摘要:

The influence of processing and cooking on the metabolic response to carrots in mixed meals was explored in two consecutive harvest years. The contribution of dietary fibre (4.4 g 1989 and 6.6 g 1990) from carrots was chosen to be different in order to compare effects with varying doses. The meals, composed of carrots, creamed potatoes, meat balls, lingonberry jam, white bread and light beer, were served in the morning after an overnight fast to 10 healthy male volunteers. Carrots were investigated raw, processed (blanched and frozen) and variously cooked (thawed, boiled and microwaved). The amount of dietary fibre from the vegetable, and the content of energy, digestible carbohydrates, fat and protein were similar in the meals compared. Significantly lower glucose, insulin and C-peptide responses and higher satiety scores were elicited with raw carrots than with microwaved ones, harvest year 1989. The next year, with a higher dietary fibre intake from carrots, there were significant effects of processing only on the glucose response. Plasmaß-carotene levels tended to be higher postprandially with raw carrots than with microwaved ones. Hence, ordinary processing and cooking of vegetables can affect the metabolic response to a mixed meal. However, the influence seems to be varying and of minor importance in ordinary meals. Increasing vegetable portions entailing a higher soluble fibre content and a higher viscosity could further reduce the influence of processing.

ISSN:0963-7486    

DOI:10.3109/09637489509003379

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

The cyanide levels were followed during protein enrichment of cassava by the fungusAspergilus oryzae.The total cyanogen level decreased by 158 mg/kg dry weight to 54.2 mg/kg dry weight as a result of the whole process including fermentation. The cyanogenic glucoside level decreased by 88% during the fermentation process while acetone cyanohydrin was retained in the cassava. The prefermentation processing which involved crushing, sundrying and milling the cassava into flour, reduced the total cyanogen levels by 40%. The process resulted in considerable reduction in the cyanogenic content of the product.

ISSN:0963-7486    

DOI:10.3109/09637489509003380

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Dropouts of a weight reduction program are not evaluated for the lasting effects of weight reduction. This study was an attempt to learn about the benefits of weight reduction received and sustained by the dropouts of the program. Ninety-seven males and females dropping out of a dietary weight management program after 16-18 weeks of treatment, and after 9-9.4 kg weight loss and wishing to rejoin the program for a second time after at least 9 months' absence from it, were considered for the study. Their body weight, serum cholesterol, serum triglyceride, and blood sugar levels at the beginning of the second attempt, were compared with the respective values at the beginning of the first attempt. All patients had regained the weight lost during their first attempt when they reported for a second attempt. However, serum cholesterol and triglyceride values were 15% and 26% less for females, and 17% and 24% less for males, compared to their respective values on the first attempt, in the subgroup of patients with normal blood sugar levels. In the subgroup with above normal blood sugar levels, however, serum cholesterol and triglyceride values showed an increase by 12% and 17% respectively, for females, and by 2% and 7% respectively, for males, compared to their baseline values on their first attempt. The mechanism responsible for this observation was not uncovered. However, the observation that even an incomplete attempt at weight reduction appears to contribute in maintaining lower levels of serum cholesterol and triglyceride of at least those with normal blood sugar levels, is useful in nutritional counseling for emphasizing the health benefits of the weight reduction.

ISSN:0963-7486    

DOI:10.3109/09637489509003381

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Recently we reported on the application of a method for protein determination which measures nitrogen in Kjeldahl digests colorimetrically. This procedure has the advantage of eliminating the distillation and titration steps of the Kjeldahl method and it is ideal for nutritional studies, since many samples can be run in a single day. Accordingly, the purpose of the present report was to extend the application of this method to the determination of the protein content of commercially available foods such as dairy products, dry cereals or cereal based products and legumes and also to evaluate this method in the determination of the protein content of the mixtures of cooked foods served during lunch at the cafeteria of the Universidad Simón Bolívar, Caracas. In both cases the results of the colorimetric nitrogen agreed very well with those obtained by the macro Kjeldahl, indicating that the colorimetric method may be used in monitoring the protein content of commercial foods and in evaluating the protein offered in institutional food services. Finally, to further demonstrate the value of this method in clinical trials, we used it to monitor the daily nitrogen intake and nitrogen losses in 43 male young children with acute diarrhoea, and 15 with persistent diarrhoea fed liquid formulae, and showed that protein digestibility and retention were higher in persistent than in acute diarrhoea. The severity of acute diarrhoea affected negatively (r= -0.62) the percentage of protein absorbed, whereas the protein absorbed (r= 0.70) and retained (r= 0.55) correlated positively with protein consumption. In general, the results of these studies indicate that the colorimetric methods may be useful in studying many aspects of protein nutrition, as it measures the protein content of raw materials, cooked foods and nitrogen intake and excretion in clinical and nutritional studies.

ISSN:0963-7486    

DOI:10.3109/09637489509003382

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Aluminium leaching from low quality (Al-Pb alloy) and high quality (Al-Mn alloy) utensils by water has been studied under different conditions of pH, boiling time and NaF concentrations. High fluoride concentration and low pH were found to enhance the leaching of Al more from low quality utensils than from high quality utensils

ISSN:0963-7486    

DOI:10.3109/09637489509003383

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Higher nitrogen and lipid digestibilities have been obtained with diets containing cottonseed flour rather than soybean flour. To explain these results,in vitrostudies were carried out to compare the effects of raw and heated glandless (without gossypol) cottonseed flours versus soybean flours on pancreatic digestive enzyme activities. These effects were compared with those obtained without addition of flour in standard assays. Apparent lipase (lipase colipase dependent) and potential lipase (lipase with saturating amounts of colipase), colipase, phospholipase A2, amylase, trypsin and chymotrypsin activities were measured on specific substrates. Phospholipase A2 and amylase activities were enhanced, while chymotrypsin activity was diminished with both raw and heated flours. Compared with raw and heated soybean flours, raw and heated cottonseed flours promoted higher potential lipase, chymotrypsin, trypsin and lipase activities. Heat treatment of cottonseed flour enhanced apparent lipase, colipase, chymotrypsin, trypsin activities and diminished potential lipase, phospholipase A2 and amylase activities. When soybean flour was heated, apparent lipase, phospholipase A2, chymotrypsin, trypsin and amylase activities were raised while those of potential lipase were decreased. Our findings show thatin vitroraw or heated cottonseed flours affect less digestive enzymes than raw or heated soybean flours, apparent lipase activity excepted. Moreover, only chymotrypsin activities were seriously lowered with both flours, especially with raw soybean flour. Hypotheses are suggested to account for the differences in alterations.

ISSN:0963-7486    

DOI:10.3109/09637489509003384

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

The foliage of 62 specimens ofAmaranthusbelonging to 10 species of grain and four of vegetable type were anlaysed for vitamin C content. The overall range of vitamin C was from 69 (A. cruentus, AG-122) to 288 mg/100g (A. hypochondriacus, Rasna) in the grain type and 62 (A. tricolor, Amar-peet) to 209 mg/100 g (A. tricolor, AV-101, exp) in the vegetable type (fresh weight). Variation of vitamin C with leaf position (age) was also studied. While the oil content in 110 lines ofA. hypochondriacusvaried from 4.4 to 13.2%, most of the specimens had promising oil composition with regard to unsaturated fatty acids.

ISSN:0963-7486    

DOI:10.3109/09637489509003385

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

This review discusses evidence from human studies on the effects of dietary phytate on zinc bioavailability.In vitroand animal experiments have implicated calcium as a potentiating factor because it reacts with phytate, and zinc binds to the precipitate. Magnesium also reacts similarly to calcium, but most studies have not considered this factor. Protein provides amino acids, some of which are able to desorb zinc from the precipitate and improve bioavailability. Some predictive ratios, derived from animal studies, have been directly applied to human studies. The studies reviewed included those on: zinc status of groups, apparent absorption of zinc in normal subjects and ileostomists, true absorption using a stable isotope, plasma tolerance, and the accumulation in the body of a radioisotope. It was concluded that detrimental effects of phytate could be demonstrated on zinc bioavailability, but that the studies had not been designed specifically to demonstrate whether the interactions found in animal studies also apply to humans. It is suggested that more targeted research is required before predictive ratios are used for humans.

ISSN:0963-7486    

DOI:10.3109/09637489509003386

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Cassava (Manihot esculentaCrantz) is an important dietary staple for more than 500 million people in developing countries. People eat 60% of the cassava produced and one third of the harvest feeds animals. All cultivars of cassava contain the cyanogenic glucoside, linamarin, but in different concentrations. The roots of those cultivars with high cyanogenic content are processed to reduce the level of linamarin, because linamarin is hydrolysed in the intestinal tract of both men and animals by microbial flora and HCN is released. Researchers have implicated the sublethal levels of HCN produced on ingestion in the development of a number of metabolic diseases in both man and animals when cassava-based diets are consumed over a long period of time but the release of HCN cannot fully explain the metabolic effects of ingested linamarin. A significant amount of linamarin remains intact and is excreted in the urine. It appears that the intact linamarin inhibits Na+K+ATPase causing electrolyte imbalance within the cell. This phenomenon is exacerbated by free radicals generated by the hypoxia/normoxia cycles created by cyanide released from linamarin, which cause lipid peroxidation and cell membrane damage. When the supply of endogenous thiosulphate is adequate, cyanide plays a very minor role in the development of lesions. The amount of damage is related to the quantity of linamarin routinely ingested at sublethal levels. There appears to be species differences in the rate of the development of diseases and the intensity.

ISSN:0963-7486    

DOI:10.3109/09637489509003387

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

It is known to all nutritionists and food scientists that the presentation of papers at (inter)national meetings is not always optimal. In this paper on effective lecturing some very practical advice is presented on how to entertain the audience scientifically. With the prerequisite of a clear scientific message, the basic elements for an optimal presentation are discussed with emphasis on the proper use of audiovisual means, including slides and overhead transparencies. Some additional comments are made about posters, chairpersons of sessions, and audiences.

ISSN:0963-7486    

DOI:10.3109/09637489509003388

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor