Abstract:
Germination generally increases the nutritive value of seeds by modulating phytochemical composition depending on processing conditions. Therefore, the current study was conducted to compare the effect of emerging processing techniques such as ultrasound (US) and microwave (MW) on phytochemicals composition of sorghum sprouts. Overnight steeped sorghum grains were divided into four groups. The first group was designated as control without applying any treatment. Second group was subjected to ultrasonic treatment using 40% & 60% amplitude for 5 & 10 min. Third group was exposed to microwave treatment at 450 W & 700 W power levels for 15 & 30 sec. Similarly, fourth group was treated with combined MW & US application for different intervals. Microwave and sonication processing significantly improved the germination percentage and growth parameters, hence the phytochemical profile improvement. After germination, sprouts subjected to different quantitative analysis showed that with increased germination significant reduction was observed in anti-nutritional components such as alkaloid, saponin, tannin and phytate contents while contents of total free amino acids, sterols, and digestible proteins and carbohydrates increased. The oil yield and fatty acid composition increased with increasing amplitude of processing techniques. Antioxidant activities and HPLC analysis for individual phenolic compounds also improved significantly with high germination. In-vitro protein digestibility was significantly higher while bio-accessibility of polyphenol and flavonoid was insignificantly affected. From the present investigation, ultrasound processed treatment US1 (40% amplitude for 5 min) and microwave processed treatment MW2 (700 watt for 5 sec) are found paramount to improve the composition and bio-accessibility of phytochemicals through enhanced germination of seeds.
