Angiotensin converting enzyme inhibitory hydrolysate and peptide fractions from chicken skin collagen, as modulators of lipid accumulation in adipocytes 3 T3-L1, after in vitro gastrointestinal digestion

Inhibitory activity against angiotensin-converting enzyme (IAACE) by chicken skin collagen hydrolysate (CSCH) and their peptide fractions before and after in-vitro gastrointestinal digestion, were evaluated; as well as their ability to modulate lipid accumulation in 3 T3-L1 adipocytes. Before digestion, peptide fraction <1 kDa (F4) showed the highest IAACE (p < 0.05) followed by CSCH. After these samples were digested, F4 presented an IAACE with IC50 similar to its digest (DF4) (188.84 and 220.03 μg/mL, respectively), which was 2-fold lower (p < 0.05) than IC50 of fraction <1 kDa from post-digested hydrolysate (FDH) (388.57 μg/mL). Nine peptides were identified as the potential ACE inhibitors in F4 and DF4. Addition of DF4 (800 μg/mL) reduced(p < 0.05) lipid accumulation by 83% within preadipocytes. A 45-60% reduction of lipid accumulation within differentiated adipocytes was obtained by adding FDH and DF4 (regardless the concentration). These results, digested CSCH and F4 with IAACE may be considered as potential adjuvants for obesity treatment.

Microbiological quality and native lactic acid bacteria diversity of artisanal Mexican cheeses: A review

This review aims to provide an overview of artisanal Mexican cheeses microbiota focused on microbiological quality and safety, as well as native Lactic acid Bacteria (LAB) diversity. For the search, key words of artisanal Mexican cheeses varieties was carried out through several online databases and original articles were screened and data about populations of indicator microorganisms, presence of pathogens, and native LAB identified were extracted. Several artisanal Mexican cheeses exceeded the permissible limit established in Mexican regulation (NOM-243-SSA1-2010) for indicator microorganisms, as well as in some types of cheese, the presence of pathogens was confirmed. However, other varieties of artisanal Mexican cheeses possess unique physicochemical characteristics, and during their manufacturing particular steps are used that contribute to ensuring their quality and safety. Additionally, strains able to control the growth of pathogenic and spoilage bacteria are part of the microbiota of some artisanal Mexican cheeses. About native LAB diversity, it is composed by species of Lactobacillus, Enterococcus, Streptococcus, Leuconostoc, Weisella, Lactococcus, Pediococus, Aerococus, Carnobacterium, Tetragenococus, among others genera. Otherwise, artisanal Mexican cheeses represent an important source of specific LAB with several approaches within human health because they showed potential for the development of functional foods, nutraceutical, and bioprotective cultures.

Molecular binding mechanism and novel antidiabetic and anti-hypertensive bioactive peptides from fermented camel milk with anti-inflammatory activity in raw macrophages cell lines

The investigation was to determine the effect of camel milk fermented with Limosilactobacillus fermentum KGL4 (MTCC 25515) on ACE-inhibiting, anti-inflammatory, and diabetes-preventing properties and also to release the novel peptides with antidiabetic and anti-hypertensive attributes with molecular interaction studies. Growth conditions were optimised on the basis of total peptide production by inoculating the culture in camel milk at different rates (1.5, 2.0, and 2.5%) along with different incubation periods (12, 24, 36, and 48 h). However, after 48 h of fermentation with a 2.5% rate of inoculum, the highest proteolytic activity was obtained. Reverse phase high-pressure liquid chromatography (RP-HPLC) was used to calculate the % Rpa from permeates of 3 kDa and 10 kDa fractions. Molecular weight distributions of fermented and unfermented camel milk protein fractions were compared using SDS-PAGE. Spots obtained from 2D gel electrophoresis were separated on the basis of pH and molecular weight. Spots obtained from 2D gel were digested with trypsin, and the digested samples were subjected to RP-LC/MS for the generation of peptide sequences. The inhibition of tumour necrosis factor alpha, interleukin-6, and interleukin-1 during fermentation was studied using RAW 264.7 macrophages. In the study, fermented camel milk with KGL4 (CMKGL4) inhibited LPS-induced nitric oxide (NO) production and pro-inflammatory cytokine production (TNF-α, IL-6, and IL-1β) by the murine macrophages. The results showed that the peptide structures (YLEELHRLNK and YLQELYPHSSLKVRPILK) exhibited considerable binding affinity against hPAM and hMGA during molecular interaction studies.

Production, characterization and molecular docking of antioxidant peptides from peptidome of kinema fermented with proteolytic Bacillus spp

Kinema is an alkaline traditionally fermented soybean product popularly consumed in Sikkim Himalayan region. Kinema was prepared by soybean fermented with different species of Bacillus and analyzed for peptide content, antioxidant activity and consequence of gastrointestinal enzymes (pepsin and pancreatin) on the antioxidant effect. Antioxidant effect was enhanced during soybean fermentation using different starters, which further increased during gastrointestinal digestion. The peptides formed during soybean fermentation were analyzed using LC-MS/MS. Soybean fermented using different starters resulted in the production of some common peptides and a large number of unique peptides, which may affect the functional property of kinema. Peptides having antioxidative amino acids (histidine, phenylalanine, methionine, tryptophan and tyrosine) and significant GRAVY value were selected for their molecular interaction with myeloperoxidase (MPO), a key enzyme responsible for elevated oxidative stress. A peptide SEDDVFVIPAAYPF produced in kinema fermented using Bacillus licheniformis 1G had interaction with four out of five catalytic residues identified in MPO. Kinema prepared using specific starter can produce unique peptides responsible for specific health benefits.

Gamma-aminobutyric acid (GABA) production in milk fermented by specific wild lactic acid bacteria strains isolated from artisanal Mexican cheeses

Purpose

The purpose of this study was to screen wild GABA-producing lactic acid bacteria (LAB) isolated from artisanal Mexican cheeses and to evaluate the fermentation conditions for the enhancement of the GABA yield in fermented milk.

Methods

A qualitative test was carried out to select the GABA-producing LAB and the GABA was quantified by reversed-phase high-performance liquid chromatography in fermented milk (FM). Two inoculum concentrations (107 and 109 CFU/mL), two incubation temperatures (30 and 37 °C), three glutamate concentrations (1, 3, and 5 g/L), and three pyridoxal 5′-phosphate (PLP) concentrations (0, 100, and 200 μM) were assessed to establish suitable conditions to enhance the GABA yield in FM.

Results

Results showed that, from a total of 94 LAB strains, fermented milk with two Lactococcus lactis strains (L-571 or L-572) presented the highest GABA production. However, 37 °C of incubation and 109 CFU/mL and 3 g/L of glutamate significantly led the highest GABA yield in FM with L-571. Further studies are needed to establish the optimum conditions for producing GABA by this strain, and in vivo studies may reveal its potential use as GABA-producing culture.

Conclusion

These results highlight the importance of wild LAB strains in order to generate new alternatives and opportunities in the development of functional foods containing GABA.

Angiotensin-I-converting enzyme inhibitory peptides in milk fermented by indigenous lactic acid bacteria

Background and Aim:

Fermented milk can be used to produce antihypertensive peptides. Lactic acid bacteria (LAB) with its proteolytic system hydrolyze milk protein during fermentation to produce several peptides, which include antihypertensive bioactive peptides. This study aimed to investigate the ability of indigenous LAB for the production of angiotensin-I-converting enzyme inhibitory (ACE-I) peptides in fermented milk and to characterize the ACEI peptides.

Materials and Methods:

Reconstituted milk (11%) inoculated with ten LAB isolates, and then incubated at 37°C until it reaches pH 4.6. The evaluation was carried out for LAB count, lactic acid concentration, peptide content, and ACE-I activity. The low molecular weight (MW) peptides (<3 kDa) were identified using Nano LC Ultimate 3000 series system Tandem Q Exactive Plus Orbitrap high-resolution mass spectrometry.

Results:

The result showed that the ten LAB isolates were able to produce ACE-I in fermented milk with the activities in the range of 22.78±2.55-57.36±5.40%. The activity of ACE-I above 50% produced by Lactobacillus delbrueckii BD7, Lactococcus lactis ssp. lactis BD17, and Lactobacillus kefiri YK4 and JK17, with the highest activity of ACE-I produced by L. kefiri YK4 (IC₅₀ 0.261 mg/mL) and L. kefiri JK17 (IC₅₀ 0.308 mg/mL). Results of peptide identification showed that L. kefiri YK 4 could release as many as 1329, while L. kefiri JK 17 could release 174 peptides. The peptides produced were 95% derived from casein. The other peptides were from ά-lactalbumin, β-lactoglobulin, and serum amyloid A. The peptides produced consisted of 6-19 amino acid residues, with MWs of 634-2079 Dalton and detected at 317-1093 m/z. A total of 30 peptides have been recognized based on literature searches as ACE-I peptides (sequence similarity: 100%).

Conclusion:

L. kefiri YK4 and JK17 are the potential to be used as starter cultures to produce the bioactive peptide as ACE-I in fermented milk.

Application of Plackett-Burman Design in Screening Casein and Prebiotics for the Production of ACE Inhibitory Peptides from Cow Milk Fermented by L. bulgaricus LB6

Prebiotics can play an important role in functional foods. In this paper, casein and five probiotics were selected to study the effects on ACE inhibitory peptides in fermented milk of L. bulgaricus LB6 through Plackett-Burman design, so as to improve the production of ACE inhibitory peptides. The results showed that xylooligosaccharides (XOS), fructosaccharide (FOS) and inulin had the most significant effect on the yield of ACE inhibitory peptides. Optimization added the amount of the three prebiotics added, that is, the amount of XOS added was 0.7%, the amount of FOS added was 1.1%, and the amount of inulin added was 0.7%. It provides a basis for subsequent optimization experiments.

Cooperation between Lactococcus lactis NRRL B-50571 and NRRL B-50572 for Aroma Formation in Fermented Milk

The aim of the present study was to characterize the aroma and volatile profiles of milk fermented by wild Lactococcus lactis NRRL B-50571 (FM-571) and NRRL B-50572 (FM-572) and co-fermented with both strains (co-FM). Milks fermented by these strains have been reported to have an antihypertensive effect, yet their sensory characteristics, which are of great importance for consumer acceptance of functional foods, have not been studied. In the study, volatiles were determined using solid-phase microextraction gas chromatography mass spectrometry (SPME-GC-MS) and aroma was determined by quantitative descriptive sensory analysis (QDA). Volatile compounds identified in FM-571, FM-572, and co-FM were mainly acids, alcohols, aldehydes, and ketones. FM-571 showed higher total relative volatile abundance than FM-572 or co-FM. Furthermore, the concentrations of specific amino acids (aa) were lower in FM-571 and co-FM than in FM-572. Thus, these results suggested that FM-571 or co-FM are more efficient in transforming specific aa into the corresponding volatiles than FM-572. Indeed, several alcohols and aldehydes, associated with the catabolism of these aa, were found in FM-571 and co-FM, but not in FM-572. Additionally, QDA showed that FM-571 and co-FM presented higher yeasty and cheesy aroma descriptors than FM-572. Also, total aroma intensity scores for FM-571 were higher than those for co-FM or FM-572. Thus, results suggested that the combination of these two specific wild L. lactis strains may complement amino acid catabolic routes that resulted in the enhancement or attenuation of aroma production of single strains, presenting new possibilities for the preparation of custom-made starter cultures.

Bioprospecting for Bioactive Peptide Production by Lactic Acid Bacteria Isolated from Fermented Dairy Food

With rapidly ageing populations, the world is experiencing unsustainable healthcare from chronic diseases such as metabolic, cardiovascular, neurodegenerative, and cancer disorders. Healthy diet and lifestyle might contribute to prevent these diseases and potentially enhance health outcomes in patients during and after therapy. Fermented dairy foods (FDFs) found their origin concurrently with human civilization for increasing milk shelf-life and enhancing sensorial attributes. Although the probiotic concept has been developed more recently, FDFs, such as milks and yoghurt, have been unconsciously associated with health-promoting effects since ancient times. These health benefits rely not only on the occurrence of fermentation-associated live microbes (mainly lactic acid bacteria; LAB), but also on the pro-health molecules (PHMs) mostly derived from microbial conversion of food compounds. Therefore, there is a renaissance of interest toward traditional fermented food as a reservoir of novel microbes producing PHMs, and “hyperfoods” can be tailored to deliver these healthy molecules to humans. In FDFs, the main PHMs are bioactive peptides (BPs) released from milk proteins by microbial proteolysis. BPs display a pattern of biofunctions such as anti-hypertensive, antioxidant, immuno-modulatory, and anti-microbial activities. Here, we summarized the BPs most frequently encountered in dairy food and their biological activities; we reviewed the main studies exploring the potential of dairy microbiota to release BPs; and delineated the main effectors of the proteolytic LAB systems responsible for BPs release.

Optimization of Fermentation Conditions for the Production of Angiotensin-Converting Enzyme (ACE) Inhibitory Peptides from Cow Milk by Lactobacillus bulgaricus LB6

The purpose of this research was to screen out the optimal -producing peptide conditions for cow milk fermented by Lactobacillus bulgaricus LB6. The effects of temperature, inoculation size, time and skim milk concentration on the ACE inhibition rate of fermented milk were investigated by single factor experiment, and the optimal fermentation conditions were determined by orthogonal experiment. The conditions of the single factor experiment were: Temperatures were 37° C, 39° C, 42° C, 44° C and 46° C. The inoculation amount was 1%, 3%, 5%, 7% and 9%, the time was 8h and 10h. At 12h, 14h and 16h, the concentration of skim milk was 8%, 10%, 12%, 14% and 16%, respectively. The results showed that the optimal fermentation conditions for ACE inhibitory peptide produced by Lactobacillus bulgaricus LB6 were 4% inoculation, 13h in time, 42°C in temperature and 13% in skim milk. Under this condition, the ACE inhibition rate reached 76.50% and the OD value was 0.330. The titration acidity was 116.4°T, the pH was 4.62, and the sensory evaluation was 75 scores.

Solid state fermentation to obtain vegetable products bio-enriched with isoflavone aglycones using lactic cultures

The consumption of soybean isoflavones (IS) is associated with several beneficial properties on human health. Some lactic acid bacteria possess β-glucosidase enzyme, that allows to obtain the active form of IS (aglycone). The solid state fermentation (SSF) has received great attention in the last years in order to obtain several valuable compounds. SSF, using soybean as substrate and Lactobacillus rhamnosus CRL 981 as starter, was studied in the present work. Sucrose was added into soybean paste to study the effect on the behavior of the selected strain. The development of L. rhamnosus CRL 981 through pH and recount measures, sugar intake, organic acid production, β-glucosidase activity and IS conversion were analyzed. No significant differences in growth and acidity were observed between soybean pastes with and without sucrose added, but the production of lactic acid was higher in the latter paste. The β-glucosidase activity was detected in both pastes and the complete hydrolysis of IS at 12h of fermentation was observed. Also, this strain was able to increase the free amino acids in soybean paste. SSF, using soybean as substrate and L. rhamnosus CRL 981 as starter culture, is an alternative process to obtain a soybean product bio-enriched in active IS with attractive nutritional characteristics.

Mechanistic Pathways Underlying the Antihypertensive Effect of Fermented Milk with Lactococcus lactis NRRL B-50571 in Spontaneously Hypertensive Rats

It has been reported that fermented milk (FM) with Lactococcus lactis NRRL B-50571 had an antihypertensive effect in spontaneously hypertensive rats (SHR) and prehypertensive subjects. Therefore, the objective of the present study was to evaluate the possible mechanisms involved (angiotensin converting enzyme inhibition (ACEI), enhancement of nitric oxide production, antioxidant activity and opioid effect), in the antihypertensive effect of FM with SHR. First, twenty one SHR were randomized into three groups to either receive in a single-oral dose of purified water (negative control), FM, or naloxone (opioid receptor antagonist) + FM. In a parallel study, twenty seven SHR were randomized into three groups to either receive ad libitum purified water (negative control), Captopril or FM. After six weeks of treatment ACEI activity, enhancement of nitric oxide production, and antioxidant activity were evaluated in plasma. Results indicated that opioid receptors were not involved in the hypotensive effect of FM. However, ACEI activity (94 U/L), the oxidative stress index (malondialdehyde/catalase + glutathione peroxidase) 0.9, and nitric oxide in plasma (4.4 ± 1.3 U/L), were significantly different from the negative control, and not significantly different from the Captopril group. Thus, these results suggested that these mechanisms are involved in the hypotensive effect of FM.

Randomized double-blind controlled clinical trial of the blood pressure-lowering effect of fermented milk with Lactococcus lactis: A pilot study

The blood pressure-lowering effect of fermented milk with Lactococcus lactis NRRL B-50571 was evaluated in a double-blind randomized controlled clinical trial with prehypertensive subjects. Participants were randomized into 2 groups (n = 18 each group): one group treated with fermented milk with Lactococcus lactis NRRL B-50571 and a control group treated with artificially acidified milk. Results revealed that during daily consumption of fermented milk for 5 wk, systolic [(116.55 ± 12.26 mmHg vs. 124.77 ± 11.04 mmHg) and diastolic blood pressure (80.7 ± 9 vs. 84.5 ± 8.5 mmHg)] from the fermented milk group was lower than the control group. Additionally, triglyceride, total cholesterol, and low-density lipoprotein in blood serum were lower in the fermented milk group than in the control group. Results demonstrated that daily consumption of fermented milk with Lactococcus lactis (NRRL B-50571) had a blood pressure-lowering effect on prehypertensive subjects. Regular consumption of this product may be used as a potential functional food.

Production of angiotensin I converting enzyme inhibitory (ACE-I) peptides during milk fermentation and their role in reducing hypertension

Fermented milk is a potential source of various biologically active peptides with specific health benefits. Angiotensin converting enzyme inhibitory (ACE-I) peptides are one of the most studied bioactive peptides produced during milk fermentation. The presence of these peptides is reported in various fermented milk products such as, yoghurt, cheese, sour milk, etc., which are also available as commercial products. Many of the ACE-I peptides formed during milk fermentation are resistant to gastrointestinal digestion and inhibit angiotensin converting enzyme (ACE) in the rennin angiotension system (RAS). There are various factors, which affect the formation ACE-I peptides and their ability to reach the target tissue in active form, which includes type of starters (lactic acid bacteria (LAB), yeast, etc.), substrate composition (casein type, whey protein, etc.), composition of ACE-I peptide, pre and post-fermentation treatments, and its stability during gastrointestinal digestion. The antihypertensive effect of fermented milk products has also been proved by various in vitro and in vivo (animal and human trials) experiments. This paper reviews the literature on fermented milk products as a source of ACE-I peptides and various factors affecting the production and activity of ACE-I peptides.

Angiotensin-converting enzyme inhibition and antioxidant activity of commercial dairy starter cultures

In this study, skim milk fermented with 14 commercial dairy starters were evaluated for their proteolysis ability, angiotensin I-converting enzyme (ACE)-I, and antioxidant properties. The antioxidant activity was determined using DPPH radical scavenging, chelating of Fe²⁺ ions, and reducing power assays. The results showed that the coagulation time, pH, and titratable acidity varied among the used starters and appeared to be starter dependent. Lactobacillus helveticus Lh-B02 starter had the highest proteolytic and ACE-I activity. Lactobacillus casei-01, Yo-Fast 1, YC-281, MYE 96, and YO-MIX 205 starters had the highest DPPH radical scavenging activity. Chelating of Fe²⁺ ions of the L. casei-01 starter was the highest, whereas the O-114 starter was the greatest in reducing power. Regarding the yogurt starters, Yo-Fast 1 starter exhibited h igh values o f proteolytic, ACE-I, and DPPH radical scavenging activity. A positive correlation was observed between the proteolytic and ACE-I or antioxidant activities of all starters.

Bioactive peptides derived from traditional Chinese medicine and traditional Chinese food: A review

There is an urgent treat of numerous chronic diseases including heart disease, stroke, cancer, chronic respiratory diseases and diabetes, which have a significant influence on the health of people worldwide. In addition to numerous preventive and therapeutic drug treatments, important advances have been achieved in the identification of bioactive peptides that may contribute to long-term health. Although bioactive peptides with various biological activities received unprecedented attention, as a new source of bioactive peptides, the significant role of bioactive peptides from traditional Chinese medicine and traditional Chinese food has not fully appreciated compared to other bioactive components. Hence, identification and bioactivity assessment of these peptides could benefit the pharmaceutical and food industry. Furthermore, the functional properties of bioactive peptides help to demystify drug properties and health benefits of traditional Chinese medicine and traditional Chinese food. This paper reviews the generation and biofunctional properties of various bioactive peptides derived from traditional Chinese medicine and traditional Chinese food. Mechanisms of digestion, bioavailability of bioactive peptides and interactions between traditional Chinese medicine and traditional Chinese food are also summarized in this review.

Effect of yogurt containing deep sea water on health-related serum parameters and intestinal microbiota in mice

Deep sea water (DSW) has health benefits and is widely used as food supplement; however, its effect in fermented products has not been explored. Here, we investigated the effect of DSW-containing yogurt on health-related serum parameters and intestinal microbiota in mice. Animals were assigned to 3 feeding groups, which received water (control), normal yogurt (N-yogurt), or DSW-containing yogurt (DSW-yogurt) with a basal diet. Mice were killed at wk 4 or 8 of feeding and analyzed for serum parameters and microbial population in the small intestine. Both yogurt groups demonstrated increased populations of intestinal lactic acid bacteria compared with the control group. The activity of serum aspartate aminotransferase and alanine aminotransferase was markedly decreased in the DSW-yogurt and N-yogurt groups, and triglyceride level tended to be lower in the DSW-yogurt group compared with that in the control mice. Furthermore, the DSW-yogurt group showed a more significant decrease in the ratio of total cholesterol to high-density lipoprotein-cholesterol than did the N-yogurt group. These findings suggest that DSW supplementation of yogurt can increase its beneficial effects on lipid metabolism.

Possible role of milk-derived bioactive peptides in the treatment and prevention of metabolic syndrome

The growing prevalence of metabolic syndrome as well as its impact on public health has garnered increased attention in recent years. As a result, metabolic syndrome is now considered one of the world's leading public health problems. Bioactive peptides deriving from milk proteins may play an important role in the prevention and treatment of metabolic syndrome and its complications via several mechanisms, such as the satiety response, the regulation of insulinemia levels and blood pressure, the uptake of free radicals, and alteration of the lipid profile. These peptides can be incorporated into functional foods or administered via nutraceuticals to decrease the risk of obesity, atherogenesis, arterial hypertension, and type 2 diabetes. Recent findings have generated considerable scientific and commercial interest in milk-derived bioactive peptides, leading to numerous publications on the effectiveness of these substances. This review summarizes the current knowledge on bioactive peptides derived from milk proteins and examines the potential value of these peptides in the treatment and prevention of metabolic syndrome and its complications.