Strong acidic electrolyzed water (SAcEW) is generated by using a diaphragm type electrolytic cell and adding a small amount of salt solution to the tap water. The acidity of this water causes chloride ions, as the major factor in sterilization process, to form hypochlorous acid. Therefore, it is said that the sterilization time with SAcEW is shorter than with sodium hypochlorite generally used for food sterilization. After being registered as a food additive (2002) in Japan, SAcEW began to be used for washing food in food processing facilities in order to improve the food sterilization level. In this research, the possibility of an enhanced sterilization effect of SAcEW generated by a water electrolyzer was evaluated by adding physical washing methods (ultrasonic, stream overflow, bubbling) and pre-washing with strong alkaline electrolyzed water (SAlEW) which is generated at the same time. As a result, the combination with pre-washing with SAlEW was found to be less effective than washing with SAcEW only when comparing the same washing time. As for the supplementation of physical washing methods, the stream type was found most effective. In addition, comparison between the sodium hypochlorite treatments (200 mg/L, soaked for 5 minutes) recommended by the Japanese Ministry of Health, Labor and Welfare for raw food materials and the SAcEW treatment for 10-30 seconds suggested equivalent sterilization effects on raw food materials.

Resumen Se presenta un balance de calor del Lago de Zapotlán que fue resuelto numéricamente mediante el método de Runge-Kutta de cuarto orden con un incremento de tiempo de un día. A semejanza de otros lagos tropicales, el presupuesto anual de calor es muy bajo. La temperatura del lago (correlacionada con la radiación atmosférica y la radiación de fondo), la acción del viento (correlacionada con la radiación solar), y los escurrimientos (correlacionados con la radiación atmosférica, la radiación de fondo, la precipitación sobre el lago y la temperatura del lago), producen el mezclado del lago durante las estaciones de invierno, primavera y verano. Pero en el inicio del otoño, al disminuir el flujo neto de calor superficial y terminar las lluvias, el hipolimnión se enfría levemente debido a que esta capa es ocupada por escurrimientos más fríos y más densos. Esta pequeña diferencia térmica provoca que la columna de agua se estratifique de manera inestable. Los episodios alternados de mezclado y estratificado afectan significativamente el ciclo de nutrientes y la dinámica de la cadena alimenticia del lago. | Abstract This paper presents a heat balance for Lake Zapotlán, which was solved numerically using the fourth-order Runge-Kutta method with a step size of one day. Like other tropical lakes, the annual heat budget of Lake Zapotlán is very low. Lake temperature (correlated with both atmospheric longwave radiation and water back radiation), wind strength (correlated with solar shortwave radiation, and runoffs (correlated with atmospheric longwave radiation, water back radiation, precipitation on lake and lake temperature) produce lake mixing during three seasons: winter, spring and summer. When fall begins, as the net surface heat flux diminishes and rainfall ends, the epilimnion is slightly cooled since this layer receives colder, denser runoff. This small difference in temperature causes the water column to stratify in an unstable manner. The alternating episodes of mixing and stratification significantly affect the nutrient cycle and the dynamics of the food chain.