Influence of added whey proteins and hydrolysates on rheological and textural characteristics of milk chocolate.

In order to improve functional characteristics of standard milk chocolate (C) was enriched by the addition of whey protein concentrate (WPC) and whey proteins hydrolyzed by trypsin (H-WPC) in the amount of 6%. The chocolate samples were analyzed by determination of antioxidant capacity, particle size distribution, textural, rheological, and sensory properties. The obtained results revealed that chocolate enriched by whey protein hydrolysate (H-WPC) possesses higher content of total polyphenols (1007.8 ± 96.8 mg GAE/100 g), increased ability to inhibit ABTS radicals (66.30 ± 1.99%), and increased ability to inhibit DPPH radicals (56.34 ± 3.20%), compared to the standard milk chocolate (C) (877.1 ± 56.0 mg GAE/100g; 48.46 ± 2.11%; 48.07 ± 2.80%, respectively). The additional ingredients do not significantly affect the hardness and enthalpy of chocolates. The hydrolyzed whey proteins increase the viscosity of chocolate (11.81 ± 0.11 Pa·s) to a greater extent than non-hydrolyzed whey proteins (9.17 ± 0.09 Pa·s), relative to the control sample (3.53 ± 0.05 Pa·s). Regardless of the fact that the WPC sample has slightly better rheological characteristics and particle size distribution compared to the H-WPC sample, no major changes in the sensory characteristics of chocolate were observed. Based on the results, whey protein hydrolysate can be marked as an exceptional ingredient for improving the quality of chocolate.

Enriching alginate matrix used for probiotic encapsulation with whey protein concentrate or its trypsin-derived hydrolysate: Impact on antioxidant capacity and stability of fermented whey-based beverages.

The present research is part of an effort to create whey-based functional food. Previously, it was concluded that proteins and peptides in an encapsulation matrix contribute to mechanical properties of beads, fermentative activity, acid and bile tolerance, and the survival of probiotics during the simulated gastrointestinal condition. This research evaluates the effects of using whey protein concentrate and trypsin hydrolysate as components of a matrix for probiotic encapsulation on the antioxidant capacity of a beverage. Carrier with hydrolysate showed better encapsulation efficiency, spherical factor, and antioxidant capacity before and after fermentation compared to the carrier with non-hydrolyzed proteins. Hydrolysis of protein used for carrier formulation positively impacts the beverage's antioxidant properties and probiotic viability during 28 days of storage. Using proteins, especially peptides, as a matrix component achieved three objectives: protection of probiotics, enrichment of products with antioxidants, and neutralization of possible bitter taste (because the bitter tasting peptides are incorporated into the matrix and as such cannot contribute to the taste of the product) that bioactive peptides usually possess.

Application of whey protein and whey protein hydrolysate as protein based carrier for probiotic starter culture.

The main object of study is application of whey protein concentrate (WPC) and whey protein hydrolysate (WPH) for probiotic encapsulation. The controlled enzymatic hydrolysis was applied to change technological properties of WPC what leads to obtained different carriers. Probiotic carriers (beads) were made by electrostatic extrusion. Bead properties (mechanical properties, FTIR fingerprint, cell release) and parameters of fermentation were examined. According to cell release, it can be concluded that WPH build less porous matrix with alginate than WPC. Beads with WPH contained more living cells and suffered more changes during fermentation than beads with WPC. Probiotic viability in simulated gastrointestinal conditions (SGIC) is the most critical parameter for probiotic encapsulation. Probiotic encapsulated in protein-alginate beads survived SGIC with more than 96% viable cells, compared to 37.43% for free culture. According to all examined parameters, it can be concluded that WPH builds more suitable carrier for probiotic culture than WPC.

Effect of immobilisation materials on viability and fermentation activity of dairy starter culture in whey-based substrate.

BACKGROUND: The main objectives of the paper were to study influence of immobilisation of dairy starter culture 'Lactoferm ABY 6' on fermentation and probiotic potential of fermented whey-based substrate. RESULTS: Fermentation with free cells takes 1.5 h less than fermentation with encapsulated cells, but samples with encapsulated cells have better characteristics after 28 days of storage. Chitosan coating provides additional protection of cells in bile salt solution (95.86% of viable cells compared to the initial number) and simulated gastric juice (37.8% for pH 2.5) compared to the alginate beads (94.54% in bile salt solution and 36.18% in simulated gastric juice for pH 2.5). Free cells had a drastic reduction in the number of viable cells (83.0% in bile salt solution and no viable cells in simulated gastric juice for pH 2.5). CONCLUSION: Samples with alginate beads and chitosan-coated alginate beads have significantly (P < 0.05) higher viable cell count than samples with free cells, during 4 h monitoring survival at pH 2.5, pH 3.0 and 0.3% bovine bile solution. These beads can be used to improve survival of probiotic cells in fermented whey-based beverage during storage and consummation, which improves the quality of the product.