Browsing by Author "Pereira, J. O."
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- Antihypertensive effect of spent brewer yeast peptidePublication . Amorim, M.; Marques, C.; Pereira, J. O.; Guardão, L.; Martins, M. J.; Osório, H.; Moura, D.; Calhau, C.; Pinheiro, H.; Pintado, M.Numerous studies have investigated dietary approaches to prevent chronic lifestyle-related diseases, including hypertension. Spent brewer's yeast is the second largest byproduct originated by the brewing industry and it deserves considerable attention because of its high nutritional value, ca. 40% of its dry mass is rich in protein which can be hydrolyzed into biologically active peptides. To upgrade this byproduct, the aim of this study was initially in vitro assessment of biological properties, e.g. ACE inhibition and antioxidant activity, and then, the in vivo effect in short-term oral antihypertensive effect of hydrolyzed yeast fractions on a well characterized model to study hypertension - Spontaneously Hypertensive Rats (SHR). Here, it was demonstrated that the fraction with molecular weight below 3 kDa containing tri and tetra- peptides with hydrophobic amino acid residues - SPQW, PWW and RYW, causes the most noticeable decrease in systolic, diastolic and mean blood pressure of SHR and shows highest antioxidant effect. These properties highlight the potential use of yeast extract as nutraceutical or functional food ingredient for the management and treatment of hypertension with antioxidant effect.
- Evaluation of antimicrobial edible coatings from a whey protein isolate base to improve the shelf life of cheesePublication . Ramos, Ó. L.; Pereira, J. O.; Silva, S. I.; Fernandes, J. C.; Franco, M. I.; Lopes-da-Silva, J. A.; Pintado, M. E.; Malcata, F. X.The objective of this work was to evaluate the effectiveness of antimicrobial edible coatings to wrap cheeses, throughout 60 d of storage, as an alternative to commercial nonedible coatings. Coatings were prepared using whey protein isolate, glycerol, guar gum, sunflower oil, and Tween 20 as a base matrix, together with several combinations of antimicrobial compounds—natamycin and lactic acid, natamycin and chitooligosaccharides (COS), and natamycin, lactic acid, and COS. Application of coating on cheese decreased water loss (~10%, wt/wt), hardness, and color change; however, salt and fat contents were not significantly affected. Moreover, the antimicrobial edible coatings did not permit growth of pathogenic or contaminant microorganisms, while allowing regular growth of lactic acid bacteria throughout storage. Commercial nonedible coatings inhibited only yeasts and molds. The antimicrobial edible coating containing natamycin and lactic acid was the best in sensory terms. Because these antimicrobial coatings are manufactured from food-grade materials, they can be consumed as an integral part of cheese, which represents a competitive advantage over nonedible coatings.
- Extractos peptídicos obtenidos por hidrólisis de proteínas lácteas y levaduras com actividades funcionalesPublication . Amorim, M. M.; Pereira, J. O.; Pereira, C. D.; Carvalho, J. E.; Pintado, M. E.
- Iron complexation using spent yeast peptides for human supplementationPublication . Oliveira, A. S.; Ferreira, C.; Pereira, J. O.; Pintado, M.; Carvalho, A. P.
- Iron-peptide complexes from spent yeast: evaluation of iron absorption using caco-2 modelPublication . Oliveira, A. S.; Ferreira, C.; Pereira, J. O.; Silva, S.; Costa, E. M.; Pintado, M.; Carvalho, A. P.
- Peptide-rich extracts from spent yeast waste streams as a source of bioactive compounds for nutraceutical marketPublication . Oliveira, A. S.; Ferreira, C.; Pereira, J. O.; Pintado, M.; Carvalho, A. P.The growing brewing industry1 generates increasing amounts of spent yeast from its fermentation processes. To apply a circular economy concept, spent yeast can be used to produce ingredients from yeast cell wall such as β-glucans and mannans2 whereas the remaining fractions are further processed to recover proteins and peptides. The high protein content of spent yeast (about 45-60%), including essential amino acids with high biological value, low cost and safety, are primarily responsible for its use in agri-food sector. Meanwhile, cosmeceutical and health sectors have also been working on yeast bioactive peptides because of their antihypertensive, antioxidant and antimicrobial properties, among others. In fact, peptides have been described as bio-functional ingredients in the nutraceutical and functional food market, and due to fewer side-effects when compared with synthetic drugs, they are becoming an option in health sector as well. To evaluate the potential of the abovementioned peptide fractions as a source of bioactive ingredients for nutraceutical market, they were chemically characterized in terms of protein amount, molecular weight (MW) distribution (Figure 1) and amino acid content, being their biocompatibility with specific colon cell lines evaluated as well. Furthermore, their potential to provide antihypertension, antioxidant, antimicrobial and anti-cholesterolemic activities were assessed. Results revealed that different yeast peptides fractions showed IC50 values between 0.99 and 1.72 mg/mL in ACE inhibition assay, highlighting the peptide fraction under 1 kDa with the greatest antihypertensive activity. On the other hand, the same fractions showed a 62 to 71% of inhibition of the enzyme HMG-CoA reductase using an HMG-CoA Reductase Activity Assay Kit for testing. Together, both results pave the way for their application in nutraceutical products.
- Peptide-rich extracts from spent yeast waste streams as a source of bioactive compounds for nutraceutical marketPublication . Oliveira, A. S.; Ferreira, C.; Pereira, J. O.; Pintado, M.; Carvalho, A. P.
- Use of whey peptide fraction in coated cashew nut as functional ingredient and salt replacerPublication . Amorim, M.; Pereira, J. O.; Silva, L. B.; Ormenese, R. C. S. C.; Pacheco, M. T. B.; Pintado, M.Consumers are increasingly concerned about healthy eating habits. The incorporation and stability of 2% antihypertensive whey peptide extract in a new coating of cashew nuts with reduced salt (less 15 and 30%) was studied. The evaluation of nutritional value, in vitro antihypertensive activity and consumer acceptance of final products was assessed. Incorporation of peptide fraction assured the production of a snack with an ACE-inhibitory activity (532.2 μgmL−1 IC50 value). The amount of lipids present in coated cashew nuts was composed mainly by essential fatty acids, mostly monounsaturated. Glutamic acid, leucine, arginine and aspartic acid were the most abundant essential aminoacids. 70% of the consumers considered both samples (15 and 30%) as “ideal taste”. The results suggest that the new coating allowed the development of a new snack with reduced salt content, opening new opportunities as carrier of other ingredients to develop more diversified and efficient functional foods.