The effect of use of red beet and starters on table olive fermentation and quality for the production of green table olives

In this study the influence of the addition of 20% beetroot (Beta vulgaris L.) and starter cultures as Lactiplantibacillus (formerly Lactobacillus) plantarum, Lactiplantibacillus (formerly Lactobacillus) pentosus, and Wickerhamomyces anomalus (formerly Pichia anomala) on fermentation and end product quality of cracked green table olives (cv. Tarsus Sarulak) was studied. Physical, chemical, and microbiological analyses were performed on brine and fruit at the beginning, middle, and end of fermentation. Within the days of 128 fermentation at room temperature, the pH, total acidity, color, sugar, organic acid, total phenol, phenolic compounds, total betalain, betalain compounds, and antioxidant activity were measured. At the end of the fermentation, the pH ranged from 3,83 to 4,53 with a total acidity of %0,84-0,90 in terms of lactic acid in the brine. Rapid acidity development and a pH reduction associated with a higher lactic acid bacteria (LAB) level were observed in red beet olives produced using the LAB starter during fermentation. It has been discovered that red beet olives fermented with L. plantarum have less oleuropein and utilize sugar more quickly. According to the sensory analysis results of the final product, red beet olives produced using L. plantarum were characterized by appropriate acidity/sourness, low salinity value, and aromatic odors such as honey, herb and spice. It was discovered that the addition of the beetroot increased the amount of total acidity, total phenolic substance, total betalain, betalain compounds, and antioxidant activity in olives. It was found that using starter lactic acid bacteria as a mixed culture with W. anomalus yeast in red beet olive fermentation increased the amount of hydroxytyrosol by 57% and the amount of lactic acid by 77%. However, this combination increased the amount of acetic acid by 85% and was not as effective as spontaneous fermentation at the hydrolysis of oleuropein. According to the findings of this study, it is possible to develop green table olives with increased functional properties by combining starter L. plantarum culture and red beet.