Embed Size (px)
Citation preview
Speaker 16
Dr Kieran Tuohy
Lecturer in Food MetabonomicsDepartment of Food Biosciences
University of Reading
• Introduction
• The human gut microflora
• Functional foods – PREBIOTICS
• Prebiotic discovery and efficacy in vitro and in vivo
• Case study – galactooligosaccharides from lactose;pectic-oligosaccharides from citrus fruit waste
• Concluding remarks
Outline
• Re-design food production process to reduce waste─ efficacy, impact on product, cost
• Stabilise, reduce, recover value (material or energy)─ economic relevance, technological issues
• Fractionate to added value products─ identify suitable technologies, high value products, lucrative markets─FUNCTIONAL FOODS
Approaches to food waste
• In our bodies there are 20 x more bacteria than human cells
• Human genome – 30,000 genes• Bacteria – 1,600 genes• More than 1,000 bacterial species within the gut• Redundancy but also genetic, evolutionary and
ecological plasticity• Microbial mega-genome with metabolic potential
many fold greater than human
The Human Gut Microflora
Gut Physiology
Diet: infant and adultGut
Microflora
Microbial Interactions: Successional Development
Homeostasis
Immune System
1. Must be non-digestible
2. Selective fermentation in the colon
3. Must improve health
PREBIOTICS‘Non digestible food ingredients that selectively stimulate a limited number of bacteria in the colon, to improve host health’
(after Gibson and Roberfroid, 1995)
Health benefits of prebiotics
Microflora
modification
Laxation Lipid metabolism
Diarrhoea/IBS
Colon cancer
Blood glucose
Mineral absorption
IBD
Immune func in children
PREBIOTICS
Prebiotic Health Benefits
Modified from Crittenden 2006
prebiotics
stimulategrowth
colonocytes
Bifidobacteria
Pathogens
faecal bulking improved bowel habit
colonisationresistance
block adhesion
reduce exogenousand endogenousintestinal infection
eliminate pro-IBDantigens
dendritic cell
M cell
Th1
Tr
Th2IFNg
IL-10TGF-b
immunomodulationanti-inflammatory
suppress IBD inflammation
allergy prevention
lamina propria
Selective proliferation of beneficial bacteria
Prebiotic Health BenefitsStimulation of beneficial microbial activities
SCFA
peristalsis
prebiotics
selectivefermentation
improvedbowel habit
reduced cancer risk and IBDinflammation
colonocytes
increasedmineralabsorption
antagonism ofpathogens andputrefactive bacteria
fewer toxicbacterialmetabolites
reduced pH
Ca++ Mg++
reduced cancer risk
trophic and anti -neoplasticeffects
induce
de novolipogenesis
controlled serum lipids and cholesterol
Modified from Crittenden 2006
• Retail prices of functional foods are typically 30 to 500 times higher than comparable conventional foods
• Depending on the definition of functional foods, estimated market size is between $30 and $60 billion (Japan, US, EU)
• Over the past ten years the market has grown at about 10% per annum (World Bank)
• Prebiotics European market alone is currently worth £59 million and is expected to increase to £121 million in 2010 (Frost & Sullivan)
• Leading prebiotics – fructans (inulin, oligofructose, galactooligosaccharides, lactulose)
Functional Foods market
Determining prebotic potential in vitro and in vivo
Caecum
Ascendingcolon
Transverse colon
Descendingcolon
Rectum
• In vitro gut models (batch, complex)
• Faecal microbiology (16S rRNA)
• Faecal metabolites (GC, NMR)
• Biomarkers of disease ─ blood lipids─ faecal water genotoxicity─ immunology
• Metabolite profiles – blood, urine, faecesTuohy et al., Curr.Pharma Design (2005)
31 Volunteers fed Prebiotic Biscuits for 21 days
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
Log 1
0 cel
ls/g
faec
es.
Total bacteria
Bacteroides spp.
Bifidobacterium spp.
Clostridium spp.
Lactobacillus spp.
Active biscuits ( ) Placebo biscuits ( )Tuohy et al., Brit. J. Nutr. (2001)
Receptor activity
Enhanced persistence
Novel structural diversity
Microbial polysaccharides
Algal polysaccharides
BacterialEPS
Monosaccharidesoligosaccharides
Con
trol
led
hydr
olys
isPh
age
hydr
olys
is
Equi
libriu
m
synt
hesi
s
Species specificity Oligosaccharides
Gly
cosy
l tr
ansf
er
Raw material Target prebiotic property
Raw material
Manufacturing technologies
Plant polysaccharides
HYDROLYSIS SYNTHESIS
Synthesis
Enzyme reactorUltrafiltration
Retentate recycle
Permeate
Lactose
GOS
Drying
Sucrose
IMO
β-Galactosidase
Dextransucrase+ dextranase
Alternansucrase
Acceptors
Prebiotics from lactose
Enzyme reactor
Lactose
GOS
Dryingβ-galactosidase
• Lactose in whey is a major problem for the dairy industry• Cost associated with disposal• Can convert to high value prebiotics
Manufactured by Friesland Foods (EU)Clasado (UK) Yakult (Japan)
Tzortzis et al., Appl. Microbiol. Biotech. (2005)
Galacto-oligosaccharidesGOS
Oligosaccharide % (dry weight)Disaccharides 33Trisaccharides 39Tetrasaccharides 18Pentasaccharides 7
Higher oligosaccharides 30 4 8 12 16 20 24 28 32 36 40
Time (min)
Galb1,4Glc
Galb1,6Galb1,4GlcGalb1,3Galb1,4GlcGalb1,4Galb1,4Glc
Galb1,3Galb1,6Galb1,4GlcGalb1,6Galb1,6Galb1,4GlcGalb1,3Galb1,3Galb1,4GlcGalb1,6Galb1,3Galb1,4GlcGalb1,3Galb1,4Galb1,4Glc Galb1,6Galb1,4Galb1,4Glc
+
b-Galactosidase Galb1,4Glc
Glc
+ …
-0.8-0.6-0.4-0.2
00.20.40.60.8
1
V1 V2 V3
Total bacteria Bifidobacterium spp.
Lactobacillus spp. Bacteroides spp.
Clostridium histolyticum group
Novel GOS
Bi2muno® GOS/B. bifidum3-stage gut model
counting by FISH with group-specific 16S rDNA probes
D Log 10bacteria
ml-1
Tzortzis et al., J. Nutr. (2005)
-0.2
-0.1
0
0.1
0.2
0.3
0.4
3.6g B2M/d 7g B2M/d 7g VGOS/d 7.6g Sucrose/d
Log1
0 (c
ell/g
)
Total Bacteria Bifidobacterium spp.
Lactobacillus spp Bacteroides spp
Clostridium histolyticum group
Novel GOS in vivo
Bi2muno® GOS/B. bifidumHuman volunteer trial, 2-weeks feeding
counting by FISH with group-specific 16S rDNA probes
Enzymereactor
U/F
Retentate recycle
Permeate
50g dextran dm-3
100120140160180200220240260
20 25 30 35 40 45 50 55 60Elution Time (min)
Ref
ract
ive
Inde
x (m
V) 19.5 kDa9.5 kDa
1.15 kDa0.18 kDa6250 U enzyme dm-3, 60 min
residence time19800 U enzyme dm-3, 90 min residence time62500 U enzyme dm-3, 60 min residence time
Hydrolysis
Pectin composition
Pectic oligosaccharides
Dead-endUF cell10 000
NMWCO
High methoxy citrus pectinLow methoxy apple pectin
Pectic oligosaccharides
Amano endo-pectinase
0 10 20 30 40 50 60Time (min)
PGA Hydrolysate
POS1(HM citrus pectin)
POS2(LM apple pectin)
46 8 10
High performance anion exchange chromatography
66.5
77.5
88.5
99.510
TotalBifid
obacter
iaBac
teroides
Clostridia
Lactobac
illiEubac
teria
051024
TotalBifid
obacter
iaBac
teroides
Clostridia
Lactobac
illiEubac
teria
0
5
10
24
Log
10ce
lls/g
Pectic oligosaccharides
Batch culture, 1% CHO, pH 6.8, bacteriology by FISH
FOS POS
* *
Manderson et al., Appl. Environ. Microbiol (2005)
Toxin
“Decoy”oligosaccharides
Antiadhesive saccharides
Bacteria
Anti-adhesive activity
0102030405060708090
100
E. coli N
CTC 129
00
E. coli N
CTC 1312
7
E. coli N
CTC 1312
8
E. coli O
111:H
27
E. coli O
119:H
4
E. coli O
128:H
12
Dsv. d
esulfu
rican
s
L. acid
ophilus
L. gas
seri
**
* * * **
*
Adh
esio
n re
lativ
e to
con
trol
(%)
0
20
40
60
80
100
120
140
No toxin 0.01 0.1 1 10 100 Toxin OnlyConcentration of POS mg ml-1
% C
ell s
urvi
vabi
lity
*
***** * *
VT1
VT2
Inhibition of verocytotoxin
Flash-extracted POS
Olana-Martin et al., FEMS Microbiol. Letts (2003)
Prebiotic potential ofBergamot POS
-10
-5
0
5
10
15
20
25
Bifidobacteria Bacteroides Lactobacilli Clostridia Eubacteria
Diff
eren
ces
in b
acte
rial p
opul
atio
n si
ze (%
)
FOSBergamot
Mandalari et al., Appl Microbiol Biotech (2007)
Biorefining of functional food ingredients
Antioxidants
Prebiotics
Glucose
Prebiotics
Antiadhesives
Pretreatment
Pectinase
Hemicellulase
Cellulase
Fractionation
Fractionation
Sugar beetpulp
Citruswaste
Distillers’grains
• Prebiotics appear to be a viable, high value option for food waste management
• Success dependant on the waste, waste transfer process and cost
• Cost:benefit ratio set to improve with increasing market growth
• Market growth dependant upon establishment of prebiotic health benefits
Concluding remarks
Thank you!• LTN
• Profs Glenn Gibson, Bob Rastall (UR)
• Dr George Tzortzis (Clasado)
• Dr Giusy Mandalari, Dr Arjan Narbad (IFR)
Speaker 17
Tom Berry
Principal Sustainability AdvisorBusiness Programme
Forum for the Future
