Application of microwave and infrared radiation was explored for thermal processing of honey and its effect on the physico-chemical characteristics as well as the microbiological quality of honey were studied. Microwave heating provided a rapid means of achieving the desired level of yeast reduction with reduced thermal damage. Though different combinations of heating duration and microwave power intensity achieved the commercially acceptable level of yeast reduction in honey, heating for a shorter duration (15 s) at higher power intensity (16 W/g) was desirable in terms of lower hydroxymethylfurfural (HMF) value (3.8 mg/kg) and higher diastase activity (12.0). Infrared heating was not as rapid as microwave heating but achieved the desired results in a relatively shorter period (3-4 min) offering advantages over the conventional method.

The extraction and concentration of isoflavones from defatted soy flour (DSF) is attempted by leaching, membrane process and liquid-liquid extraction. The optimized extraction conditions by response surface methodology (RSM) resulted in an isoflavone content of 3.2 mg/g of DSF. The extracted isoflavones are processed by ultrafiltration for preliminary purification resulting in 3.0 mg/g of DSF, and then concentrated by liquid-liquid extraction with diethyl ether (4.8 mg/g DSF). The final isoflavone content is 69 mg/g of dried extract with an overall recovery of 57.5%. The optimization of extraction conditions resulted in an about 2.5 fold enhancement of isoflavones and concentration step enriched the isoflavones by about 8.5 fold compared to initial extract.

The purification of lipoxygenase in soybeans (richest known source) was attempted by precipitation, using polyethylene glycol, followed by aqueous two-phase extraction (ATPE). The preliminary purification by precipitation was standardized which resulted in two-fold purification. The influence of process parameters such as phase forming salt, molecular weight of phase forming polymer, tie line length, and phase volume ratio on the partitioning behavior of lipoxygenase during ATPE was investigated. The aqueous two-phase system of polyethylene glycol 6000 and ammonium sulfate, with inherent pH of 5.2, was found to be most suitable. The tie line length of 41.25% and volume ratio of 1.7 have resulted in 125% activity recovery with the overall purification factor of 4.38 compared to crude enzyme extract.