View
251
Download
1
Category
Preview:
Citation preview
7/28/2019 Analisis pangan (karbohidrat)
1/32
Analisis karbohidratBagian 1
7/28/2019 Analisis pangan (karbohidrat)
2/32
overview
Pendahuluan
Preparasi Sampel
Mono- dan Oligosakarida
Polisakarida
Dietray Fiber
7/28/2019 Analisis pangan (karbohidrat)
3/32
Water
Protein
Carbohydrate
Lipida
Vitamin &Mineral
Komponen Alami: Komponen Tambahan:
Emulsifier
Antioxidant
Preservative
Thickener
Sweetener
Etc.
MUTU & KEAMANAN
PANGAN
Enzim
Antioksidan
Asam
Pigmen Citarasa
7/28/2019 Analisis pangan (karbohidrat)
4/32
Pendahuluan
Karbohidrat merupakan komponendalam makanan yang merupakansumber energi utama bagi organismehidup.
senyawa organik yang terdiri dari bahanekstrak tanpa nitrogen (BETN ) dan seratkasar, unsurnya terdiri dari karbon (C),hidrogen (H) dan oksigen (O).
senyawa polihidroksi aldehid ataupolihhidroksi keton (CnH2nOn). Berdasarkan jumlah monomer
penyusunnya, dapat dikelompokkan mjd
mono-, di-, oli-, dan polisakarida.
7/28/2019 Analisis pangan (karbohidrat)
5/32
Pendahuluan
7/28/2019 Analisis pangan (karbohidrat)
6/32
Pendahuluan
Monosakarida mungkin dapat bergabung satu samalain, dengan mengambil satu molekul air untuk tiapgabungan, menghasilkan, di-, tri-, atau polisakaridayang mengandung 2,3 atau lebih monosakarida.
KH dibagi menjadi 2 golongan gula (mono-tetrasakarida) dan non-gula (homopolisakarida,heteropolisakarida).
HOMOPOLISAKARIDE Pentosan
Heksosan
HETEROPOLISAKARIDE Hemiselulose
Gummi
Musilage
Zat Peptik
Mukopolisakaride dari hewan
7/28/2019 Analisis pangan (karbohidrat)
7/32
CARBOHYDRATECx(H2O)y
Mono
saccharides
POLY
SACCHARIDES
Di
saccharides
Hexose (C-6)
Pentose (C-5)
a. D-Glucose
b. D-Galactose
c. D-Mannose
d. D-Fructose
1. Xylose2. Arabinose
3. Ribose
Sucrose (a+d)
Lactose (a+b)
Maltose (a+a) -> a Cellobiose (a+a) ->b
Oligo
saccharides
Rafinose (b+a+d)
Stachyose (b+b+a+d)
Verbacose
Cellulose (-> a)
Starch (-> a)
Chitin
Agar (->b)
Carrageenan (->b)
Alginat
7/28/2019 Analisis pangan (karbohidrat)
8/32
Pendahuluan
Humans can digest only sucrose,lactose, maltooligosaccharides/maltodextrins, and starch. All aredigested with enzymes found in the small
intestine. Hanya amilum (jenis polisakarida) yg
dpat dicerna manusia. Nondigestible polysaccharides can be
divided into soluble and insolubleclasses. Along with lignin and othernondigestible, nonabsorbed substances,they make up dietary fiber (sbgkomponen tambahan dlm produkpangan)
7/28/2019 Analisis pangan (karbohidrat)
9/32
POLYSACCHARIDES
STARCH NON-STARCH
POLYSACCHARIDES
Alginate
Carrageenan
Agar
Furcellaran
Daratan:
Cellulose
Pectin
Perairan:
Chitosan
Gum
Lainnya
Lainnya
7/28/2019 Analisis pangan (karbohidrat)
10/32
Struktur Kimia
C
OH
H
C
C
C
C
C
H
H
H
HO
OH
OH
H
H
O
H OH
=
OH
HO
OH
OHOH
H
CH2OH
H
H
a-D-Glukosa
123
4
5
6
1
2
3
4
5
6
a-D-Glukosa(Aldosa)
(Aldohexose)
Gugus Karbonil (CO)
Gugus Aldehid (CHO) = gugus reduksi
Atom C asimetris terjauh dari karbonil (CO)Sebagai dasar penamaan D (OH dikanan) dan
L (OH di kiri)
H
OH
1
b
Atom C Chiral
7/28/2019 Analisis pangan (karbohidrat)
11/32
Struktur Kimia
7/28/2019 Analisis pangan (karbohidrat)
12/32
Struktur Kimia
C
OH
H
C
C
C
C
C
H
H
H
HO
OH
OH
H
H
O
H OH
=
OH
HO
OH
OHOH
H
CH2OH
H
H
a-D-GlukosaKonfigurasi Haworth
123
4
5
6
1
2
3
4
5
6
Aldehydo-D-Glukose
C
OH
H
C
C
C
C
C
H
H
H
HO
OH
O
H
H OH
H OH
1
2
3
4
5
6
a-D-Glucopyranosa
7/28/2019 Analisis pangan (karbohidrat)
13/32
Struktur Kimia
C
OH
H
C
C
C
C
C
H
H
H
HO
OH
OH
H
H
O
H OH
=1
2
3
4
5
6
a-D-Glukosa(Aldosa)
Gugus Karbonil (CO)
Gugus Aldehid (CHO) = gugus reduksi
C
OH
H
C
C
C
C
C
H
H
H
HO
OH
OH
H
H
OH
H OH
1
2
3
4
5
6
H
Reduksi
Sorbitol
Na-Amalgam
Li-Al-hydride
hydrogenation
7/28/2019 Analisis pangan (karbohidrat)
14/32
Struktur Kimia
C
OH
H
C
C
C
C
C
H
H
H
HO
OH
OH
H
H
O
H OH
=1
2
3
4
5
6
a-D-Glukosa(Aldosa)
(Hexose)
(C6H12O6)
Gugus Karbonil (CO)
Gugus Aldehid (CHO) = gugus reduksi
C
O
H
C
C
C
C
C
H
H
HO
OH
OH
H
H
OH
H OH
1
2
3
4
5
6
H
=
a-D-Fruktosa(Ketosa)
(Hexulose)
(C6H12O6)
Gugus Keton
R
O
H
C
CHO
=
R = H AldehydeR = CH2OH
Keton
Saccharose group
7/28/2019 Analisis pangan (karbohidrat)
15/32
Struktur Kimia
Carbonyl group
Keton Aldehid
Aldehydes are readily oxidised to
carboxylic acids:
If copper (II) (blue Cu2+) is used as
the oxidising agent it is converted intocopper (I) which forms red copper
oxide (Cu2O) as a precipitate. This is
how Benedicts reagent and Fehlings
solution are used to test for aldehydes
and reducing sugars.
7/28/2019 Analisis pangan (karbohidrat)
16/32
OH
HO
OH
OHOH
H
CH2OH
OH
HOOHOH
OH
H
CH2OH
OHO
H
OH
OHOH
H
CH2OH
H
H
HH
H
H
a-D-Glukosa
a-D-Manosa
a-D-Galaktosa
O
OH
CH2
OHOHCH2
H
OH
OH
H
1
23
4
5
6
1
2
34
5
6
a-D-Fructose
H
MONOSAKARIDA
a a
a a
7/28/2019 Analisis pangan (karbohidrat)
17/32
OH
HO
OH
OHO
H
CH2OH
H
H
a-D-Maltosa(Glukosa-a-(14)-Glukosa)
OH
OH
OHOH
H
CH2OH
H
H
DISAKARIDA
a-D-Glukosa a-D-Glukosa
terdiri atas 2 molekul glukosa
dari hydrolysis pati oleh b-amylase gula reduksi
7/28/2019 Analisis pangan (karbohidrat)
18/32
O
LactosaGalaktose-b-(14)-Glukosa)
OH
OH
OHOH
H
CH2OH
H
H
DISAKARIDA
a-D-Glukosa
terdiri atas Galaktosa dan Glukosa
terdapat pada susu :
Mamalia : 2 8.5%
Cow and Goat : 4.5 4.8%
Human : 7 %
gula reduksi
OHO
H
OH
OHH
CH2OH
H
H
a-D-Galaktosa
7/28/2019 Analisis pangan (karbohidrat)
19/32
SukrosaGlukosa-a-(12)-Fruktosa)
DISAKARIDA
terdiri atas Glukosa dan Fruktosa
terdapat pada cane atau beet
gula non-reduksi
table sugar
OH
HO
OH
OH O
H
CH2OH
H
H
a-D-Glukosa
O
OH
CH2OHOHCH
2
OH
OH
H
1
2
34
5
6
a-D-Fructose
H
7/28/2019 Analisis pangan (karbohidrat)
20/32
OHOH O
H
CH2OH
H
OH
OH
OHH
CH2OH
H
H
CELLULOSE
a-D-Glukosa a-D-Glukosa
n
POLISAKARIDA
ikatan-b-(14)-Glikosidik)OH
OHO
A
A
B
B O1 4
2
1
4
4
1
7/28/2019 Analisis pangan (karbohidrat)
21/32
POLISAKARIDA
7/28/2019 Analisis pangan (karbohidrat)
22/32
POLISAKARIDA
7/28/2019 Analisis pangan (karbohidrat)
23/32
Pendahuluan
Evolution of analytical methods for carbohydrates hasfollowed the succession:
qualitative color tests, adaptation of the color test for reducingsugars based on reduction of Cu(II) to Cu(I) (Fehling test) toquantitation of reducing sugars,
qualitative paper chromatography,
quantitative paper chromatography, gas chromatography (GC) of derivatized sugars,
qualitative and quantitative thin layer chromatography,
enzymic methods, and
highperformance liquid chromatography (HPLC).
nuclear magnetic resonance,
near-infrared (NIR) spectrometry,
antibodies (Immunoassays)
Fluorescence spectrometry
CE dan MS
7/28/2019 Analisis pangan (karbohidrat)
24/32
Pendahuluan
Pelabelan (FDA): Total carbohydrate calculated by subtraction of
the sums of the weights ofcrude protein, total fat,moisture, and ash in a serving from the totalweight of the food in a serving.
Othercarbohydrate (formerlycalledcomplex carbohydrate) is obtained bycalculating the difference between the amount oftotalcarbohydrate and the sum of the amountsof dietary fiber and sugars.
Sugars are defined as the sum of all freemonosaccharides (D-glucose and -fructose)and disaccharides [sucrose, lactose, and maltose(if a maltodextrin or glucose/corn syrup has beenadded)]
7/28/2019 Analisis pangan (karbohidrat)
25/32
Pendahuluan
Total KH = 100% - (% crude protein + %crude fat + kadar air + kadar abu)
KH kompleks = total KH (serat pangan+ gula)
Serat pangan = jenis KH yang tidak bisadicerna (selulose, hemiselulose danpolisakaride lain yang berfungsi sebagai
bahan pelindung tanaman, serta lignin) Gula = jumlah monosakarida bebas +
disakarida/ maltodextrin
7/28/2019 Analisis pangan (karbohidrat)
26/32
7/28/2019 Analisis pangan (karbohidrat)
27/32
Preparasi Sampel
vacuum oven and drying to constant
weight at 55C and 1mm Hg pressure
Soxhlet extractor
Removed
contaminants
M d T t l Ph l lf i
7/28/2019 Analisis pangan (karbohidrat)
28/32
Mono- dan
Oligosakarid
aMetodeanalisis
Totalkarbohidrat
Phenol-sulfuricmethod
Total reducingsugar
Somogyi-Nelsonmethod
Metodekhusus
HPLC
GC
Enzimatis
MS
TLC
CE
Total Carbohydrate: Phenol
7/28/2019 Analisis pangan (karbohidrat)
29/32
Total Carbohydrate: Phenol-
Sulfuric
Acid Method Prinsip KH didigesti dgn asam danatau suhu panas, tjd reaksi dehidrasi,
menghasilkan turunan furan. Lalu
dikondensasi dgn senyawa fenolik(fenol, resorsinol, naphtol) dan amin
aromatis (anilin)
Total Carbohydrate: Phenol
7/28/2019 Analisis pangan (karbohidrat)
30/32
Total Carbohydrate: Phenol-
Sulfuric
Acid Method
Prosedur umum :1. A clear, aqueous solution of carbohydrate(s) is
transferred using a pipette into a small tube. A blankof water also is prepared.
2. An aqueous solution of phenol is added, and thecontents are mixed.
3. Concentrated sulfuric acid is added rapidly to the tubeso that the stream produces good mixing. The tube isagitated. (Adding the sulfuric acid to the waterproduces considerable heat.) A yellow-orange colorresults.
4. Absorbance is measured at 490 nm.5. The average absorbance of the blanks is subtracted,
and the amount of sugar is determined by referenceto a standard curve. D-glucose is used to prepare thestandard curve.
7/28/2019 Analisis pangan (karbohidrat)
31/32
Total Reducing Sugar: Somogyi-
Nelson Method Prinsip terjadi reaksi reduksi-oksidasi.
Gula pereduksi yaitu gula ygmengandung gugus aldehid (donorelektron/ reduktor) mengalami oksidasi,
menghasilkan gugus asam karboksilat. Gugus keton merupakan gula pereduksi
yg lemah.
The SomogyiNelson method is basedon the reduction of Cu(II) ions to Cu(I)ions by reducing sugars.
7/28/2019 Analisis pangan (karbohidrat)
32/32
Total Reducing Sugar: Somogyi-
Nelson Method Prosedur umum:1. A solution of copper(II) sulfate and an alkaline
buffer are added by pipettes to a solution ofreducing sugars(s) and a water blank.
2. The resulting solution is heated in a boilingwater bath.
3. A reagent prepared by mixing solutions ofacidic ammonium molybdate and sodiumarsenate is added.
4. After mixing, dilution, and remixing, absorbanceis measured at 520 nm.
5. After subtracting the absorbance of the reagentblank, the A250 is converted into glucoseequivalents using a standard plot of
micrograms of glucose vs absorbance
Recommended