Probiotic potential of blueberry jam fermented with lactic acid bacteria

Abstract

The present study assesses the feasibility of blueberry as a raw substrate for the production of the probiotic blueberry jam by lactic acid bacteria (L. plantarum DB-2, L. fermentum J-1, P. acidilactici M-3, L. plantarum SK-3, and P. pentosaceus SM-2). Changes in pH, titratable acidity (lactic acid), cell survival, antioxidant properties, and in vitro cholesterol reduction properties of lacto- fermented as well as non-fermented blueberry jam were examined during fermentation and up to 28 days of storage. All the strains grew well in a lacto-fermented blueberry jam after 48 h fermentation. Set A (5.88 g/100 ml) and Set B (5.96 g/100 ml) produced less lactic acid than Set C (6.67 g/100 ml) which has the consortia of probiotic strains. After 28 days of cold storage, all the tested strains survived the low-pH conditions in lacto-fermented blueberry jam. The blueberry jam fermented with the consortia of probiotic strains (Set C) had a high antioxidant capacity (71.47±3.57) in comparison with Set A, Set B, and control which showed anti-oxidant capacity viz. 70.52±3.52, 70.25±3.18, and 64.12±2.47, respectively after 28 days of refrigerated storage. The lacto- fermented blueberry jam in Set C (58.48%) had shown the in vitro cholesterol-lowering ability better than Set B (18.87%) whereas Set A and control did not show any in vitro reduction in cholesterol level after 28 days of storage. Sensory quality studies were carried out after 28 days of storage. Sensory evaluation data showed the considerable acceptability of the lacto-fermented blueberry jam. Finally, we found that L. plantarum DB-2, L. fermentum J-1, P. acidilactici M-3, L. plantarum SK-3, and P. pentosaceus SM-2 are optimal probiotics for fermentation with blueberry jam. In this investigation, the results could be an indicator of the development of health-promoting fruit jam. Conclusion This lacto-fermented blueberry jam is a low-cost healthy food product, provide better nutrition and good health to the population.