Physicochemical Behaviour of Green Gram during Soaking and Sprouting
Mallela Prem Kumar *
Department of Processing and Food Engineering, College of Agricultural Engineering, University of Agricultural Sciences, Bengaluru-560065, India and Division of Agricultural Engineering, ICAR-Indian Agricultural Research Institute, New Delhi, India.
P. N. Krishnamma *
Department of Processing and Food Engineering, College of Agricultural Engineering, University of Agricultural Sciences, Bengaluru-560065, India.
M. S. Sreedevi
AICRP (FIM), Zonal Agricultural Research Station, V.C. Farm, Mandya, Karnataka, India.
G. S. Krishna Reddy
Agriculture Research Station, Balajigapade, Chikkaballapur-562101, India.
C. Suneetha
Department of Horticulture, College of Agriculture, University of Agricultural Sciences, Bengaluru-560065, India.
Sampath Teggi
Department of Processing and Food Engineering, College of Agricultural Engineering, University of Agricultural Sciences, Bengaluru-560065, India.
*Author to whom correspondence should be addressed.
Abstract
Green gram is a highly nutritious legume with considerable potential to address malnutrition and protein deficiency, particularly in developing regions like India. This study focused on evaluating the physical, biochemical, and hydration characteristics of both fresh and sprouted green gram, emphasizing the effect of soaking time on sprouting efficiency. Sprouting resulted in notable changes in physical attributes, including increased grain dimensions, geometric mean diameter, and sphericity, while both bulk and true densities declined due to water absorption. Biochemical analysis indicated considerable enhancements in nutritional quality, with protein content rising from 22.56 % to 24.35 %, crude fibre increasing from 3.21 % to 4.12 %, and moisture content elevating with sprouting. In contrast, total soluble sugars, ash, and fat content decreased as these components were utilized during germination. To study hydration and sprouting behaviour, Soaking was carried out for green gram seeds for 3, 6, and 9 h. It was observed that soaking for longer periods (6 and 9 h) led to higher moisture levels (53.69 % and 58.34 %) and improved sprouting rates (97 % and 98 %) compared to shorter durations. Hydration kinetics were modelled using Lewis and Page equations, with the Page model showing superior accuracy (R² = 0.99). These findings demonstrate that optimal soaking durations not only enhance water uptake but also stimulate metabolic activity and reduce anti-nutritional factors. Overall, the study highlights the importance of adequate soaking time in improving the nutritional value and sprouting potential of green gram for better dietary outcomes.
Keywords: Green gram, soaking, sprouting, nutritional value, physicochemical