Bee pollen as a novel substrate in pilot-scale probiotic-mediated lactic fermentation processes

Abstract

Different process conditions were evaluated to induce lactic acid fermentation of bee pollen at the pilot scale using three different commercial starter cultures. Clean and dry Colombian high Andean bee pollen was used as the sole source of nutrients (substrate). The effect of substrate preparation conditions (water:pollen ratio and initial substrate acidity) on lactic fermentation was evaluated by monitoring pH, titratable acidity, and pollen morphology in 6-kg-fermentation units. A 2:1 water:pollen mixture with an initial pH adjusted to 5.8, pretreated with heat/pressure (10 min; 80 kPa; 115 °C), was determined to be an adequate substrate for pilot-scale lactic fermentation for all lactic starter cultures. At the selected conditions, the kinetics of lactic acid production and the growth of specific lactic bacteria were determined. The fermentation process time was 30 h, after which a significant decline in bacterial populations was observed. Among the starter cultures tested, one constituted exclusively by probiotic Lactobacillus acidophilus NCFM presented the best performance in terms of lactic acid production, with a concentration of 1.65% wt, after 30 h. The results highlight the feasibility of producing fermented bee pollen at a commercial scale as a functional food product with probiotic features.