Health benefits of probiotics and production of inhibitors of angiotensin converting enzyme (ACE) released during milk fermentation are well known. That is why in this investigation the proteolytic profile and ACE inhibitory capacity of peptide fractions from protein hydrolysis of milk during fermentation processes was analyzed. Milk fermentation was carried out inoculating 10⁶ CFU of L. rhamnosus GG, S. thermophilus SY-102 and with both bacteria. The proteolytic profile was determined using: TNBS, SDS-PAGE and SEC-HPLC techniques. In vitro ACE inhibition capacity was measured. The pH of 4.5 was reached at 56 h when the milk was fermented with L. rhamnosus, at 12 h with S. thermophillus and at 41 h in the co-culture. Production of free amino groups corresponded with the profile of low molecular weight peptides observed by SDS-PAGE and SEC-HPLC. Co-culture fermentation showed both the highest concentration of low molecular weight peptides and the ACE inhibitory activity (>80%). Results indicated that the combination of lactic cultures could be useful in manufacture of fermented milk with an added value that goes beyond basic nutrition, such as the production of ACE-inhibitory peptides.

Whey accounts for up to 90% of the total milk volume and is often discarded directly into drains. Due to its rich protein composition—particularly β-lactoglobulin, α-lactalbumin, and serum albumin—whey has been recognized as a valuable source of bioactive peptides, many of which exhibit antihypertensive properties via ACE inhibition. In this study, whey protein concentrate (WPC-80) was subjected to controlled enzymatic hydrolysis using Proteinase K, a broad-specificity serine protease known for its ability to cleave peptide bonds adjacent to hydrophobic and aromatic amino acids—residues frequently found in ACE-inhibitory peptide sequences (e.g., IPP, VPP). This hydrolysis yielded a degree of hydrolysis reflected by 29.98 µg/mL of free amino groups, generating a pool of intermediate peptides and oligopeptides with exposed C- and N-termini. Subsequently, three fermentations were performed using Streptococcus thermophilus SY-102 and Lactobacillus rhamnosus GG—individually and in co-culture—to further process the hydrolysate. Lactic acid bacteria possess cell-envelope proteinases (e.g., PrtS in S. thermophilus and PrtP in L. rhamnosus) and intracellular peptidases that can selectively hydrolyze larger fragments into smaller, bioactive peptides (often 2–12 amino acids), enhance peptide stability, and modify peptide sequences to optimize ACE-binding affinity (e.g., by enriching C-terminal tripeptides with Pro or aromatic residues). The antihypertensive capacity was evaluated via in vitro ACE inhibition assay. Fermentation with S. thermophilus SY-102 achieved the highest ACE inhibition (81.96%), likely due to its robust proteolytic system and preferential release of potent tripeptides such as IPP/VPP. In contrast, the co-fermentation showed significantly lower inhibition (19.73%), possibly due to competitive or antagonistic interactions between the strains altering peptidase expression, substrate preference, or peptide degradation profiles. These results demonstrate that a sequential strategy—initial hydrolysis with Proteinase K to unfold and partially cleave whey proteins, followed by targeted microbial fermentation—synergistically enhances the generation and/or preservation of ACE-inhibitory peptides, offering a promising valorization route for whey byproducts. Graphical

El Agave salmiana es un maguey endémico de México, su principal producto es el pulque, fermento del aguamiel. Cuando el aguamiel se agota, las pencas del maguey se utilizan como forraje para ganado. El objetivo fue elaborar y evaluar extractos de pencas de maguey, para ello se utilizó agua caliente y tres estadios de pencas, sin raspar (SR), siendo raspado (RM) y completamente raspado (RC). A los extractos se les cuantificó el contenido de compuestos fenólicos, ácido ascórbico, capacidad antioxidante (DPPH) y actividad quelante, durante su elaboración y hasta 8 meses de almacenamiento. El contenido de compuestos fenólicos (2913.33±277.9 mg AG/L), ácido ascórbico (758.02±56.57 mg AA/L) y la capacidad antioxidante (930.7±44.09 µmol ET/L) aumentaron durante la elaboración de los extractos. Se cuantificó un 12.6-16.4% de fibra dietética en los extractos. Además, se identificaron compuestos fenólicos (kaempferol y quercetina) en los 3 extractos elaborados. Durante su almacenamiento aumentaron los compuestos fenólicos y su capacidad antioxidante al final del octavo mes en los extractos RM y RC. Se concluye que las pencas de maguey Agave salmiana se pueden emplear para obtener extractos acuosos ricos en compuestos bioactivos con capacidad antioxidante y fibra dietética, sustancias implicadas en el tratamiento y prevención de enfermedades.

The increasing demand for functional foods has led to an interest in fermentation processes that enhance the production of antioxidant peptides. This study aimed to perform a bibliometric analysis of lactic acid bacteria (LAB) used in the fermentation of wheat to produce antioxidant peptides. To achieve this, data from 2010 to 2023 were gathered from the Web of Science® database, focusing on publications related to LAB, wheat proteins, and antioxidant peptides. The search results were analyzed using the bibliometrix R package, which allowed for an in-depth examination of research trends, collaborations, and influential studies. Results indicated increased research activity, with an average annual growth rate of 13.18% and contributions from countries such as China and Italy. The primary focus areas included fermentation methods, peptide production, and health-related applications of bioactive compounds. Collaboration networks highlighted the importance of international partnerships in advancing this field. The results provided insights into the development and application of LAB in food science, emphasizing the potential of bioactive peptides produced from wheat in promoting health through antioxidant activity. This study contributes to understanding the research landscape and the future potential of using LAB to produce functional food ingredients.