Comparative analysis of functionality of spray dried whey protein hydrolysates obtained by enzymatic and microbial hydrolysis

Salem Embiriekah,Maja Vukasinovic-Sekulic,Danica Zaric,Maja Bulatovic,Marica Rakin,Marija Gnjatovic,Tanja Krunic

doi:10.2298/hemind171121019e

Abstract

The aim of this study was to examine the bioactive potential of hydrolysate powders produced by enzymatic and microbial hydrolysis of whey proteins followed by spray drying, in order to reveal which one of these processes result in a product with significantly improved functional properties. Hydrolysate powders produced by the two different biotechnological processes were compared based on their antioxidant (DPPH and FTC), antibacterial as well as erythrocyte membrane stabilizing activities. The performed tests revealed that the concentration of at least 178.4 mg mL-1 of the whey protein hydrolysate powder, produced by tryptic digestion, could inhibit the process of lipid peroxidation by 50 %, suppress the microbial contamination caused by S. aureus ATCC25923, B. cereus ATCC 11778 and L. monocytogenes, and provide the antioxidant and membrane stabilizing activities greater than 50 %. On the other hand, the hydrolysate powder obtained by whey fermentation at the concentration of at least 811.5 mg mL-1 achieved 50 % of all tested bioactivities, with the emphasis on the significantly more pronounced antibacterial activity against all tested strains. In that sense, tryptic hydrolysis could be highlighted as an optimal process that provides production of the whey hydrolysate with pronounced bioactive properties that could be considered as a very promising natural food supplement.

Highlights

In recent years, awareness and knowledge about health implications relating to food consumption have increased
The whey protein hydrolysates (WPH)-P showed a significantly (p < 0.05) higher DPPH radical scavenging activity, corresponding to the IC50 value of 90.5 ± 1.4 mg mL-1, compared to the fermented whey hydrolysate (FWH)-P that expressed a DPPH radical scavenging activity corresponding to the IC50 value of 123.4 ± 4.2 mg mL-1
Regardless the proteolytic activity of lactic acid bacteria, it could be assumed that enzymatic hydrolysis probably releases much smaller peptides with higher antioxidant activities, which significantly improve the antioxidant activity of produced hydrolysate

Summary

Introduction

Awareness and knowledge about health implications relating to food consumption have increased. Research of natural bioactive compounds as alternatives to synthetic ones, and development of new healthy products that respond to both, food industry expectations and consumer demands for the healthy lifestyle, in recent years became the main objective of food industry developments with great interest among researchers [2]. Free radicals are responsible for the development of rancidity and reduction of food shelf-life [3] Delay of these oxidative processes through the use of antioxidants, especially from natural sources, is of great interest in food industry. Functional ingredients, such as whey protein hydrolysates (WPH) seem to have vast potentials as effective antioxidants [4,5]. According to Vavrusova et al [6], the inclusion of relatively high amounts of WPH in products has the potential to enhance the product stability by preventing radical formation

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