Functional Properties of High-Pressure Assisted Enzymatic Tamarind Kernel Protein Hydrolysate and Foam-Mat Powder Characteristics as Affected by HPMC Concentration and Drying Temperature

The functional properties of high-pressure processing (HPP)-assisted protein hydrolysate from tamarind kernel powder (TKP-HD) and the physicochemical characteristics of its foam-mat powder were studied. TKP-HD consisted of more non-polar than polar amino acids, with higher solubility at pH 5 and 7 than soy protein isolate (SPI) but lower than egg white (EW). The water-binding capacity of TKP-HD increased at pH 5 while TKP-HD had a higher foaming capacity than SPI at pH 5, and the highest oil-binding capacity. The physicochemical properties of TKP-HD after foam-mat drying were investigated using 1 and 1.5% (w/w) hydroxypropyl methylcellulose (HPMC), with drying at 60, 70, and 80 °C. Samples with 1.5% HPMC had lower water activity than those with 1% HPMC at all drying temperatures. The sample with 1% HPMC had higher antioxidant capacity at 60 °C than at 70 °C, but this decreased at 1.5% HPMC. Samples with 1.5% HPMC and dried at 60 °C recorded the highest solubility and viscosity, with increased porosity of the powder structure. The most suitable foam-mat drying conditions for TKP-HD were the addition of 1.5% HPMC and drying at 60 °C.