Browsing by Author "Voss, Glenise B."
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- Bioactive properties of peptides obtained from Argentinian defatted soy flour protein by Corolase PP hydrolysisPublication . Coscueta, Ezequiel R.; Amorim, Maria M.; Voss, Glenise B.; Nerli, Bibiana B.; Picó, Guillermo A.; Pintado, M. E.Enzymatic hydrolysis of soybean meal protein isolate (SPI) obtained under two temperature conditions with Corolase PP was studied, assessing the impact of hydrolysis on potential antioxidant and antihypertensive activities. The protein was isolated from soybean meal under controlled conditions of time and temperature (70 C, 1 h; 90 C, 30 min). Degree of hydrolysis assessed the progress of hydrolysis at different sampling times. For hydrolysates the antioxidant and angiotensin-converting-enzyme (ACE) inhibitory activities were measured. As observed, the DH was increasing until reaching 20% at 10 h with disappearance of globular proteins and generation of low molecular weight peptides (less than 3 kDa). A significant increase in antioxidant and ACE inhibitory capacities was observed. Five main peptides were identified, which may explain through their sequences the bioactive properties analyzed. Through this study was possible to obtain for the first time with Corolase PP soy hydrolysates with potential antioxidant and ACE inhibitory activities, which can be used to obtain new added value functional ingredients from soy meal.
- Effect of autoclaving process and enzymatic hydrolysis of okara (byproduct from soy beverage) on growth of nile tilapia o. niloticusPublication . Voss, Glenise B.; Rema, Paulo; Pintado, M. Manuela E.; Valente, Luisa M. P.
- Enzymatic hydrolysis of soymilk byproduct (Okara) by proteases extracted from Cynara CardunculusPublication . Voss, Glenise B.; Coscueta, Ezequiel; Valente, Luisa M. P.; Pintado, Maria M.Soybeans are the main oilseed produced and consumed worldwide. Currently, Brazil, Argentina and China are the largest producers of soybeans. This oilseed has great commercial interest, especially, because of the oil extraction, soy proteins and soymilk. Soymilk is used as a base in a wide variety of products, including tofu, soy yogurt and cheese. This soybean product is achieved by aqueous extraction of whole soybeans. During this process, a by-product known as okara rich in fiber, protein and fat, is obtained (3,4 5). Okara is produced in high amounts, since for each 1 kg of processed soybeans about 1.1 kg of okara is produced (1). The okara by-product has a high nutritive value, as previously mentioned. However, during soymilk manufacturing, this by-product is submitted to a severe heat treatment, which causes a large protein denaturation and the resulting okara protein isolate has poor solubility, which restricts its direct use in food. Studies reported that protein can be produced from the okara and that the protein isolates are characterized as having good amino acid profile and showing good digestibility (2). Beyond other functional properties emulsification, foaming and binding properties were comparable to those of commercial soy isolate. Therefore, the main objective of this work was to study the enzymatic hydrolysis of two okara substrates (dry okara, previously autoclaved (OA) and not autoclaved (ONA)), achieved by an enzymatic aqueous extract of Cynara cardunculus. The okara used in this study was provided by a local soybean producer in Portugal (NUTRE). After collection the okara samples were divided in two batches and one was submitted to heat treatment (1 atm, 121 ° C for 20 minutes) and the other was not heat treated. Finally, both were dried at 65 °C until constant weight and then milled with a 1 mm mesh. Two hydrolysis factors (reaction time and ratio of enzyme/substrate, E/S) were selected. The following parameters were analyzed: degree of hydrolysis (DH), antioxidant activity (ABTS) and the profile of hydrolysis (RH) determined by FPLC (fast protein liquid chromatography gel filtration). The hydrolysis was performed using commercial crude extract of Cynara cardunculus at 55 ° C and pH 5.2 for 2.5 to 5 h. No significant differences on the DH were observed between OA and ONA or between hydrolysis factors tested using the method of o-phthaldialdehyde (OPA). However, chromatographic analysis by FPLC showed strong protein hydrolysis after 2.5 h with formation of peptides fractions, with no significant difference between OA and ONA, but showing increasing concentration according increasing E/S rations. The antioxidant activity results showed a higher antioxidant potential for OA than for ONA and directly proportional to the time of hydrolysis, which proves that previous protein denaturation may promote the release of more antioxidant peptides. Therefore, it can be concluded that the hydrolysis of okara protein with C. cardunculus generated peptide extracts with relevant antioxidant activity, which is affected by the denaturation state of the proteins.
- Functional characterisation and sensory evaluation of a novel symbiotic okara beveragePublication . Voss, Glenise B.; Monteiro, Maria João P.; Jauregi, Paula; Valente, Luísa M.P.; Pintado, Manuela E.This study aimed to produce four different beverages from okara (soybean by-product) previously hydrolyzed by Cynara cardunculus enzymes and fermented by probiotic bacteria or unfermented beverage. The probiotic viable cells, the isoflavones profile and organic acids were evaluated in the okara beverage. In addition, total phenolic content, antioxidant and ACE inhibitory activities were evaluated at storage time and during in vitro gastrointestinal digestion of all beverages. The probiotic was viable throughout storage in all fermented beverages. The significant bioconversion of the isoflavone glycosides into their corresponding bioactive aglycones was observed in fermented beverage. Furthermore, the beverages showed a good ACE inhibitory activity. After gastrointestinal tract, all beverages showed an increase in the antioxidant and ACE inhibitory activities. In conclusion, this study shows that the application of okara for a multifunctional beverage could be a promising strategy in the disease prevention and contribution to a zero waste approach in food industry.
- Impact of fructose and fructooligosaccharides supplementation upon the fermentation of hydrolyzed okara and its impact upon bioactive componentsPublication . Voss, Glenise B.; Valente, Luísa M. P.; Pintado, Manuela E.Okara provide compounds of biological interest such as isoflavones and an increase of aglycone content can be obtained through fermentation with foodgrade bacteria. This study aimed to evaluate the effect of fructose and fructooligosaccharides (FOS) on the growth of probiotic bacteria in hydrolyzed (by Cynara cardunculus enzymes) okara beverage, as well as on the antioxidant activity, isoflavones and total phenolic content of fermented okara beverage. Okara beverages were fermented using Bifidobacterium animalis ssp. lactis Bb-12 and Lactobacillus rhamnosus R11 alone or as mixture of both, at 37 ºC, until it reached a pH value of 4.5. The growth of lactobacilli and bifidobacteria was evaluated throughout the fermentation, with increases of viable cells ranging from 1.5 to 3 log CFU/mL. Moreover, okara samples supplemented with a carbon source presented a higher growth rate than their non-supplemented counterpart, as expected. In addition, significant differences in aglycone content and antioxidant activity were observed for the okara samples fermented by different species, with the overall content of isoflavone aglycones increasing, the genistein presented the highest increase (ca. 16-fold) in the fermented okara by B. animalis ssp. lactis Bb-12. However, the antioxidant capacity was maintained in the okara without carbon source after fermentation by L. rhamnosus R11, while all fermented okara presented a decrease after fermentation process. Considering the hereby reported results, probiotic hydrolyzed fermented okara can be considered a good carrier for probiotic bacteria and a good source of aglycone isoflavones, combining all the other benefits resulting from probiotic metabolism and the hydrolyzed okara itself.
- Impact of thermal treatment and hydrolysis by Alcalase and Cynara cardunculus enzymes on the functional and nutritional value of OkaraPublication . Voss, Glenise B.; Osorio, Hugo; Valente, Luís M. P.; Pintado, Manuela E.Enzymatic hydrolysis of dried okara (autoclaved and non-autoclaved) with Alcalase (AL) and Cynara cardunculus extract (CY) was studied, assessing the impact of heat treatment and hydrolysis on potential antioxidant and antihypertensive activities of final hydrolysates. This study showed that the thermal treatment (sterilization at 121 °C, 1 atm and 15 min) facilitated the enzymatic access to substrate and increased the degree of hydrolysis (DH), especially for AL (37.9%) when compared to CY (3.6%). The antioxidant activity of dried Okara (either autoclaved or not) when hydrolysed with AL was higher (4.2 mg Trolox/mL) than that observed for CY. Additionally, the potential ACE-inhibitory activity was high for samples hydrolysed with both enzymes, however the highest ACE inhibition was also found for AL (IC50 = 9.97 µg/mL). This study allowed the identification of new peptide sequences in dried okara hydrolysed with both enzymes, and some sequences that can explain their bioactivities. The results indicate that dried okara hydrolysates can either be used as functional ingredient or as food supplement for blood pressure lowering or antioxidant applications in the future.
- Processed by‐products from soy beverage (Okara) as sustainable ingredients for nile tilapia (o. niloticus) juveniles: effects on nutrient utilization and muscle qualityPublication . Voss, Glenise B.; Sousa, Vera; Rema, Paulo; Pintado, Manuela E.; Valente, Luísa M. P.The apparent digestibility coefficients (ADCs) of differently processed okara meals were assessed in Nile tilapia diets: dried okara not autoclaved (FOK), dried okara autoclaved (AOK), okara hydrolyzed with Alcalase (ALOK) or Cynara cardunculus proteases (CYOK), and hydrolyzed okara fermented with lactic bacteria: Lactobacillus rhamnosus R11 (CYR11OK) or Bifidobacterium animalis ssp. lactis Bb12 (CYB12OK). Okara processing significantly affected nutrient digestibility: dry matter ADC was highest in CYR11OK (80%) and lowest in FOK (40%). The lowest protein digestibility was observed in CYR11OK (72%), and the highest in AOK (97%) and CYOK (91%), evidencing the effectiveness of the autoclave and the use of C. Cardunculus proteases to increase okara protein bioavailability. The inclusion of up to 20% of AOK or CYOK did not affect fish growth, nutrient utilization, or whole body composition of Nile tilapia. The flesh quality (color, pH, water activity, cohesiveness, elasticity and resilience) was not affected by the dietary incorporation of AOK or CYOK. Fish fed with AOK diets stand out for their high density of muscle fibers, particularly in AOK20, which can explain their high muscle firmness and may result in further hypertrophic growth. Altogether, results suggest that hydrolyzed or autoclaved okara are valuable ingredients for Nile tilapia diets.
- Properties of fermented beverages from food wastes/by-productsPublication . Alexandre, Elisabete M. C.; Aguiar, Nuno F. B.; Voss, Glenise B.; Pintado, Manuela E.Current global research aims to explore the key role of diet and understand the benefits of a balanced diet. Furthermore, many authors have pointed to the added value of by-products as a solution to make food production chains more environmentally and economically sustainable. By-products emerge as an alternative matrix to fermentation, and the fermentation process has the potential to transform by-products into value-added products through an efficient and sustainable process. During fermentation, besides the consumption of molecules to grow, microbial enzymes act on several phytochemical compounds, creating new derivative compounds that affect the flavour and function of fermented beverages. As an alternative for consumers with lactose intolerance or vegan or vegetarian diets, new beverages produced from plant by-products and probiotic bacteria hold great promise for the global functional food market. Several challenges were overcome in developing these new products from by-products, namely the availability and quality/standardization of raw materials, adapted microbial starter cultures for fermentation, and optimization of production processes to maximize consumer acceptance and product yield. This review provides an overview of recent research/developments in the field of new fermented beverages from by-products, and aspects related to their functionality, beyond the challenges of these new beverages.