Lactic Acid Fermentation of Red Beet Juice Supplemented with Waste Highbush Blueberry-Sucrose Osmotic Syrup as a Method of Probiotic Beverage Production

The objective of this study was to design the process of production of a novel probiotic beverage based on lactic acid fermentation of red beet juice supplemented with waste sucrose syrup following three runs of osmotic dehydration of highbush blueberries. At the end of fermentation, which was conducted by probiotic bacteria of the genus Lactobacillus, counts of lactic acid bacteria, acidity, total polyphenols and betalain pigment content were determined in the resulting juices. Lactic acid was quantified by the enzymatic method and by high-performance liquid chromatography. It was found that probiotic bacteria content depended on the amount of sucrose syrup added to red beet juice and on the bacterial strain used. Total polyphenol content was about 30-45% higher in fermented juices containing equal amounts of red beet juice and sucrose syrup than in the control. It was found that the studied bacterial strains produced mostly L(+) lactate. Practical ApplicationsThe known methods involving hypertonic solutions (which are side products of osmotic dehydration) are not cost-effective, mainly because of the high levels of impurities and microbial contamination in the solutions. Therefore, none of those methods has been implemented on a large industrial scale. The results of this work provide evidence that waste osmotic syrups may be used for the production of lacto-fermented beverages, thus making osmotic dehydration more attractive in economic terms due to reduced costs of side product utilization. Juices obtained by lactic acid fermentation of red beet juice supplemented with sucrose syrups following several runs of osmotic dehydration may become attractive, alternative probiotic foods for consumers who either suffer from intolerance to dairy products or do not consume them as a matter of preference. The use of highbush blueberry-sucrose osmotic syrup for the production of lacto-fermented fruit and vegetable beverages may yield functional products having both nutritional and health-promoting properties.