Microalgae have been described as a source of bioactive compounds, such as peptides. Microalgae are easy to produce, making them a sustainable resource for extracting active ingredients for industrial applications. Several microalgae species have interesting protein content, such as Chlorella vulgaris with around 52.2% of protein, making it promising for peptide hydrolysate production. Therefore, this work focused on the production of water-soluble hydrolysates rich in proteins/peptides from the microalgae C. vulgaris and studied bioactive properties. For that, a design of experiments (DOE) was performed to establish the optimal conditions to produce hydrolysates with higher levels of protein, as well as antioxidant and antihypertensive properties. Four experimental factors were considered (cellulase percentage, protease percentage, hydrolysis temperature, and hydrolysis duration) for three responses (protein content, antioxidant activity, and antihypertensive activity). The optimal conditions determined by the DOE allowed producing a scaled-up hydrolysate with 45% protein, with antioxidant activity, measured by oxygen radical absorbance capacity assay, of 1035 µmol TE/g protein, IC₅₀ for angiotensin-converting enzyme inhibition activity of 286 µg protein/mL, and α-glucosidase inhibition of 31% (30 mg hydrolysate/mL). The obtained hydrolysates can be used as functional ingredients for food and nutraceuticals due to their antioxidant, antihypertensive, and antidiabetic potential. Moreover, the antioxidant potential of the extracts may be relevant for the cosmetic industry, especially in antiaging formulations.

This work aimed to evaluate the digestive stability of the peptides previously identified from a Corolase PP soy protein hydrolysate (SPH) and to respond to the uncertainty about the merit of controlled hydrolysis. For this purpose, we applied an empirical and theoretical analysis, determining peptide sequences, oxygen radical scavenging (ORAC) and ACE inhibitory (iACE) activities, and the effect of hydrolysis on solubility. Results showed that during digestion most of SPH peptides were degraded as smaller ones. However, both SPH bioactivities improved significantly after digestion (3.9 ± 0.1 μmol TE/mg protein for ORAC and IC50 = 52 ± 4μg protein/mL for iACE) with similar values for soy protein isolate (SPI). With respect to solubility, the controlled hydrolysis considerably increased this functional property. In conclusion, the results indicated that controlled enzymatic hydrolysis of SPI with Corolase PP produced an ingredient more apt to be incorporated in certain nutritional or nutraceutical formulations.

Food-derived bioactive peptides are of great interest to science and industry due to evolving drivers of food product innovation, including health and wellness. This study aims to draw attention through a critical study on how bioinformatics analysis is employed in the identification of bioactive peptides in the laboratory. An in silico analysis (PeptideRanker, BIOPEP, AHTpin, and mAHTPred) of a list of peptides from goat casein hydrolysate was performed to predict which sequences could potentially be bioactive. To validate the predictions, the in vitro antihypertensive potential of the five peptides with the highest potential was first measured. Then, for three of these, gastrointestinal digestion was simulated in vitro, followed by the analysis of the resulting ACE inhibitory activity as well as antioxidant capacity. We thus observed that the use of new computational biology technologies to predict peptide sequences is an important research tool, but they should not be used alone and complementarity with various in vitro and in vivo assays is essential.

In this study, antioxidant-rich extracts from brewer's spent grain (BSG) extracted by solid-to-liquid extraction using different solvents water and ethanol and their mixtures at two ratios (80% ethanol : water (v/v) and 60% ethanol : water (v/v)) were characterized. Nutritional composition was evaluated for the extracts and for the solid residues obtained after extraction. Additionally, the extracts were analyzed for the total phenolic content and individual phenolic compounds and related biological properties including antioxidant capacity (ABTS; ORAC and DNA protection), antihypertensive capacity, antibacterial activity and antibiofilm capacity. Safety was also demonstrated through genotoxicity and cytotoxicity tests. The results obtained showed that while all the extracts exhibited high antioxidant capacity (except ethanolic extract), the highest values were obtained for the 60% ethanol : water extract. The identification of phenolic compounds using HPLC showed that catechin and vanillin were the main compounds identified with the highest concentration being obtained for 60% ethanol : water extraction. In the biological activity assays, water and hydroethanolic extracts were multifunctional (antioxidant and antihypertensive capacity, antibacterial and antibiofilm activity), and the 80% ethanol : water presented better results in some assays. All were non-genotoxic, but the cytotoxicity was dependent on the extract concentration, with complete safe application for all up to 1 mg mL⁻¹. Therefore, this study shows the potential of a viable green solvent based and low cost extraction recovery method of bioactive compounds from brewer's spent grain.