Thumbnail Image

Theses

Browse

20191
Reset filters
Subject: Horticulture × Author: Borah, Mriganka Shekhar × End date: 2019 × Start date: 2019 × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    QUALITY OF SWEET POTATO FLOUR AS AFFECTED BY BY PRE–TREATMENT AND DRYING METHODS
    (AAU, Jorhat, 2019-07) Borah, Mriganka Shekhar; Samindra Baishya
    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.