1. E-mail: ooawolu@futa.edu.ng, Registrant ID# 2156
Sp24-12
Effect of some chemical modification methods on physico-chemical, functional and pasting properties of native and modified water yam (Dioscorea alata) starches.
Olugbenga Olufemi Awolu1*.
Department of Food Science and Technology, Federal University of Technology, Akure, Nigeria.
Registrant ID# 2156
Introduction
Starch, as a major reserve substance of plant sources, contributes to the appearance, structure and quality of food products (Lawal and Adebowale, 2005). Native starches are undesirable for many industrial applications because of their inability to withstand processing conditions such as extreme temperature, diverse pH and high shear rate (Singh et al., 2007). Modification of native starches improves its desirable functional properties. In this study, Water yam starch was isolated and subjected to chemical modification by acetylation, oxidation and acid thinning. Chemical composition, functional properties and pasting characteristics of native and modified starches were analyzed using standard methods and compared with commercially available cassava starch.
M&M
Water yam was locally obtained. Cassava starch was obtained from Matna Industries, Owo, Nigeria. Starch extraction (Riley et al. 2006), Acetylation and acid thinning (Sathe and Salunkhe, 1981), Oxidation (Lawal, 2004); Proximate properties (AOAC, 2005), Functional properties and pasting characteristics of native and modified water yam starches were evaluated
Results
Table 1: Result of Proximate composition of Native and Acetylated Water Yam Starches
Table 2: Functional Properties, Resistant Starch and Sugar Content of Native and Acetylated Samples
Table 3:
NaYS AcYS
* NaYS = Native water yam starch, AcYS = Acetylated water yam starch, AtYS = Acid thinned water yam starch, OxYS = Oxidized water yam starch, CaVS = Commercial starch
Conclusion OxYS AtYS
chemical modification improved AtYS
the attributes hence good
sources of edible and industrial
starches CaVS
(use the bottom of the poster only is necessary)
Starch
Yield (%)
Moisture (%)
Ash (%)
Fat (%)
Crude fibre (%)
Protein (%)
Amylose (%)
NaYS
21.67d±1.80
8.09d
0.35b
3.37a±0.02 ND
0.44b
12.53b±0.08
AcYS
97.30a±0.82
11.65a±0.04
0.20d
2.27c±0.02
0.33c±0.02
9.42e±0.03
AtYS
85.30c±0.61
9.69c±0.02
0.55a
2.11d±0.01
0.43b
10.57c±0.02
OxYS
90.33b±1.30
9.96b±0.01
0.35c
2.87b±0.02
0.41b
9.95d±0.01
CaVS
6.43e
0.15e
0.92e±0.03
1.29a±08
21.50a±0.05
Starch
WAC (g/g)
OAC (g/g)
Bulk density (g/cm3)
Resistant starch (%)
Total sugar (%)
NaYS
1.17a±0.01
0.40b±0.58
0.85a±0.02
18.25d±0.25
0.064b±0.002
AcYS
1.09b±0.01
0.46b±0.01
0.81b±0.03
21.47c±0.03
0.053d±0.001
AtYS
0.99c±0.01
0.88ab±0.01
0.79b±0.02
18.35d±0.05
0.063b±0.001
OxYS
0.68e±0.01
0.59b±0.01
21.95b±0.05
0.056c±0.003
CaVS
0.90d±0.03
1.18a±0.01
0.73c±0.01
23.70a±0.20
0.085a±0.002
Starch
P.V (BU)
Tr (BU)
FV (BU)
SV (BU)
BV (BU)
PT (min.)
P (oC)
NaYS
32.85
3.69
78.67
45.82
29.17
6.85
93.65
AcYS
34.42
3.92
83.56
49.14
30.50
6.55
94.45
AtYS
66.08
62.08
235.42
169.33
4.00
6.93
94.52
OxYS
76.58
32.00
64.42
-12.16
44.58
6.49
92.58
CaVS
802.83
609.75
257.25
192.25
6.92
92.42