ABSTRACT
In order to clarify the disputing view-points in some publications, that the soy products are whether unfavourable or not to the bioavailability of diet iron, we estimated the relative bioavailability of the iron from soy flour by hemoglobin regeneration method in rats suffered from iron deficiency anemia. In this experiment the ferrous sulfate was used as a standard, wheat flour as a vehicle, and the pig blood powder as a reference substance. The iron content in the regeneration diet fed to rats of each group was 32 ppm in total, and among it 24ppm was originated from (1) soy flour, (2) soy flour plus wheat flour (half and half), (3) pig blood powder, (4) pig blood powder plus wheat flour (half and half), and (5) ferrous sulfate respectively.The experimental results showed that during the 5-week regeneration period the regenerated hemoglobin level of the rats of corresponding groups were (1) 6.6?1.6→9.4?1.7, (2) 7.0?0.9→10.4 ?1.5, (3) 6.4?1.6→ 11.4?1.4, (4) 6.1?0.6-11.1?1.9, and (5) 5.3?1.2-12.8 1.0, thereby the percentage of iron relative bioavailability of five groups were (1)45.4, (2)65.0, (3)74.0, (4)72.0, (5)100.0 respectively. The iron from soy flour showed a lowest bioavailability aalong the different diet sources in our exper-iment, and therefore the iron from soy products was unfavourable to prevent and treat the iron deficiency anemia. We also made some discussions and suggestions in this paper.
ABSTRACT
The neutron activation analysis of a stable isotope (58Fe)was used successfully in the study of iron absorption from different diets in children suffering from iron deficient anemia. The method was correct and convenient, and uninjured to human body. The principle, procedure and the control of errors were also discussed. The iron absorbability of the balance diet,soy protein diet and soy protein diet plus vitamin-C were (group average?SD) 12.0? 3.6%, 10.7?4.7%, and 18,1?3.6% respectively. According to the results and the animal experiments which were reported in another paper, we agreed that soy protein unfavor or reduce the bioavailability of iron from diet, which was made by International Nutritional Anemia Consultative Group (INACG) and others, but it is still a disputing question. The data of iron absorbability from diets in children suffering from iron deficient anemia and the method of neutron activation analysis of a stable isotope (58Fe) have not be seen up to now in China. This paper will be valuable for studing, preventing and treating iron deficient anemia in our country.
ABSTRACT
The nutritional and food hygienic character of the new developed soy protein concentrate and soy protein isolate in Heilongjiang province were studied by chemical analysis and rat experiment. These products have not yet been reported in China. The results indicated that the content of protein of soy protein concentrate and isolate was 69.76 and 83.11%(as anhydr-ate basic), the PER 2.00 and 1.34, the apparent digestibility 77.54 and 85.72%, the true digestibility 84.33 and 93.19%, the biological value 79.80 and 62.54%, the NPU 67.39 and 58.28% respectively.The essential amino acid composition of the two samples was the same as the products prepared in the other countries. By the hematological and pathological examination in rats, the contents of serveral harmful substan- ces were allowable or not detected. The authors belived that the nutritional quality of the two soy protein products was nearly the same as those in other countries, and its food safety was satisfactory.
ABSTRACT
One hundred and ten college students, 66 males and 44 females, were studied for the evaluation of vitamin C status by use of the ratio of reduced vitamin C to creatinine in a random urine sample. During the experimental period, the dietary source of creatinine was strictly abstained. After voiding in the morning, the volunteers were weighed and their urine were collected at the end of 1st, 2nd, 4th, 8th, 12th and 24th hr respectively. The contents of reduced vitamin C and creatinine in each collected urine sample were analysed, and then the total amounts in 24 hrs were calculated.The experimental results showed:1. The distribution of the creatinine excretion in 24 hrs was nearly constant.2. The percentage of reduced vitamin C excretion per hour to the total 24 hrs excretion was similar in subjects of different vitamin C status and was lowest in 12 hrs of night urine. A curvilinear regression was given for the percentage of reduced vitamin C excretion in relation to the time.3. The ratio of reduced vitamin C (as mg) to creatinine (as gm) and the ratio of reduced vitamin C to creatinine (as mg) per body weight (as kg) were calculated from their contents in 12 hrs urine in those who exc- reted reduced vitamin C in urine less than 80 mg in 24 hrs. The relationship between these two ratios and the excretions of reduced vitamin C in 24 hrs urine was studied and four equations of curvilinear regressions were given.4. According to these equations, the correlated values of vitamin C/ crcatinine and vitamin C/creatinine/body weight in random urine samples in respect of four different grades of vitamin C excretion of 24 hrs urine were recommended.It was shown to be a new simplified method for evaluating the nutritional status of vitamin C in human body. The practical aspect of its application was discussed.
ABSTRACT
A series of research results on the influence of soybean to the bioavai?lability of non-heme iron in diet are reported. It is proved that Soybean and some of its products decrease the bioavailability of non-heme iron in diet by human observation and animal experiments. This result is due to insufficient control over the inhibitors and utilization of the enhancers of the bioavailability of iron in soybean itself.Experiments show that through some special treatment processes such as sprouting, fermenting and making bean curd, the above disadvantages may be effectively reduced and remarkably increase the bioavailability of the non-heme iron. These conclusions possess both theoretical and practical meaning for full utilization of soybean protein and effective prevention of iron deficiency anemia.