This study investigated the antioxidative activities and quality characteristics of gruel as a home meal replacement with Angelica keiskei powder pre-treated by far-infrared radiation or freeze-drying methods. Far-infrared treated Angelica keiskei powder (F-IAP) showed significantly lighter, weaker green, and stronger yellow color values than powder subjected to freezedrying (FAP) (p<0.001). F-IAP showed higher total phenolic compound contents than that of the FAP. ABTS radical scavenging activity of F-IAP was 50.31%, which was significantly higher than that of FAP, at 43.51% (p<0.05). Color values of gruel significantly decreased with increased addition of Angelica keiskei powder (p<0.05). Gruels containing far-infrared treated Angelica keiskei powder (F-IAG) showed higher total phenolic compound contents as well as ABTS radical scavenging activities compared to the gruels containing freeze-dried Angelica keiskei powder (FAG). Gruels containing 5 g of Angelica keiskei powder showed 2.0 to 2.5 times higher antioxidant activities than those containing powder alone due to the presence of other ingredients with antioxidant activities such as black soybean or sweet pumpkin. In the results of sensory evaluation, F-IAG containing more than 5 g of Angelica keiskei powder had higher sweetness and roasted grain flavor, as well as lower bitterness and astringency compared to FAG. Sensory acceptance tests of all samples showed higher scores than 5.0 representing possibilities of successful development of gruels as a home meal replacement containing Angelica keiskei powder.

This study aimed to analyze the physicochemical properties and antioxidant activity of low molecular weight peptides produced by the enzymatic hydrolysis of soy protein. Soy protein isolate was treated with 0.1% and 0.3% protease (w/w), and then each hydrolyzate was ultrafiltered using 3 kDa and 10 kDa membranes. The pH value of the hydrolyzate was significantly lower at higher enzyme concentrations, but there was no difference according to the molecular weight cut-off. The salinity did not show a significant variation in any of the treatment groups, and the total dissolved solids were the highest at 0.3% in the 10 kDa sample. The enzyme concentration of hydrolyzate affects its color more significantly than the molecular weight cut-off. The DPPH and ABTS radical scavenging activities were the highest in the sample, with 0.3% enzyme concentration and 10 kDa cut-off. Peptides under 3 kDa also had a significant effect on the antioxidant activity. The principal component analysis of the electronic tongue (e-tongue) data significantly distinguished 3 kDa and 10 kDa fractions with a 0.1% enzyme concentration. Based on these results, using the 0.3% enzyme for the enzymatic hydrolysis of soy protein can be an efficient method to produce seasoning materials that have functional properties from plant protein.

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