The sunflower protein concentrate studied in this paper is a new developed food protein resource in Heilongjiang Province. Up to now the studied report on this product has not been seen in China. Using casein as reference protein and soy protein isolate and gluten from wheat flour as comparable substances we studied the content of major nutrients and the composition of essential amino acid in the sunflower protein concentrate by chemical analysis method, and also studied protein efficiency ratio (PER) and other indicators related to nitrogen metabolism in the animal experiment by the recommended method of AOAC. Some common harmful substances in the samples were examined quantitatively. The results showed that the protein content (as anhydrate basic), the PER, apparent digestibility, the true digestibility, the biological value, and NPU of the sunflower protein concentrate were 62.43%, 1.96, 96.83%, 98.51%, 96.81% and 95.35% respectively. The essential amino acid composition was the same as analogous products prepared in other countries. The blood indicators and pathological observation of tested rats were normal. The content of several harmful substances in the product was allowable.All of these results indicated that the nutritional quality of the sunflower protein concentrate is about the same with some similar porducts prepared in other countries. We believe that these products are safe to consumers in the aspect of food hygiene.

The inhibiting effect of 11 kinds of ordinary vegetables including eggplant, cucumber, Chinese cabbage, fresh kidney bean, tomato, paprika, spinach, carrot, onion and celery on the formation of N-nitroso compounds was studied. Most vegetables inhibited the formation of N-nitrosodimethylamine when am-inopyrine and nitrite added to the vegetable juice and citric acid buffer were incubated in a model system simulated stomach condition (pH 3.00, T 37℃) for 1 hr. The inhibiting rate related to the contents of ascorbic acid in the vegetables ranged from 32.70% to 97.61%. Onion, fresh kidney bean, spinach and eggplant inhibited the formation of N-nitrosodimethylamine effectively with the inhibiting rate of 77.91%, 73.40%, 57.48% and 30.75% respectively (the inhibiting effect of ascorbic acid contained in the vegetables had been excluded). The relationship between the dose and the inhibiting effect of onion, fresn kidney bean, spinach and eggplant was good with the correlation coeffecient 0.756, 0.917, 0.607 and 0.801 (p

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.

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.

The absorptioa of zinc in the fermented soybean weaning food was studied using methed of neutron activation analysis of a stable isotope 70Zn. The results indicated that the rate of zinc absorption (38.7%), activity of alkaline phosphatase in serum (102.3V/L) and the increment of weight (0.5kg) of the infants (7-18m) eating the soybean fermented weaning food were higher than those eating the nonfermented soybean weaning food (30.9%, 71.0V/L, 0.4kg) and the traditional grain weaning food (rice gruel and noodle) (27.5%, 61.5V/L, 0.4kg)

The apparent digestibilities of two preparations of corn as staples in men were estimated during March and April in 1979. Seven healthy adult men, who lived in this region for many years, were accustomed to eat corn as their staple diets. Each of the two preparations from the same batch of corn was used in the experiment. One preparation was "cooked corn meal" and the other was Jian-bing, the latter was considered the better way of cooking. Other ingredients of food in these two test diets were the same. During the test periods, the volunteers ate the test diets and drank boiled water ad lib, but the quantities were recorded. No other foodstuffs and drinks were allowed. The nutritive values of test diets were sufficient to meet the subjects' physiological needs. The 12 days period was divided into adaptative and testing periods of three days each for the two kinds of test diets. During the test periods, the total foodstuffs and the volunteers' faeces were analysed for the contents of water, anhydrates, total ni- trogen, crude fat, ash and fiber in the samples. From the data obtained, the apparent digestibilities of anhydrates, total nitrogen and crude fat ware calculated. Urine nitrogen was analysed and the nitrogen balance was calculated. The body weight at the beginning and the end of test periods were measured.The apparent digestibility (%) of anhydrates was 93.31?0.393 and 94.79 ? 0.578, total nitrogrn 84.60 ? 0.843 and 87.77 ? 1.080 and crude fat 86.32 ? 1.296 and 94.68 ? 0.838 in cooked corn meal diet and the corn flour Jian-bing diet respectively. The apparent digestibility in corn Jian-bing diet was higher statistically than that of cooked corn diet. Body weights fluctuated within the normal range. The nitrogen balances of all subjects were positive and the difference of nitrogen balance studies between the two test diets was not statistically significant.The results of the experiment suggest that, the differences of apparent digestibility between two diets was mainly due to the methods of preparation, Jian-bing being better than cooked corn diet in human nutrition.

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.

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.