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Materi Kimia Kelas XII Semester 2
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KOMPOSISI DAN SIFAT BAHAN PANGANKOMPOSISI DAN SIFAT BAHAN PANGAN
Water
Protein
Carbohydrate
Lipida
Vitamin &Mineral
Komponen Alami:Komponen Alami: Komponen Tambahan:Komponen Tambahan:
Emulsifier
Antioxidant
Preservative
Thickener
Sweetener
Etc.
MUTU & KEAMANANPANGAN
Enzim
Antioksidan
Asam
Pigmen Citarasa
KARBOHIDRATKARBOHIDRAT
1. PENDAHULUAN2. KARBOHIDRAT DALAM BAHAN PANGAN3. KLASIFIKASI DAN STRUKTUR KIMIA4. REAKSI KIMIA KARBOHIDRAT5. SIFAT FUNGSIONAL KARBOHIDRAT
1. PENDAHULUAN1. PENDAHULUAN
• 75 % of Biological World• 80 % of the Calorie Intake of humankind
75 – 80 % starch• In USA : Composition of Calorie Intake
Carbohydrate : 46% • 47 % Starch• 52% Sucrose
Fats : 42% Protein : 12%
• Rumus Umum : Cx(H2O)y
• Modifikasi struktur Sifat Fungsional
2. KARBOHIDRAT DALAM 2. KARBOHIDRAT DALAM BAHAN PANGANBAHAN PANGAN
Karbohidrat utama dalam :• animal : glucose, glycogen• milk : lactose • plant : cellulose, starch• seaweed : alginate, carrageenan, agar
2. KARBOHIDRAT DALAM 2. KARBOHIDRAT DALAM BAHAN PANGANBAHAN PANGAN
Food Sugar (%)
• Coke• Crackers• Ice Cream• Orange Juice• Cake (dry mix)
9
12
18
10
36
Sugar in Fruits :Sugar in Fruits :
FruitFree Sugar (%)
Glucose Fructose Sucrose
• Apple• Grape• Peach• Pear• Strawberry
1.17
6.86
0.91
0.95
2.09
6.04
7.84
1.18
6.77
2.40
3.78
2.25
6.92
1.61
1.03
Sugar in Vegetables:Sugar in Vegetables:
VegetablesFree Sugar (%)
Gluc Fruc Suc
• Broccoli• Carrot• Cucumber• Spinach• Sweetcorn• Tomato
0.73
0.85
0.86
0.09
0.34
1.12
0.67
0.85
0.86
0.04
0.31
1.34
0.42
4.24
0.06
0.06
3.03
0.01
Sugar in Legumes :Sugar in Legumes :
LegumesFree Sugar (%)
Gluc Fruc Suc
• Snap bean• Lima Bean• Pea
1.08
0.04
0.32
1.20
0.08
0.23
0.25
2.59
5.27
Sugar in Fruits (per 100 gram)Sugar in Fruits (per 100 gram)
Macam BuahJumlah
Gula (%)
Jenis Gula (g)Energi (kcal)Gluc Fruc Suc
• Kurma• Pisang• Kismis• Apel• Nanas• Anggur• Pear• Jeruk Manis• Mangga• Blewah
48.8
19.6
14.2
11.0
10.6
9.3
8.7
8.5
7.4
6.5
24.9
5.2
-
1.2
2.3
4.8
2.5
2.5
-
1.1
23.9
5.9
-
6.0
1.4
4.3
5.0
1.8
-
1.3
-
8.5
14.2
3.8
6.9
0.2
1.2
4.2
7.4
4.1
271
98 *)
289
64 *)
57 *)
68
61
51 *)
73 *)
30Sumber : Food and Nutrition Encyclopedia (1994) *) Daftar Analisis Bahan Makanan (1992)
3. KLASIFIKASI DAN 3. KLASIFIKASI DAN STRUKTUR KIMIASTRUKTUR KIMIA
Photosynthesis
Carbohydrates are synthesised in green plants by photosynthesis. Solar energy is absorbed by the green pigment in plants, chlorophyll. This energy is used to drive many enzyme-catalysed processes. The overall effect is to reduce carbon dioxide to carbohydrates and oxidise water to oxygen:
Lingkungan
Tanaman Lingkungan
CARBOHYDRATECx(H2O)y
Monosaccharides
POLYSACCHARIDES
Disaccharides
Hexose (C-6)
Pentose (C-5)
a. D-Glucoseb. D-Galactosec. D-Mannosed. D-Fructose
1. Xylose2. Arabinose3. Ribose
• Sucrose (a+d)• Lactose (a+b)• Maltose (a+a) -> • Cellobiose (a+a) ->
Oligosaccharides
• Rafinose (b+a+d)• Stachyose (b+b+a+d)• Verbacose
• Cellulose (-> a)• Starch (-> a)• Chitin • Agar (->b)• Carrageenan (->b)• Alginat
POLYSACCHARIDES
STARCH NON-STARCHPOLYSACCHARIDES
Alginate
Carrageenan
Agar
Furcellaran
Daratan:
Cellulose
Pectin
Perairan:
Chitosan
Gum
Lainnya
Lainnya
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
-D-Glukosa
1
23
45
6
1
2
3
4
5
6
-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
OH1
Atom C Chiral
Struktur Kimia
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
-D-GlukosaKonfigurasi Haworth
1
23
45
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
-D-Glucopyranosa
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
-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
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
-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
=
-D-Fruktosa(Ketosa)
(Hexulose)(C6H12O6)
Gugus Keton
R
O
H
C
CHO
=
R = H AldehydeR = CH2OH Keton
Saccharose group
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 into copper (I) which forms red copper oxide (Cu2O) as a precipitate. This is how Benedict’s reagent and Fehling’s solution are used to test for aldehydes and reducing sugars.
Struktur Kimia
OH
HO
OH
OHOH
H
CH2OH
OH
HOOHOH
OH
H
CH2OH
OHO
H
OH
OHOH
H
CH2OH
H
H
HH
H
H
-D-Glukosa
-D-Manosa
-D-Galaktosa
O
OH
CH2OHOHCH2
H
OH
OH
H
1
23
45
6
1
2
34
5
6
-D-Fructose
H
MONOSAKARIDA
OH
HO
OH
OH O
H
CH2OH
H
H
-D-Maltosa(Glukosa--(14)-Glukosa)
OH
OH
OHOH
H
CH2OH
H
H
DISAKARIDA
-D-Glukosa -D-Glukosa
• terdiri atas 2 molekul glukosa• dari hydrolysis pati oleh -amylase• gula reduksi
O
LactosaGalaktose--(14)-Glukosa)
OH
OH
OHOH
H
CH2OH
H
H
DISAKARIDA
-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
-D-Galaktosa
SukrosaGlukosa--(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
-D-Glukosa
O
OH
CH2OHOHCH2
OH
OH
H
1
2
34
5
6
-D-Fructose
H
OHOH O
H
CH2OH
H
OH
OH
OHH
CH2OH
H
H
CELLULOSE
-D-Glukosa -D-Glukosa
n
POLISAKARIDA
ikatan--(14)-Glikosidik)
OH
OHO
A
A
B
B O1 4
2
14
41
POLISAKARIDA
POLISAKARIDA
REAKSI-REAKSI KARBOHIDRAT
1. HYDROLYSIS2. NON-ENZYMATIC BROWNING
As shown in Table 4.29, the C1 and Cx factors, which were found to be endo- and exo-1,4-β-glucanases respectively, hydrolyze cellulose to cellobiose. Since the C1 factor is increasingly inhibited by its product, a cellobiase is needed sothat cellulose breakdown is not rapidly brought to a standstill. However, cellobiase is also subject to product inhibition. Therefore, complete cellulosedegradation is possible only if cellobiase is present in large excess or the glucose formed is quickly eliminated.
REAKSI-REAKSI KARBOHIDRAT
• HYDROLYSIS :• Pembuatan HFCS
POLYSACCHARIDES
Acid Treatment
Heat Treatment
Enzyme Treatment
1
2
3 PRODUCTS
HFCS
4. REAKSI-REAKSI KARBOHIDRAT
• HYDROLYSIS :• Fermentasi Tape
BAHAN BAKU Fermentation
• Jenis Mikrobia• Suhu• Waktu
PRODUCTS
• Ketela Pohoh• Ketan
• Tape singkong• Tape Ketan
Starch Glucose Alcohol Acid
BROWNING
• ENZIMATIS
• NON-ENZIMATIS
• Reaksi Enzimatis• Dipengaruhi oleh :
• Substrat• Enzim• Suhu• Waktu
• Reaksi Maillard
• Karamelisasi
• Reaksi Gula & Protein• Dipengaruhi oleh :
• Jenis Gula• Suhu• Waktu
• Pemanasan Gula• Dipengaruhi oleh :
• Suhu• Waktu
• Ascorbic acid oxidation
BROWNING
Reaksi Maillard• Ilmuwan Perancis : Louis Maillard (1912) glucose + glycine• Carbonyl – Amine Reaction action of amino acids/protein on reducing sugars• Related to aroma, taste and color• Roasting of coffee and cacao beans, baking of bread and cakes, toasting of cereals, cooking of meats•
BROWNING
REDUCINGSUGAR
AMINOACID
CARBONYL
AMINE
Melanoidins (Brown
Pigments)• Dipengaruhi oleh :
• Jenis Gula• Asam Amino• pH• Suhu• Katalis• Kadar Air
5-Hydroxymethyl-2-Furfuraldehyde
(HMF)
REAKSI MAILLARD• Reaksi antara gula pereduksi dan Protein (asam amino)• Dipengaruhi oleh suhu, waktu dan jenis gula• Menghasilkan warna coklat • Prosesnya berlangsung pada suasana basa• Proses yang terjadi pada reaksi maillard:
1. Gugus karbonil pada gula menghasilkan N-glukosamin dan air
2. Gugus glukosamin yang tidak stabil mengalami pengaturan kembali membentuk ketosamin
3. Ketosamin mengalami proses lanjut:• Memproduksi air dan redukton• Menghasilkan diasetil, aspirin, pyruvaldehid, dan
ikatan hidrolitik lain• Membentuk melanoidin.
MAILLARD REACTION
(i) Initial stage (colourless)a. sugar-amine condensationb. Amadori rearrangement
(ii) Intermediate stage (colourless to yellow)c. sugar dehydrationd. sugar fragmentatione. amino acid degradation
(iii)Final stage (highly coloured)f. aldol condensationg. aldehyde-amine polymerisation, formation of heterocyclic nitrogen compounds.
Maillard Reaction
0,06
0,08
0,1
0,12
0,14
0,16
0,18
0,2
0 1000 2000 3000 4000 5000
Time (Minutes)
DL
-Leu
cin
e (m
illi
mo
le/m
l)
0 oC
23 oC
40 oC
Fig. 1. Effect Temperature on the reaction rate of D-Glucose with DL-Leucine
Maillard Reaction
Fig. 1. Effect pH on the reaction rate of D-Glucose with DL-Leucine
0,05
0,07
0,09
0,11
0,13
0,15
0,17
0,19
0,21
0 1000 2000 3000
Time (minutes)
DL
-Leu
cin
e (M
illi
mo
le/m
l)
pH 8,65
pH 9,2
pH 9,5
BROWNING REACTIONS
SUCROSE SUCROSE +FRUCTOSE
SUCROSE +LACTOSE
Maillard Reaction : (Lysine + Sugars)
BROWNING NON ENZIMATIS : MAILLARD
Produk : Bakpia
CARAMELIZATION
• Caramelization is defined as the thermal degradation of sugars leading to the formation of volatiles (caramel aroma) and brown-colored products (caramel colors).
• The process is acid or base catalyzed and generally requires temperatures > 120 oC at 9<pH<3 (pH < 3 or pH > 9)
• Caramelization occurs in food, when food surfaces are heated strongly, e.g. the baking and roasting processes, the processing of foods with high sugar content such as jams and certain fruit juices, or in wine production.
TEKNOLOGI KARBOHIDRAT
SUMBERKARBOHIDRAT
TEKNOLOGIPROSES
CARBOHYDRATE-BASEDPRODUCT
1. Ketela Pohon2. Beras Ketan3. Jagung4. Gandum
1. Tape Ketela Pohon2. Tape Ketan3. HFCS4. Karamel5. Candy6. Modified (CMC)
1. Asam2. Basa3. Panas4. Enzimatis5. Mikrobiologis
SIFAT FUNGSIONALSIFAT FUNGSIONAL1.SWEETNESS &
SWEETENERS2.HYGROSCOPICITY
1.Reduced Aw Preservative
2.Adsorbent Baby care products
3.Moisture Beauty care products
3.TEKSTURAL CONTRIBUTION1.Rigidity : Roti2.Viscosity : Saus
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