Isolation, modification and quality evaluation of starch from pearl millet varieties and development of ready-to-eat extruded snacks
| dc.contributor.advisor | Grewal, Raj Bala | |
| dc.contributor.author | Kaushik, Isha | |
| dc.date.accessioned | 2017-09-29T04:54:05Z | |
| dc.date.available | 2017-09-29T04:54:05Z | |
| dc.date.issued | 2017 | |
| dc.description.abstract | The present study was carried out to evaluate the physico-chemical characteristics and functional properties of thirteen different pearl millet varieties/hybrids to standardize the procedure for extraction and modification of starch from pearl millet; and to evaluate the physical, chemical, functional and pasting properties of native and modified pearl millet starch. The process for preparation of RTE extruded snacks by incorporation of pearl millet starch was standardized using RSM. 1000 kernel weight, bulk density and swelling capacity of different varieties of pearl millet grain ranged from 7.23-10.90 g, 0.78-0.85 g/ml and 0.004-0.006 ml/seed. Different varieties of pearl millet contained 10.03-13.66% protein, 4.92-6.55% fat, 1.70-1.95% ash, 1.82-2.03% crude fibre and 77.44-81.33% total carbohydrate. Yield and purity of starch extracted from different methods ranged from 24-50% and 87.34-90.39%, respectively. On the basis of concentration of chemical used for extraction, yield, functional properties, light transmittance, syneresis and pasting characteristics; 0.1% Na2S2O5 (T4 method) was selected for extraction of starch from different varieties of pearl millet. Yield and purity of starch extracted from thirteen different varieties ranged from 41.6-50.5% and 88.34-90.38%, respectively. Less impurities and high yield (50.5%) of starch was obtained from white seeded hybrid (HHB-256). Starch obtained from HHB- 256 white seeded hybrid exhibited 2.57 g/g swelling power, 2.54% solubility, 184.5% WHC; (5.7-4.4%) high light transmittance and (0.30-2.27%) low syneresis during period of study of syneresis. Starch extracted from HHB-256 white seeded hybrid of pearl millet was used for modification using physical, chemical and enzymatic methods. Starch modified by all the methods except pregelatinized starch (PM) showed significantly lower swelling power (1.78 to 2.57 g/g) than native starch. Highest solubility was observed for starch modified by enzymatic method (EM). Gel consistency of modified pearl millet starch (23.3 to 86.7 mm) was significantly lower than native starch (109 mm). Starch modified by enzymatic method (EM) showed highest light transmittance whereas light transmittance exhibited by starch modified by 0.5% epichlorohydrin method (CM3) was lowest. Syneresis of starch modified by all the methods except pregelatinized starch (PM) and 0.1% phosphorus oxy trichloride method (CM4) was significantly higher than native starch. As compared to native starch, peak viscosity, final viscosity, peak time and pasting temperature of starch modified by chemical methods was higher whereas setback and breakdown was lower. On the other hand, starch modified by 0.5% epichlorohydrin method (CM3) and enzymatic method (EM) exhibited lower peak and final viscosity than native starch. Addition of pearl millet starch upto 15% resulted in increase in expansion ratio and sensory score and decrease in bulk density and hardness. Further increase in level of starch in the formulation decreased expansion ratio and sensory score. Acceptable RTE pearl millet snacks can be prepared by incorporating 15% pearl millet starch in formulation of pearl millet flour with 17.8% moisture content extruded at 25 kg/hr feed rate and 121 0C temperature with 8 rpm cutter speed. Pearl millet can be processed for flour and starch, utilized in the formulation for development of RTE extruded snacks with improved physical and sensory attributes. Thus, processing of pearl millet into starch can be used as an alternative source of corn starch and can be used for preparation of pearl millet based RTE snacks. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810031943 | |
| dc.keywords | Pearl millet, Pearl millet starch, Modification, RTE, RSM | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | CCSHAU | en_US |
| dc.sub | Food Science and Technology | en_US |
| dc.subject | null | en_US |
| dc.theme | Isolation, modification and quality evaluation of starch from pearl millet varieties and development of ready-to-eat extruded snacks | en_US |
| dc.these.type | Ph.D | en_US |
| dc.title | Isolation, modification and quality evaluation of starch from pearl millet varieties and development of ready-to-eat extruded snacks | en_US |
| dc.type | Thesis | en_US |