Diagnosis of lactose intolerance through the quantification of hydrogen in exhaled air.

Considerations are made on diarrhea secondary to intestinal malabsorption of carbohydrates and on the diagnostic means available in our environment, among which are the reactive strip, the clinitest tablet, tolerance curves and research of intestinal enzymes. The quantification of exhaled hydrogen is mentioned as a diagnostic method, used by several other authors, and a review of the literature on the subject is made. Considerations are made on a hydrogen quantification in the breath of patients with a transitory lactose intolerance. 16 patients were studied, 15 of whom showed an increase in the exhaled H2. 32 children with diarrhea, free from lactose intolerance, were studied. The method used did not show a significant increase in the exhaled hydrogen. 27 patients showed no H2 in their breath. In 4 there was elimination of H2 (false positives). 17 diarrhea-free children were studied. A significant difference was found when comparing the children with diarrhea and lactose intolerance to the other two groups who were free from lactose-intolerance. It is considered that this method can be useful in the diagnosis of intolerance to lactose and other sugars.

[Nutritive quality of ayocote beans (Phaseolus coccineous) supplemented with methionine at different cooking stages]. / Calidad nutritiva del ayocote (Phaseolus coccineous) suplementado con metionina en diferentes etapas de la cocción.

The purpose of the present study was to evaluate the nutritive quality of the Ayocote bean (Phaseolus coccineous) and to determine whether it could be increased by the addition of methionine. Methionine (0.6%) and salt (4%) were added at the beginning of cooking, 30 min before the beans were cooked or at the end when they were cooked, dried and ground. The beans were dried with or without broth. Proximate analysis, amino acids determination, available lysine, in vitro and in vivo digestibility as well as PER were determined in the bean flours. A second experiment was carried out using diets supplemented with increasing amounts of methionine (0.1-1%). The addition of this amino acid improved the chemical score, but methionine continued to be the first limiting amino acid. The beans dried with broth showed lower chemical score values than those dried without broth. The concentration of available lysine was lower in the beans dried with broth; the content of it in the beans was, however, still high. No significant differences were found in the PER's of the beans supplemented with different concentration of methionine. The addition of the amino acid can be effected at any step of cooking, since it was found that the thermic treatment did not reduce the utilization of the methionine added.

Determination of net protein utilization using whole carcass, hind leg or liver of the rat and its relationship with protein efficiency ratio determination.

Experiments were conducted to test the simplified NPU method designed by Lachance and Miller with diets of different protein quality and to determine the NPU using the liver nitrogen concentration instead of that in the hind limb. The NPU determination was done after 10- and 21-day periods instead of a 28-day period. The second part of the study was the analysis of the relationship between NPU and PER done with the same rats. The NPU calculated from whole carcass nitrogen concentration showed a high correlation with the NPU calculated from the nitrogen concentration in the leg (r = 0.990) and also with the NPU calculated from the liver nitrogen concentration. The Tukey's "t" test showed that in the 10-day experiment discrimination between the effect of the different diets upon NPU was not as good as was the case at 21 days. However, the NPU values at 10 days were in the same sequence as those at 21 days. For practical purposes it is more reliable and easier to perform the NPU determination using the liver instead of the whole carcass or leg. The statistical analysis of PER and NPU showed the same discriminating value when the test diets were isoenergetic.

Trypsin inhibitors and hemagglutinins in certain edible leguminosae.

All raw legumes contain, in different proportion, several toxic substances that prevent consumption in their natural form. In this study the contents of the two main toxic products and their degree of destruction after thermic treatment similar to home cooking techniques were determined in 13 edible legumes. Proximate chemical analysis was made, and in vitro digestibility, contents of trypsin inhibitors and hemagglutinins in raw and cooked samples were studied. In the cooking treatment the legumes were boiled for two hours at boiling temperature under atmospheric pressure. Protein content in the samples was high, as in most legumes (20 per cent or more). Peas, lentils and broad beans had the lowest content of trypsin inhibitors and hemagglutinins. Cooking destroyed these substances, but did not improve in vitro digestibility, probably because of the reactions between their components when exposed to heat.