QUALITY OF SWEET POTATO FLOUR AS AFFECTED BY BY PRE–TREATMENT AND DRYING METHODS
Loading...
Date
2019-07
Authors
Borah, Mriganka Shekhar
Journal Title
Journal ISSN
Volume Title
Publisher
AAU, Jorhat
Abstract
Sweet potato (Ipomoea batatas, family:Convolvulaceae) is a perennial crop,
grown in tropical and subtropical lowland agro-ecologies, although it is well adapted
to other zones and can be grown in different environmental conditions. Sweet potato
is an excellentsource of energy, but due tolow digestibility of the starch it is suitable
fordiabetic or overweighed people. Because of its highly perishable nature, there are
many problems related to storage and transport of the raw sweet potatoes. However,
it can be processed into flour, which is less bulky and more stable than the highly
perishable fresh root.The present investigation was aimed to evaluate the effect of
pre-treatment and drying methods on chemical composition and the functional
properties of sweet potato flour.
Fourpre-treatment methods (soaking in water, T1;blanching, T2; calcium
chloride solution, T3 and pre-drying at 100oC for 5minutes, T4along with thecontrol,
T5) and three drying methods (sun drying,D1 oven drying,D2 and microwave
drying,D3) were employed in the preparation of flour from three varieties of sweet
potato (Dergaon red, Shree Bhadra and ST-14).Drying methods and pre-treatment
were found to influence all the parameters studied, titratable acidity remained
unaffected by the drying methods.The pre-treatments caused significant reduction in
the nutritional parameters compared to control with T4 being the worst. Sun drying
was found better in maximum retention of crude protein, crude fat, starch and
amylose over the other two. Microwave drying was found better for crude fibre and
ash content. Functional properties of sweet potato flour were also affected by the
pre-treatment and the drying methods with T4 and D3 affecting the most of them.
The interactive effect of variety, pre-treatment and drying method was found to have
a significant effect in all the attributes of sweet potato flour. Orange fleshed variety,
ST-14 was found nutritionally superior over the other two and the quality and
functional properties of flour was best with treatment combinations, T5D1. Sun
drying of sweet potato slices with no pre-treatment was found better in preparing
sweet potato flour over any other combinations used in the study.
Description
Keywords
null