Tofu is obtained by heating soymilk, to which a coagulant, such as calcium sulfate or magnesium chloride, is added to make it curdle. This study aimed to parameterize the effects of the following three alternative organic coagulant types: apple, rice, and white vinegars, used in different proportions. Six treatments were established with three concentrations (1%, 3%, and 5%), evaluating the coagulation time and curd yield. The treatments with the lowest coagulation time were analyzed for texture by TPA, color through the CIEL*a*b scale, protein content, and moisture. The results showed that the rice vinegar + 3% white vinegar (T6C3) treatment showed the lowest coagulation time (0.78 min). The 5% apple vinegar (T1C5) treatment provided the highest curd yield, averaging 23.73%. This treatment’s protein and moisture contents were 3.93% protein and 69.73% moisture, confirming that better texture characteristics are recorded in tofu at lower pH values. The TPA results showed that using apple and rice vinegars as coagulants provided a challenging, less cohesive, more adhesive, and less elastic tofu. White vinegar provided a soft, more cohesive, less adhesive, and more elastic tofu. In the color analysis, it was observed that tofu coagulated with apple vinegar showed a tendency toward a yellow color, and tofu coagulated with rice and white vinegars showed a tendency toward a white color. These findings parameterize the effects of using each type of vinegar as a coagulant. These organic coagulants provide faster coagulation times and desirable texture characteristics, thus offering a practical alternative to traditional coagulants in tofu manufacturing.

In the field of convective drying, several models have been proposed by different research groups, both theoretical and empirical. However, research on theoretical mathematical models has been superficial and needs to be extended. Empirical models present difficulties in their implementation in other research. It is suggested that further research should focus on obtaining models adaptable to different species and environmental conditions. The aim of this work was to analyse the current state of research on the drying process and mass transfer. It is concluded that drying is a mathematically complex process that must be modelled with differentiated equations in two stages: constant drying rate stage and decreasing drying rate stage. The modelling of the constant drying phase can be based on the convective mass transfer equation, although the prediction of the coefficient with analogies to heat transfer has deviations in biomass. Modelling of the variable rate drying phase should focus on the variation of water diffusivity in porous materials or vapour permeability as a function of material moisture and temperature. A database of homogenised equations particularised for each material needs to be generated to predict drying rates and times under predetermined convection conditions. This represents a scientific challenge and suggests that research in drying kinetics still needs development.

Resumen: Esta investigación estudió el efecto del pardeamiento enzimático en la calidad nutricional del banano, para lo cual se analizó la composición nutricional antes y después de los cambios que sufrió el fruto por efecto del pardeamiento. También se evaluó el contenido de antioxidantes y la actividad enzimática para comprender cómo influye el pardeamiento y su impacto en la calidad nutricional. Además, se investigaron métodos para inhibir o retrasar la reacción buscando así preservar la calidad nutricional y prolongar la vida útil del banano, para lo cual se aplicó una investigación y contrastación de información bibliográfica con un universo magnánimo aplicando técnicas e instrumentos de búsqueda, luego de un análisis detallado y riguroso de las causas del fenómeno se determinó que la actividad de la enzima polifenol oxidasa es un factor clave en el proceso de pardeamiento enzimático, los estudios revisados han demostrado consistentemente que el proceso de pardeamiento enzimático tiene un impacto significativo en la composición afectando la calidad nutricional y organoléptica del banano, el uso de antioxidantes, como el ácido ascórbico (vitamina C), y tratamientos térmicos se han mostrado como opciones efectivas para preservar la calidad nutricional y apariencia de la fruta.

Milk is considered a food of high nutritional value, necessary for food and nutrition. Milk production in Ecuador is one of the most important livestock activities in terms of the country's economy. For this reason, it is necessary to control milk from milking to marketing. The parameters to determine the quality of milk prior to industrialization are evaluated through physical, chemical and microbiological analyses. The purpose of this research was the physicochemical characterization of raw milk from dairy industries and collection centers located in the Province of Chimborazo. To carry out the physical-chemical analysis, milk samples were collected from each supplier, determining quality parameters established by the INEN 9 Standard, such as temperature, density, percentage of fat, protein and total solids. This sampling was carried out with the purpose of identifying compliance and non-compliance with these parameters in the different collection centers and dairy industries, evidencing a 4% non-compliance with these quality parameters; In order to improve milk quality, it is proposed to implement consecutive controls at these establishments, in addition to promoting good milking practice programs. In this study, a labeling was carried out where 90% of the dairy industries and collection centers are labeled green, which indicates that they maintain adequate compliance with the quality parameters, 8%, however, are labeled yellow and the 2% are found in red labeling

El cultivo del cacao pertenece a los más dinámicos dentro de la economía de la nación, en sus últimos años el cacao ha sido de enorme contribución para el PIB, sin embargo, producto de los cambios en el mercado mundial se han presentado diferentes comportamientos, en tal sentido, el objetivo del presente trabajo es comparar el impacto económico del cultivo del cacao en Ecuador del primer semestre 2019 con el primer semestre 2020. Se usó un análisis comparativo y descriptivo, obteniendo datos estadísticos del 2019 y 2020 sobre la economía y el desarrollo social del cacao. Los resultados fueron presentados mediante cuatro indicadores: primero, exportaciones e importaciones de cacao por países, segundo; costo del cacao, tercero; bloque económico por zona o región, cuarto; valores mensuales. Se concluye que el flujo de exportaciones no presento alteraciones por la pandemia dado que en 2020 ascendieron a $908.102.645 millones, un aumento de $223.851.917 millones respecto al período de 2019 ($684.250.728 millones); en cuestión a la demanda del producto, se registra que sus principales mercados son Estados Unidos (20%), Indonesia (26%), Malasia (11%). Ecuador importa cada año una pequeña cantidad de productos a base de cacao, en el 2020 presento una disminución de 5,31 miles toneladas métricas, y en comparación del FOB; asimismo, disminuyó en 25.574,77 millones; así también hay variaciones de importaciones en algunos países, como el aumento de Colombia (1%), Estados Unidos (4%); mientras tanto, existe una disminución de Brasil (-2%), seguido de Perú (-2%) y por último Chile (-4%). En cuanto a la materia prima (Cacao en grano) el precio por tonelada (USD) fue de 2.170, mientras que para el 2020 fue de 2.240.