Plant proteases for bioactive peptides release: A review.

Proteins are a potential source of health-promoting biomolecules with medical, nutraceutical, and food applications. Nowadays, bioactive peptides production, its isolation, characterization, and strategies for its delivery to target sites are a matter of intensive research. In vitro and in vivo studies regarding the bioactivity of peptides has generated strong evidence of their health benefits. Dairy proteins are considered the richest source of bioactive peptides, however proteins from animal and vegetable origin also have been shown to be important sources. Enzymatic hydrolysis has been the process most commonly used for bioactive peptide production. Most commercial enzymatic preparations frequently used are from animal (e.g., trypsin and pepsin) and microbial (e.g., Alcalase® and Neutrase®) sources. Although the use of plant proteases is still relatively limited to papain and bromelain from papaya and pineapple, respectively, the application of new plant proteases is increasing. This review presents the latest knowledge in the use and diversity of plant proteases for bioactive peptides release from food proteins including both available commercial plant proteases as well as new potential plant sources. Furthermore, the properties of peptides released by plant proteases and health benefits associated in the control of disorders such as hypertension, diabetes, obesity, and cancer are reviewed.

Determination of short-chain free fatty acids in lipolyzed milk fat by capillary electrophoresis.

The objective of this study was to monitor the release of short-chain free fatty acids (FFA) from milk fat during hydrolysis with lipase using capillary electrophoresis. Sample and run buffer allowed FFA to be maintained in solution by using cyclodextrin and methanol. Indirect UV detection at 270 nm was used, employing p-anisate as a chromophore. Calibration curves constructed for each individual FFA followed linear relationships with highly significant (p < 0.01) correlation coefficients. Electrophoretic FFA profiles of fresh milk fat and lipolyzed milk fat showed marked qualitative and quantitative differences. Butanoic acid (C4) was found in a concentration of 64 ppm, while hexanoic (C6) and octanoic (C8) acids were found in concentrations of 3.8 ppm in fresh milk fat. After a 60-min hydrolysis with commercial lipase, FFA released from milk fat consisted mainly of high concentrations (ppm) of butanoic (C4) (900), followed by hexanoic (C6) (427), octanoic (C8) (282), decanoic (C10) (92), pentanoic (C5) (47), and dodecanoic (C12) (37.5) acids. Ratios of FFA that were associated with flavor balance were calculated. The application of CE for lipolysis monitoring in milk fat offers a simple and fast method for the determination of FFA. Quantitative data can be obtained in 20 min, including sample preparation. The lengthy and laborious steps required in traditional chromatographic techniques, such as lipid extraction, FFA isolation, and derivatization, were not required in this CE method. The implementation of CE for milk fat lipolysis monitoring may be a useful quality control tool for dairy flavor development and production.