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Enhancing sweet potato (Ipomoea batatas Lam.) starch extract ability using enzymes
The study entitled “Enhancing sweet potato (Ipomoea batatas Lam.) starch extractability using enzymes” was conducted at the Division of Crop Utilization, CTCRI during 2013-2014, with an objective to lead to a technology to maximize the extraction of starch from sweet potatoes and also to enhance the...
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| Format: | Ph.D Thesis |
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Vellayani
Department of Plant Biotechnology, College of Agriculture
2014
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| LEADER | 04054nam a22001697a 4500 | ||
|---|---|---|---|
| 082 | |a 660.6 |b DHA/EN | ||
| 100 | |a Dhanya Thankachan | ||
| 245 | |a Enhancing sweet potato (Ipomoea batatas Lam.) starch extract ability using enzymes | ||
| 260 | |a Vellayani |b Department of Plant Biotechnology, College of Agriculture |c 2014 | ||
| 300 | |a 70p | ||
| 502 | |a MSc(INT) | ||
| 520 | 3 | |a The study entitled “Enhancing sweet potato (Ipomoea batatas Lam.) starch extractability using enzymes” was conducted at the Division of Crop Utilization, CTCRI during 2013-2014, with an objective to lead to a technology to maximize the extraction of starch from sweet potatoes and also to enhance the utilization prospects of sweet potato starch for food product development. Sweet potato (Ipomoea batatas Lam.) is cultivated throughout the tropics and warm temperate regions of the world for its starchy roots which can provide nutrition, besides energy. The edible tuberous root is either long and tapered, ovoid or round with a skin colour ranging from white, brown, purple or red and the flesh colour ranging from white, pale cream, orange or purple. Sweet potato starch finds commercial application in the production of noodles, sugar syrups, thickener etc. However, poor extractability of starch as well as the discolouration limits the use of sweet potato starch. Enzyme assisted as well as conventional method of starch extraction was done and comparative studies on the properties of extracted starch were performed. The distinctive feature of enzymes is that they can operate at mild conditions, at atmospheric pressure and at reasonably low or ambient temperatures. Mainly six enzyme combinations were tried for the extraction of the starch. Out of the six enzyme combinations, the use of Accellerase 1000 alone and Cellic C Tec 2 alone were found to be the effective enzyme treatment for the maximum extraction of starch from sweet potatoes. Enhanced starch recovery of 89.68 % and 84.95 % was obtained in the Accellerase and Cellic treatments, in comparison to only 56.94 % in the conventional method. The extracted starch had purity in the range of 90 – 93 % compared to 96 % in the conventional method. The physico-chemical properties of extracted starch samples were studied such as viscosity, swelling volume and solubility. The viscosity is much related to swelling volume of starch. The colour of the starch obtained from various treatments were measured using colorimeter and it was observed that there was slight difference in whiteness of starch, which may be due to action of enzyme used for the extraction. Thermal properties of starch samples from the best treatments were also studied along with the control starch. Starch gelatinization plays an important role during the processing of starch based system and it considerably affects their physiochemical and functional properties. The addition of enzyme retarded the onset of gelatinization relative to native starch. Ultrastructural studies were conducted for starch samples as well as their residues. This indicated that enzyme treatments to facilitate enhanced extraction of starch did not alter the surface morphology of most of the starch granules and the residues from the best treatment clearly displayed the fibrillar honey comb structure, typical of cellulose. Enzyme mediated extraction of sweet potato starch led to increase in the resistant starch content (25- 33 %) compared to 15.72 % in conventional method, which is probably due to fragmented fibers. Excellent pasta products with good cooking characteristics and appearance could be prepared with the extracted starch. Pasta from the Accellerase extracted starch had a very high RS content (73.20 %) in cooked product and hence has high value as a food for diabetic/obese people. | |
| 650 | |a Plant Biotechnology | ||
| 700 | |a G Padmaja (Guide) | ||
| 942 | |2 ddc |c TH | ||
| 999 | |c 141393 |d 141393 | ||
| 952 | |0 0 |1 0 |4 0 |6 660_600000000000000_DHAEN |7 1 |8 REF |9 140298 |a KAUCLV |b KAUCLV |c THESES |d 2015-02-09 |o 660.6 DHA/EN |p 173448 |r 2015-02-09 |y TH | ||