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The effectiveness on several fruits by the application of alternative methods against fungi is summarized in the present chapter. Several investigations have reported the efficacy of these technologies for controlling fungal infections. Currently, high post-harvest loses have been reported due to several factors such as inefficient management, lack of training for farmers, and problems with appropriate conditions for storage of fruits and vegetables. Even now, in many countries, post-harvest disease control is led by the application of chemical fungicides. However, in this time, awareness about fungi resistance, environmental, and health issues has led to the research of eco-friendly and effective alternatives for disease management. The pathogen establishment on fruits can be affected by the application of GRAS compounds like chitosan, essential oils, salts, among others; besides, their efficacy can be enhanced by their combination with other technologies like ultrasound. Thus, the applications of these alternatives are suitable approaches for post-harvest management of fruits.

The objective of this study was to determine the optimal thermoultrasound processing conditions for jackfruit nectar by applying response surface methodology and comparing the physicochemical parameters, antioxidant properties, microbiology, and fatty acid profile with pasteurized jackfruit nectar. Optimal condition was 80% of amplitude at 45 ± 1°C for 20 ± 1 min, allowing physical stability of 68%, 60% of pectin methylesterase activity, ascorbic acid of 420 mg AA/L, total phenolic of 134 mg GAE/L, ABTS, DPPH, and chelating activity of 3,510 µmol TE/L, 75 µmol TE/L, and 96%, respectively. The thermoultrasonicated jackfruit nectar had lower microbial load and higher total soluble solids, ascorbic acid content, total phenolic content, antioxidant activity than pasteurized, and similar unsaturated fatty acids to the untreated sample. Our results demonstrated that thermoultrasound could be an option for processing jackfruit nectar as an alternative to pasteurization that allows successful inactivation of microorganisms, inactivation of enzymes, and good quality parameters. Practical applications Based on consumer demand for more natural or fresh‐like products, alternative technologies have been evaluated by research works looking to reduce the effects of heat treatments in the Food Industry. Among these technologies, thermoultrasound technology have gained relevance and seems to be a good replacement to inactivate microorganisms and enzymes without affecting the quality parameters, maintaining the unsaturated fatty acids content, and even increasing bioactive compounds. For example, the thermoultrasound application in jackfruit nectar has been demonstrated as a viable preservation technique to develop an innocuous nectar without affecting their food quality. Nevertheless, in order to solve the challenges about potential applications of ultrasound technology, further research is needed to obtain optimal processing conditions according to the food matrix quality required.

EVALUACIÓN in vitro DE PRODUCTOS QUÍMICOS NO CONVENCIONALES PARA EL CONTROL DE Penicillium citrinum. In vitro EVALUATION OF NON-CONVENTIONAL CHEMICALS FOR Penicillium citrinum CONTROL.

Se llevó a cabo la obtención de extractos de hoja de carambola (Averrhoa carambola L.) con el objetivo de evaluar su actividad antioxidante y capacidad antifúngica. La extracción fue asistida por ultrasonidos. Se aplicaron tres diferentes tratamientos, donde el tiempo de extracción, el ciclo de pulso y la amplitud de sonicación fueron evaluados. Una vez obtenidos los extractos a las diferentes condiciones de sonicación, se determinó para cada uno de ellos el contenido de fenoles totales y la actividad antioxidante por tres métodos: DPPH, ABTS y FRAP. Además se evaluó la actividad antifúngica de los extractos, lo cual fue determinado mediante su capacidad de inhibir el desarrollo de Colletotrichum sp en condiciones in vitro. Los resultados indican que los extractos logran una inhibición de hasta el 53% del crecimiento micelial del hongo in vitro, así como una reducción en la esporulación del fitopatógeno. Estos resultados contribuyen a la generación de evidenciapara el desarrollo de nuevas alternativas para el control de enfermedades poscosecha utilizando hojas de carambola como fuente de compuestos con capacidad antifúngica.

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Blueberry (Vaccinium corymbosum L.) is a crop with great potential for exportation and is very important for its antioxidant properties. However, this fruit is susceptible to different factors of deterioration and attack by pathogens. Botrytis cinerea is the main cause of post-harvest losses in this crop. Antagonistic yeasts from the Debaryomyces hansenii species, which is of marine origin, have been proposed as an alternative method for fungal control. For this reason, this study evaluated the in vitro and in vivo antagonistic capacity of the yeast against B. cinerea. The in vitro growth of the fungus was inhibited by 90% and germination was reduced by 100%, and through the production of volatile organic compounds, the growth of the pathogen was inhibited by 32.5%. Photographic evidence by electron microscopy revealed the effects caused by D. hansenii on B. cinerea. The incidence study showed a 50% reduction in the incidence of the disease caused by B. cinerea in blueberries, while quality parameters—such as soluble solids, titratable acidity, and pH—presented stable values, delaying the maturation process of the fruits. Likewise, the rate of reduction in firmness and physiological weight loss was lower, and the blueberries preserved their quality for a longer time.