Cheese Whey Fermentation by Its Native Microbiota: Proteolysis and Bioactive Peptides Release with ACE-Inhibitory Activity

María J Torres-Llanez,Belinda Vallejo-Córdoba,Miguel A Mazorra-Manzano,Glen R Robles-Porchas,Aarón F González-Córdova,Celia O García-Sifuentes,Daniel A González-Velázquez,Marcel Martínez-Porchas

doi:10.3390/fermentation6010019

María J Torres-Llanez, Belinda Vallejo-Córdoba + Show 6 more

Open Access

https://doi.org/10.3390/fermentation6010019

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Abstract

Cheese whey contains about 20% of the total milk protein and has high nutritional and technological value, as well as attractive biological properties. Whey protein represents an important source of bioactive peptides with beneficial effects on health (e.g., antioxidant, antidiabetic, antihypertensive, etc.). Microbiota in cheese whey can hydrolyze proteins and generate bioactive peptides through a fermentation process. The objective of this study was to evaluate the effect of temperature on the fermentation of cheese whey by its native microbiota, and the action of microbial proteolytic activity on whey proteins to release peptides with inhibitory activity of the angiotensin-converting enzyme (ACE). Whey proteins hydrolysis occurred at all incubation temperatures evaluated (32–50 °C), with the major proteolytic effect within the range of 35–42 °C. Minor whey proteins (i.e., Lf, bovine serum albumin (BSA), and IgG) were more susceptible to degradation, while β-lactoglobulin and α-lactalbumin showed major resistance to microbial proteolytic action. Alfa-amino groups increased from 36 to 360–456 µg Gly/mL after 120 h of fermentation. A higher lactic acid production (11.32–13.55 g/L) and lower pH (3.3–3.5) were also observed in the same temperature range (32–42 °C). In addition, ACE-inhibitory activity increased from 22% (unfermented whey) to 60–70% after 120 h of fermentation. These results suggest that the fermentation of cheese whey by its native microbiota represents an attractive process to give value to whey for the production of whey-based beverages or functional foods with potential antihypertensive properties.

Highlights

Cheese whey is the remaining liquid of milk that has been curdled and transformed into cheese.World cheese production increased by 2% annually and reached around 22 million MT in 2015.This sector produces more whey than any other dairy industry; approximately 8–9 L of whey is generated per Kg of cheese produced, globally estimated at 180–190 million ton/year [1]
Whey from queso fresco production was used in this study and had a pH close to neutral
The average content of lactose, ash, protein, and non-protein nitrogen was 4.8%, 0.51%, 0.72%, and 0.08%, respectively. These characteristics are comparable to those previously reported for sweet whey [17,18]

Summary

Introduction

Cheese whey is the remaining liquid of milk that has been curdled and transformed into cheese.World cheese production increased by 2% annually and reached around 22 million MT in 2015.This sector produces more whey than any other dairy industry; approximately 8–9 L of whey is generated per Kg of cheese produced, globally estimated at 180–190 million ton/year [1]. In Latin American countries most of the cheese industry is considered a low-tech or artisanal industry, where whey is traditionally considered a product of “low economic value”, discarding daily a large volume of whey to the environment without prior treatment. This practice is considered unacceptable from economical, ecological, and nutritional perspectives, considering that whey retains about 55% of the original nutrients of milk (e.g., lactose, protein, minerals, and fat), which could be recovered or converted into valuable compounds by diverse bio/technological processes [2,3]

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