a

Acetic acid 234 plusmn 013c 386 plusmn 038b 619 plusmn 092a

Total organicacid 416 725 752

Values are expressed as the mean plusmn SD Values with different letters (a sim c) in the same row are significantly different at 119901 lt 005

group (produces lactic acid and other products such as aceticacid) [63] These organic acids are important secondarycarbon sources for numerous microbial genera that prolif-erate during food fermentation The fermentation of papayajuices resulted in a significant change in the compositionof the organic acids (Table 4) and the changes in organicacids between the two cultures were similar Lactic acidformic acid pyruvic acid malic acid and acetic acid weresignificantly increased after fermentation (119901 lt 005) Lacticacid was the most abundant organic acid formed after fer-mentation with L plantarum producing 57129mg100mLof lactic acid L plantarum produced more acetic thanL acidophilus (619 versus 386mg100mL) Oxalic aciddid not change significantly throughout the fermentation

process (119901 lt 005) Tartaric acid which may be usedfor microbial metabolism during the fermentation processdecreased significantly (119901 lt 005) during fermentationmore with L acidophilus (036 to 010mg100mL) than withL plantarum (016mg100mL) Tofalo et al [64] reportedthat the content of lactic acid and acetic acid increased afterfermented raw milk cheese with mesophilic lactobacilli andlactococci which is similar to our results In contrast Yanget al [65] observed a decrease in the content of malic acidand acetic acid in soymilk fermented with Bifidobacteriumand Streptococci strains Lee et al [66] reported that the aceticacid increased and citric acid remained essentially unchangedthroughout the fermentation in papaya wine fermented withthree Williopsis saturnus yeasts which is similar to our


results However malic acid had a different trend in bothfermentation processes

34 Volatile Composition of Papaya Juices before and afterFermentation Volatile components of various papaya cul-tivars have been widely studied by many scholars Morethan 300 different aroma compounds have been identifiedin papaya fruits Esters and alcohols are the main aromacomponents of papaya [67] Various volatile componentsincluding acids alcohols esters aldehydes ketones andphenols were detected in papaya juice before and afterfermentation (Table 5) The volatiles present in papaya juiceschanged significantly after fermentation and some differedbetween the two cultures

Among the volatile acids identified acetic acid and 3-methyl-butanoic acid were the only two volatile acids pro-duced by both cultures 2-Methyl-propanoic acid was newlyproduced by L plantarum

Alcohols were the most abundant key volatiles extractedfrom the fermented papaya juices The alcohols primarilyconsisted of ethanol 3-methyl-1-butanol and linalool Somespecies in the Lactobacillus genus has the ability to produceethanol having alcohol dehydrogenase enzymes that canconvert acetaldehyde into ethanol [68] 3-Methyl-1-butanolhas a pleasant aroma and is a major volatile compoundof cheese The metabolic pathway for the production of3-methyl-butanol is the catabolism of amino-acids [69]Globally L plantarum produced more alcohols than Lacidophilus In studies of the volatile components of manyvarieties of papaya linalool is one of the key aromaticcompounds contributors in papaya fruit [70]

Among the major volatile compounds identified theester compounds are the most common A total of 25 esterswere identified in papaya juice before and after fermentation(Table 5) Pino [71] reported that esters were the primaryclass of volatile chemical compounds in papaya fruit Acetateesters are formed by alcohol acetyltransferases from thereaction between acetyl-CoA and alcohols Most volatileesters can enhance fruit flavor especially ethyl acetate [72]A high level of ethyl acetate and butanoic acid ethyl ester(pineapple fragrance) was produced by the two cultures(Table 5)

Ketones and lactones were the next most diversegroup of volatile compounds in papaya juices bothbefore and after fermentation (Table 5) As expectedacetone 2-butanone acetoin and 6-methyl-5-hepten-2-one were dominant volatile compounds Acetone and2-butanone have pungent odors and their concentrationsdecreased after fermentation In contrast the quantityof acetoin (3-hydroxy-2-butanone) which has a milkaroma increased throughout the fermentation processAcetoin was observed to be produced from the metabolismof citrate [73] 2-Heptanone 1-hydroxy-2-propanone2-hydroxy-3-pentanone 2-nonanone 2-dodecanone and2-tetradecanone were also produced after fermentationTheywere likely derived from the 120573-oxidation of saturated freefatty acids and the further decarboxylation of 120573-ketoacids[74]

Melgarejo et al [75] observed a negative relationshipbetween juice quality and a high concentration of aldehydesAldehydes are easily reduced to alcohols or oxidized to acidsin food matrices especially in the presence of microbialactivity [76] The aldehydes became more abundant afterfermentation L plantarum produced more new aldehydesthan L acidophilus throughout the fermentation processAcetaldehyde and benzaldehyde were present at high levels inboth FPJA and FPJP It has been reported that benzaldehydecan provide ideal sensory properties such as almonds cher-ries and sweetness [77] Volatile phenols were also detectedin the papaya juice before and after fermentation and 24-di-tert-butylphenol was the main volatile phenol detected in thepapaya juices (Table 5)

In summary a large number of volatiles were identified inpapaya beverages before and after fermentationWe observedthat the aroma components were similar after fermentationbut in different proportions Their contribution to the finalflavor of beverages is being further studied Lee et al [25]reported that in papaya wine fermented with Williopsissaturnus var mrakii NCYC 2251 a wide range of volatilecompounds were produced during fermentation includingacids alcohols esters and aldehydes with esters being themost abundant volatile compounds produced In our studyvolatile compounds have similar results with papaya winealso esters being the most abundant volatile compounds inpapaya juicesThe volatile profiles given by L acidophilus andL plantarum were quite similar although more alcohols andaldehydes were globally found with L plantarum

4 Conclusion

The present study investigated the use of papaya beveragesas the main substrate for fermentation by two lactic acidbacteria and a strain more suitable for fermentation wasselected by comparing the different physicochemical prop-erties of fermentation The results show that during papayajuice fermentation both strains produced a large amount ofvolatiles with generally similar changes However the pHdecrease was 005 units less with L acidophilus than withL plantarum which was consistent with the organic acidcontents especially lactic acid This shows that L plantarumis more suitable for growth and stronger acid productioncapacity is based on papaya juice Antioxidant activity tendedto differ between L acidophilus and L plantarum Theantioxidant capacity of FPJA decreased significantly whereasthe antioxidant capacity of FPJP increased after fermentationshowing a better oxidation resistance Through comparisonsof the pH organic acids antioxidant components andvolatile compounds especially the change in antioxidantactivity it was found that L plantarum is more suitable forthe production of fermented papaya beverages It is worthnoting that both FPJA and FPJP produce a large numberof flavonoids which has become a hot research topic inrecent years because of its pharmacological activity We willconduct additional relevant tests to study the efficacy of LABfermentation of papaya such as the effect of weight loss andlipid lowering In a word fermented papaya juice could be anovel probiotic beverage for consumers


Table 5 Major volatile compounds and relative peak area in papaya juices before and after 48 h fermentation

Volatile compounds RT RI Papaya juice FPJA 48 h FPJP 48 hPA times 106 PA times 106 PA times 106

AcidsAcetic acid 1936 1444 31980 plusmn 1704c 180978 plusmn 8037a 75341 plusmn 2064b

Propanoic acid 2181 1537 2348 plusmn 356a ndash ndash2-Methyl-propanoic acid 2256 1567 ndash ndash 2815 plusmn 155a

Butanoic acid 2394 1623 15719 plusmn 948b 19587 plusmn 1158a 19554 plusmn 836a

3-Methyl-Butanoic acid 2497 1666 ndash 5583 plusmn 264b 22829 plusmn 1157a

2-Methyl-Butanoic acid 2500 1668 ndash ndash 19949 plusmn 2060a

Hexanoic acid 2893 1845 9980 plusmn 594a ndash ndash2-Ethyl-Hexanoic acid 3115 1953 1754 plusmn 121a 1676 plusmn 175a ndashOctanoic acid 3333 2063 10510 plusmn 635b 10405 plusmn 536b 14715 plusmn 917a

Nonanoic acid 3545 2174 2518 plusmn 281b 3254 plusmn 127a ndashn-Decanoic acid 3744 2281 2254 plusmn 138a ndash ndash

AlcoholsEthanol 428 930 47570 plusmn 2914c 507047 plusmn 15645a 330628 plusmn 18067b

1-Propanol 711 1043 ndash 1578 plusmn 236b 2335 plusmn 148a

2-Methyl-1-propanol 914 1113 ndash ndash 4367 plusmn 350a

1-Butanol 1071 1160 ndash 700 plusmn 027b 2701 plusmn 236a

1-Penten-3-ol 1114 1173 886 plusmn 035a 262 plusmn 013c 378 plusmn 005b

3-Methyl-1-butanol 1266 1219 1245 plusmn 150c 110719 plusmn 4215b 154259 plusmn 3775a

3-Methyl-3-buten-1-ol 1384 1255 ndash ndash 1517 plusmn 258a

1-Pentanol 1396 1259 953 plusmn 132b ndash 1893 plusmn 186a

Prenol 1600 1325 ndash 1001 plusmn 083a 1264 plusmn 287a

3-Pentanol 1643 1340 ndash 2902 plusmn 148b 4642 plusmn 340a

1-Hexanol 1695 1357 1244 plusmn 274c 3882 plusmn 139b 5103 plusmn 365a

1-Heptanol 1977 1459 850 plusmn 046a 592 plusmn 027c 743 plusmn 024b

2-Ethyl-1-hexanol 2069 1493 83635 plusmn 3285a ndash ndashLinalool 2204 1546 94470 plusmn 7491a 60017 plusmn 2761c 76651 plusmn 3067b

1-Octanol 2239 1560 2264 plusmn 367c 5657 plusmn 340a 3345 plusmn 142b

1-Nonanol 2482 1660 4083 plusmn 736a ndash 3966 plusmn 582a

1-Decanol 2715 1762 ndash 4284 plusmn 416a 1781 plusmn 127b

Geraniol 2894 1845 ndash ndash 9705 plusmn 743a

Benzyl alcohol 2944 1869 1958 plusmn 097c 9093 plusmn 734b 13385 plusmn 861a

Phenylethyl alcohol 3020 1905 ndash 11729 plusmn 697b 22219 plusmn 2185a

Nerolidol 3283 2037 ndash ndash 212 plusmn 003a

AldehydesAcetaldehyde 205 6956 37089 plusmn 2364a 28747 plusmn 1234b 36809 plusmn 1528a

Pentanal 519 970 ndash ndash 8482 plusmn 634

Hexanal 829 1085 ndash ndash 1247 plusmn 072

2-Methyl-2-heptenal 1011 1142 2095 plusmn 178a ndash 2167 plusmn 181a

Heptanal 1166 1188 ndash ndash 2497 plusmn 094a

Octanal 1493 1289 ndash ndash 3047 plusmn 435a

26-Dimethyl-5-heptenal 1680 1352 279 plusmn 008a ndash ndashNonanal 1796 1392 10487 plusmn 265b 4984 plusmn 1045c 15320 plusmn 645a

Benzaldehyde 2124 1514 2789 plusmn 184b 2753 plusmn 163b 5756 plusmn 261a

Dodecanal 2590 1706 ndash 913 plusmn 027b 1950 plusmn 088a

24-Dimethyl-benzaldehyde 2802 1801 ndash 358 plusmn 080b 2692 plusmn 147a


Table 5 Continued


EstersAcetic methyl ester 274 820 697 plusmn 007b 466 plusmn 026c 1162 plusmn 062a

Acetic ethyl ester 338 881 393 plusmn 012b 4289 plusmn 390a 3762 plusmn 355a

Butanoic acid methyl ester 541 979 1135 plusmn 058a 335 plusmn 021c 723 plusmn 074b

Butanoic acid ethyl ester 696 1038 ndash 3588 plusmn 154a 1837 plusmn 093b

Hexanoic acid methyl ester 1177 1191 941 plusmn 140a ndash 277 plusmn 007b

Hexanoic acid ethyl ester 1331 1239 ndash 855 plusmn 130a ndashThiocyanic acid methyl ester 1422 1267 701 plusmn 065a 309 plusmn 132b 429 plusmn 068b

Acetic acid 2-ethylhexyl ester 1775 1385 654 plusmn 128a 315 plusmn 047b 582 plusmn 085a

Octanoic acid methyl ester 1789 1390 4807 plusmn 367a 555 plusmn 024c 1189 plusmn 152b

Octanoic acid ethyl ester 1914 1436 988 plusmn 042b 1659 plusmn 137a 1012 plusmn 073b

n-Butyric acid 2-ethylhexyl ester 2144 1522 20711 plusmn 1037c 22753 plusmn 539b 25575 plusmn 674a

Decanoic acid methyl ester 2323 1593 7510 plusmn 343a 1432 plusmn 150b 1017 plusmn 064c

Decanoic acid ethyl ester 2427 1637 993 plusmn 027b 1359 plusmn 064a 930 plusmn 055bc

Hexanoic acid 2-ethylhexyl ester 2597 1709 6019 plusmn 539a 5084 plusmn 3276b 6042 plusmn 346a

Dodecanoic acid methyl ester 2798 1799 3323 plusmn 127a 2009 plusmn 235b 992 plusmn 357c

Dodecanoic acid ethyl ester 2888 1842 275 plusmn 006b 454 plusmn 061a 262 plusmn 024b

Tetradecanoic methyl ester 3228 2009 3671 plusmn 185a 2128 plusmn 365b ndashMyristoleate methyl ester 3302 2047 1354 plusmn 064a ndash ndashTetradecanoic acid ethyl ester 3306 2049 ndash 964 plusmn 015a ndashBenzoic acid 2-ethylhexyl ester 3538 2171 2412 plusmn 134a 2147 plusmn 076b 1918 plusmn 051c

Hexadecanoic acid methyl ester 3622 2216 672 plusmn 268a ndash ndashDodecanoic acid ethyl ester 3690 2252 ndash 871 plusmn 034a ndash9-Hexadecenoate ethyl ester 3737 2277 3739 plusmn 637a 761 plusmn 069b ndash12-Benzenedicarboxylic acid bis(2-methylpropyl) ester 4166 2506 ndash 3224 plusmn 231a 2312 plusmn 316b

Dibutyl phthalate 4409 2636 ndash 1225 plusmn 320a 971 plusmn 091b

Ketones and lactonesAcetone 262 809 48380 plusmn 3245a 41131 plusmn 1638b 41072 plusmn 1127b

2-Butanone 355 897 23415 plusmn 1184a 14693 plusmn 1475b 16603 plusmn 2084b

23-Butanedione 516 968 10729 plusmn 687a 11363 plusmn 855a 8482 plusmn 698b

2-Heptanone 1161 1187 ndash ndash 2526 plusmn 527a

Acetoin 1479 1285 75258 plusmn 5528c 280469 plusmn 9638b 168842 plusmn 6738a

1-Hydroxy-2-Propanone 1515 1296 ndash ndash 435 plusmn 076a

6-Methyl-5-Hepten-2-one 1636 1337 27658 plusmn 1594a 13980 plusmn 2370b 7995 plusmn 1156c

2-Hydroxy-3-pentanone 1691 1356 ndash 3881 plusmn 285b 5103 plusmn 344a

2-Nonanone 1786 1389 ndash 2028 plusmn 174a ndash3-(Hydroxymethyl)-2-Nonanone 1792 1391 4807 plusmn 295a 5078 plusmn 364a 479 plusmn 012b

2-Octanone 2330 1596 560 plusmn 014c 2043 plusmn 138a 1185 plusmn 130b

2-Dodecanone 2812 1806 ndash 563 plusmn 047a ndash2-Tetradecanone 2812 1806 ndash ndash 803 plusmn 114

Phenols26-Bis(11-dimethylethyl)-4-(1-oxopropyl)phenol 3052 1921 ndash 1433 plusmn 092a 1422 plusmn 117a

Phenol 3198 1994 ndash 4380 plusmn 451a 2682 plusmn 395b

24-Di-tert-butylphenol 3778 2299 8452 plusmn 687a 4558 plusmn 363b 3654 plusmn 329c

26-Di-tert-butyl-4-methoxyphenol 4652 2765 544 plusmn 123a ndash ndashValues are expressed as the mean plusmn SD Values with different letters (a sim c) in the same row are significantly different at 119901 lt 005 RT retention time RIretention index PA peak area RPA ratio of peak area ldquondashrdquo not detected


Conflicts of Interest

The authors declare that they have no conflicts of interest

Acknowledgments

This investigation was supported by the Production andResearch Integration of Special Projects of Hainan Province(CXY20150032) and the Natural Science Fund of HainanProvince of China (317002)

References

[1] S J Rhee J-E Lee and C-H Lee ldquoImportance of lactic acidbacteria in Asian fermented foodsrdquoMicrobial Cell Factories vol10 no 1 article no S5 2011

[2] F Altay F Karbancıoglu-Guler C Daskaya-Dikmen and DHeperkan ldquoA review on traditional turkish fermented non-alcoholic beverages microbiota fermentation process andquality characteristicsrdquo International Journal of Food Microbi-ology vol 167 no 1 pp 44ndash56 2013

[3] A Czyzowska E Klewicka and Z Libudzisz ldquoThe influence oflactic acid fermentation process of red beet juice on the stabilityof biologically active colorantsrdquo European Food Research andTechnology vol 223 no 1 pp 110ndash116 2006

[4] R Soukand A Pieroni M Biro et al ldquoAn ethnobotanicalperspective on traditional fermented plant foods and beveragesin Eastern Europerdquo Journal of Ethnopharmacology vol 170 no1 pp 284ndash296 2015

[5] I Salmeron K Thomas and S S Pandiella ldquoEffect of poten-tially probiotic lactic acid bacteria on the physicochemicalcomposition and acceptance of fermented cereal beveragesrdquoJournal of Functional Foods vol 15 pp 106ndash115 2015

[6] B Bigliardi and F Galati ldquoInnovation trends in the foodindustry the case of functional foodsrdquo Trends in Food Scienceamp Technology vol 31 no 2 pp 118ndash129 2013

[7] C Puerari K TMagalhaes andR F Schwan ldquoNew cocoa pulp-based kefir beverages Microbiological chemical compositionand sensory analysisrdquo Food Research International vol 48 no2 pp 634ndash640 2012

[8] F C Prado J L Parada A Pandey and C R Soccol ldquoTrendsin non-dairy probiotic beveragesrdquo Food Research Internationalvol 41 no 2 pp 111ndash123 2008

[9] A P Mestry A S Mujumdar and B N Thorat ldquoOptimizationof spray drying of an innovative functional food Fermentedmixed juice of carrot and watermelonrdquo Drying Technology vol29 no 10 pp 1121ndash1131 2011

[10] K Y Yoon E E Woodams and Y D Hang ldquoProbiotication oftomato juice by lactic acid bacteriardquo Journal ofMicrobiology vol42 no 4 pp 315ndash318 2004

[11] A L F Pereira T C Maciel and S Rodrigues ldquoProbioticbeverage from cashew apple juice fermented with Lactobacilluscaseirdquo Food Research International vol 44 no 5 pp 1276ndash12832011

[12] K Ghosh M Ray A Adak et al ldquoRole of probiotic Lacto-bacillus fermentum KKL1 in the preparation of a rice basedfermented beveragerdquo Bioresource Technology vol 188 pp 161ndash168 2015

[13] F Leroy and L de Vuyst ldquoLactic acid bacteria as functionalstarter cultures for the food fermentation industryrdquo Trends inFood Science amp Technology vol 15 no 2 pp 67ndash78 2004

[14] H Lee H Yoon Y Ji et al ldquoFunctional properties of Lactobacil-lus strains isolated from kimchirdquo International Journal of FoodMicrobiology vol 145 no 1 pp 155ndash161 2011

[15] R Kumar S Grover and V K Batish ldquoHypocholestero-laemic effect of dietary inclusion of two putative probiotic bilesalt hydrolase-producing Lactobacillus plantarum strains inSprague-Dawley ratsrdquo British Journal of Nutrition vol 105 no4 pp 561ndash573 2011

[16] S Parvez K A Malik S A Ah Kang and H-Y KimldquoProbiotics and their fermented food products are beneficial forhealthrdquo Journal of AppliedMicrobiology vol 100 no 6 pp 1171ndash1185 2006

[17] D Chen X Pang J Zhao et al ldquoComparing the effects of highhydrostatic pressure and high temperature short time on papayabeveragerdquo Innovative Food Science and Emerging Technologiesvol 32 pp 16ndash28 2015

[18] D M Rivera-Pastrana E M Yahia and G A Gonzalez-Aguilar ldquoPhenolic and carotenoid profiles of papaya fruit(Carica papaya L) and their contents under low temperaturestoragerdquo Journal of the Science of Food and Agriculture vol 90no 14 pp 2358ndash2365 2010

[19] P Udomkun M Nagle D Argyropoulos B Mahayothee SLatif and J Muller ldquoCompositional and functional dynamicsof dried papaya as affected by storage time and packagingmaterialrdquo Food Chemistry vol 196 pp 712ndash719 2016

[20] R Ming S Hou Y Feng et al ldquoThe draft genome of thetransgenic tropical fruit tree papaya (Carica papaya Linnaeus)rdquoNature vol 452 no 7190 pp 991ndash996 2008

[21] T Kokila P S Ramesh and D Geetha ldquoBiosynthesis ofAgNPs using Carica Papaya peel extract and evaluation ofits antioxidant and antimicrobial activitiesrdquo Ecotoxicology andEnvironmental Safety vol 134 pp 467ndash473 2016

[22] P Udomkun M Nagle B Mahayothee D Nohr A Koza andJ Muller ldquoInfluence of air drying properties on non-enzymaticbrowning major bio-active compounds and antioxidant capac-ity of osmotically pretreated papayardquo LWT- Food Science andTechnology vol 60 no 2 pp 914ndash922 2015

[23] J P Fabi B R Cordenunsi G P D M Barreto A ZMercadante F M Lajolo and J R O Do Nascimento ldquoPapayafruit ripening Response to ethylene and 1-methylcyclopropene(1-MCP)rdquo Journal of Agricultural and Food Chemistry vol 55no 15 pp 6118ndash6123 2007

[24] C M Peres C Peres A Hernandez-Mendoza and F XMalcata ldquoReview on fermented plant materials as carriers andsources of potentially probiotic lactic acid bacteria - With anemphasis on table olivesrdquo Trends in Food Science amp Technologyvol 26 no 1 pp 31ndash42 2012

[25] P-R Lee B Yu P Curran and S-Q Liu ldquoEffect of fusel oiladdition on volatile compounds in papaya wine fermented withWilliopsis saturnus var mrakii NCYC 2251rdquo Food ResearchInternational vol 44 no 5 pp 1292ndash1298 2011

[26] P-R Lee Y-L Ong B Yu P Curran and S-Q Liu ldquoProfileof volatile compounds during papaya juice fermentation bya mixed culture of Saccharomyces cerevisiae and Williopsissaturnusrdquo Food Microbiology vol 27 no 7 pp 853ndash861 2010

[27] R Di Cagno G Minervini C G Rizzello M De Angelis andM Gobbetti ldquoEffect of lactic acid fermentation on antioxidanttexture color and sensory properties of red and green smooth-iesrdquo Food Microbiology vol 28 no 5 pp 1062ndash1071 2011


[28] A A N Saqib and P J Whitney ldquoDifferential behaviour of thedinitrosalicylic acid (DNS) reagent towards mono- and di-saccharide sugarsrdquo Biomass amp Bioenergy vol 35 no 11 pp4748ndash4750 2011

[29] V M Moo-Huchin I Estrada-Mota R Estrada-Leon etal ldquoDetermination of some physicochemical characteristicsbioactive compounds and antioxidant activity of tropical fruitsfrom Yucatan Mexicordquo Food Chemistry vol 152 pp 508ndash5152014

[30] L Z CM de Sa P F S Castro F M A Lino et al ldquoAntioxidantpotential and vasodilatory activity of fermented beverages ofjabuticaba berry (Myrciaria jaboticaba)rdquo Journal of FunctionalFoods vol 8 no 1 pp 169ndash179 2014

[31] P Wu G Ma N Li Q Deng Y Yin and R Huang ldquoInvestiga-tion of in vitro and in vivo antioxidant activities of flavonoidsrich extract from the berries of Rhodomyrtus tomentosa(Ait)Hasskrdquo Food Chemistry vol 173 pp 194ndash202 2015

[32] J M Carbonell-Capella M Buniowska M J Esteve and AFrıgola ldquoEffect of Stevia rebaudiana addition on bioaccessibilityof bioactive compounds and antioxidant activity of beveragesbased on exotic fruits mixed with oat following simulatedhuman digestionrdquo Food Chemistry vol 184 Article ID 17342pp 122ndash130 2015

[33] S Li Y Zhao L Zhang et al ldquoAntioxidant activity of Lac-tobacillus plantarum strains isolated from traditional Chinesefermented foodsrdquo Food Chemistry vol 135 no 3 pp 1914ndash19192012

[34] M Um G-J Shin and J-W Lee ldquoExtraction of total phenoliccompounds from yellow poplar hydrolysate and evaluation oftheir antioxidant activitiesrdquo Industrial Crops and Products vol97 pp 574ndash581 2017

[35] A Morales-Soto P Garcıa-Salas C Rodrıguez-Perez et alldquoAntioxidant capacity of 44 cultivars of fruits and vegetablesgrown in Andalusia (Spain)rdquo Food Research International vol58 pp 35ndash46 2014

[36] E Kondakci M Ozyurek K Guclu and R Apak ldquoNovel pro-oxidant activity assay for polyphenols vitamins C and e usinga modified CUPRAC methodrdquo Talanta vol 115 pp 583ndash5892013

[37] L Zou Y-Y Hu and W-X Chen ldquoAntibacterial mechanismand activities of black pepper chloroform extractrdquo Journal ofFood Science and Technology vol 52 no 12 pp 8196ndash8203 2015

[38] J Zhao H Li W Xi et al ldquoChanges in sugars and organic acidsin wolfberry (Lycium barbarum L) fruit during developmentand maturationrdquo Food Chemistry vol 173 pp 718ndash724 2015

[39] P Fuggate C Wongs-Aree S Noichinda and S KanlayanaratldquoQuality and volatile attributes of attached and detached rsquoPlukMai Liersquo papaya during fruit ripeningrdquo Scientia Horticulturaevol 126 no 2 pp 120ndash129 2010

[40] LW LeeMW Cheong P Curran B Yu and S Q Liu ldquoCoffeefermentation and flavor - An intricate and delicate relationshiprdquoFood Chemistry vol 185 pp 182ndash191 2015

[41] D Klupsaite G Juodeikiene D Zadeike E Bartkiene ZMaknickiene and G Liutkute ldquoThe influence of lactic acidfermentation on functional properties of narrow-leaved lupineprotein as functional additive for higher value wheat breadrdquoLWT- Food Science and Technology vol 75 pp 180ndash186 2017

[42] L M R Da Silva E A T De Figueiredo N M P S Ricardo etal ldquoQuantification of bioactive compounds in pulps and by-products of tropical fruits fromBrazilrdquo Food Chemistry vol 143pp 398ndash404 2014

[43] Y Xiao G Xing X Rui et al ldquoEnhancement of the antioxidantcapacity of chickpeas by solid state fermentation with Cordy-ceps militaris SN-18rdquo Journal of Functional Foods vol 10 pp210ndash222 2014

[44] J Yang Y Ji H Park et al ldquoSelection of functional lactic acidbacteria as starter cultures for the fermentation of Korean leek(Allium tuberosum Rottler ex Sprengel)rdquo International Journalof Food Microbiology vol 191 pp 164ndash171 2014

[45] R V Malbasa E S Loncar J S Vitas and J M Canadanovic-Brunet ldquoInfluence of starter cultures on the antioxidant activityof kombucha beveragerdquo FoodChemistry vol 127 no 4 pp 1727ndash1731 2011

[46] N J Kim H L Jang and K Y Yoon ldquoPotato juice fermentedwith Lactobacillus casei as a probiotic functional beveragerdquoFood Science and Biotechnology vol 21 no 5 pp 1301ndash13072012

[47] B Escudero-Lopez I Cerrillo G Herrero-Martın et al ldquoFer-mented orange juice Source of higher carotenoid and flavanonecontentsrdquo Journal of Agricultural and Food Chemistry vol 61no 37 pp 8773ndash8782 2013

[48] R Bhat L C Suryanarayana K A Chandrashekara P Krish-nan A Kush and P Ravikumar ldquoLactobacillus plantarummediated fermentation of Psidium guajava L fruit extractrdquoJournal of Bioscience and Bioengineering vol 119 no 4 pp 430ndash432 2015

[49] D Kantachote A Ratanaburee W Hayisama-ae A Sukhoomand T Nunkaew ldquoThe use of potential probiotic Lactobacillusplantarum DW12 for producing a novel functional beveragefrom mature coconut waterrdquo Journal of Functional Foods vol32 pp 401ndash408 2017

[50] B S Oladeji C T Akanbi and S O Gbadamosi ldquoEffects offermentation on antioxidant properties of flours of a normalendosperm and quality protein maize varrietiesrdquo Journal ofFoodMeasurement and Characterization vol 11 no 3 pp 1148ndash1158 2017

[51] S K Panda S K Behera X Witness Qaku et al ldquoQualityenhancement of prickly pears (Opuntia sp) juice throughprobiotic fermentation using Lactobacillus fermentum - ATCC9338rdquo LWT- Food Science and Technology vol 75 pp 453ndash4592017

[52] M Ohata S Uchida L Zhou and K Arihara ldquoAntioxidantactivity of fermented meat sauce and isolation of an associatedantioxidant peptiderdquo Food Chemistry vol 194 pp 1034ndash10392016

[53] S Simsek S N El A Kancabas Kilinc and S Karakaya ldquoVeg-etable and fermented vegetable juices containing germinatedseeds and sprouts of lentil and cowpeardquo Food Chemistry vol156 pp 289ndash295 2014

[54] F Nazzaro F Fratianni A Sada and P Orlando ldquoSynbioticpotential of carrot juice supplemented with Lactobacillus sppand inulin or fructooligosaccharidesrdquo Journal of the Science ofFood and Agriculture vol 88 no 13 pp 2271ndash2276 2008

[55] R-Y Gan N P Shah M-F Wang W-Y Lui and H CorkeldquoLactobacillus plantarum WCFS1 Fermentation DifferentiallyAffects Antioxidant Capacity and Polyphenol Content in Mungbean (Vigna radiata) and Soya Bean (Glycine max) MilksrdquoJournal of Food Processing and Preservation vol 41 no 1 ArticleID e12944 2017

[56] S Li C Ma G Gong Z Liu C Chang and Z Xu ldquoTheimpact of onion juice on milk fermentation by Lactobacillusacidophilusrdquo LWT- Food Science and Technology vol 65 pp543ndash548 2016


[57] D Hervert-Hernandez C Pintado R Rotger and I GonildquoStimulatory role of grape pomace polyphenols on Lacto-bacillus acidophilus growthrdquo International Journal of FoodMicrobiology vol 136 no 1 pp 119ndash122 2009

[58] C Ankolekar M Pinto D Greene and K Shetty ldquoIn vitrobioassay based screening of antihyperglycemia and antihyper-tensive activities of Lactobacillus acidophilus fermented pearjuicerdquo Innovative Food Science and Emerging Technologies vol13 no JANUARY pp 221ndash230 2012

[59] D Das and A Goyal ldquoAntioxidant activity and 120574-aminobutyricacid (GABA) producing ability of probiotic Lactobacillus plan-tarum DM5 isolated from Marcha of Sikkimrdquo LWT- FoodScience and Technology vol 61 no 1 pp 263ndash268 2015

[60] W Tang Z Xing C Li J Wang and Y Wang ldquoMolecularmechanisms and in vitro antioxidant effects of LactobacillusplantarumMA2rdquo Food Chemistry vol 221 pp 1642ndash1649 2017

[61] N Camu T De Winter K Verbrugghe et al ldquoDynamics andbiodiversity of populations of lactic acid bacteria and acetic acidbacteria involved in spontaneous heap fermentation of cocoabeans in Ghanardquo Applied and Environmental Microbiology vol73 no 6 pp 1809ndash1824 2007

[62] J C Piard andM Desmazeaud ldquoInhibiting factors produced bylactic acid bacteria 1 Oxygen metabolites and catabolism end-productsrdquo Le Lait vol 71 no 5 pp 525ndash541 1991

[63] A L Freire C L Ramos and R F Schwan ldquoEffect of symbioticinteraction between a fructooligosaccharide and probiotic onthe kinetic fermentation and chemical profile of maize blendedrice beveragesrdquo Food Research International vol 100 pp 698ndash707 2017

[64] R Tofalo M Schirone G Fasoli et al ldquoInfluence of pigrennet on proteolysis organic acids content and microbiotaof Pecorino di Farindola a traditional Italian ewersquos raw milkcheeserdquo Food Chemistry vol 175 pp 121ndash127 2015

[65] S-O Yang S-H Kim S Cho et al ldquoClassification of fer-mented soymilk during fermentation by 1H NMR coupledwith principal component analysis and elucidation of free-radical scavenging activitiesrdquo Bioscience Biotechnology andBiochemistry vol 73 no 5 pp 1184ndash1188 2009

[66] P-R Lee Y-L Ong B Yu P Curran and S-Q Liu ldquoEvolutionof volatile compounds in papaya wine fermented with threeWilliopsis saturnus yeastsrdquo International Journal of Food Scienceamp Technology vol 45 no 10 pp 2032ndash2041 2010

[67] H Kelebek S Selli H Gubbuk and E Gunes ldquoComparativeevaluation of volatiles phenolics sugars organic acids andantioxidant properties of Sel-42 and Tainung papaya varietiesrdquoFood Chemistry vol 173 pp 912ndash919 2015

[68] W Randazzo O Corona R Guarcello et al ldquoDevelopment ofnew non-dairy beverages from Mediterranean fruit juices fer-mented with water kefir microorganismsrdquo Food Microbiologyvol 54 pp 40ndash51 2016

[69] J Gallegos C Arce R Jordano L Arce and L M MedinaldquoTarget identification of volatile metabolites to allow the dif-ferentiation of lactic acid bacteria by gas chromatography-ionmobility spectrometryrdquo Food Chemistry vol 220 pp 362ndash3702017

[70] B L Gomes J P Fabi and E Purgatto ldquoCold storage affects thevolatile profile and expression of a putative linalool synthase ofpapaya fruitrdquo Food Research International vol 89 pp 654ndash6602016

[71] J A Pino ldquoOdour-active compounds in papaya fruit cv RedMaradolrdquo Food Chemistry vol 146 pp 120ndash126 2014

[72] P-R Lee I S-M Chong B Yu P Curran and S-Q LiuldquoEffects of sequentially inoculated Williopsis saturnus andSaccharomyces cerevisiae on volatile profiles of papaya winerdquoFood Research International vol 45 no 1 pp 177ndash183 2012

[73] T K Singh K R Cadwallader and M Drake ldquoSection XIVMilk and Milk Products Biochemical Processes in the Produc-tion of Flavor in Milk and Milk Productsrdquo Handbook of FoodProducts Manufacturing vol 2 pp 715ndash748 2006

[74] M Servili C G Rizzello A Taticchi et al ldquoFunctional milkbeverage fortified with phenolic compounds extracted fromolive vegetationwater and fermentedwith functional lactic acidbacteriardquo International Journal of Food Microbiology vol 147no 1 pp 45ndash52 2011

[75] P Melgarejo A Calın-Sanchez L Vazquez-Araujo et alldquoVolatile composition of pomegranates from9 Spanish cultivarsusing headspace solid phase microextractionrdquo Journal of FoodScience vol 76 no 1 pp S114ndashS120 2011

[76] R Di Cagno R F Surico A Paradiso et al ldquoEffect ofautochthonous lactic acid bacteria starters on health-promotingand sensory properties of tomato juicesrdquo International Journalof Food Microbiology vol 128 no 3 pp 473ndash483 2009

[77] R Di Cagno P Filannino and M Gobbetti ldquoLactic acidfermentation drives the optimal volatile flavor-aroma profile ofpomegranate juicerdquo International Journal of Food Microbiologyvol 248 pp 56ndash62 2017

Hindawiwwwhindawicom

International Journal of

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Zoology

Hindawiwwwhindawicom Volume 2018

Anatomy Research International

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medicine Its fruits stems leaves and roots are used in awide range of medical applications including the productionof two important bioactive compounds (chymopapain andpapain) which are widely used for digestive diseases [19ndash21] However postharvest losses of papaya occur throughoutthe value chain due to rapid deterioration of its chemicalcomponents and pulp softening which results in a short shelflife of the fresh fruit [22 23]Many studies have demonstratedthe feasibility of using fruits such as oranges pineapplesbananas and cranberries to produce probiotic beverages[24] However other fruits such as papaya have not beenadequately studiedThus far only a small amount of researchhas been conducted on fermented papaya beverages Amongthese most have studied the use of papaya for wine-making[25 26] Di Cagno et al [27] demonstrated the growthand survival of L plantarum and L pentosus in a papayajuice-based medium All of these studies have demonstratedthat papaya beverages are suitable for microbial growth Toexplore the feasibility of LAB fermentation of papaya bev-erages to improve the utilization value of papaya this studyassessed two lactic acid bacteria for fermentation

2 Materials and Methods

21 Materials

Samples and Bacteria Papaya puree skim milk powder andedible glucose were purchased from the Nanguo Supermar-ket and Hainan Dachuan Food Co Ltd (Haikou China)Lactobacillus acidophilusGIM1731 (L acidophilus) andLacto-bacillus plantarum GIM1140 (L plantarum) were purchasedfrom GuangdongMicrobiology Culture Center (GuangzhouChina)

Preparation of Papaya Juices and Fermentation Each samplewas formulated to 200 g for fermentation According tomass45 papaya puree 45 distilled water 5 edible glucose and5 skim milk powder (10-fold diluted skim milk powder)were added to a conical flask heat sterilized at 90∘C for10min and then cooled in a water bath Each LAB strain wasinoculated at 5 of the mass ratio of the fermentation brothand the mixture was incubated at 37∘C for 48 h under staticconditions Samples were stored at minus80∘C Fermentationprocesses were repeated three times

22 Methods

221 Determination of pH The pH of the samples wasmeasured by a digital pH meter (FE20 laboratory pHmeter)

222 Determination of Reducing Sugars The reducing sugarscontent of fermented juice was analyzed as glucose equiva-lents by the 35-dinitrosalicylic acid (DNS) method of Saqib[28] with somemodification In this application 2mL of 250-fold diluted sample and 4mL DNS reagent were added to the10-mL graduated tube and heated in a boiling water bath for5 minutes When removed the tube was immediately placedin cold water cooled to room temperature supplementedwith water to 10mL and shaken well The absorbance was

measured at 540 nmThe results were expressed asmilligramsof glucose equivalents

223 Determination of Vitamin C The 26-dichloropheno-lindophenol titrimetric method was used to measure thelevels of reduced ascorbic acid [29]

224 Determination of Total Phenolic Content Extracts wereprepared by mixing 5 g of sample with 25mL of 50 ethanolThe mixture was placed in a thermostat oscillator set at100 rmin for 1 h and was then centrifuged at 4000 rminfor 10min Extracts were transferred into test conical flasksand stored at 4∘C before analysis Total phenolic content wasdetermined using the Folin-Ciocalteu method described byde Sa et al [30] with some modifications A 1mL aliquotof each fermented papaya beverage extract was mixed with02mL of Folin-Ciocalteursquos reagent and was incubated atroom temperature for 3minThen themixture was dissolvedin 75 Na2CO3 and adjusted to a volume of 10mL After30min the absorbance was measured at 765 nm The resultswere expressed asmilligrams of gallic acid equivalents (GAE)

225 Determination of Total Flavonoids Content The totalflavonoids content of samples was measured according tothe method of Wu et al [31] with some modifications A06mL aliquot of each sample was mixed with 12mL of 80methanol then 018mL of 20 NaNO2 was added After6min 036mL of 8 Al(NO3)3 was added followed by theaddition of 12mL of 1molL NaOH after 5min After 15minthe absorbance was measured at 510 nm The results wereexpressed as milligrams of rutin equivalents (RE)

226 Determination of Total Carotenoid Content The totalcarotenoid content was measured according to the methodof Carbonell-Capella et al [32] with some modification A1mL aliquot of each sample was homogenized with 5mLof extraction solvent (hexaneacetonemethanol 50 25 25VV) The mixture was placed in a thermostat oscillator set at100 rmin for 30min and then was centrifuged at 6000 rminat 4∘C for 10minThe top colored hexane layer was recoveredand transferred to a 25mL volumetric flask and the volumewas then adjusted to 25mL with hexane The absorbanceof the samples was measured at 450 nm The results werecalculated as described by Ritter and Purcell (1981) using theextinction coefficient of 120573-carotene 1198641 = 2505

227 Determination of the Total Antioxidant Capacity In Vitro

(1) 22-Diphenyl-1-Picrylhydrazyl (DPPH) Radical ScavengingAssay The DPPH∙+ assay was performed according to Liet al [33] with some modifications Briefly 002 g of DPPHwas transferred to a 25 mL volumetric flask the volume wasadjusted to 25mLwithmethanol and after the flask was fullyoscillated the solution was subjected to ultrasound for 5minThe 08mgmL solution of DPPH in methanol was dilutedwith methanol until the solution had an absorbance of 12ndash13at 517 nm A 012mL aliquot of sample was added to 4mL ofthe DPPH radical solutionThemixture was incubated in the













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4 Conclusion











































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4 Conclusion











































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Volume 2018





Acknowledgments


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Documents

Comparative Evaluation of the Antioxidant Capacities