Influence of Enzymatic Hydrolysis on Composition and Technological Properties of Apple Pomace and Its Application for Wheat Bread Making.

The aim of this work was to evaluate the influence of enzymatic hydrolysis on dietary fiber, phenolic compounds and technological properties of apple pomace as wheat bread supplement. Apple pomace was hydrolyzed with Viscozyme® L, Pectinex® Ultra Tropical, Celluclast® 1.5 L for 1 and 5 h. Soluble (SDF) and insoluble (IDF) dietary fiber, reducing sugars and the total phenolic contents (TPC), along with the technological properties (water and oil retention capacities, solubility index, emulsion stability) of treated apple pomace were evaluated. The prebiotic activity of apple pomace water-soluble fraction on two probiotic strains Lactobacillus acidophilus DSM 20079 and Bifidobacterium animalis DSM 20105 was investigated. Treatment with Celluclast® 1.5 L increased SDF, reducing sugars, SDF/IDF ratio and decreased IDF of apple pomace. While treatment with Viscozyme® L, Pectinex® Ultra Tropical increased reducing sugars, solubility index and TPC, but in most cases reduced oil and water retention capacities, decreased SDF and IDF content. All apple pomace extracts promoted growth of probiotic strains. Addition of 5% of apple pomace hydrolyzed with Celluclast® 1.5 L did not have negative impact on wheat bread, while addition of other enzymatically hydrolyzed apple pomaces decreased pH, specific volume and porosity of wheat bread. Obtained results suggest that apple pomace enzymatically hydrolyzed with Celluclast® 1.5 L can be potentially used for wheat bread supplementation with dietary fiber.

Technological Properties and Composition of Enzymatically Modified Cranberry Pomace.

Cranberry pomace obtained after juice production is a good source of dietary fiber and other bioactive compounds. In this study, cranberry pomace was hydrolyzed with Viscozyme® L, Pectinex® Ultra Tropical, Pectinex® Yieldmash Plus, and Celluclast® 1.5L (Novozyme A/S, Denmark). The soluble and insoluble dietary fiber was determined using the Megazyme kit, while the changes in mono-, disaccharide and oligosaccharides' contents were determined using HPLC-RI; the total phenolic contents were determined by Folin-Ciocalteu's Assay. Prebiotic activity, using two probiotic strains Lactobacillus acidophilus DSM 20079 and Bifidobacterium animalis DSM 20105, was investigated. The technological properties, such as hydration and oil retention capacity, were evaluated. The enzymatic treatment increased the yield of short-chain soluble saccharides. The highest oligosaccharide content was obtained using Viscozyme® L and Pectinex® Ultra Tropical. All of the tested extracts of cranberry pomace showed the ability to promote growth of selected probiotic bacteria. The insoluble dietary fiber content decreased in all of the samples, while the soluble dietary fiber increased just in samples hydrolyzed with Celluclast® 1.5L. The highest content of total phenolic compounds was obtained using Viscozyme® L and Pectinex® Ultra Tropical (10.9% and 13.1% higher than control, respectively). The enzymatically treated cranberry pomace exhibited lower oil and water retention capacities in most cases. In contrast, water swelling capacity increased by 23% and 70% in samples treated with Viscozyme® L and Celluclast® 1.5L, respectively. Enzymatically treated cranberry pomace has a different composition and technological properties depending on the enzyme used for hydrolysis and can be used in various novel food products.

Investigation of Antibacterial Activity and Probiotic Properties of Strains Belonging to Lactobacillus and Bifidobacterium Genera for Their Potential Application in Functional Food and Feed Products.

For novel food/feed product formulation, the selection of the right culture with probiotic properties is essential. The purpose of this research was to evaluate antibacterial activity and probiotic features of Lactobacillus and Bifidobacterium spp. for its potential application in functional food/feed products as supplement. The evaluation of antibacterial activities was carried out by agar diffusion assay and broth inhibition assay methods against twelve pathogenic strains belonging to Staphylococcus aureus, Escherichia coli, Staphylococcus chromogenes, and Staphylococcus hyicus species. Metabolites produced by Lactobacillus paracasei subsp. paracasei DSM 20020, L. paracasei subsp. paracasei DSM 4905, and L. gasseri DSM 20077 inhibited the growth of all tested pathogens. The strains were characterized in vitro for their probiotic characteristics such as resistance to low pH and bile salts, antibiotic sensitivity by gradient diffusion using MIC Test Strips, autoaggregation and coaggregation assay with E. coli DSM 27503, and antioxidant activity by 1-diphenyl-2-picrylhydrazyl (DPPH) and 2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assays. The results demonstrated that tested probiotic properties varied among the strains. Lactobacillus spp. tolerated pH 3 for 4 h, while 8 of 14 strains survived 4 h in pH 2. Most of tested strains were able to tolerate 0.3% bile salts for 4 h. All tested strains were sensitive to ampicillin. No gelatinase and hemolytic activities were detected. These results suggest Lactobacillus acidophilus DSM 20079, Bifidobacterium pseudolongum DSM 20099, and Bifidobacterium animalis DSM 20105 as probiotic candidates for the development of functional food/feed.