摘要:

A reversed-phase HPLC method developed for the simultaneous determination of carotenoids and retinol in foods of vegetable and animal origin was applied to the study of 100 samples of human serum. The subjects were urban adult Malaysians of Malay, Chinese and Indian descent with a mean age of 52.8 years (range 17–78 years). For comparison, all serum samples were also simultaneously determined using the direct spectrophotometric method for carotenoids and the Carr-Price colorimetric method for retinol. Compared to the conventional methods, the HPLC method was found to give significantly higher results for retinol and total carotenoid concentrations. The major advantages of the liquid chromatographic method are that it is more specific and that it overcomes the problems associated with the Carr-Price method. In addition, only the HPLC procedure could provide an account of the serum carotenoid profile, a knowledge of which is now of increasing health importance in view of the possible inverse association of carotenoid intake and some forms of cancer. Six major carotenoids—lutein, cryptoxanthin, lycopene,γ-carotene,α-carotene andβ-carotene—were quantitated, the most abundant being lutein and cryptoxanthin, each contributing to about one quarter of all the carotenoids quantitated.β-carotene and lycopene were the next abundant carotenoids, each contributing to about 20% of all carotenoids.γ- andα-carotenes together made up about 10% of all the carotenoids detected and quantitated. The mean content of total carotenoids was 196.0±83.2μg/dl, with no statistically significant difference between levels for female and male subjects. The mean serum retinol level was 74.2±23.0μg/dl and none of the subjects in this study could be regarded to be vitamin A deficient.

ISSN:0963-7486    

DOI:10.3109/09637489409166154

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

There is now substantial evidence indicating that a critical genetic determinant in the propensity to fatness and leanness resides in the way in which the metabolic machinery manages a surplus or a deficit in food intake. From an integrated analysis of past and new data on the pattern of lean and fat tissue deposition or mobilisation during experimental overfeeding, underfeeding and refeeding, this review brings into focus the main determinants of interindividual variability in the regulation of body composition, and discusses their importance in the capacity to adapt to intermittent food availability under conditions of subsistence, and upon their role in susceptibility to obesity in more affluent societies.

ISSN:0963-7486    

DOI:10.3109/09637489409166155

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

Anin vitromethod to determine rates of pancreatic lipase-catalyzed hydrolysis of long-chain triacylglycerols is reported. This assay is designed to simulate more closely than do existingin vitroassays, conditions that prevail in the human duodenum. This assay is potentially useful for rapidly determining rates of lipolysis as influenced by lipid type and by various dietary components such as fiber. Included in the assay mixture are olive oil, lipase, colipase, emulsifiers (Span 60TM, Tween 60TM), buffer solution (2-[N-morpholino]ethanesulfonic acid), pH 6.5, four bile salts, calcium and sodium. The reaction is conducted at 37d`C and 150 rpm. Appropriate emulsion stability and particle size are achieved by sonification. The assay procedure was validated with respect to stopping the reaction, recovery of known amounts of added oleic acid and precision.

ISSN:0963-7486    

DOI:10.3109/09637489409166156

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The influence of bean proteins onin vitroFe and Zn dialysability was studied. Albumin and globulins (G1, G2) fromPhaseolus vulgariswere characterised by SDS-PAGE and disc electrophoresis. Fe and Zn dialysability from whole flour was 2.28 and 27.5% respectively. Among protein fractions, albumin showed the lowest mineral dialysability (0.4% for Fe, 2.5% for Zn) in spite of having the highest Fe and Zn content. Globulins (G1 and G2) differed mainly in Fe dialysability (2.99 and 5% respectively), while presenting a similar Zn dialysability (20.3 and 23.6% respectively). Protein dialysability from bean protein fractions showed the same trend observed for minerals (albumin

ISSN:0963-7486    

DOI:10.3109/09637489409166157

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The balances and content of the most abundant minerals (sodium, potassium, calcium and magnesium) in the body of Wistar, Zucker lean and Zucker obese rats fed a reference or cafeteria diet from days 30 to 60 after birth have been studied. Obese rats ingested more sodium when available, and retained it more than lean rats. Absorption of minerals was inversely correlated with their abundance in the diet and the amount of food consumed, and was affected by consumption of the cafeteria diet, which was poorer in minerals than the reference. Urinary excretion was maximal under conditions of highest internal availability for sodium, potassium and calcium, but was not affected by magnesium content of the diet. The accumulation in the body of the elements studied was more uniform when related to the amount of the element contained in the body. Genetic obesity showed a distinct pattern of management of minerals to cafeteria-diet-induced overweight, since the effects of diet on mineral content were less immediate than the differences due to strain or genetic obesity. In general, there were only slight differences due to strain in animals subjected to the same diet, and even more homogeneous data for all animals when provision for the diluting effect of fat on body mass was taken into account. It is concluded that the cafeteria diet is not deficient in potassium, calcium or magnesium, since the rat adapts its absorbing and retaining strategies to match the dietary availability of these minerals. The excess dietary sodium is excreted in the urine.

ISSN:0963-7486    

DOI:10.3109/09637489409166158

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

Our earlier studies have clearly shown that vitamin A in the form of retinyl palmitate added to refined soybean oil remains stable during cooking and storage and that fortification of commercial vegetable oils is feasible in Brazil and in other developing countries. The objective of the present study was to evaluate the biological value of vitamin A fortified soybean oil in normal adults by measuring the postabsorptive peak rise in plasma vitamin A and the total area under the absorption curve. Healthy subjects 20–51 years of age, serving as their own controls, were given a rice-based diet containing either unfortified soybean oil (control), or vitamin A fortified soybean oil added during cooking (cooked), or vitamin A fortified soybean oil added after cooking (uncooked). The results of this study demonstrated that vitamin A in the form of retinyl palmitate when added to soybean oil is well absorbed in human even after the heat treatment it received during cooking. It can be concluded from this study so far that vitamin A fortified soybean oil is very well utilised by human and that it can be an important source of vitamin A for populations in countries such as Brazil, where vitamin A deficiency is prevalent.

ISSN:0963-7486    

DOI:10.3109/09637489409166159

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The determination of ingredient composition and the study of manufacturing process effect on the mineral (calcium, magnesium and phosphorus) content of homogenised infant beikosts with a meat base was studied. The beikost types were chicken with rice (CR), veal with varrot (VC) and lamb with vegetables (LV). Beikosts are a good source of protein, because all samples showed protein levels above the international recommendations (4.2 g/100 kcal [1 g/100 kJ]). In general, phosphorus and magnesium are both widely distributed in all ingredients, and the calcium/phosphorus ratio varies widely in ingredients and beikosts, such as 0.07–0.09/1 for CR, 0.07–0.10/1 for VC and 0.23–0.26/1 for LV. The mean nutrient densities for calcium, magnesium and phosphorus were 6.38, 13.57, 82.40 mg/100 kcal (1.52, 3.24, 19.68 mg/100 kJ) for CR, 5.36, 13.76, 109.65 mng/100 kcal (1.28, 3.29, 26.19 mg/100 kJ) for VC, and 15.52, 16.19, 62.60 mg/100 kcal (3.71, 3.87, 14.95 mg/100 kJ) for LV. According to the recommended dietary allowances (RDA) supplied, meat-based beikosts are poor sources of calcium (from 1.32% to 4.84%) and phosphorus (from 14.64% to 27.2%), but a good source of magnesium (from 31.04% to 50.46%).

ISSN:0963-7486    

DOI:10.3109/09637489409166160

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The effect of cereal source and processing on postprandial glycaemic and insulinaemic responses to test meals of commercially-available cereal products was investigated in two groups of six healthy, non-obese volunteers. The first study investigated the possible effect of different cereal sources used to make bread. Portions of a wholemeal wheat bread containing 50 g carbohydrate were compared with portions of bread containing either 20% oat flour or 50% rye, selected on the basis of similar processing and composition except for cereal source and containing an equivalent amount of carbohydrate. The second study investigated the effect of different processing on cereal starch from one source. Portions of three wheat-based breakfast cereals, processed by puffing, flaking or shredding and containing 50 g carbohydrate were compared. In the first study no significant differences were found in the postprandial incremental responses (0–180 min) between the breads for either glucose, insulin or the insulin-stimulating gastrointestinal hormone glucose-dependent insulinotropic polypeptide (GIP). In the second study, the incremental responses (0–180 min) for glucose and insulin were significantly lower following consumption of puffed wheat compared with shredded wheat. There were no significant differences in postprandial GIP responses between the three breakfast cereals. We conclude that substitution of starches from different cereal sources in commercially available bread is without effect on glucose tolerance and insulin secretion. Processing in wheat-starch breakfast cereals did influence glucose tolerance and insulin secretion, but the effect was small. It appears that the starch processing undergone in the production of commercially-available breads and breakfast cereals is severe enough to render the starch readily digestible, regardless of cereal source and processing used, thus minimising any differences in metabolic responses.

ISSN:0963-7486    

DOI:10.3109/09637489409166161

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor