A waste product of tofu production called soy whey can be treated to produce a soy whey protein hydrolysate that could be used as an antioxidant and protein rich additive in liquid foods.
The findings come from a study by Singh et al. published in the Food Science Biotechnology journal.
Functional properties of soy whey
Soybean proteins, such as tofu, soy protein isolate and soy protein concentrate, are already used as a food ingredients.
“Nevertheless, soybean processing operations generate a large proportion of protein rich liquid effluent termed as soy whey,” said the researchers.
“If these proteins can be further utilized for bioactive peptide generation, they will be at least as valuable as those in the tofu, isolate, or concentrate now being produced,” they continued.
The study team said that there was previously limited research into the biofunctionality of soy whey, but said treating the protein would bring out its antioxidant potential.
To reach these conclusions, they enzymatically treated soy whey protein with a protease called Aspergillus awamori nakazawa.
This produced antioxidant peptides which showed an increased scavenging activity up to 70%.
“Better antioxidant property of soy whey protein hydrolysate gave it an advantage of being used as a food ingredient for liquid and semi-liquids foods,” concluded the researchers.
Food Sci. Biotechnol. 22(S): 65-71 (2013)
‘Peptide Enriched Functional Food Adjunct from Soy Whey: A Statistical Optimization Study’
Authors: Anshu Singh and Rintu Banerjee