Browsing by Author "Amorim, M."
Now showing 1 - 7 of 7
Results Per Page
Sort Options
- 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.
- Comparison of spray drying, freeze drying and convective hot air drying for the production of a probiotic orange powderPublication . Barbosa, J.; Borges, S.; Amorim, M.; Pereira, M. J.; Oliveira, A.; Pintado, M. E.; Teixeira, P.Survival of two LAB in orange powders obtained by spray-(SD), freeze-(FD) and convective hot air drying (CD) was investigated during drying and subsequent storage. Colour and vitamin C content of the powders were also evaluated. There was no decrease in the cell number during SD and FD, but a reduction of ~2 log cycles was obtained in CD. During storage at 4 °C no significant differences (p > 0.05) in the survival of Lactobacillus plantarum 299v were observed for the orange powder obtained by the different techniques. However, during storage at room temperature, its survival was better in orange powders prepared by CD. For Pediococcus acidilactici HA-6111-2, reductions during storage were minimal for most of the conditions investigated. Considering the initial cell number obtained after each drying process, SD and FD allowed survival of an increased number of cells after storage period. The best colour retention was obtained by FD, with no maltodextrin, and the higher total vitamin C retention was achieved in SD and FD powders. By the high production costs and long drying times of FD, it can be concluded that SD could be a good method to produce a new functional non-dairy product, such as a probiotic orange juice powder
- Encapsulation of rosmarinic acid into chitosan nanoparticlesPublication . Silva, S. B.; Amorim, M.; Oliveira, A.; Ramos, O.; Pintado, M.; Ferreira, D.; Sarmento, B.Introduction: The use of nanotechnology in medical sciences is a innovation that promises a new age of health. Among the different approaches explored so far, chitosan exhibits favourable and unique biological properties, such as biocompatibility, biodegradability, non-antigenic, non-toxicity and mucoadhesiveness . On the other hand, natural extracts have been incorporated in chitosan films, or macro/microparticles, becoming more effective as antimicrobial or improving the antioxidant protection. The combination of antioxidants and nanoparticles is seen as the key to success in the topical administration of therapeutic antioxidants . Phenolic compound like rosmarinic acid are potent natural antioxidant with a multitude of biological activities like anti-inflammatory, antimutagen, antibacterial and antiviral as well as high potential radical scavenging activity.
- Nanoencapsulation of bovine lactoferrin for oral hygiene applicationsPublication . Costa, C. I.; Morsy, T. A.; Matos, C. M.; Amorim, M.; Pintado, M. E.; Gomes, A. P.; Teixeira, J. A.; Balcão, V. M.
- Optimisation, by response surface methodology, of degree of hydrolysis and antioxidant and ACE-inhibitory activities of whey protein hydrolysates obtained with cardoon extractPublication . Tavares, T. G.; Contreras, M. M.; Amorim, M.; Martín-Álvarez, P. J.; Pintado, M. E.; Recio, I.; Malcata, F. X.The hydrolysis of bovine whey protein concentrate (WPC), alpha-lactalbumin (alpha-La) and caseinomacropeptide (CMP), by aqueous extracts of Cynara cardunculus, was optimized using response surface methodology. Degree of hydrolysis (DH), angiotensin-converting enzyme (ACE)-inhibitory activity and antioxidant activity were used as objective functions, and hydrolysis time and enzyme/substrate ratio as manipulated parameters. The model was statistically appropriate to describe ACE-inhibitory activity of hydrolysates from WPC and alpha-La, but not from CMP. Maximum DH was 18% and 9%, for WPC and alpha-La, respectively. 50% ACE-inhibition was produced by 105.4 (total fraction) and 25.6 mu g mL(-1) (<3 kDa fraction) for WPC, and 47.6 (total fraction) and 22.5 mu g mL(-1) (<3 kDa fraction) for alpha-La. Major peptides of fractions exhibiting ACE-inhibition were sequenced. The antioxidant activities of WPC and alpha-La were 0.96 +/- 0.08 and 1.12 +/- 0.13 mmol trolox equivalent per mg hydrolysed protein, respectively.
- Study of in vitro digestion of Tenebrio molitor flour for evaluation of its impact on the human gut microbiotaPublication . Carvalho, N. Mota de; Walton, G. E.; Poveda, C. G.; Silva, S. N.; Amorim, M.; Madureira, A. R.; Pintado, M. E.; Gibson, G. R.; Jauregi, P.Human diet has evolved to include not only nutritious foods but also health-promoting ones. Moreover, there is an increasing interest in replacing animal proteins as the main protein source. Insect based foods, e.g. Tenebrio molitor insect flour (TMIF), show potential as alternative protein sources for the human diet. This work aims to provide insights into the effect of TMIF upon the human gut microbiota and their metabolic end products by using an in vitro fecal model. Digested TMIF had a positive impact on gut microbiota, observed as an increase and/or upkeep of health promoting bacterial groups and by the production of SCFA (1.7 and 2.6 times higher acetate and propionate produced respectively than in the negative control at 48 h) and BCFA. A path is opened to acknowledge TMIF as a possible healthy nutritional source for human consumption, although in vivo trials would be necessary to confirm this.
- 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.