Editorial: Sustainable food systems in Ibero-America

Sustainability and the search for products with improved functionalities that address the demands of the consumer for a healthier diet are the main challenges facing the development of a new trustworthy and healthy food production system. These topics, also addressed by the participants in the 3rd BioIberoAmerica 2022 conference (Braga, Portugal), have allowed for the publication of four original articles in this SI.info:eu-repo/semantics/publishedVersio

Modelling the Effects of Ageing Time of Starch on the Enzymatic Activity of Three Amylolytic Enzymes

The effect of increasing ageing time (t) of starch on the activity of three amylolytic enzymes (Termamyl, San Super, and BAN) was investigated. Although all the enzymatic reactions follow michaelian kinetics, vmax decreased significantly (P < 0.05) and KM increased (although not always significantly) with the increase in t. The conformational changes produced in the starch chains as a consequence of the ageing seemed to affect negatively the diffusivity of the starch to the active site of the enzymes and the release of the reaction products to the medium. A similar effect was observed when the enzymatic reactions were carried out with unaged starches supplemented with different concentrations of gelatine [G]. The inhibition in the amylolytic activities was best mathematically described by using three modified forms of the Michaelis-Menten model, which included a term to consider, respectively, the linear, exponential, and hyperbolic inhibitory effects of t and [G]

Enhancement and inhibition effects on the corneal permeability of timolol maleate: polymers, cyclodextrins and chelating agents

This study investigates how both bioadhesive polymers (chitosan, hyaluronic acid and alginate) and permeability enhancers (ethylene glycol- bis(2-aminoethylether)- N, N, N', N'- tetraacetic acid (EGTA) and hydroxypropyl-ß-cyclodextrin) influence the permeability of the anti-glaucoma drug timolol maleate through ex vivo bovine corneas. Our results showed that only the permeability enhancers alone were able to increase drug permeability, whereas the polymers significantly reduced drug permeation, and however, they increased the pre-corneal residence of timolol. Ternary systems (polymer-enhancer-drug) showed a reduced drug permeability compared to the polymers alone. Fluorescence microscopy analysis of the epithelium surface confirmed there was no evidence of epithelial disruption caused by these formulations, suggesting that polymer-enhancer interactions reduce drug solubilization and counteract the disruptive effect of the permeability enhancers on the surface of the cornea. Further mucoadhesive tests, revealed a stable interaction of chitosan and hyaluronic acid with the epithelium, while alginate showed poor mucoadhesive properties. The differences in mucoadhesion correlated with the permeability of timolol maleate observed, i.e. formulations containing mucoadhesive polymers showed lower drug permeabilities. The results of the present study indicate polymers acting as an additional barrier towards drug permeability which is even more evident in the presence of permeability enhancers like EGTA and hydroxypropyl-ß-cyclodextrin. Then, this study highlights the need to adequately select additives intended for ocular applications since interactions between them can have opposite results to what expected in terms of drug permeability

Characterisation of β-lactoglobulin nanoparticles and their binding to caffeine

The production of β-Lg nanoparticles by a simple heat-induced denaturation method without the need to add chemicals was performed at different conditions of pH, and temperature of denaturation. Optimum conditions were set as 0.2% β-Lg, pH 6 and simply heating at 75 °C for 45 min. At these conditions, a monodisperse solution with colloidal stability was obtained and the yield of aggregation was over 90%. Shape and size of nanoparticles were determined by Dynamic Light Scattering and by electron microscopy. A monodisperse particle size distribution of spherical shape particles (200 nm-300nmin diameter) was obtained. The stability of the aggregates towards various types of dissociating buffers was studied. Sodium dodecyl sulphate (SDS) and urea had a strong effect on the size of the nanoparticles, while 2-Mercaptoethanol and Dithiothreitol (DTT) had no significant effect. Therefore hydrogen bonding and hydrophobic interactions were the predominant interactions responsible for the microstructure. Maximum yield of caffeine encapsulation of 13.54% was obtained at caffeine to β-Lg molar ratio of 50:1. Rapid nanoparticle degradation and increase in polydispersity during the incubation of β-Lg nanoparticles at simulating stomach conditions was observed due to enzymatic attack. Nevertheless, little release of entrapped caffeine was noted. Total release was achieved at intestinal conditions. Finally, the adsorption of caffeine to both native and denatured β-Lg followed a Langmuir adsorption isotherm model and caffeine had three times more affinity for partially denatured β-Lg in nanoparticles than for native protein

Interactions affecting gibberellic acid production in solid-state culture: A factorial study

7 páginas, 6 figuras, 2 tablasThe production of GA3 in solid-state culture was studied using systems composed of maize cob particles soaked in an amylaceous efluent, as a function of three variables-particle diameter, volume of liquid phase, and substrate concentration-with a determinant influence on the response. The empirical model obtained provides an explanation of the behavior of the system in terms of a series of interactions with underlying problems of water activity and mass transfer, that can, however, be manipulated in a simple and reproducible manner. This model also allows the suitable orientation of production improvement, the interpretation of the mechanism of substrate inhibition detected, as well as means of correcting it without reducing the initial concentration of the substrate, and leads to an 11 -fold increase in the production obtained in the preliminary assays.The authors thank CICYT and Xunta de Galicia for their financial support (projects ALI 789-90, AMB 93-O 136, and XUGA-40204B-92).Peer reviewe

Amylase production by solid state culture of Aspergillus oryzae on polyurethane foams. Some mechanistic approaches from an empirical model

8 páginas, 6 figuras, 4 tablasUsing systems formed by particles of polyurethane foam of different densities soaked in an amylaceous effluent, the production of amylases by Aspergillus oryzae in solid state culture was studied by a complete factorial plan with four variables -- support density, particle diameter, volume of liquid phase and substrate concentration. The empirical model obtained is consistent and allows a simple control of the response, superior in several respects to that of the corresponding submerged cultures. Moreover, it enables a mechanistic approach to the behaviour of the system, whose principal kinetic characteristics can be interpreted in terms of intra- and interparticular diffusional effects, which have a determining influence on basic state variables, such as water activity and gas transfer.The authors would like to thank CICYT and Xunta de Galicia for their financial support (projects AMB 93-0136 and XUGA-40204B-92).Peer reviewe

Production of natural nano-gel from pineapple polysaccharides complexes for controlled release of bioactive compounds

São Paulo School of Advanced Sciences on Reverse Engineering of Processed Foods[Excerpt] Pineapple (Ananas cosmosus) is the third most important tropical fruit in world production, seventy percent of the pineapple produced in the world is consumed as fresh fruit. In the agro-food sector, several materials are eliminated as waste throughout production and processing chain. These residues (skins, seed and pulp remnants) contain high content of bioactive compounds, but in generally not directly available, and for that reason is necessary to extract and characterize the feasible bioactive compounds (do Espírito Santo et al., 2012). Therefore, the study of the wastes and by-products generated during pineapple production and post-harvest processing is relevant and interesting to valorise them and reduce their environmental impact. The development of vehicles using these residues that deliveries the compounds as well promotes the maintenance of bioactivity, has been widely study, but lacks the search of new structures that could be easily used in food industry. Therefore, the focus of this research work was to developed nanocarriers using pineapple residues to extract pineapple polysaccharides for delivery of bioactive compounds. Frozen pineapple wastes were submitted to a milling and pressing processes, creating a pineapple juice and a solid semi-dried extract. Characterization was made for both parts comprised proteins, sugars, fibers, lipids and polyphenol contents. The soluble fraction was fractionated by centrifuge filter tubes with cut-off of 50 kDa and after by cut-off of 3 kDa, and three fractions were obtained: above 50 kDa, between 50 and 3 kDa and below 3 kDa. The insoluble part was submitted to hot aqueous extraction. The supernatant and the pellet of this extraction were separated and studied separately. Pineapple polysaccharides were identified and quantified by HPLC method and phenol-sulphuric method, respectively. [...]info:eu-repo/semantics/publishedVersio

Evaluation of antioxidant, antimicrobial and prebiotic activities of a xylooligosaccharide rich grape pomace extract

info:eu-repo/semantics/publishedVersio

Assessment of potential prebiotic activity of pineapple by-products (peels and stems) extracts and maintenance of bioavailability through in vitro gastrointestinal tract system

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