Volatilomics of Spanish style cv. Chalkidiki green table olives spontaneously fermented in Reduced NaCl Content Brine

Abstract

w>Table olives are important components of the Mediterranean diet, and their consumption is expanding worldwide due to their potent health benefits related to the presence of polyphenols, fatty acids and vitamins. Reducing NaCl content in table olive processing is important to establish the product as a functional food [1]. However, it is challenging as it influences the complex microbiota evolving in the fermentation process, which has an impact on the safety and quality of the final product. Volatilomic approaches have been used to detect specific molecules indicative of the metabolic activities of the microbial communities occurring on table olive fermentation and are associated with desirable flavors or defects [2]. In this context, in the present study, the volatile organic compounds of reduced NaCl brines (NaCl-KCl-CaCl2, 4 – 3%-1%) [3] were determined during spontaneous fermentation of Spanish style cv. Chalkidiki green table olives in pilot scale plastic vessels (220 L) for two processing periods (2020/21, 2021/22) using SPME/GC-MS. In control brine, NaCl was adjusted to 8%. A total of fifty-five metabolites comprising of acids, alcohols, aldehydes, esters and phenols were identified. In both treatments, acetic acid, propanoic acid, ethanol, 3-methyl-1-butanol, phenylethyl alcohol, ethyl acetate, 3-methyl-1-butanol acetate ethyl hexanoate and ethyl octanoate were the superior volatiles. Principal component analysis of the data helped to discriminate the tested samples according to treatment, processing period and fermentation time. This is the first systematic study on the volatile profile of table olives from cv. Chalkidiki processed under reduced salt.