We have investigated the antioxidant activity of hydrolysates from whey proteins bovine alpha-lactalbumin (alpha-La) and beta-lactoglobulin A (beta-Lg A) by commercial proteases (pepsin, trypsin, chymotrypsin, thermolysin, and Corolase PP). Corolase PP was the most appropriate enzyme to obtain antioxidant hydrolysates from alpha-La and beta-Lg A (ORAC-FL values of 2.315 and 2.151 micromol of Trolox equivalent/mg of protein, respectively). A total of 42 peptide fragments were identified by HPLC-MS/MS in the beta-Lg A hydrolysate by Corolase PP. One of the sequences (Trp-Tyr-Ser-Leu-Ala-Met-Ala-Ala-Ser-Asp-Ile) possessed radical scavenging (ORAC-FL value of 2.621 micromol of Trolox equivalent/micromol of peptide) higher than that of butylated hydroxyanisole (BHA). Our results suggest that whey protein hydrolysates could be suitable as natural ingredients in enhancing antioxidant properties of functional foods and in preventing oxidation reaction in food processing.

Bioactive food peptides are encrypted within the sequence of food proteins but can be released during food processing (by enzymatic hydrolysis or fermentation) or during gastrointestinal transit. Among bioactive food peptides, those with antihypertensive activity are receiving special attention due to the high prevalence of hypertension in the Western countries and its role in cardiovascular diseases. This paper reviews the current literature on antihypertensive food peptides, focusing on the main methodologies for their production, such as enzymatic hydrolysis, fermentation and the use of recombinant bacteria. This paper also describes the structure/activity relationship of angiotensin-converting enzyme (ACE)-inhibitory peptides, as well as their bioavailability, physiological effects demonstrated by both in vitro and in vivo assays, and the contribution of mechanisms of action other than ACE inhibition. Finally, current reported strategies for incorporation of antihypertensive peptides into foods and their effects on both availability and activity are revised in this manuscript.

High blood pressure is considered as a significant health problem worldwide. In addition to numerous preventive and therapeutic drug treatments, important advances have been achieved in the identification of dietary compounds that may contribute to cardiovascular health. Among these compounds, peptides with antihypertensive properties received special attention in the past 15 years. Although milk proteins are still the main source of antihypertensive peptides, recently a remarkable increase has been noticed in the report of antihypertensive peptides released from other dietary sources. Most of these peptides have demonstrated their properties by in vitro assays. However, the evidence for their beneficial antihypertensive effects has to be based on animal experiments and clinical trials. This paper reviews the current data of the blood pressure-lowering activity of food-derived peptides demonstrated in vivo (animal models and humans). Other aspects, such as the mechanism of action and bioavailability of these peptides which play a key role in their antihypertensive effects are also summarized in this review.

Tacrine and melatonin are well-known drugs with activities as an acetylcholinesterase (AChE) inhibitor and free radical scavenger, respectively. In this work, we report new hybrids of both drugs that display higher in vitro properties than the sum of their parts. As selective inhibitors of human AChE, their IC(50) values range from sub-nanomolar to picomolar. They exhibit a higher oxygen radical absorbance capacity than does melatonin and are predicted to be able to cross the blood-brain barrier to reach their targets in the central nervous system.

Quinoa (Chenopodium quinoa Willd.) is a pseudocereal traditionally consumed by Andean cultures that is attracting attention worldwide as a functional food. Because of its tolerance to extreme environmental conditions and its nutritional and biological properties, quinoa has been defined as "one of the grains of the 21 st century". In addition to its high content in protein, lipids, fiber, vitamins, and minerals, and its excellent balance of essential amino acids, quinoa has been found to contain numerous phytochemicals including saponins, phytosterols, phytoecdysteroids, phenolics and bioactive peptides. These compounds may exert beneficial effects on metabolic, cardiovascular, and gastrointestinal health. This review summarizes the nutritional and functional role of quinoa emphasizing on the evidence demonstrated by animal and clinical studies.

The angiotensin-converting enzyme (ACE)-inhibitory activity and antioxidant properties of a commercial fermented milk from Europe were evaluated. This dairy product showed moderate ACEinhibitory activity and ABTS • + radical-scavenging capacity. The peptides from most active fractions collected by reverse phase high-performance liquid chromatography (RP-HPLC) were sequenced by RP-HPLC-tandem mass spectrometry. This technique allowed rapid identification of peptides included in the most active fractions, and various potentially active peptides were recognised according to previous studies of structure-activity relationship. Three of the identified sequences had previously been described as potent ACE inhibitors. The structure of some sequences substantiated the presence of peptides with ACE-inhibitory, antioxidant and immunomodulatory activities.

No abstract

No abstract