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2016 - 20182
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Author: Gurpreet Kaur × End date: 2019 × Start date: 2016 × Thesis Type: Ph.D ×
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    Formulation and nutritional evaluation of cereal-pulse based extruded snacks supplemented with dehydrated herbs
    (Punjab Agricultural University, Ludhiana, 2018) Gurpreet Kaur; Singla, Neerja
    In the present investigation, a combination of wheat and chickpea (80:20) was used for formulation of extruded snacks which were supplemented with varying levels of 1-5 percent dried herbs namely Basil (BL), Mint (ML), Drumstick leaves (DL) and a mixture of all these herbs (MXL) having one percent of each herb. While comparing fresh and dried leaves of herbs, It was found that dried leaves had significantly higher (p<0.01) levels of crude protein, fibre, fat, ash, β-carotene, minerals (Ca, Fe and Zn) and bioactive components. Organoleptically extrudates were found to be most acceptable at three percent level of supplementation for all the herbs. Overall acceptability of various extrudates was in order of MXL>DL>ML>BL. A significant change (p<0.05) in physical parameters namely mass flow rate, bulk density, moisture retention, expansion ratio, water absorption index, water solubility index and water holding capacity (WHC) of supplemented extrudates was observed as compared to their control counterparts. The moisture, ash, crude protein, fibre and fat content of supplemented extruded snacks ranged from 3.40 to 3.88, 2.32 to 2.90, 11.35 to 12.20, 3.0 to 3.36 and 1.67 to1.75 g/100g, respectively. Ascorbic acid and β-carotene content of supplemented extruded snacks ranged from 9.72 to 12.98 mg/100g and 54.71-98.10 µg/100g, respectively. Total iron, calcium and zinc content in supplemented extruded snacks were found to increase in the range of 19-29, 38-77 and 52-63%, respectively in comparison to control. The total phenol and flavonoid content of supplemented extruded snacks varied from 153.45 to 184.76 mg GAE/100g and 222.38 to 384.40 mg RE/100g, respectively. The percent increase in total antioxidant capacity (TAC) in supplemented snacks ranged from 97-124, 93-125, 96-154 and 25-46%, respectively by DPPH, ABTS, FRAP and RPA, respectively as compared to control. The percent decrease in moisture, ash, protein, fat and fibre ranged from 58-60, 14-18, 0.73-0.87, 19-23, 5-8 %, respectively among the supplemented extrudates in comparison to their raw mixtures. The reduction in vitamin C and β-carotene content was 18-21 and 2-3%, respectively after extrusion. The reduction in phytate, oxalate and trypsin inhibitor content after extrusion was 8-9, 14-15 and 21-24%, respectively after extrusion. Percent increase in total phenols and flavonoid content after extrusion was in the range of 24-28 and 2-3%, respectively. A significant increase (p<0.05) in TAC as measured by DPPH, ABTS, FRAP and RPA was observed among supplemented extrudates as compared to their raw mixtures. An increase of 20, 26 and 35 % for in vitro carbohydrate, protein digestibility and iron bioavailability was observed in supplemented extrudates after extrusion. While determining the effect of storage period and type of packaging on organoleptic parameters like appearance, colour etc. were not much affected while changes were observed in texture, taste and flavour. Statistically significant increase in moisture content and decrease in TAC was observed on storage of extrudates in both the packaging materials aluminium laminates (AL) and Ziploc pouches (ZL). However, the rate of loss in TAC was comparatively lower in aluminium laminate stored extrudates as compared to Ziploc pouches. However, moisture and the microbial count were found to be within the permissible limits even after four months of storage period. It can be concluded that supplementation of some of the commonly used dehydrated herbs leaves in the powder form to the cereal-pulse based extruded snacks can help to introduce a new type of value added snacks which will not only satisfy consumers short time hunger but also provide numerous health benefits especially in terms of bioactive components.
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    Genotypic variation for water and salt stress induced proline dynamics in wheat
    (Punjab Agricultural University, Ludhiana, 2016) Gurpreet Kaur; Asthir, Bavita
    The present study was conducted to evaluate the proline metabolism and its cross talk with various biochemical parameters in nineteen wheat genotypes viz. C 306, C 273, C 591, C 518, Type 11, Excalibar, Krichauff, Babax, Gladius, Drysdale, Kharchia, Krl 1-4, Krl 19, PBW 175, HD 2967, PBW 621, WH 1105, HD 3086 and PBW 660 raised under water deficit (8% PEG – 6000), water withholding and salt stress (300 mM NaCl) conditions. Enzymes involved in proline synthesis [glutamate dehydrogenase (GDH), pyrroline-5-carboxylate synthetase (P5CS) and δ-pyrroline-5-carboxylate reductase (P5CR)] and degradation [proline dehydrogenase (PDH)] were studied in the roots and shoots of seven day old seedlings. Based on various biochemical parameters, these genotypes were categorized into four groups i.e tolerant towards water stress (Excalibar, Krichauff, Babax, Drysdale, Gladius and C 306), tolerant towards salinity stress (Kharchia, Type 11, Krl 1-4 and Krl 19), intermediate tolerant (C 273, C 518 and C 591) and susceptible towards water and salinity stress (HD 2967, PBW 621, WH 1105, HD 3086, PBW 660 and PBW 175). Genotypes tolerant to water and salt stress revealed increased proline content and 1,1 diphenyl-picryl hydrazyl radical scavenging activity alongwith reduced content of thiobarbituric acid reactive species in parallel with decreased H2O2 content. Correspondingly, higher activities of GDH, P5CS and P5CR were also observed in these genotypes. However, the declining trend of PDH activity and low contents of TBARS and H2O2 were recorded in all studied genotypes except for HD 2967, PBW 621, HD 3086, PBW 175 and WH 1105. Results were further strengthened by studying the effect of ABA and its cross talk with various parameters under different stresses in selected five genotypes viz. Gladius, Drysdale, Kharchia, PBW 660 and PBW 175. Exogenous ABA application triggered the upregulation of proline synthesis in tolerant genotypes (Kharchia, Gladius and Drysdale) which indicated a predominant role of this osmolyte in maintaining root/shoot elongation and thereby, ameliorating the deleterious effect of ROS on membrane stability both under water and salt stress conditions. Overall, results indicated that increased proline content might have contributed in upregulating proline synthesizing enzymes and thereby overcoming oxidative stress more in tolerant genotypes than susceptible ones. In crux, results indicated that GDH activity was particularly responsible in proline synthesis pathway via enhancing P5CS activity and would trigger abiotic stress tolerance. Proline metabolizing enzymes particularly P5CS and GDH could be used as a marker for enhancing tolerance to these stresses by breeders and plant biotechnologists.