Blueberry juice with high polyphenol concentration was spray- or freeze-dried using different coating materials: HP-β-cyclodextrin and β-cyclodextrin. The quality of the obtained powders was characterised by their anthocyanin content, total polyphenols and antioxidant capacity. SEM was used for monitoring structures and size (2–20 μm) of the microparticles. The losses of total phenolic compounds during spray-drying reached 76–78% on average, while these of anthocyanins about 57%. Freeze-dried powders showed better retention values of anthocyanins, which was about 1.5-fold higher than for the spray-dried counterparts. All blueberry preparations studied were characterised by very high radical scavenging activity

This study set out to identify the composition and the biological activity of pectin-derived oligosaccharides (POS) generated from mild acid or enzymatic hydrolysis of apple pomace (AP). The effect of the polymerization of the structural units of POS contained in the AP hydrolysate on the growth and metabolism of microbiota from the human gastrointestinal tract and the adhesion of lactic acid bacteria (LAB) or pathogens to human gut epithelial cells was investigated in vitro. Mild acid hydrolysis followed by pectinolysis with Rohapect MaPlusT yielded the highest concentration of POS. In contrast, pure enzymatic processing of the AP performed with a mixed preparation of cellulase and Rohapect MaPlusT resulted in 1.8-fold lower overall POS. The concentration of higher-order oligosaccharides (degree of polymerization (DP) 7–10), however, was 1.7-fold higher. The increased ratio of higher-order oligosaccharides caused an increase in the bifidogenic effect, as well as affecting the amount and nature of short-chain fatty acid produced. Inhibition of Enterobacteriaceae was also observed. The strongest stimulation of LAB adhesion to the human epithelial cells occurred in the presence of the preparation containing the highest concentration of higher-order oligosaccharides. The fecal bacteria and pathogens showed much weaker adhesion to intestinal cells in the presence of all the tested AP hydrolysates. Both of the tested POS preparations, containing structurally different oligosaccharides (DPs 2–10 with different ratios of higher-order oligosaccharides), have the potential to be used as prebiotics for humans and animals. They stimulate bowel colonization with lactic acid bacteria and inhibit the development of infections caused by pathogens.

The aim of this study was to evaluate the effects of alginate entrapment on fermentation metabolites of Kluyveromyces marxianus grown in agrowastes that served as the liquid culture media. K. marxianus cells entrapped in Na-alginate were prepared using the traditional liquid-droplet-forming method. Whey and pomaces from processed tomatoes, peppers, and grapes were used as the culture media. The changes in the concentrations of sugar, alcohol, organic acids, and flavor compounds were analyzed using gas chromatography-mass spectrometry (GC-MS) and high pressure liquid chromatography (HPLC). Both free and entrapped, K. marxianus were used individually to metabolize sugars, organic acids, alcohols, and flavor compounds in the tomato, pepper, grape, and acid whey based media. Marked changes in the fermentation behaviors of entrapped and free K. marxianus were observed in each culture. A 1.45-log increase was observed in the cell numbers of free K. marxianus during fermentation. On the contrary, the cell numbers of entrapped K. marxianus remained the same. Both free and entrapped K. marxianus brought about the fermentation of sugars such as glucose, fructose, and lactose in the agrowaste cultures. The highest volume of ethanol was produced by K. marxianus in the whey based media. The concentrations of flavor compounds such as ethyl acetate, isoamyl alcohol, isoamyl acetate, 2-phenylethyl isobutyrate, phenylethyl acetate, and phenylethyl alcohol were higher in fermented agrowaste based media compared to the control.