Food-grade production of an antihypertensive casein hydrolysate and resistance of active peptides to drying and storage

Role of Food Digestion and Digestive System in the Nutritional, Functional and Health Properties of Food Bioactives

The impact of food components on the human digestive system is an important area of research in the fields of nutrition and food science [...].

CCK and GLP-1 response on enteroendocrine cells of semi-dynamic digests of hydrolyzed and intact casein

A semi-dynamic gastrointestinal device was employed to explore the link between protein structure and metabolic response upon digestion for two different substrates, a casein hydrolysate and the precursor micellar casein. As expected, casein formed a firm coagulum that remained until the end of the gastric phase while the hydrolysate did not develop any visible aggregate. Each gastric emptying point was subjected to a static intestinal phase where the peptide and amino acid composition changed drastically from that found during the gastric phase. Gastrointestinal digests from the hydrolysate were characterized by a high abundancy of resistant peptides and free amino acids. Although all gastric and intestinal digests from both substrates induced the secretion of cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) in STC-1 cells, GLP-1 levels were maximum in response to gastrointestinal digests from the hydrolysate. The enrichment of protein ingredients with gastric-resistant peptides by enzymatic hydrolysis is proposed as strategy to deliver protein stimuli to the distal gastrointestinal tract to control food intake or type 2 diabetes.

Bioactive food-derived peptides for functional nutrition: Effect of fortification, processing and storage on peptide stability and bioactivity within food matrices

New challenges in food production and processing are appearing due to increasing global population and the purpose of achieving a sustainable food system. Bioactive peptides obtained from food proteins can be employed to prevent or pre-treat several diseases such as diabetes, cardiovascular diseases, inflammation, thrombosis, cancer, etc. Research on the bioactivity of protein hydrolysates is very extensive, especially in vitro tests, although there are also tests in animal models and in humans studies designed to verify their efficacy. However, there is very little published literature on the functionality of these protein hydrolysates as an ingredient in food matrices, as well as the effect that thermal or non-thermal processing, and storage may have on the bioactivity of these bioactive peptides. This review aims to summarize the published literature on protein hydrolysates as a functional ingredient including processing, storage and simulated gastrointestinal digestion regarding the bioactivity of these peptides inside food matrices.

Stability and bioactivity of peptides in food matrices based on processing conditions

Bioactive peptides (BPs) generated from food proteins can serve therapeutic purposes against degenerative and cardiovascular diseases such as inflammation, diabetes, and cancer. There are numerous reports on the in vitro, animal, and human studies of BPs, but not as much information on the stability and bioactivity of these peptides when incorporated in food matrices. The effects of heat and non-heat processing of the food products, and storage on the bioactivity of the BPs, are also lacking. To this end, we describe the production of BPs in this review, followed by the food processing conditions that affect their storage bioactivity in the food matrices. As this area of research is open for industrial innovation, we conclude that novel analytical methods targeting the interactions of BPs with other components in food matrices would be greatly significant while elucidating their overall bioactivity before, during and after processing.

Peptidomic Characterization and Amino Acid Availability after Intake of Casein vs. a Casein Hydrolysate in a Pig Model

It is known that casein hydrolysis accelerates gastrointestinal transit in comparison to intact casein, although the effect of the protein hydrolysis on the composition of the digests is not fully understood. The aim of this work is to characterize, at the peptidome level, duodenal digests from pigs, as a model of human digestion, fed with micellar casein and a previously described casein hydrolysate. In addition, in parallel experiments, plasma amino acid levels were quantified. A slower transit of nitrogen to the duodenum was found when the animals received micellar casein. Duodenal digests from casein contained a wider range of peptide sizes and a higher number of peptides above five amino acids long in comparison with the digests from the hydrolysate. The peptide profile was markedly different, and although β-casomorphin-7 precursors were also found in hydrolysate samples, other opioid sequences were more abundant in the casein digests. Within the same substrate, the evolution of the peptide pattern at different time points showed minimal changes, suggesting that the protein degradation rate relies more on the gastrointestinal location than on digestion time. Higher plasma concentrations of methionine, valine, lysine and amino acid metabolites were found in animals fed with the hydrolysate at short times (<200 min). The duodenal peptide profiles were evaluated with discriminant analysis tools specific for peptidomics to identify sequence differences between both substrates that can be used for future human physiological and metabolic studies.

Development and sensory test of a dairy product with ACE inhibitory and antioxidant peptides produced at a pilot plant scale

A scale-up process was carried out to obtain potent bioactive peptides from whey protein through a simple hydrolysis process. The scale-up was satisfactory, with results similar to those obtained at lab scale: a fraction of peptides < 1 kDa with ACE inhibitory activity of 18.44 ± 2.47 μg/mL, a DPPH value of 69.40 ± 0.44%, and an ORAC value of 3.37 ± 0.03 μmol TE/mg protein. The peptide sequences responsible for the ACE inhibitory activity were also similar to those identified at lab scale: PM, LL, LF, HFKG and PT. The hydrolysate was used as a functional ingredient in a low-fat yoghurt. The consumer sensory taste panel found no significant difference (p > 0.05) between the bitterness of the control and the functional yoghurt, and about 50% of consumers would buy it. The hydrolysate maintained its bioactivities for 4 months at -20 °C (after thawing and pasteurisation), and for 1 week in yoghurt at 4 °C.

Plant-derived proteins as a sustainable source of bioactive peptides: recent research updates on emerging production methods, bioactivities, and potential application

The development of novel protein sources to compensate for the expected future shortage of traditional animal proteins due to their high carbon footprint is a major contemporary challenge in the agri-food industry currently. Therefore, both industry and consumers are placing a greater emphasis on plant proteins as a sustainable source of protein to meet the growing nutritional demand of ever increasing population. In addition to being key alternatives, many plant-based foods have biological properties that make them potentially functional or health-promoting foods, particularly physiologically active peptides and proteins accounting for most of these properties. This review discusses the importance of plant-based protein as a viable and sustainable alternative to animal proteins. The current advances in plant protein isolation and production and characterization of bioactive hydrolysates and peptides from plant proteins are described comprehensively. Furthermore, the recent research on bioactivities and bioavailability of plant protein-derived bioactive peptides is reviewed briefly. The limitations of using bioactive peptides, regulatory criteria, and the possible future applications of plant protein-derived bioactive peptides are highlighted. This review may help understand plant proteins and their bioactive peptides and provide valuable suggestions for future research and applications in the food industry.

Antidiabetic Food-Derived Peptides for Functional Feeding: Production, Functionality and In Vivo Evidences

Bioactive peptides released from the enzymatic hydrolysis of food proteins are currently a trending topic in the scientific community. Their potential as antidiabetic agents, by regulating the glycemic index, and thus to be employed in food formulation, is one of the most important functions of these peptides. In this review, we aimed to summarize the whole process that must be considered when talking about including these molecules as a bioactive ingredient. In this regard, at first, the production, purification and identification of bioactive peptides is summed up. The detailed metabolic pathways described included carbohydrate hydrolases (glucosidase and amylase) and dipeptidyl-peptidase IV inhibition, due to their importance in the food-derived peptides research field. Then, their characterization, concerning bioavailability in vitro and in situ, stability and functionality in food matrices, and ultimately, the in vivo evidence (from invertebrate animals to humans), was described. The future applicability that these molecules have due to their biological potential as functional ingredients makes them an important field of research, which could help the world population avoid suffering from several diseases, such as diabetes.

Implication of Opioid Receptors in the Antihypertensive Effect of a Bovine Casein Hydrolysate and αs1-Casein-Derived Peptides

The antihypertensive activity of two α_s1-casein-derived peptides and casein hydrolysate containing these sequences was evaluated in the presence of naloxone. The activity was abolished by this opioid antagonist at 2, 4, and 6 h post-administration. Similarly, the antihypertensive effect of the α_s1-casein peptides ⁹⁰RYLGY⁹⁴ (-23.8 ± 2.5 mmHg) and ¹⁴³AYFYPEL¹⁴⁹ (-21.1 ± 3.2 mmHg) at 5 mg/kg of body weight was antagonized by the co-administration of naloxone. Because peptide ¹⁴³AYFYPEL¹⁴⁹ had recently shown opioid activity, a molecular dynamic simulation of this peptide with human μ-opioid receptor was performed to demonstrate its favorable structure and interaction energy, despite the presence of Ala at the N terminus. Altogether, these results revealed that the in vivo effect on systolic blood pressure of the studied α_s1-casein peptides is mediated by interaction with opioid receptors and the antihypertensive activity of casein hydrolysate can be very likely ascribed to them with the possible contribution of other mechanisms.

Protein extraction from agri-food residues for integration in biorefinery: Potential techniques and current status

The biorefinery concept is attracting scientific and policy attention as a promising option for enhancing the benefits of agri-food biomass along with a reduction of the environmental impact. Obtaining bioproducts based on proteins from agri-food residues could help to diversify the revenue stream in a biorefinery. In fact, the extracted proteins can be applied as such or in the form of hydrolyzates due to their nutritional, bioactive and techno-functional properties. In this context, the present review summarizes, exemplifies and discusses conventional extraction methods and current trends to extract proteins from residues of the harvesting, post-harvesting and/or processing of important crops worldwide. Moreover, those extraction methods just integrated in a biorefinery scheme are also described. In conclusion, a plethora of methods exits but only some of them have been applied in biorefinery designs, mostly at laboratory scale. Their economic and technical feasibility at large scale requires further study.

Whey protein membrane processing methods and membrane fouling mechanism analysis

Whey is a byproduct with nutritional value and high organic and saline content. It is an important source of organic contamination in dairy industry. In this paper, we gave an overview of the current use of membrane materials and membrane processing in cheese whey protein recovery and discussed recent developments in membrane technology. Different types of membranes, such as polymers, ceramic membranes and modification membranes, are used for various purposes, such an increasing permeation flux, reducing membrane fouling, and increasing the protein rejection rate, concentration, fractionation and purification of whey protein. New membrane processing methods and integrated membrane methods to recover whey protein were reviewed. Membrane fouling factors during whey protein ultrafiltration process, which included whey protein conformation, membrane filtration conditions and the interaction between proteins and the membrane surface or pores, were also discussed and analyzed to reveal membrane fouling mechanism.

Oligopeptide derived from solid-state fermented cottonseed meal significantly affect the immunomodulatory in BALB/c mice treated with cyclophosphamide

In this study, the immunomodulatory activity of oligopeptide (CP) derived from solid-state fermented cottonseed meal were investigated in immunosuppressed BALB/c mice models by treatment with cyclophosphamide (CY). Results indicated that oligopeptide increased the thymus and spleen indices of CY-treated mice. The count of plague forming cells (PFC) and the content of half serum hemolysis (HC₅₀) in immunosuppressive mice were restored to the normal level in CP-10 and CP-20 groups while the cytokines interleukin (IL)-2, IL-6, and tumor necrosis factor alpha (TNF-α) were increased significantly in CP-20 group. Similar increasing the immunoglobulin of IgG and IgM content in the serum of CP-10 group were also observed. These findings indicated that oligopeptide derived from solid-state fermented cottonseed meal had a strong immune-enhancing activity as well as a protective effect against immunosuppression induced by cyclophosphamide in mice.

Identification and characterization of an angiotensin-converting enzyme inhibitory peptide derived from bovine casein

In this study, we identified a novel angiotensin-I-converting enzyme (ACE) inhibitory peptide, YQKFPQYLQY (YQK), derived from bovine casein. Casein was hydrolyzed using pepsin and trypsin. The target peptide, YQK, was separated from the hydrolysate by ultrafiltration and Sephadex G-15chromatography. The IC₅₀ value of YQK was 11.1μM. YQK retained its ACE inhibitory activity under various temperature and pH conditions. It was also stable against the digestive enzymes pepsin and trypsin. The Lineweaver-Burk plot suggested that the inhibitory mode of YQK was competitive. Furthermore, its antihypertensive effects in spontaneously hypertensive rats (SHRs) also revealed that oral administration of YQK can significantly decrease systolic blood pressure. These results suggested that YQK may have potential applications in functional foods or pharmaceuticals as an antihypertensive agent.

Preparation, properties, and uses of enzymatic milk protein hydrolysates

Enzymatic hydrolysis of milk proteins has been a subject of numerous research studies and patents. The driving force for these studies has been the increased utilization of milk proteins. The industrial uses of milk proteins are based on their unique composition, functionality, and nutritive values. The diversity of milk protein fraction, the large number of proteinases, and controlled hydrolysis conditions used resulted in the preparation of hydrolysates suitable for several purposes. Enzymatic hydrolysis of milk proteins modifies the techno-functional and biofunctional properties of hydrolysates depending on the enzyme(s) and hydrolysis conditions used. Milk protein hydrolysates (MPH) are used commonly in normal and clinical nutrition and as a functional food ingredient. In the present review, emphasis has been made to highlight methods applied for the preparation of MPH, and the functional properties and utilization of the obtained hydrolysates.

Recent Research in Antihypertensive Activity of Food Protein-derived Hydrolyzates and Peptides

Year to year obesity prevalence, reduced physical activities, bad habits/or stressful lifestyle, and other environmental and physiological impacts lead to increase in diseases such as coronary heart disease, stroke, cancer, diabetes, and hypertension worldwide. Hypertension is considered as one of the most common serious chronic diseases; however, discovery of medications with high efficacy and without side effects for treatment of patients remains a challenge for scientists. Recent trends in functional foods have evidenced that food bioactive proteins play a major role in the concepts of illness and curing; therefore, nutritionists, biomedical scientists, and food scientists are working together to develop improved systems for the discovery of peptides with increased potency and therapeutic benefits. This review presents a recent research carried out to date for the purpose of isolation and identification of bioactive hydrolyzates and peptides with angiotensin I converting enzyme inhibitory activity and antihypertensive effect from animal, marine, microbial, and plant food proteins. Effects of food processing and hydrolyzation conditions as well as some other impacts on formation, activity, and stability of these hydrolyzates and peptides are also presented.

Antihypertensive peptides: production, bioavailability and incorporation into foods

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.