Characterization of goat whey proteins and their bioactivity and toxicity assay

Goat whey is an industry-discarded dairy by-product that has interesting nutritional value and a nutrient composition with important functional potential, where proteins have a high biological value and play an important role in the organism's physiology. Therefore, the aim of this study was to identify, quantify, concentrate and investigate the capacity of goat whey proteins to perform different biological activities and to evaluate their acute toxicity. Concentrated proteins were quantified and identified by Bradford, Kjehdal and SDS-PAGE methods. Antibacterial activity was performed against Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli microorganisms and showed MIC ranging from 15 to 120 mu g mL(-1), with the highest inhibition for L. monocytogenes growth. Antiproliferative activity was performed against human malignant melanoma cells and their proliferation inhibition was up to 66.8% within 72 h of exposure. The highest antioxidant capacity was obtained at concentration 2 mg that showed 29.69% of inhibition of DPPH radical oxidation. The acute toxicity test was performed using Artemia franciscana larvae in which whey proteins were able to preserve larval survival throughout exposure. Thus, we can conclude that goat's whey has proteins that can play a positive effect on health, with antimicrobial activity and without toxicity. The present study highlights the great potential of goat's whey to be developed as a safe biopreservative or as a functional ingredient in the food industry.