Effect of pre‐treatments on sprouting rate and nutritional quality of green gram ( Vigna radiata L. ) malt

Abstract

The aim of the present study is to investigate the effect of physical treatments (ultra‐sonication and warm water) on the overall sprouting and malting of green gram. Green gram samples on ultra‐sonication (US) for 30 min and warm water (WW) treatment for 15 min had showed highest sprouting percentage of 99% (in 16 hr) and 98.5% (in 14 hr), respectively. Further, freeze‐dried malt presented the highest protein content. Lower protein content in tray dried malt indicates the degradation of protein during drying. In addition, WW treated and radio frequency dried (RFD) sample showed the highest in vitro protein digestibility (86.18%) and protein efficiency ratio (1.24). In conclusion, among all the pre‐treatments, WW treatment followed by RFD can be consider as best way to accelerate the malting process while retaining the protein quality, hence such protein rich malt will be more beneficial for the food sectors focusing on the infant food formulations. PRACTICAL APPLICATIONS: Malting is one of the important processing techniques to improve the nutritional significance of green gram and utilizing it for the protein‐rich infant food formulations. Sprouting, which is an essential step in malting, takes longer time thus, making the whole process time‐consuming. Physical treatments such as US and warm water treatments proved to accelerate the sprouting process. Comparative study of conventional tray drier, radio frequency drier, and freeze drier helped to confirm the effective drying technique for the protein‐rich malt preparation. Malt quality was judged on the basis of overall nutritional composition and protein quality by analyzing digestibility and amino acid profile before using for infant food formulations. Improved protein quality of the malt prepared from the warm water treatment and RFD helped to confirm the usage of traditional pre‐treatment and commercial drying techniques for the industrial application.