[Suitability study for super sweet corn on the ears hybrids under refrigerated conditions evaluating chemicals microbiological and sensorial characteristics]. / Estudio de la estabilidad de las características químicas, microbiológicas y sensoriales de mazorcas refrigeradas de híbridos de maíz super dulce.

Krispy King, Víctor and 324, super sweet hybrids (sh2) were cultivated in San Joaquín, estado Carabobo, Venezuela. The scheme was stablished to produce refrigerated fresh ears to be commercialized. The chemistry, microbiology and sensorial characteristics were evaluated at 0; 7; 14; 21 and 28 days of storage. One hundred ears of each hybrid were picked at the ripe fresh stage and packed in polystyrene trays covered with polyethylene. The storage temperature was 4 degrees C +/- 1 degree C. The scheme used was well adapted, allowing a good stability of the ears until 28 days of storing. The plastic cover avoid the lost of humidity. The soluble solids, total sugars and pH went down during the storage. The acidity and the microorganisms increased as expected. The sensorial variables kept the same for Krispy king and Víctor, while the hybrid 324 shown the lowest humidity content, the highest count of microorganisms and the poorest sensorial quality.

Glucose and orthophosphate incorporation and lactate release in the perfused hind limb of the rat during lactic acidemia.

A perfused preparation of the hind limb of normal and diabetic rats was used to study the effects of lactic acidosis, alone or associated with hypoinsulinemic diabetes, on the incorporation of glucose and inorganic orthophosphate (Pi) into the skeletal muscle. A well oxygenated perfusate was recirculated for ninety minutes during which the lactic acid accumulated into the medium with the ensuing pH drop. The perfusions were practiced in the hind limb of alloxanized diabetic rats, in the hind limb of diabetic rats with perfusate containing 200 microU of insulin/ml, in the hind limb of 24 hour fasted rats, and on the hind limb of fed rats, and they were compared to similar groups with normalized pH perfusate with a sodium bicarbonate infusion. In the diabetic perfusions with lactic acidemia, it was observed that the addition of insulin increased the uptake of Pi and of glucose, and reduced the release of Pi by the muscular tissues. A smaller release of Pi by the preparations obtained from fed rats was observed when compared to the hind limb preparations of fasted rats. The diabetic preparations showed an increased glucose uptake when the pH was normalized, and a decrease of Pi released by the muscles, even in the absence of insulin, and at the same time, the administration of insulin associated with the normalization of pH increased the uptake of Pi and of glucose, and decreased the Pi released by the muscles. In all the groups, the administration of sodium bicarbonate significantly increased the lactate release into the medium. It was also found that the lactic acidosis reduced the uptake of Pi by the preparations inducing hyperphosphatemia. According to these results, muscular tissue plays a role in the hypophosphatemia that has been reported in the insulin treated diabetic ketoacidosis by increasing the incorporation of Pi and reducing its release by the same tissue.

Effect of fasting and insulin on the glucagon-induced orthophosphate incorporation to the isolated perfused rat liver.

Isolated perfused fed rat livers spontaneously liberated glucose and orthophosphate to the medium; 24-hr fasted rat livers did not exhibit these phenomena. In perfused fed rat livers, glucagon (2 mug) increased glucose output and promoted orthophosphate incorporation. In perfused fed rat livers, insulin (250 or 500 mU) inhibited the spontaneous liberation of glucose and orthophosphate. Comparable doses of insulin significantly reduced the glucagon (2 mug)-induced increase in glucose output from perfused fed rat liver, but did not affect orthophosphate uptake by the organ.