Effects of freezing pretreatment on the quality of fermented black garlic from Ly Son garlic

Abstract

The study aimed to determine duration and temperature suitable for pretreatment by freezing method to improve the quality and efficiency of fermentation on black garlic from Ly Son garlic. Before starting the fermentation process, the samples were pretreated at different temperatures, which are -5℃, -10℃, -15℃ over a course of 1 - 4 days. The experiment had shown that the fermentation efficiency and quality (especially the content of some biologically active ingredients that are beneficial to health) of black garlic products when pretreated at -10℃ for 2 days yields the greatest quality of black garlic. After fermentation, black garlics had a soft, chewy and jelly - like texture, brown-black color, unique odor and sweetness; Gluxit content is 52.73%, 268.75 mgGAE/g Polyphenol, 198.73 µg/g S-allyl cysteine, 22.17 mg/100 g Allicin; fermentation efficiency was 30.40%.