Changes in the levels of off-flavor generation in soybean through biotic elicitor treatments.

Abstract

The nutritional benefits of soybean remain underutilized as the off-flavor present in it limits the consumption and acceptability among people. The aim of the present study was to unveil the effect of the phytohormones methyl jasmonate (MJ: 0, 50 μM, 1 mM, and 15 mM) and salicylic acid (SA: 0, 50 μM, 0.1 mM, and 10 mM) as elicitors on two contrasting off-flavor soybean varieties at different growth stages (1, bloom; 2, pod development; 3, seed development). The effects of two elicitors varied widely and were found to be dose dependent and growth stage independent. SA reduces the lipoxygenase (LOX) and hydroperoxide lyase (HPL) activity, which in turn resulted in reduction in the TBA number and carbonyl value in contrast to MJ. SA 0.1 mM is the most effective dose in reduction of off-flavor determining parameters and protein oxidation, and it reduces the LOX and HPL activity by 2.3- and 2.4-fold, respectively in "high off-flavor" cultivar 'Bragg' compared to "low off-flavor" cultivar 'DS 2706' which showed 1.4- and 2.1-fold, respectively. This reduction in protein oxidation is also supported by enhanced content of antioxidant enzymes. Thus, phytohormone SA can be used in reduction of off-flavor generation, more effectively than MJ treatments, in soybean.