Microbial and Chemical Characterization of Fermented Olives and Brines in Synergism With Fennel, Lemon, and Chili

Abstract

Olive fermentation is renowned for its ability to enhance the olives nutritional value. In this study, we embark on a comprehensive exploration of the intricate interplay among various brine formulations. Our findings underscore significant variations in critical parameters. Total phenolic content in the five brine solutions spans a wide spectrum, with values ranging from 2.80 mg equivalent gallic acid (EGA) mL⁻¹ (Chétoui olive/fennel/lemon) to 6.72 mg EGA mL⁻¹ (Meski olive/chili/fennel). Moreover, the antioxidant activities exhibit pronounced distinctions. In brine samples, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition ranges from 35.15% (Chétoui olive/lemon) to 57.09% (Meski olive/chili/fennel), whereas in olives, we witness the highest DPPH inhibition at a striking 62.95% (Meski olive/lemon). The flavor profile is dominated by the presence of ethanol and acetic acid, complemented by intriguing notes of d-limonene and trans-anethole. Remarkably, the “Meski olive/chili/fennel” formulation exhibits notable antibacterial activity, featuring the highest inhibitory effect with a remarkable inhibition zone against Listeria innocua. The microbial analysis reinforces the presence of lactic acid bacteria (LAB) and yeast species, with a commendable control over potential pathogens. The presence of LAB may indicate a probiotic potential of the fermented olives and their brines. This comprehensive study provides profound insights into the intricate factors that define the quality and safety of fermented olives, shedding light on the fascinating world of olive fermentation.

Practical Applications: The findings of our research hold significant practical implications for various sectors. In the food industry, the optimized brine formulations and fermentation techniques identified in our study can be directly applied to enhance the nutritional value, flavor, and shelf-life of fermented olives. Specifically, the formulation highlighted for its notable antibacterial activity against Listeria innocua holds promise for developing natural preservatives in food products. Additionally, our insights into the microbial dynamics provide valuable guidance for improving food safety measures during olive fermentation processes. Furthermore, the characterization of olive brine as a potential source of phenolic compounds underscores its potential application in functional food and nutraceutical industries. Overall, our research contributes to the advancement of olive processing techniques and the development of healthier, safer, and more flavorful food products. Our study investigates the impact of different brine formulations on the profile of fermented olives, revealing significant variations in phenolic content, antioxidant activities, and antibacterial effects. These findings provide valuable insights for optimizing olive fermentation processes and developing natural preservatives in food products.