Melting processes of refrigerated fruits and vegetables (Jonathan apple, sour cherry, red currant, onion, cauliflower and cucumber) were studied using the DSC method. Prior to the tests apple and onion were stored without and the other products with refrigeration. The refrigerated products were melted in microwave space, then chopped and homogenized. Measuring was carried out with the juice obtained from the homogenized sample, and the sample containing the fibre was also measured. Besides the DSC examinations, the water content of the samples was also determined by drying in exsiccator at 105 C/degrees/ to constant weight. The DSC curve of the samples examined is a characteristic endotherm curve, with phase shift temperatures varying from product to product. An analysis of the temperature dependence of the phase shift temperature showed that at the beginning of intensive melting 7-23 o/o, while at the usual temperature of cold storage 1-10 o/o of the water content was in liquid state

The present review describes the processes occurring in the degradation of pesticides in soil and persues their entry to groundwater, air and food plants. To avoid groundwater pollution the adsorption and mineralization of pesticides in soil must be at least 99,98% of the soil-reaching substances. At lower retention rates groundwater protection is achieved only by minimizing the amount of application or by enlarging the intervals between the use of the same chemical ingredients

Se han revisado diversos metodos de determinacion de la actividad del agua. Los metodos pueden dividirse en aquellos que requieren el uso de instrumentos comunes de laboratorio y en aquellos que necesitan para su determinacion aparatos especiales. La principal ventaja de los que necesitan aparatos especiales es que la actividad del agua puede determinarse mas rapidamente.

A thermal conductivity prediction regression equation was developed for four food materials as a single function of moisture content, porosity and initial thermal conductivity. It was assumed that temperature has a negligible effect on thermal conductivity. Thermal conductivity values of beef, apple, potato, pear and squid were used to develop the regression equation considering 122 points from the literature. The regression coefficient was 0.992. Squid gave the maximum mean per cent deviation of 11.89% (standard deviation 14-39). Potato gave minimum mean per cent deviation of 4.10% (standard deviation 1.74).