PubMed Health⌕ Search

Biomedical subjects

W Feldheim

Publications and source records attributed to W Feldheim.

At least 19 recordsLinked to original sources
PubMed2001

Anka and anka pigment production.

This study was conducted to determine the time-dependent changes of solid-state fermentation of rice with Monascus purpureus to produce anka and anka pigments. Growth of the fungus occurred prior to the synthesis of anka pigments. A steady increase in the yield of pigments occurred between the 5th and 15th days. After 15 days, growth of the fungus on rice substrate ceased and the yield of yellow anka pigments remained constant; however, orange anka pigments were reduced with a decreasing rate of 3.6 mg/g anka/day.

Ascomycota↗
PubMed2000

Short-chain fatty acids produced in vitro from fibre residues obtained from mixed diets containing different breads and in human faeces during the ingestion of the diets.

It was studied whether the type of bread (i.e. a low-fibre wheat-rye mixed bread and coarse or fine wholemeal rye bread) either as part of a diet or alone, had an influence on the short-chain fatty acids (SCFA) produced during in vitro fermentation. Fermentation substrates were dietary fibre residues obtained from diets and breads. In addition, it was investigated whether the faecal SCFA pattern in the inoculum donors, who ingested the experimental diets, could be predicted by in vitro fermentation. Yields of SCFA in vitro were 0.51-0.62 g/g fermented polysaccharide. In vitro, the molar ratios of butyrate were higher for the two high-fibre diets containing coarse or fine wholemeal bread than for the low fibre diet containing wheat-rye mixed bread; the difference was significant for the coarse (P < 0.01), but not for the fine bread diet (P = 0.0678). The coarse wholemeal bread alone produced a higher molar ratio of butyrate than the fine wholemeal bread (P < 0.05) and the wheat-rye mixed bread (P < 0.01). Ingestion by the inoculum donors of the diets containing wholemeal bread led to higher faecal butyrate ratios (molar ratios: coarse bread diet 19.6, fine bread diet 17.7) compared with the wheat-rye mixed bread-containing diet (14.9), but the differences between the diets were not significant. For the diets investigated, there were no significant differences between faecal and in vitro SCFA patterns.

Acetates↗
PubMed1998

Purification and characterization of retinyl ester hydrolase as a member of the non-specific carboxylesterase supergene family.

Hepatic retinyl ester hydrolase (REH) activity was isolated from porcine and human liver and characterized, and some of its properties were compared with those of other retinyl-ester-splitting enzymes. Sequence analysis revealed that the REH proteins are structurally similar to non-specific carboxylesterases and distinct from bile salt-activated lipases and cholesterol esterases. Pig REH, a 64-kDa protein, hydrolyzed retinyl palmitate at a rate of 595 nmol x h(-1) x mg(-1) protein in the presence of 100 mM Chaps with an apparent Km value for retinyl palmitate of 27.5 microM. The pH optimum was 7.0-9.2. Its human counterpart has a molecular mass of 65 kDa and a pH optimum near 6.5. In the presence of Chaps, pig REH activity was stimulated up to 1.7-fold by various non-ionic detergents. The ranking order of retinyl palmitate cleavage initiated by the stimuli was n-dodecylglucoside > octanoyl-N-methylglucamide > n-octyglucoside > n-dodecylmaltoside > Triton X-114 > Triton X-100. Porcine REH was effectively inhibited by alpha-tocopherol and bis-(4-nitrophenyl) phosphate [(Np)2P]. The structural, immunological and catalytic features, pH dependence, and the effect of (Np)2P on enzyme activity of pig REH are similar to those reported for the non-specific carboxylesterase ES-4. However, ES-4 differed from REH in molecular mass and the requirement of Chaps or Chaps-like detergents as cofactor. Judging from these results, pig REH may be a non-specific carboxylesterase isoform.

Amino Acid Sequence↗
PubMed1998

Fermentation of non-starch polysaccharides in mixed diets and single fibre sources: comparative studies in human subjects and in vitro.

The present study investigated whether the extent of fermentation of NSP in human subjects could be predicted by an in vitro batch system. Fibre sources studied were five mixed diets containing different amounts and types of fibre and three single fibre sources (citrus fibre concentrate, coarse and fine wholemeal rye bread). Fermentation in human subjects was determined in balance experiments in women who were also donors of the faecal inocula. In vitro fermentations were performed with fibre residues prepared from duplicates of the fibre-containing foods consumed during the balance trials. Fermentation of total NSP in vivo was between 65.8 and 88.6% for the mixed diets and 54.4, 58.0 and 96.9% for the coarse and fine wholemeal rye breads and the citrus fibre concentrate respectively. For the mixed diets and the citrus fibre concentrate, mean differences between the extent of NSP degradation after 24 h in vitro incubation and that in vivo were between -0.7 and 5.0%. Differences were significant for one diet (P < 0.05). For the wholemeal rye breads, the fermentation in vitro exceeded that in vivo significantly, but the magnitude of the difference in each case was small and without physiological importance. Particle size of breads had no influence on the extent of NSP degradation. These results indicate that the in vitro batch system used could provide quantitative data on the fermentation in vivo of NSP in mixed diets and some single fibre sources. An in vitro incubation time of 24 h was sufficient to mimic the NSP degradation in vivo.

Adult↗
PubMed1997

Energy values of non-starch polysaccharides: comparative studies in humans and rats.

Energy values of non-starch polysaccharides (NSP) were estimated from NSP fermentability and from digestible energy balances in human subjects and in rats. During four studies, humans consumed four low fiber control diets and six high fiber diets. For the rat diets, duplicates of the foods consumed by humans were mixed together, freeze-dried and ground. Calculated from fermentability, partial digestible energy values of NSP in humans and rats, respectively, were 8.2 +/- 1.3 and 5.7 +/- 1.2 (P = 0.0013, fruits and vegetables), 11.4 +/- 0.7 and 5.7 +/- 3.2 (P = 0.0001, citrus fiber), 5.0 +/- 2.1 and 2.2 +/- 3.3 (P = 0.0429, barley fiber at high protein intake), 4.4 +/- 1.8 and 2.4 +/- 2.0 (P = 0.0561, barley fiber at low protein intake), 6.7 +/- 1.4 and 7.6 +/- 1.2 (P = 0.296, coarse whole meal rye bread), and 7.1 +/- 0.6 and 6.1 +/- 1.7 (P = 0.157, fine whole meal rye bread) kJ/g NSP. Calculated from energy balances, partial digestible energy values of NSP in humans and rats, respectively, were 2.1 +/- 3.5 and -5.0 +/- 4.0 (P = 0.026, fruits and vegetables), 10.7 +/- 5.1 and 1.4 +/- 5.6 (P = 0.003, citrus fiber), 1.6 +/- 5.1 and -17.8 +/- 8.6 (P = 0.0001, barley fiber at high protein intake), -2.6 +/- 4.9 and -9.3 +/- 8.2 (P = 0.044, barley fiber at low protein intake), -3.0 +/- 7.0 and 0.9 +/- 2.5 (P = 0.27, coarse whole meal rye bread), and 0.9 +/- 5.1 and 0.6 +/- 3.7 (P = 0.89, fine whole meal rye bread) kJ/g NSP. Net energy values were 70% of digestible energy values. Differences between species were significant for NSP in fruits and vegetables, citrus fiber, and barley fiber at high protein intake. Most energy values calculated from energy balances were significantly lower than values calculated from NSP fermentation, with differences being greater in rats than in humans. Thus, the energy values of some types of NSP contained in mixed diets could not be estimated accurately from NSP fermentability either in humans or rats. In addition, our results suggest that the rat is not always a suitable model of humans for predicting energy values of NSP in mixed diets.

Adult↗
PubMed1997

Fermentation in human subjects of nonstarch polysaccharides in mixed diets, but not in a barley fiber concentrate, could be predicted by in vitro fermentation using human fecal inocula.

The fermentation of nonstarch polysaccharides (NSP) contained in a low fiber diet, two high fiber diets high or low in protein, and a barley fiber concentrate was determined in balance experiments in six women and in an in vitro batch system using fecal inocula obtained from these same women. In vitro fermentations were performed with fiber residues prepared from duplicates of the fiber-containing foods consumed during the balance trials. Fermentation of total NSP in humans was 83.8 +/- 0.9% (low fiber diet), 61.8 +/- 3.6% (high fiber diet high in protein), 59.2 +/- 3. 9% (high fiber diet low in protein) and 31.2 +/- 7.4% (barley fiber concentrate). Fermentation in vitro differed from fermentation in humans by -4.0 +/- 1.6% (low fiber diet, P < 0.05,), 4.9 +/- 3.7% (high fiber diet high in protein), 8.8 +/- 3.0% (high fiber diet low in protein, P < 0.01) and 19.7 +/- 8.0% (barley fiber concentrate, P < 0.05). Differences between in vivo and in vitro fermentation were most pronounced for NSP-glucose, i.e., cellulose. Production of short-chain fatty acids in vitro corresponded to the fermentability of NSP. The yield of short-chain fatty acids per gram of fermented NSP was similar for the diets (8.8-9.4 mmol) but lower for the barley fiber concentrate (7.4 mmol, P < 0.05). Although differences between the fermentation measured in humans and in vitro were significant for two diets, the magnitude of the differences was such that fermentation of NSP in mixed diets could be predicted with sufficient accuracy in vitro, whereas agreement between the fermentation in vivo and in vitro of NSP in the barley fiber concentrate was not satisfactory.

Adult↗
PubMed1996

Digestibilities of energy, protein, fat and nonstarch polysaccharides in a low fiber diet and diets containing coarse or fine whole meal rye are comparable in rats and humans.

The apparent digestibility of energy, protein, fat and nonstarch polysaccharides (NSP) of a low fiber diet and two high fiber diets containing coarse or fine whole meal rye bread was studied in experiments with humans and rats. Human subjects consumed the experimental diets for 3 wk each in a 3 x 3 cross over design. For the rat diets, duplicate portions of the foods consumed by the human subjects were mixed together, freeze dried and ground. There was a good agreement in the digestibility of energy (humans: 94.7 +/- 0.9, 91.2 +/- 1.2 and 91.6 +/- 1.4%; rats: 95.0 +/- 0.8, 92.5 +/- 1.4 and 91.7 +/- 1.8%) and fat (humans: 95.2 +/- 1.5, 94.4 +/- 1.0 and 94.8 +/- 2.5%, rats: 95.4 +/- 0.9, 94.0 +/- 0.4 and 94.0 +/- 0.4%) for the low fiber diet and the diets containing coarse or fine whole meal bread, respectively. Apparent and true digestibility of protein was consistently lower (P < 0.0001) in humans (apparent digestibility: 90.6 +/- 1.5, 86.2 +/- 1.4 and 86.3 +/- 2.3%; true digestibility: 95.1 +/- 1.5, 90.7 +/- 1.4 and 90.8 +/- 2.2%) than in rats (apparent digestibility: 92.3 +/- 1.1, 89.4 +/- 0.9 and 88.9 +/- 1.0%; true digestibility: 98.3 +/- 1.1, 94.9 +/- 0.9 and 94.2 +/- 1.0%) for all three diets. The digestibility of NSP tended to be lower (P < 0.066) in rats than in humans for the diet containing fine whole meal bread (rats: 59.6 +/- 8.0%, humans: 68.0 +/- 5.2%) and the low fiber diet (rats: 72.1 +/- 10.8%; humans: 80.5 +/- 7.1%), whereas it was similar in both species for the diet containing the coarse whole meal bread (rats: 66.1 +/- 6.0%; humans: 65.8 +/- 9.3%). In spite of some differences in digestibility values, our results suggest that the rat is a suitable model for humans to predict digestibility of nutrients in mixed diets containing cereal fiber sources.

Adult↗
PubMed1994

Fibre-mediated physiological effects of raw and processed carrots in humans.

Fibre-mediated physiological effects of raw and processed carrots were investigated in twenty-four young women under strict dietary control in two randomized crossover studies. For 3 weeks between 405 and 688 g of either raw frozen, blanched or canned carrots (first study), or raw or raw frozen carrots (second study) were consumed in addition to a low-fibre basal diet. Carrots provided 15 g dietary fibre (DF)/d. Total DF intake was 16.0 to 19.0 g (control periods) and 31 to 34 g (experimental periods). Faecal bulking effects of raw and processed carrots were similar (between 2.4 and 3.7 g additional stool/g carrot fibre in the diet). Faecal excretion of dry matter, fibre, and protein also increased significantly during carrot consumption. Fermentability of carrot fibre constituents was high (91-94%) and independent of processing, in spite of differences in the distribution of soluble and insoluble fibre and in the texture of raw and processed carrots. There was no effect of either type of carrot on serum total and high-density-lipoprotein-cholesterol or on faecal bile acid excretion.

Adult↗
PubMed1994

Digestibility of energy, protein, fat and non-starch polysaccharides in mixed diets: comparative studies between man and the rat.

The apparent digestibility of energy, protein, fat and non-starch polysaccharides (NSP) of low and high dietary fibre (DF) mixed diets were studied in three series of experiments with man and the rat. Low DF diets were used as control diets in each experimental series and the DF level was increased by adding fruits and vegetables (Study 1), citrus fibre concentrate (Study 2) and insoluble barley fibre (Study 3). In Study 3 the high DF diet was fed at two protein levels. There was in most cases good agreement between the digestibility of energy between man and the rat, with the digestibility of energy of the low DF control diets of 0.941-0.950 in man compared with 0.933-0.952 in the rat and of the high DF diets of 0.897-0.931 in man and 0.865-0.920 in the rat. The biggest difference in digestible energy between the two species was found for the diet enriched with fruits and vegetables (0.032 absolute units) and citrus fibre concentrate (0.025 absolute units). Apparent digestibility of protein was slightly lower in man than in the rat for all diets in Studies 1 and 2. In Study 3, however, apparent digestibility of protein was consistently lower in man than in the rat with differences in absolute digestibilities between the two species varying from 0.023 (high DF/high protein) to 0.071 (high DF/low protein). The digestibility of fat was the same in man and in the rat in all but the high DF diet of Study 2. The rat appears to have a lower capacity to digest fibre polysaccharides than man and the digestibility of NSP was consistently lower in the rat than in man. The biggest difference between the two species was found for the diets in Study 2 where the digestibility of NSP in man was measured to be 0.774-0.885 compared with only 0.501-0.517 in the rat. For the other diets the differences in NSP digestibility were 0.077-0.137 absolute units. In spite of some differences between man and the rat in their ability to digest nutrients the various diets are ranked in the same order by the two species.

Adult↗
PubMed1993

The influence of lecithin on plasma choline concentrations in triathletes and adolescent runners during exercise.

An investigation was carried out on the effect of lecithin (phosphatidylcholine, 90%) on the plasma choline concentrations during continuous strain in 10 top level triathletes (4 women and 6 men), trial I, and 13 excellent adolescent runners (3 girls and 10 boys), trial II. Venous blood, collected before and immediately after the race, was separated and plasma was assayed by an improved high performance liquid chromatography method for choline. Each study comprised three experiments. In trial I the triathletes performed two periods of bicycle exercise each lasting 2 h at an average speed of 35 km.h-1, and in the second study (trial II) the subjects were subjected to severe physical stress on two occasions during cross-country races of durations between 30-60 min according to their ages. The participants received either a placebo or 0.2 g lecithin.kg body mass-1, 1 h before each exercise. As a control the same dose of lecithin was administered without any exercise (both trials I and II). Bicycle exercise without lecithin supply decreased plasma choline concentrations in all the triathletes, on average by 16.9% (P < or = 0.01). When lecithin was given before exercise, average plasma choline concentrations remained at the same level as the initial values. The supply of lecithin without exercise led to a significant increase of the plasma choline concentrations, on average by 26.9% (P < or = 0.01). In trial II, when running without a supply of lecithin, the mean plasma choline concentrations in the adolescent runners remained stable which may have been due to the duration of the physical stress.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Is there a correlation of dietary fiber to the calculation of calorific value of food? Comparison of the experimental determination and the calculated metabolizable energy of 16 diets with different fiber content].

The metabolizable energy (ME) of 16 diets containing various amounts and sources of dietary fibre was calculated by different energy assessment procedures and determined experimentally in balance studies in humans. ME was calculated by the German procedure (section 35 LMBG; 4/9/4) and by the British procedure (4/9/3.75). In addition, both calculation procedures were modified to take into account the energy value of dietary fibre. Dietary fibre was multiplied by an energy conversion factor of 1 or 2 kcal/g, respectively. The best agreement between measured and calculated ME was obtained when a conversion factor of 1 kcal/g fibre (German procedure) or of 2 kcal/g (British procedure) was used.

Adult↗
PubMed1991

Calcium, magnesium, zinc, and iron balances in young women: effects of a low-phytate barley-fiber concentrate.

The effects of a low-phytate barley-fiber concentrate on calcium, magnesium, and zinc balances and on apparent iron absorption were measured by balance experiments. During the three experimental periods of 22 d each, all subjects consumed the basal diet alone, the basal diet with 15 g barley fiber (high-fiber, high-protein diet), and a modified basal diet containing less protein with 15 g barley fiber (high-fiber, low-protein diet), respectively. The mean daily intake of the cations was 24.4, 25.4, and 22.9 mmol Ca; 10.4, 10.1, and 10.0 mmol Mg; 165.2, 166.8, and 119.3 mumol Zn; and 154.0, 186.2, and 154.0 mumol Fe, respectively. Mean balances were 0.2, 1.9, and -0.8 mmol Ca; 0.3, -0.2; and -0.5 mmol Mg; 3.0, -4.6, and -18.4 mumol Zn. The mean apparent iron absorption was 16.1, 5.4, and -23.2 mumol when these three diets, respectively, were consumed.

Adult↗
PubMed1990

Metabolizable energy of diets low or high in dietary fiber from fruits and vegetables when consumed by humans.

The metabolizable energy (ME) of two diets, which differed in their content of dietary fiber mainly from fruits and vegetables, was determined in balance experiments in eight young women. The ME of the diets was also calculated by the specific factors of Merrill and Watt, by the general factors of Atwater, by the modification of Atwater's procedure used in the Federal Republic of Germany, and also by the equations of Southgate, of Miller and Payne, and of Miller and Judd. The daily intake of fruits, vegetables and potatoes was 505 and 1235 g with the low and the high fiber diets, respectively. Normally, young German women consume only 350 g of these foods each day. Dietary fiber intake was 18.8 g/d with the low fiber diet and 52.0 g/d with the high fiber diet. Daily gross energy intakes were 8540 and 8916 kJ (2041 and 2131 kcal) with the low and the high fiber diets, respectively. The apparent digestibility of energy was lower when the high fiber diet was consumed. Measured ME was 7665 and 7544 kJ/d (1831 and 1802 kcal/d) with the low and high fiber diets, respectively. It was calculated that fiber from fruits and vegetables contributed to ME about 3 kJ (0.7 kcal) per gram of fiber. On the average, the ME of the low fiber diet could be predicted by all calculation procedures except the formula of Miller and Judd. The ME of the high fiber diet could best be predicted by the specific factors of Merrill and Watt and by the Southgate formula.

Adult↗
PubMed1990

[Is sugar a nutrient robber?].

There is no scientifically based evidence, that sucrose as currently consumed interferes with the metabolism of micronutrients. Thiamine is essential and needed for the metabolism of sucrose but for all the other carbohydrates as well. The observation, that sucrose is diminishing the calcium stores of animal bodies (1926) was proved to be false in 1956 already.

Animal Nutritional Physiological Phenomena↗
PubMed1989

Iron, zinc, folate and vitamin B12 nutritional status and milk composition of low-income Brazilian mothers.

The purpose of this study was to assess the nutritional status of low-income Brazilian mothers, who were supplemented with iron and vitamin B12 during pregnancy, in terms of iron, zinc, folate and vitamin B12, in different stages of lactation and to determine the influence of the maternal nutritional status on milk composition. The effect of folate supplementation during pregnancy on folate status of the nursing mothers and milk composition was investigated. The effect of partial weaning on maternal status and milk composition was also studied. In general, the nutritional status of iron, zinc, folate and vitamin B12 of the mothers appears adequate. However, some of the mothers had indices of status lower than normal limits for non-pregnant women. These values, particularly after 30 d post-partum, indicate that these mothers might be at nutritional risk and that the nutrient supplementation received during pregnancy was insufficient to meet demands. There was an increase with the stage of lactation for haematocrit, serum vitamin B12, serum zinc, serum albumin, milk folate and saturation of its binding protein, but there was a decrease for milk protein, total and whey-bound iron and zinc, and lactoferrin. Mothers who took folate supplements during pregnancy had higher serum folate levels immediately after birth than those not taking the supplements but no differences were found at later stages of lactation. Milk composition was not affected. Partial weaning did not affect the maternal nutritional status or the milk composition except for iron which was higher in milk from mothers who were partially breastfeeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Brazil↗
PubMed1988

Metabolizable energy of diets low or high in dietary fiber from cereals when eaten by humans.

The metabolizable energy (ME) of two diets that differed in their content of dietary fiber (DF) from cereal products was measured in balance experiments in six human subjects. DF intake was 19.7 g/d with the low fiber diet and 48.3 g/d with the high fiber diet. Daily gross energy intakes were 2114 kcal (8845 kJ) and 2341 kcal (9795 kJ)/d with the low and the high fiber diets, respectively. DF contributed 83 kcal (347 kJ) and 203 kcal (849 kJ) to daily gross energy intake with the low and the high fiber diets, respectively, when heat of combustion of DF of 4.2 kcal (17.6 kJ)/g was assumed. Increasing the intake of DF resulted in an increase in stool weight and a greater fecal energy loss. Total energy losses were 253 kcal (1056 kJ) and 409 kcal (1711 kJ)/d with the low and the high fiber diets, respectively. ME provided by the low and the high fiber diet were 1861 kcal (7786 kJ) and 1932 kcal (8083 kJ)/d. The total increase in energy losses due to the increase in DF consumption exceeded the gross energy provided by additional DF. Compared with the low fiber diet, ME provided by protein and fat was decreased during the high fiber diet. Calculation of the apparent digestibility of DF indicated that fiber may have provided ME in the form of short-chain fatty acids during the low as well as during the high fiber intake. However, estimation of the amount of fecal gross energy indicated that available components of the diet, such as starch, must have been utilized incompletely during both experimental periods.

Adult↗