No abstract

Over the past decade, interest has risen in fermented dairy foods that promote health and could prevent diseases such as hypertension. This biological effect has mainly been attributed to bioactive peptides encrypted within dairy proteins that can be released during fermentation with specific lactic acid bacteria or during gastrointestinal digestion. The most studied bioactive peptides derived from dairy proteins are antihypertensive peptides; however, a need exists to review the different studies dealing with the evaluation of antihypertensive fermented milk before a health claim may be associated with the product. Thus, the objective of this overview was to present available information related to the evaluation of fermented milk containing antihypertensive peptides by in vitro and in vivo studies, which are required before a fermented functional dairy product may be introduced to the market. Although commercial fermented milks with antihypertensive effects exist, these are scarce and most are based on Lactobacillus helveticus. Thus, a great opportunity is available for the development of functional dairy products with new lactic acid bacteria that support heart health through blood pressure- and heart rate-lowering effects. Hence, the consumer may be willing to pay a premium for foods with important functional benefits.

No 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.

The objective of this study was to evaluate the efficacy of propolis extract (PE) to reduce lipid oxidation and microbial growth on beef patties during refrigerated storage. Beef patties were manufactured by incorporating PE in 4 different treatments: (1) Control (no PE addition); (2) commercial propolis 1 (2% w/w; CP1); (3) commercial propolis 2 (2% w/w; CP2); and (4) noncommercial propolis (2% w/w; NCP). Raw patties were wrapped with polyvinyl chloride and stored at 2 °C for 8 d. Total phenolic content (TPC), free-radical scavenging activity (FRS), and polyphenolic content of the PE were evaluated using high-performance liquid chromatography (HPLC). Lipid oxidation (thiobarbituric acid-reactive substances (TBARS), conjugated dienes (CnDs), metmyoglobin (MetMb%), pH variation, and color (L*, a*, b*, C*, and h*), and microbial growth (mesophilic and psychrotrophic bacteria) of patty samples were measured. NCP treatment demonstrated the highest FRS (64.8% at 100 μg/mL), which correlated with TPC and the presence of polyphenolic compounds. Lipid oxidation (78.54%, TBARS; 45.53%, CnD; 58.57%, MetMb) and microbial mesophilic and psychrotrophic growth (19.75 and 27.03%, respectively) values were reduced by NCP treatment in refrigerated samples after 8 d. These results indicate that PE has great potential as a natural antioxidant and antimicrobial additive to extend the shelf life of beef patties.