Synbiotic Functional Malt Beverage Supplemented with Inulin and Probiotic Strains

Abstract

Background: Cereal-based beverages can provide essential nutrients and phytochemicals as well as being suitable carriers for probiotics. Prebiotic ingredients present in grains or incorporated into beverages can improve the growth of probiotics leading to the emergence of functional synbiotic beverages. Objective: This study aimed to produce a malt-based synbiotic beverage containing inulin as a prebiotic and three strains of probiotics and evaluate its physiochemical and antioxidant properties during storage. Methods: A synbiotic malt beverage containing 2.25% inulin and 2.25% sucrose with three probiotic strains including Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum was produced and its chemical properties, antioxidant activity, total phenolic compounds and viability of probiotics were determined during 28 days of storage. Results: The results showed that although the viability of probiotic bacteria in synbiotic malt beverage was decreased during refrigerated storage, it remained above 107 cfu/mL. The lowest and the highest viability was observed in the case of L. acidophilus and L. plantarum, respectively after 28 days of storage. pH, brix and total sugar decreased due to probiotic growth and activity. Ethanol concentration increased, but was lower than 0.1% in all samples and thus the final product can be considered as non-alcoholic. Moreover, the content of phenolic compounds was increased in samples with probiotics due to the hydrolysis of glycosylic phenolic compounds and the generation of free phenolic compounds. The samples containing L. casei presented the highest total phenolic content followed by L. acidophilus and L. plantarum, respectively. Malt beverages containing L. casei showed the highest antioxidant activity followed by samples with L. acidophilus and L. plantarum. Conclusion: It can be concluded that proper probiotic strains besides inulin as a prebiotic can be used for the development of a functional synbiotic malt beverage with high phenolic content and antioxidant activity.