Open AccessApplication of mild-subcritical alkaline water extraction: optimum condition for phenolic antioxidant extracted from cold-pressed defatted KDML 105 rice bran and its phenolic profile
Author(s) -
W. Pungwa,
Amporn SaeEaw,
Jintana Sripui,
Supawan Thawornchinsombut
Publication year - 2022
Publication title -
food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.218
H-Index - 7
ISSN - 2550-2166
DOI - 10.26656/fr.2017.6(1).195
Subject(s) - chemistry , gallic acid , ferulic acid , trolox , extraction (chemistry) , bran , abts , response surface methodology , antioxidant , food science , chromatography , phenolic acid , browning , organic chemistry , antioxidant capacity , dpph , raw material
This research was aimed at optimizing the process of the mild-subcritical alkaline water(pH 9.5) extraction (mild SAW) of cold-pressed defatted Khao Dawk Mali 105 rice bran(CDRB) in order to achieve the maximum antioxidants with minimal brown colour.Response surface methodology and central composite design were performed with twovariables: extraction temperature (107-129°C) and time (21-149 mins). The elucidatedoptimum conditions were 119°C and 85 mins with predicted response values: the totalphenolic content of 16.9 mg gallic acid/g; protein of 64.3 mg/g; an ABTS radicalscavenging activity of 14.4 mg Trolox/g; a browning index of 0.41; and reducing sugar of62.0 mg/g. Proto-catechuic acid and p-coumaric acid were major phenolic compounds inthe CDRB, while trans-ferulic acid, proto-catechuic acid, and p-coumaric acid were allabundant in the mild SAW extract. The results confirmed that the mild SAW extractionprocess for antioxidants is an environmentally friendly approach, which can increase therelease of value-added compounds from rice bran residues.