Multi-Stage Bioprocessing of Bee Pollen by LAB Fermentation and Enzymatic Hydrolysis: Enhancing Phenolic and Flavonoid Content and Bioactivity.

Bee pollen is a rich natural source of phenolic compounds and other bioactive constituents; however, the resistant pollen cell wall restricts the release of these compounds. This study investigated the effect of multi-stage bioprocessing involving bacterial fermentation, spontaneous fermentation, and enzymatic hydrolysis on the recovery of bioactive compounds from ten bee pollen collected from different regions of Lithuania. First-stage treatments included fermentation with Lactobacillus acidophilus, L. rhamnosus, L. reuteri, Bifidobacterium animalis, spontaneous fermentation, or enzymatic hydrolysis using Viscozyme® L, cellulase, or Clara-diastase. Second-stage bioprocessing combined the initial treatment with either bacterial fermentation or enzymatic hydrolysis. Total phenolic content (TPC), total flavonoid content (TFC), radical scavenging activity (RSA), and inhibition of heat-induced bovine serum albumin (BSA) denaturation (BSA-DI) were determined using spectrophotometric assays. Statistical analysis demonstrated that multi-stage bioprocessing significantly enhanced the chemical composition and bioactivity of bee pollen compared with single-stage treatments. The greatest improvements were achieved when enzymatic hydrolysis preceded bacterial fermentation, resulting in increases of up to 5.0-, 4.2-, 6.3-, and 5.3-fold in TPC, TFC, RSA, and BSA-DI activity, respectively. These findings suggest that combining enzymatic hydrolysis with bacterial fermentation may be a promising approach for improving the recovery of bioactive compounds and selected functional properties of bee pollen.