Alimentos Ciencia e Ingeniería

Growth Kinetics of Aspergillus niger in Solanum tuberosum

Danae Fernández Rivero, Denise Ivone Apunte Benalcazar, Rodney Hechavarría Díaz — Wed, 28 Dec 2022 00:00:00 -0500

En esta investigación se estudió la cinética de crecimiento del hongo Aspergillus niger en Solanum tuberosum. Se realizó la fermentación microbiana en un medio formulado con residuos orgánicos de Solanum tuberosum con una humedad del 61%. Se tomaron muestras cada dos días para estimar el crecimiento celular por el método del peso seco. Los parámetros cinéticos del microorganismo fueron determinados obteniendo una tasa específica de crecimiento de utilizando un modelo lineal. Se evaluaron los modelos de Gompertz, Logístico, Brody y Bertalanffy, de los cuales Bertalanffy y Brody fueron los que mejor se ajustaron a los datos, con un coeficiente de determinación (R²) de 0,994 en ambos modelos.

Biodegradable Packaging Made from Banana Peels

Wed, 28 Dec 2022 00:00:00 -0500

Given the increase in production, the excessive use of plastic, and the negative impact it has on the environment, sustainable alternatives are being sought to replace this material; that is why there is a great demand for the development of new materials that are friendly to our mother earth. The current work aims to prepare bioplastic sheets made from banana peel as the primary raw material. A mixture of glycerin, corn starch, and vinegar (acetic acid) was added, resulting in brown biodegradable containers and sheets, similar to the results of other research using this biological material, and with more time to show signs of deterioration compared to other bioplastics.

Susceptibility analysis of mutations that confer resistance to inhibitors of the SARS-CoV-2 main protease (Mpro) and RNA-dependent RNA polymerase (RdRp)

Wed, 28 Dec 2022 00:00:00 -0500

Enormous efforts have been made worldwide to generate therapeutic options to prevent the transmissibility of SARS-CoV-2 and reduce its replication in humans. Currently, the emergence of new variants of the virus is of great concern because the evolution of the viral genome and the inherent mutations introduced in the viral proteins could decrease the effectiveness of the first-line therapeutic agents used to prevent and treat COVID-19. The present study evaluated the susceptibility of two important pharmacological drug targets of SARS-CoV-2, the major protease (M^pro) and the RNA-dependent RNA polymerase (RdRp), to suffer point mutations that could produce resistance to inhibitors of these enzymes. The results showed that the residues that contour the inhibitor binding site in RdRp are extremely conserved between the different RNA virus species. This suggests the RdRp enzyme has a low probability to suffer mutation that could confer resistance to therapeutic drugs, such as Remdesivir, an FDA approved compound to treat COVID-19. In contrast, we observed that the M^pro enzyme could undergo up to ten-point mutations in the active site, which is the binding site of several experimental drugs under development, such as Carmofur and N3. Molecular docking analysis showed that the presence of single point mutations in the M^pro active site produces an increase in the binding affinity of carmofur, probably due to the small size and high flexibility of this molecule. However, the Pro168Ser and Ala191Val mutations significantly decrease the affinity of N3 binding to M^pro, suggesting the possible emergence of resistance to this drug. These results could help to anticipate the effect of different mutations on the way M^proinhibitors bind to the enzyme, and design new inhibitors that address the effect of resistance.

Evidence-Based Ruminal Microbiota

Andrés Haro Haro, María José Andrade Rojas, Andrés Suarez — Wed, 28 Dec 2022 00:00:00 -0500

Ruminants break down the fiber of the feed intake in the rumen through a microbial symbiosis, which performs its enzymatic hydrolysis and subsequent fermentation. The objective was demonstrating the activity of rumen microorganisms consisting of bacteria, protozoa, fungi and methanogenic archaea. Bacterial populations are located at three different levels in the rumen: attached to the solid. The concentration of bacteria in the rumen is higher than that of protozoa. Protozoa support a fundamental role in fiber degradation, store large amounts of starch and slow down the production of acids that reduce rumen pH. Fungi have an important function in the digestion of the cell walls of plants, especially those of low quality. Archaea in the rumen are strictly anaerobic microorganisms and produce methane from CO₂ and hydrogen. Conclusion: Rumen microorganisms establish complex relationships among themselves, which allow the degradation of the feed that reaches the rumen and consequently the use of the nutrients it contains.

Production of Bioplastic and their Applications as Food Packaging: PLA AND PHB

Mayra Fernanda Chico, Tatiana Sampedro — Wed, 28 Dec 2022 00:00:00 -0500

The food industry contributes around 40% of the containers and packaging used and discarded until 2020 worldwide. Social, environmental, and political interest in the development of biodegradable containers is growing, as is the demand of consumers for fresh and quality food products. Bioplastics are classified according to their chemical composition, origin, and synthesis process. Polyhydroxyalkanoates (PHA) are materials of microbial origin, while polylactic acid (PLA) is obtained from lactic acid and the chemical reaction of lactide that produces the biomaterial. This work explores, through a bibliographic review, the principles and production of bioplastics made from polylactic acid (PLA) and polyhydroxybutyrate (PHB) and their application in food packaging. These materials constitute particularly interesting materials due to their potential in a wide range of applications. Physical-chemical properties of the biomaterials requested to make food packaging are permeability to moisture, oxygen permeability, and mechanical properties. The requirements established for the different types of packaging used in the food industry can be achieved by these biomaterials. In the same way, the environmental, economic, and industrial advantages and the challenges encountered for their massive use have been estimated. It was identified that the reduction of manufacturing costs can be achieved through the use of agricultural biomass residues as a source of substrate for fermentation processes. PLA and PHB are particularly interesting materials due to their potential in a wide range of applications in the food industry due to their biodegradation capacity and efficiency.

Valorization of Cocoa by Products: Applications and Perspectives in the Food Industry

Mayra Fernanda Chico — Wed, 28 Dec 2022 00:00:00 -0500

Cocoa (Theobroma cacao L.) is a native species of the Amazon region in South America. Its fruit weight fluctuates between 200 g to more than 1 kg. The cocoa industry mainly uses the seeds contained in de cocoa pod husk as the fraction with the highest commercial value for the production of chocolate. During the pre-processing stages, approximately 80% of the cocoa fruit is discarded as residual biomass. From the by-products generated, a series of chemical components with high-added value has been studied. They can be recovered through the use of sustainable technologies. This document explores the current uses and application prospects in the food industry of cocoa by-products and their bioactive compounds. The current situation in the cocoa market worldwide and in Ecuador will be briefly presented, followed by a description of the structural and chemical composition of cocoa fruits. Next, the process of transforming cocoa into a final product and the by-product streams generated will be detailed. Finally, current applications and prospects for applications through the use of sustainable technologies will be addressed.