Valorization of Bilberry (Vaccinium myrtillus L.) Pomace by Enzyme-Assisted Extraction: Process Optimization and Comparison with Conventional Solid-Liquid Extraction

Abstract

Bilberry (Vaccinium myrtillus L.) pomace contains a significant amount of polyphenols and can serve as a basis for food additives, nutraceuticals, and functional foods. Although various techniques can be employed to recover bioactive fractions from berry pomaces, data on enzyme-assisted extraction (EAE) of bilberry pomace are rather scarce. This study aimed to optimize critical EAE parameters using Viscozyme L to obtain a high-yield extract with enhanced antioxidant capacity. Central composite design and response surface methodology evaluating the effect of four independent variables, namely, pH, temperature, extraction time, and enzyme concentration on three responses, were employed to define optimal EAE conditions. Under the optimal conditions (pH: 4.5, temperature 46 °C, 1 h of extraction, and 2 active units (AU) of Viscozyme L/g of pomace), EAE yielded 56.15 g/ 100 g DW of the water-soluble fraction. Comparison with conventional maceration indicated that EAE, besides the yield, significantly increased the in vitro antioxidant capacity measured by the total phenolic content, ABTS, ORAC, and CUPRAC assays. Moreover, an increase was observed for the measured mono- and disaccharide as well as anthocyanin content. Overall, this study demonstrates the improved efficiency of EAE over conventional solid–liquid extraction to recover fractions with a higher yield and enhanced functional properties in a fast and sustainable manner.

Technological Properties and Composition of Enzymatically Modified Cranberry Pomace

“…For the saccharide analysis, 10 mg of the freeze-dried water-soluble fraction, was dissolved in 1 mL of Millipore water (10 mg/mL). The saccharide analysis was performed as previously described by Syrpas et al [ 16 ]. The total oligosaccharides were recorded as the sum of all of the detected and quantified fractions of oligosaccharides with a degree of polymerization (DP) DP 7–10, DP 5–6, DP4, DP3, while the total mono- and disaccharides were recorded as a sum of the sucrose, glucose, fructose, sugar alcohols, and galacturonic acids.…”

Alternative Methods of Bioactive Compounds and Oils Extraction from Berry Fruit By-Products—A Review

“…A water-soluble fraction obtained in SLE was used as a control sample. Values for yield, TPC, ABTS, ORAC and CUPRAC assays were higher when EAE was applied [142]. Kitryte et al [143] optimized the EAE of bioactive compounds from chokeberry pomace using cellulolytic and xylanolytic enzymes.…”

Optimisation of Polyphenols Extraction from Wild Bilberry Leaves—Antimicrobial Properties and Stability Studies

“…There are a limited number of studies focused on the design of phytocompounds extraction, mainly on non-edible residues, such as sea buckthorn leaves [11][12][13], winery by-products [14,15], apples [16] and potato peels [17][18][19]. The polyphenols extraction from bilberry pomace was studied through central composite design and response surface methodology (RSM) [20], while bilberry fruit extraction using the Box-Behnken design [7] or RSM [21] was also reported. A study of bilberry leaf extract after LED irradiation was also performed [22].…”