Influence of appropriate starter cultures on the sensory qualities and volatiles of fermented broccoli and onion pickles

Abstract

In addition to the limitations in infrastructure and existing low technologies in most developing countries, lack of experience in applying starter cultures in small-scale operations presents a significant obstacle and an exciting challenge to food technology. In this study, fresh yogurt and baker's yeast were used as appropriate starter cultures for the pickling of broccoli and onion through fermentation as a source of lactic acid bacteria and Saccharomyces cerevisiae. Traditional broccoli and onion pickles produced via preservation in vinegar and salt were used as a control sample. The organoleptic evaluation demonstrated that fermented pickles with fresh yogurt were the best in all sensory attributes and the overall acceptability, followed by pickles fermented with baker's yeast autolysate and control ones. Significant differences in the color parameters were observed between fermented pickles and control. Thirty - two volatile compounds were identified using Gas Chromatography-Mass Spectrometry in the fermented and preserved onion, while 37 constituents were revealed in the fermented and preserved broccoli. Acetic acid, dimethyl disulfide, ethyl butanoate, 2,5-dimethyl thiophene, and 1,3-butanediol were the predominant components in fermented and preserved onion with a quantitative variation. In fermented broccoli, dimethyl disulfide, pentenol and hexenol derivatives, and ethyl hexadecanoate were the most abundant aroma volatiles, while the same pattern was detected in the control sample except for hexenol derivatives. Therefore, the present study opens perspectives for healthier solutions employing appropriate starter cultures as a source of probiotics in the food industry.