CHANGES IN AMINOACID AND PHENOLIC PROFILE OF AMARANTH SEEDS SUBJECTED TO SOUS VIDE TREATMENT

Abstract

The aim of this study is to evaluate the impact of sous-vide method on amaranth seeds amino acids and individual phenolics content. The sous-vide method was applied at different temperatures (75 °C, 80 °C and 85 °C) for different times (60 minutes, 120 minutes, 180 minutes and 240 minutes), at different solid/liquid ratios (1/4, 1/5, 1/6). Eight phenolic acids (rosmarinic acid, p-coumaric acid, chlorogenic acid, vanillic acid, caffeic acid, p-hydroxybenzoic acid, protocatechuic acid, and gallic acid) and four flavonoids (kaempferol, luteolin, myricetin, and quercetin) were studied. The extraction and identification of free amino acids were carried out using 15% trichloroacetic acid. Variance analysis of the amino acid content in the composition of sous-vide treated amaranth seeds highlighted five essential amino acids (valine, leucine, isoleucine, threonine, and phenylalanine), and the variance analysis of the composition of amaranth seeds treated with the sous-vide method revealed a high total content, particularly influenced by temperature. The Box-Behnken model was applied to study the combined effects of three parameters (temperature, time, and solid-to-liquid ratio) on the total amino acid and polyphenol content during sous-vide treatment. The models developed for total amino acids and polyphenols were statistically significant according to ANOVA, and the regression for both models was higher than 0.75.