present by mr. prasert techacheewapong effect of coagulants on solubility and emulsifying properties...
TRANSCRIPT
Present by
Mr. Prasert Techacheewapong
EFFECT OF COAGULANTS ON SOLUBILITY AND EMULSIFYING PROPERTIES OF
PROTEIN CONCENTRATES FROM MUNG BEAN AND ADZUKI BEAN
Protein concentratesMinimum of 70% proteinLegumes, Cereals and Whey
Legumes Protein 18 – 26 % (d.b.)pI = 4.0 – 5.0
INTRODUCTION
CoagulantsOrganic acid : citric acid, acetic acid and lactic acid
Inorganic acid : hydrochloric acid and sulfuric acid
INTRODUCTION
PREPARATION OF PROTEIN CONCENTRATES
Mung bean or Adzuki bean Flour : Distilled
water 1:10 (w/v)
Adjusted to pH 9.5 with 1M NaOH
Centrifuged at 3,500xg for 20 min
Adjusted to pH 5.0 and 4.5
with different two coagulants
HCl
Citric acid
Centrifuged at 3,500xg for 20 min
Protein precipitate (pH 7.0)
was dried in Tray dryer
55 OC8 hr.
PREPARATION OF PROTEIN CONCENTRATES
Mung bean
HCl
HCl
Citric acid
Citric acid
MPC-HCl
Adzuki bean
MPC-CA
APC-HCl
APC-CA
Four protein concentrates were determined for their chemical composition according to the standard methods of analysis that is AOAC (2000).
CHEMICAL COMPOSITION ANALYSIS
Protein solubility: Adebowale and Lawal (2003) pH 2 – 10
Water holding capacity (WHC): Quinn and Paton (1979) pH 3.5, 5.5 and 7.5
Emulsifying properties: Pearce and Kinsella (1976) Emulsifying activity index (EAI) Emulsifying stability index (ESI)
FUNCTIONAL PROPERTIES
Table 1: Chemical composition of mung bean and adzuki bean protein concentrates treated with HCl and citric acid.
CHEMICAL COMPOSITION
Chemical compositio
nMPC-HCl MPC-CA APC-HCl APC-CA
Moisture 5.17b ±0.31 5.14b ±0.29 5.83a ±0.31 5.69a ±0.11
Lipid 1.10c ±0.11 0.84c ±0.14 1.61a ±0.27 1.43a ±0.48
Protein 80.67a ±0.35 77.71b ±1.34 73.70c ±0.81 71.45d ±1.53
Ash 4.38b ±0.28 4.89a ±0.14 4.40b ±0.07 4.69a ±0.18
Carbohydrate 8.68d ±0.45 11.42c ±1.12 14.46b ±0.94 16.74a
±1.88*(a,b,c,d): Different superscript letters in the same row indicate significant difference (p≤0.05).† Carbohydrate content is calculated from 100 – (moisture – lipid – protein – ash).
PROTEIN SOLUBILITY
Figure 1. Protein solubility (%) of (a) mung bean protein concentrate and (b) adzuki bean protein concentrate treated with HCl and citric acid at pH-range 2-10.
Mung bean
Adzuki bean
80.12%
91.59%
77.40%86.36
%
Glu & Asp
Table 2: Water holding capacity of mung bean and adzuki bean protein concentrates treated with HCl and citric acid at pH 3.5, 5.5 and 7.5.
WATER HOLDING CAPACITY
sampleWHC (g water/g protein)
pH 3.5ns pH 5.5 pH 7.5
MPC-HCl 2.64b ±0.12 2.45Ab ±0.09 3.13Ca ±0.10
MPC-CA 2.53b ±0.06 2.23Bc ±0.07 2.89Da ±0.04
APC-HCl 2.73b ±0.14 2.63Ab ±0.14 3.67Aa ±0.12
APC-CA 2.65b ±0.04 2.46Ac ±0.06 3.39Ba ±0.01
*(A,B,C,D): Different superscript letters in the same column indicate significant difference (p≤0.05).*(a,b,c,d): Different superscript letters in the same row indicate significant difference (p≤0.05).*ns = no significant difference (p>0.05) in the same column.
High protein content
High protein content
Table 3: Emulsifying properties of mung bean and adzuki bean protein concentrates treated with HCl and citric acid.
EMULSIFYING PROPERTIES
sample EAI (m2/g) ESI (min)
MPC-HCl 12.36b ±0.04 135.31b ±2.50
MPC-CA 10.19c ±0.09 152.58a ±0.87
APC-HCl 13.02a ±0.50 126.00c ±2.83
APC-CA 12.41d ±0.15 135.96b ±1.90
*(a,b,c,d): Different superscript letters in the same column indicate significant difference (p≤0.05).
High Solubility
High Solubility
Flocculation and Coalescence
High protein content
High protein content
Using different coagulants had a significant effect on chemical composition and functional properties of protein concentrates.
The protein precipitated with HCl exhibited higher protein content, solubility, WHC and EAI but lower ESI than those treated using citric acid.
Protein concentrates from adzuki bean showed higher solubility, WHC and EAI but lower protein content and ESI than mung bean protein concentrates.
CONCLUSIONS
PROTEIN SOLUBILITY
1% (w/v) protein solution
Adjusted to pH 2 to 10with 1M HCl or NaOH
Stirred for 1 hour
Centrifuged at 4000xg for 15 min
Protein content in supernatant
𝐏𝐫𝐨𝐭𝐞𝐢𝐧𝐬𝐨𝐥𝐮𝐛𝐢𝐥𝐢𝐭𝐲 (%)=𝐚𝐦𝐨𝐮𝐧𝐭𝐨𝐟 𝐩𝐫𝐨𝐭𝐞𝐢𝐧𝐜𝐨𝐧𝐭𝐞𝐧𝐭 𝐢𝐧𝐭𝐡𝐞𝐬𝐮𝐩𝐞𝐫𝐧𝐚𝐭𝐚𝐧𝐭𝐚𝐦𝐨𝐮𝐧𝐭𝐨𝐟 𝐩𝐫𝐨𝐭𝐞𝐢𝐧𝐜𝐨𝐧𝐭𝐞𝐧𝐭 𝐢𝐧𝐭𝐡𝐞𝐬𝐚𝐦𝐩𝐥𝐞
Lowry’s method
WATER HOLDING CAPACITY
1 g Sample 10 ml water
Adjusted to pH 3.5, 5.5 and 7.5
with 0.1 M HCl or NaOH
Centrifuged at 8200xg for 15 min
The supernatant was removed and the sample was weighed
Water holding capacity=gramof watergramof sample