Development of a freeze-dried symbiotic obtained from rice bran

Abstract

This study aimed to assess the growth potential of L.acidophilus and L.plantarum in rice bran, a co-product from the food industry, and subsequently develop a freeze-dried symbiotic. Furthermore, phytochemicals and antioxidant properties were analysed. The growth was measured using growth kinetics over 72 h. The total phenolic compounds were analysed by the Folin-Ciocalteau method and antioxidant potential by DPPH and ABS methods. Freeze-drying process occurred using a pilot-scale equipment (Liotop LP510), verification and quantification of probiotics occurred through molecular analyses, as DNA extraction and qPCR. As a result, there was a good growth in rice bran (p = 0.04), suggesting its prebiotic potential. Rice bran also showed significant concentrations of phenolic compounds (3.69 mgEAG/mL ± 0.04) and antioxidant activity according ABTS (8.35 μmol ET/mL ± 0.106) and DPPH (24.71 μmol ET/mL ± 7.90) methods. The bacteria concentration decreased significantly when submitted to the freeze-drying process (p = 0.001), however, they remained by the minimum concentration required for a product to be considered a symbiotic. Therefore, it was concluded that rice bran and these analysed bacteria proved to be effective for a symbiotic formulation.

Keywords

• Probiotics
• Rice bran
• Freeze-drying
• Cell viability