Digestion-resistant whey peptides promote antioxidant effect on Caco-2 cells.

Enteric endothelial cells are the first structure to come in contact with digested food and may suffer oxidative damage by innumerous exogenous factors. Although peptides derived from whey digestion have presented antioxidant potential, little is known regarding antioxidant pathways activation in Caco-2 cell line model. Hence, we evaluated the ability to form whey peptides resistant to simulated gastrointestinal digestive processes, with potential antioxidant activity on gastrointestinal cells and associated with sequence structure and activity. Using the INFOGEST method of simulated static digestion, we achieved 35.2% proteolysis, with formation of peptides of low molecular mass (<600 Da) evaluated by FPLC. The digestion-resistant peptides showed a high proportion of hydrophobic and acidic amino acids, but with average surface hydrophobicity. We identified 24 peptide sequences, mainly originated from ß-lactoglobulin, that exhibit various bioactivities. Structurally, the sequenced peptides predominantly contained the amino acids lysine and valine in the N-terminal region, and tyrosine in the C-terminal region, which are known to exhibit antioxidant properties. The antioxidant activity of the peptide digests was on average twice as potent as that of the protein isolates for the same concentration, as evaluated by ABTS, DPPH and ORAC. Evaluation of biological activity in Caco-2 intestinal cells, stimulated with hydrogen peroxide, showed that they attenuated the production of reactive oxygen species and prevented GSH reduction and SOD activity increase. Caco-2 cells were not responsive to nitric oxide secretion. This study suggests that whey peptides formed during gastric digestion exhibit biological antioxidant activity, without the need for previously hydrolysis with exogenous enzymes for supplement application. The study's primary contribution was demonstrating the antioxidant activity of whey peptides in maintaining the gastrointestinal epithelial cells, potentially preventing oxidative stress that affects the digestive system.

In vitro inhibition of glucose gastro-intestinal enzymes and antioxidant activity of hydrolyzed collagen peptides from different species.

The growing value of industrial collagen by-products has given rise to interest in extracting them from different species of animals. Intrinsic protein structure variation of collagen sources and its hydrolysis can bring about different bioactivities. This study aimed to characterize and evaluate the differences in vitro biological potential of commercial bovine (BH), fish (FH), and porcine hydrolysates (PH) regarding their antioxidant and hypoglycemic activities. All samples showed percentages above 90% of protein content, with high levels of amino acids (glycine, proline, and hydroxyproline), responsible for the specific structure of collagen. The BH sample showed a higher degree of hydrolysis (DH) (8.7%) and a higher percentage of smaller than 2 kDa peptides (74.1%). All collagens analyzed in vitro showed inhibition of pancreatic enzymes (α-amylase and α-glucosidase), with the potential to prevent diabetes mellitus. The PH sample showed higher antioxidant activities measured by ORAC (67.08 ± 4.23 µmol Trolox Eq./g) and ABTS radical scavenging (65.69 ± 3.53 µmol Trolox Eq./g) methods. For the first time, DNA protection was analyzed to hydrolyzed collagen peptides, and the FH sample showed a protective antioxidant action to supercoiled DNA both in the presence (39.51%) and in the absence (96.36%) of AAPH (reagent 2,2'-azobis(2-amidinopropane)). The results confirmed that the source of native collagen reflects on the bioactivity of hydrolyzed collagen peptides, probably due to its amino acid composition. PRACTICAL APPLICATIONS: Our data provide new application for collagen hydrolysates with hypoglycemiant and antioxidant activity. These data open discussion for future studies on the additional benefits arising from collagen peptide consumption for the prevention of aging complications or hyperglycemic conditions as observed in chronic diseases such as diabetes mellitus type II (DM 2). The confirmation of these results can open new market areas for the use of collagen with pharmacological applications or to produce new supplements. Furthermore, provides a solution for waste collagen from meat industries and adds value to the product.

Impact of Gluten-Free Sorghum Bread Genotypes on Glycemic and Antioxidant Responses in Healthy Adults.

Sorghum is used to provide good quality gluten-free products due to phytochemicals and low glycemic index (GI). This study aimed to determine the chemical composition, the antioxidant activity and capacity, and the glycemic and insulinemic responses of gluten-free (GF) sorghum bread. GF bread samples were produced with three different sorghum genotypes. The samples were analyzed for chemical composition, resistant starch and dietary fiber content; antioxidant activity by ORAC; antioxidant capacity by FRAP; GI; and insulinemic responses. This double-blind, crossover, randomized clinical trial was conducted with 10 healthy men aged 28.0 ± 4.9 years (77.6 ± 11.7 kg and 24.2 ± 2.3 kg/m2). All sorghum bread showed significantly more fiber than rice bread (control). Brown sorghum bread was classified as low GI, bronze and white as medium GI, and control as high GI. Brown sorghum bread presented a low carbohydrate content, a significant amount of fiber, and a significantly lower 3 h AUC glucose response than those of the control, aside from the highest antioxidant activity value (p ≤ 0.001). Therefore, brown sorghum was superior to other genotypes analyzed in this study, and its production should be encouraged to provide gluten-free products with a better nutritional profile. More research is required to explore the effects of different sorghum genotypes in food products on human health.

Chemical Composition and Glycemic Index of Gluten-Free Bread Commercialized in Brazil.

Nowadays, the world is experiencing an increased demand for gluten-free products associated with the high prevalence of gluten-related disorders (GRD). As this market thrives, bread stands out as the most demanded and consumed product, highlighting the need to evaluate its nutritional quality. In this sense, this cross-sectional study aimed to assess the ingredients, chemical composition, and glycemic index of gluten-free bread (GFB) commercialized nationwide in Brazil. The labels were analyzed according to their ingredients and composition. In addition, centesimal composition analysis (moisture, carbohydrates, protein, ash, lipid, and fiber) was performed using the official methods, as well as the in vivo glycemic index. Significant differences between manufacturing lots of each brand and between different gluten-free bread samples were found. There is a mismatch from what is stipulated by the Brazilian legislation between analytical data and the data described on sample labels. Samples showed predominantly refined starch and high glycemic index profile. Most samples (75%, n = 6) of the non-whole gluten-free bread (n = 8) presented high glycemic index (GI). From four whole food/multigrain gluten-free bread samples, three of them (75%) presented medium GI. However, two samples presented GI near the value to be considered high. The results suggest a lack of production control, impairing the gluten-free nutritional label as a reliable information source and tool for dietary control. Therefore, it is necessary to standardize the process of gluten-free bread production and labeling, as well as to improve the nutritional characteristics of these products, aiming the give accurate information to consumers and provide a healthier product beyond the sensory characteristics.

Cataracts and strabismus associated with hand rearing using artificial milk formulas in Bengal tiger (Panthera tigris spp tigris) cubs.

The aim of this investigation is to describe the potential contributing nutritional factors involved in the development of ophthalmic and dermatologic changes in four Bengal tiger (Panthera tigris spp tigris) cubs fed an artificial milk formula. The affected animals were compared with two other tiger cubs that had been nursed by their dam naturally. After the first clinical signs appeared, the tiger cubs underwent ophthalmic evaluation. Severe symmetric generalized alopecia over the trunk, sparing the head and distal portion of the front and rear limbs, bilateral cataracts and strabismus were noticed. Milk and blood from the mother, as well as blood from the healthy and affected cubs were collected in order to evaluate complete blood counts, serum chemistry values, and amino acid levels. The amino acid concentrations in the artificial formula were also evaluated for comparison to the milk from the dam. The concentration of taurine, arginine, phenylalanine, tryptophan and histidine were very low in the artificial formulas as compared to the dam´s milk. The tiger cubs that received the artificial formula had lower levels of the amino acids listed previously as compared to those that nursed from the dam naturally. Taurine, as well as arginine, phenylalanine, tryptophan and histidine deficiency appeared to be possible causes of the development of skin problems, cataracts and strabismus in the tiger cubs fed with these particular artificial milk replacers. In the future, special attention should be given in order to make sure that adequate levels of these amino acids are present in artificial milk for tiger cubs.

Development of low-calorie guava preserves with prebiotics and evaluation of their effects on carcinogenesis biomarkers in rats.

Faced with the search for healthy products that provide additional benefits to consumers' health, the main objectives of this work were to develop a low-calorie preserve containing prebiotics (lactulose and polydextrose) and to evaluate the effects of these prebiotics on oxidative stress and colon carcinogenesis in male rats treated with 1,2-dimethylhydrazine (DMH). A total of 62.5% w/w of the sucrose in conventional preserves was replaced by polydextrose, and lactulose was added at 0%, 16%, 19.5% or 23% w/w concentrations. The acceptance of these four low-calorie guava preserve samples and the conventional sample was equal (P>0.05), with a score of 6.49. The level of degradation of lactulose was low (18.45 g100 g(-1)lactulose), ensuring that even at a lower concentration of this prebiotic (16% w/w), the concentration remained above the minimum level considered functional. We found that consumption of the low-calorie preserves with prebiotics does not have an effect on the development of mucin-negative ACF and classical ACF in the initiation phase of the mutagenic process. However, the consumption of 1.5 g of the preserve/rat/day potentiated lipid peroxidation and proteic oxidation in the liver.