Abstract:
Sweet potato (Ipomoea batatas L.) root is a traditional raw material for industrial starch
production in central Asia (particularly China, Vietnam, Taiwan, and Korea). Sweet
potato starch has superior free swelling and non-congealing characteristics, and
therefore is a potential source of raw material for modified starch industry. In this
research, a preliminary study has been performed to observe the effect of several process
conditions on the physicochemical and functional properties of phosphorylated sweet
potato starch. Phosphorylation of sweet potato starch was carried out at a temperature
of 125 °C and initial pH level of reaction of 8-10 using a mixture of sodium
tripolyphosphate and sodium trimetaphosphate (STPP and STMP, weight ratio of STPP/
STMP= 2.5:1) and an intake of 5%-weight STPP based on dry starch. The experimental
result shows that phosphorous content of the products is accessible in the range of
0.154-0.180%-P. A significant improvement on solubility (6.56-14.10 %-w/w) and
swelling power (9.36-12.82 g/g) has been achieved for the phosphorylated products
compared to native starch (solubility = 2.33 %-w/w and swelling power = 7.36 g/g).
Paste viscosity of the phosphorylated starch suspension (0.180 %-P, 1 g starch /100 ml)
is higher (0.75 cP) compared to native starch (0.62 cP). Phosphorylated products also
show improvement on paste clarity, and water absorption capacity. The result suggests
that phosphorylation is a potential method to enhance the properties of sweet potato
starch.
Description:
Makalah dipresentasikan pada The 2nd International Symposium on Agricultural and Biosystem Engineering. Lombok, Indonesia, 9-11 Agustus 2016. p. 1-5.
