Production of Synbiotic Malt Beverage Using Inulin and Different Probiotic Strains of Lactobacillus Bacteria

Today, the food consumption culture has changed in societies, and as a result, the need to produce a variety of new products such as enriched beverages has increased. Enrichment of beverages with functional components like probiotics and prebiotics is a recent progress in the field of beverage production.

In this study, suitable amount of inulin as a prebiotic compound was used, and the malt beverages produced by probiotic bacteria including Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum were investigated.

In general, the viability of probiotic bacteria in synbiotic malt beverage decreased but remained in the standard range >107 during the refrigerated storage. After 28 days of storage, Lactobacillus acidophilus had the lowest count among the prebiotic bacteria. pH and acidity of the samples were decreased and increased, respectively due to the addition of probiotic strains. The results showed that the amount of sugar and Brix of the samples decreased with increasing of storage time. The amount of ethanol was lower than 0.1% in all samples. Moreover, the content of phenolic compounds was increased in all samples except the control counterpart during the storage time due to the hydrolysis of glycosylic phenolic compounds and production of free phenols. The results of antioxidant tests revealed that the antioxidant activity of samples also improved during fermentation.

The sample containing 2.25% inulin and 2.25% sucrose was selected as the optimum sample. After 28 days storing of the synbiotic malt beverages at a refrigerated temperature, the probiotic bacteria showed a standard viability. Moreover, samples containing probiotic bacteria had a higher antioxidant activity in comparison with the control sample. In general, the results of this research proposes that we can produce a synbiotic malt beverage with appropriate biochemical and nutritional properties by using proper probiotic strains