Water adsorption properties are necessary for determining and analyzing water sorption in dried and roasted cocoa beans during storage. Thus, this study aimed to determine the water adsorption isotherms and thermodynamic properties at temperatures of 25, 30, and 40°C and water activities between 0.10 and 0.85 using dynamic dew point method. Thirteen different models were fitted to experimental data to represent the dependence of the equilibrium moisture content. Additionally, the thermodynamic properties were determined using the best-fit isotherm model. The isotherms of dried and roasted cocoa beans showed typical behavior of products rich in soluble components, according to Brunauer-Emmett-Teller (BET) classification, which was satisfactorily modeled using the Iglesias and Chirife and Kuhn equations, respectively. The thermodynamic properties showed that the net isosteric heat of adsorption and the Gibbs free energy decreased with the equilibrium moisture content, indicating the energy changes and spontaneity during the adsorption process. The integral entropy of adsorption indicated the best conditions for product stability during storage. ARTICLE HISTORY

Sorption isotherms represent an efficient and valuable tool for predicting the equilibrium moisture content of foods under different humidities and temperatures; thus, they are useful for determining shelf-life and safe storage conditions. The aims of this study were to determine the sorption isotherms of parchment specialty coffee at water activity values of 0.1−0.8 and temperatures of 25, 30, and 40 °C using the dynamic dew point method. The experimental sorption data were modeled using 12 different equations to represent the dependence of equilibrium moisture content on water activity and temperature. Thermodynamic properties were also obtained from the experimental data. The results showed a type II sigmoid shape according to Brunauer-Emmett-Teller (BET) classification, and the double log polynomial (DLP) equation successfully modeled the effects of temperature on the sorption isotherms, obtaining a good fit (R 2 adj = 0.99 and RMSE = 0.1 % dry basis). The dynamic dewpoint isotherm (DDI) method was advantageous for modelling due to its high availability of experimental data. Thermodynamic analyses showed that the net isosteric heat of sorption, Gibbs free energy, and sorption entropy decreased as equilibrium moisture content increased, and the compensation theory provided evidence that the sorption process was controlled by enthalpy (T β > T hm ).

We assessed the degree of freshness of gutted and ungutted red tilapia (Oreochromis ssp) using physicochemical and microbiological analyses of samples of gutted red tilapia on days 0, 3, 5, 8, 11, 14 and 17 and of ungutted red tilapia on days 0, 3, 6, 9, 11, 14 and 16. The total sample size was five fish stored in ice at temperatures between 0 and 4 °C. Different methods were used to study the degree of freshness: pH, water holding capacity (WHC) and microbiological analysis (aerobic mesophilic count). Once we obtained the results, a one-way analysis of variance (ANOVA) was used to determine possible correlations between the values of deterioration and the data obtained by other analysis methods. The one-way ANOVA showed that statistically significant differences (P<0.05) were found in almost all of the parameters analyzed throughout the storage times, indicating the loss of freshness in the fish. In the gutted fish, the firmness of the fillets and the whole fish presented the most noticeable statistically significant deterioration on day eight of storage, when the six logarithmic cycles of aerobic mesophilic bacteria counts were exceeded, and the fillets presented a statistically significant deterioration of the WHC. The ungutted fish began to lose freshness that limited the consumption of the food between the third and sixth day of storage, with aerobic mesophilic bacteria counts of 7.33±1.07 Log CFU g -1 and 7.14±1.60 Log CFU g -1 , respectively. Similarly, significant decreases in firmness in the fillets and abdomen were noticed on the third day of storage.

La uva Isabella (Vitis labrusca) es una variedad tinta que se cultiva en el corregimiento de la Ulloa perteneciente al municipio de Rivera (Huila), teniendo una demanda en los mercados locales para su consumo en fresco. El objetivo principal de esta investigación fue conocer si era posible la producción de un vino competente frente a los vinos comerciales, para lo cual se evaluó el proceso de fermentación alcohólica con levaduras Saccharomyces cerevisiae var Bayanus para el mosto de esta uva, realizando chaptalización con miel de abejas. Para esto se analizaron parámetros fisicoquímicos como pH, sólidos solubles, acidez, viscosidad y color, durante la fermentación; estos parámetros se midieron en el producto final para ser evaluados frente a un vino comercial. Los resultados muestran que la variedad de uva y el tipo de maduración influyen en el producto final, por lo que al evaluar ambos vinos se encontraron diferencias significativas (p<0.05) en los parámetros medidos. Finalizado el proceso de maduración se realizó un análisis sensorial comparativo con un vino tinto variedad Cabernet Sauvignon, dónde se obtuvo un alto nivel de aceptación para el vino de uva Isabella-Huila con diferencias significativas (p<0.05) entre vinos. Posteriormente, se realizó un maridaje en el cual se conocieron los posibles alimentos que mejor complementan en el paladar de las personas al consumir el vino de uva Isabella-Huila, siendo el queso maduro el de mayor aceptación, seguido de jamón, cerezas y finalmente el queso fresco.

Coffee pulp is the first by-product generated from coffee processing, a contaminating residue due to its composition and production volume. So, this research presents the use of coffee pulp with honey and sugar cane juice to elaborate alcoholic beverage and infusion. The harvested coffee was washed, pulped; the pulp was distributed in 3 treatments, by duplicates, (T) coffee pulp and water, (M) coffee pulp, water and honey, (G) coffee pulp and sugar cane juice. Then, each treatment was brought to 85 °C for 15 minutes, warmed up and yeast was added to each container. Fermentation was carried out for 14 days at 15 °C. After the liquid was separated from the pulp, the liquid fraction was left to ferment another 14 days, it was clarified with bentonite, it was bottled and for 102 days mature, the degrees of alcohol was measured by simple distillation. The pulp was placed in an oven at 75 °C for 3 days, the chemical composition was analyzed by FTIR, it was packed in hermetic bags, the dry coffee pulp was used to prepare an infusion. For its use, a fermented drink and an infusion were elaborated, evaluating physicochemical, microbiological, and sensorial characteristics through three treatments. The fermented drinks presented values of alcohol degrees 7°-6°. The treatment with honey obtained a greater acceptance followed by the treatment with sugar cane juice. The infusions were acceptable, differentiated by herbal notes, pleasant aromas, and sweet flavors. In the pulp, the following were characterized by FTIR chemical compounds and wavelengths that show their absorbencies; caffeine with ranges of 2920-2850 and 1620 cm -1 , 3280 cm -1 H 2 O, 1740 cm -1 lipids, 1240 cm -1 chlorogenic acid, and 1015 cm -1 carbohydrates. Finally, the infusions with coffee pulp were accepted by the evaluators, especially those that went through the fermentation process with honey and sugar cane.