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- Release of health-related compounds during in vitro gastro-intestinal digestion of okara and okara fermented with Lactobacillus plantarumPublication . Quintana, Gabriel; Spínola, Vítor; Martins, Gonçalo N.; Gerbino, Esteban; Gómez-Zavaglia, Andrea; Castilho, Paula C.Okara is a highly perishable by-product remaining after filtration of the smashed soybeans seeds in the production of soymilk. Due to its nutritional value, different approaches have been developed to use it as functional ingredient. Fermentation of okara appears as an interesting strategy to preclude spoilage, providing a more stable matrix to be incorporated in the formulation of functional foods. Okara has antioxidant compounds but the effect of fermentation, and their bioaccessibility still need to be investigated. To achieve this aim, the phenolic compounds (as determined by TPC and TFC assays) and the antioxidant properties (as determined by ABTS ·+, DPPH · , O2·- assays) of okara and okara fermented with Lactobacillus plantarum CIDCA 83114 were assessed both before and after exposure to simulated gastro-intestinal conditions. Before digestion, okara showed higher values of TPC and TFC than the fermented counterpart. Although a decrease of TPC and TFC was observed after exposing okara to gastric conditions, no significant differences between okara and fermented okara were detected. No further decrease of TPC were observed in intestinal conditions. Okara showed higher antioxidant activity than fermented okara. There was a considerable decrease in the antioxidant activity for both samples when exposed to gastric and intestinal conditions. A good correlation between TFC and antioxidant activities was detected, suggesting that flavonoids play an important role as antioxidants. As a whole, this work provides a solid support for the stability of phytochemicals along the digestive process of both okara and fermented okara.
- Recent advances in β-galactosidase and fructosyltransferase immobilization technologyPublication . Ureta, Maria Micaela; Martins, Gonçalo Nuno; Figueira, Onofre; Pires, Pedro Filipe; Castilho, Paula Cristina; Gomez-Zavaglia, AndreaThe highly demanding conditions of industrial processes may lower the stability and affect the activity of enzymes used as biocatalysts. Enzyme immobilization emerged as an approach to pro mote stabilization and easy removal of enzymes for their reusability. The aim of this review is to go through the principal immobilization strategies addressed to achieve optimal industrial proc esses with special care on those reported for two types of enzymes: b-galactosidases and fructo syltransferases. The main methods used to immobilize these two enzymes are adsorption, entrapment, covalent coupling and cross-linking or aggregation (no support is used), all of them having pros and cons. Regarding the support, it should be cost-effective, assure the reusability and an easy recovery of the enzyme, increasing its stability and durability. The discussion provided showed that the type of enzyme, its origin, its purity, together with the type of immobilization method and the support will affect the performance during the enzymatic synthesis. Enzymes’ immobilization involves interdisciplinary knowledge including enzymology, nanotechnology, molecular dynamics, cellular physiology and process design. The increasing availability of facilities has opened a variety of possibilities to define strategies to optimize the activity and re-usability of b-galactosidases and fructosyltransferases, but there is still great place for innovative developments.
- Chickpeas’ and Lentils’ Soaking and Cooking Wastewaters Repurposed for Growing Lactic Acid BacteriaPublication . Martins, Gonçalo Nuno; Carboni, Angela Daniela; Hugo, Ayelén Amelia; Castilho, Paula Cristina; Gómez-Zavaglia, AndreaLegumes processing involves large amounts of water to remove anti-nutrients, reduce uncomfortable effects, and improve organoleptic characteristics. This procedure generates waste and high levels of environmental pollution. This work aims to evaluate the galacto-oligosaccharide (GOS) and general carbohydrate composition of legume wastewaters and assess their potential for growing lactic acid bacteria. Legume wastewater extracts were produced by soaking and/or cooking the dry seeds of chickpeas and lentils in distilled water and analysed using high-performance liquid chromatography with refractive index detection. GOS were present in all extracts, which was also confirmed by Fourier transform infrared spectroscopy (FTIR). C-BW extract, produced by cooking chickpeas without soaking, provided the highest extraction yield of 3% (g/100 g dry seeds). Lentil extracts were the richest source of GOS with degree of polymerization ≥ 5 (0.4%). Lactiplantibacillus plantarum CIDCA 83114 was able to grow in de Man, Rogosa, and Sharpe (MRS) broth prepared by replacing the glucose naturally present in the medium with chickpeas’ and lentils’ extracts. Bacteria were able to consume the mono and disaccharides present in the media with extracts, as demonstrated by HPLC and FTIR. These results provide support for the revalorisation of chickpeas’ and lentils’ wastewater, being also a sustainable way to purify GOS by removing mono and disaccharides from the mixtures.
- Lactic Acid Bacteria in the Production of Traditional Fermented Foods and Beverages of Latin AmericaPublication . Carboni, Angela; Martins, Gonçalo N.; Gomez-Zavaglia, Andrea; Castilho, Paula C.Traditional fermented foods are inherent to the human diet and represent an important part of the culture of each country. The fermentation process has been traditionally used as a method of food preservation. It allows modifying the technological, sensory, and nutritional attributes of raw ingredients. Latin America has a vast history with these products, but they are not always known worldwide. One of the most used microorganisms in fermented foods is lactic acid bacteria. This review aims to provide insight into the main attributes, benefits, and nutritional characteristics of traditional fermented foods and beverages from Latin America made with lactic acid bacteria. A bibliography analysis of the general aspects of fermented products from this region was carried out, focusing on the foods and beverages (with and without alcohol), their representation in native communities, nutritional value and effect on health, as well as the risk of their consumption. It is concluded that traditional fermented products of Latin America are usually prepared with specific ingredients of the region (such as cassava and corn), and that the lactic acid bacteria present in these foods are not always identifiable due to the inherent variability of artisanal production. The bacteria observed include Lacticaseibacillus, Lactiplantibacillus, Lactobacillus, Limosilactobacillus, Leuconostoc, Streptococcus, and Weisella, among others.
- Release of adsorbed ferulic acid in simulated gastrointestinal conditionsPublication . Martins, Gonçalo N.; Spínola, Vítor; Castilho, Paula C.Ferulic acid (FA) is a natural antioxidant with limited absorption when conjugated with biomolecules but whose free form is readily absorbed in the stomach and, to a lesser extent, in the ileum. The latter sufers from infammation and oxidative stress, so a novel strategy for the delivery of FA in this compartment of the gastrointestinal tract was developed. Using the neutral un-functionalized resin Lewatit® VP OC 1064 MD PH, under optimized conditions, a loading of 144 mg FA/g of dry resin was obtained. By means of an in vitro simulated digestion, an average release of 32 mg FA/g of dry loaded resin (recovery of 22%) was observed in intestinal conditions. The incorporation/release of FA onto/from the resin was confrmed by ATR-FTIR spectroscopy and by HPLC-DAD. This work showed that the free form of FA can efectively be delivered in the small intestine, after immobilization in solid matrices.
- Release of resin-bound ferulic acid during an in vitro digestion simulation and antioxidant activity evaluationPublication . Martins, Gonçalo Nuno Gouveia; Castilho, Paula Cristina Machado FerreiraFerulic acid is one of the most abundant hydroxycinnamic acids in Nature, with impact in human health whereas an antioxidant protection might be implicated. It has uses in cosmetics and food industry. It can be found in various foodstuffs, but mostly present etherified to lignins or esterified to carbohydrates or sterols, which hinders its absorption by the organism during the digestive process. The free form of ferulic acid is rapidly absorbed from the stomach, jejunum and, in a much lesser extent, from the ileum, in a pH dependent process. Since the ileum is particularly susceptible to inflammation and oxidative stress it is important to ensure that ferulic acid is able to exert its action in that part of the body without being absorbed from the stomach. A possible way to increase ferulic acid’s bioavailability to the ileum is by immobilization in solid matrixes resistant to low pH but not neutral or basic conditions. In the present work, the adsorption of ferulic acid onto the polystyrene adsorbent resin Lewatit® VP OC 1064 MD PH was studied, and a loading of 144 mg/g dry resin was obtained. To evaluate the release of the resin-bound ferulic acid, an in vitro “digestion” was performed with simulated gastrointestinal juices. The intestinal step was the most relevant with a release of 13-35 % of FA from the loaded resin. After each step of the in vitro digestion simulation, the antioxidant activity of ferulic acid was evaluated using the DPPH radical scavenging assay and all samples successfully maintained antioxidant activity throughout the digestive process. The confirmation of the incorporation of ferulic acid onto the resin was made by ATRFTIR spectroscopy and morphological analysis was made by SEM. The quantification of ferulic acid in solution was performed by HPLC-DAD throughout the entire work. This work showed that the free form of ferulic acid can be delivered in the intestine, after immobilization of solid matrixes, maintaining its antioxidant activity. This study is probably the first on this subject with these materials and methods.
- Technological aspects of the production of fructo and Galacto-Oligosaccharides. Enzymatic Synthesis and HydrolysisPublication . Martins, Gonçalo N.; Ureta, Maria Micaela; Tymczyszyn, E. Elizabeth; Castilho, Paula C.; Gomez-Zavaglia, AndreaFructo- and galacto-oligosaccharides (FOS and GOS) are non-digestible oligosaccharides with prebiotic properties that can be incorporated into a wide number of products. This review details the general outlines for the production of FOS and GOS, both by enzymatic synthesis using disaccharides or other substrates, and by hydrolysis of polysaccharides. Special emphasis is laid on technological aspects, raw materials, properties, and applications.