Agrawal, SanjeevJadhav, Reshma Ravindra2022-07-112022-07-112022-03https://krishikosh.egranth.ac.in/handle/1/5810185381The present investigation was carried out to study the effect of key starch metabolizing enzymes on resistant starch accumulation during grain filling stages and to modify the wheat flour for high resistant starch using different physico-chemical methods. The activities of starch metabolizing enzymes viz. AGPase, SSS, SBE, GBSS and DBE were determined during grain filling stages at S1, S2, S3, S4 and S5 stages (7, 14, 21, 28 and 35 DAA, respectively) in wheat genotypes.The activities of AGPase, SSS and SBE weresignificantly higher in UP-2785, UP-262 and UP-2584 than the other genotypes. These genotypes also showed comparatively higher grain weight (TKW), total starch and amylopectin accumulation, hence these enzymes play important role in regulating the kernel weight at grain filling stage. Genotypes UP-2748, UP-2903 and UP- 2584 were observed to be higher inaverage GBSS and DBE activities,amylose and resistant starch content. These enzymes may play important role in amylose and resistant starch accumulation. Higher fold increase in AGPase, SSS SBE activities and total starch, amylopectin accumulation and TKW was observed at stage, S2(14DAA), whereas higher fold increase in GBSS and DBE activities, amylose and resistant starch accumulation was observed at S3 stage (21DAA). So, duration of these twostages S2 and S3 may be the important for maintaining kernel weight, starch quality and quantity. AGPase, SSS and SBE enzymes were positively and significantly correlated with total starch, amylopectin and TKW, whereas GBSS and DBE enzymes were positively and significantly correlated with amylose and resistant starch accumulation. After the harvesting, genotypes UP-2309, UP -262 and UP-2748 were screened among the nine genotypes on the basis of different characters like chapatti making, iron, zinc content and resistant starch content and other quality parameters. These three genotypes were irradiation with gamma rays with different intensity, which affects positively in increasing amylose and resistant starch content. Genotype UP-262 was found to have comparatively higherpercent of increased resistant starch content followed by UP-2903 and UP-2748 due to irradiation treatment. The treatment 5 and 7 KGy showed the better performance for high resistant starch content compared to other treatments. The maximum decreases in transmittance was observed at 5KGy (UP-2478) and7 KGy (UP-262 and UP-2748) at 1047 and 1022 cm-1 spectra, which was important to be noticed when compared to the control (non irradiated). The results thus point out strong molecular reorganization in 5 and 7 KGy irradiated wheat flour compared to control. Wheat flour fortified with chickpea, finger millet or soybean showed high resistant starch and low glycemic index. Highest value of resistant starch content was observed in wheat–soybean blend i.e soybean blend showed better performance followed by chickpea and finger millet.EnglishThesis