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PubMed1992

Effect of overcooked soybean meal on chicken performance and amino acid availability.

Studies were conducted to evaluate the effect of overcooked soybean meals (SBM) on chick growth and amino acid availability. The SBM were custom-prepared at a commercial processing plant by changing the conditions of a desolventizer-toaster (DT) unit. Six progressively overcooked meals (designated SBM1 to 6 with SBM1 as normal, and SBM6 overcooked) were produced by increasing temperature by up to 50% and extending retention time by up to 75% above normal. The meals measured .05, .03, .01, .09, .00, and .00 delta pH of urease activity; 6.10, 5.01, 4.62, 4.83, 2.32, and 1.78 mg/g SBM of trypsin inhibitor activity; 92, 89, 91, 88, 81, and 81% of protein solubility in .2% KOH; and 46, 43, 41, 40, 23, and 19% of protein solubility in .1 M borate at 40 C, respectively. Glucose content in the hydrolysate of the soluble carbohydrate extract did not differ among the meals, indicating no differences in the degradation of sucrose, raffinose, and stachyose with increasing heat treatment. In a chick growth experiment with a methionine-adequate, low-protein diet, chicks fed SBM1 showed significantly greater weight gain than chicks fed SBM3, 5, or 6. The SBM1, 2, 5, and 6 were chosen for a study of amino acid availability. No differences were observed in amino acid content. There were significant differences in apparent amino acid availability to growing chicks, but not in true amino acid availability by adult roosters among the four meals. The results suggest that the temperature or the retention time of a DT unit may be increased by 50% over the usual operating conditions without reducing amino acid availability from SBM.

Amino Acids↗

PubMed1991

Pornography and rape: theory and practice? Evidence from crime data in four countries where pornography is easily available.

We have looked at the empirical evidence of the well-known feminist dictum: "pornography is the theory--rape is the practice" (Morgan, 1980). While earlier research, notably that generated by the U.S. Commission on Obscenity and Pornography (1970) had found no evidence of a causal link between pornography and rape, a new generation of behavioral scientists have, for more than a decade, made considerable effort to prove such a connection, especially as far as "aggressive pornography" is concerned. The first part of the article examines and discusses the findings of this new research. A number of laboratory experiments have been conducted, much akin to the types of experiments developed by researchers of the effects of nonsexual media violence. As in the latter, a certain degree of increased "aggressiveness" has been found under certain circumstances, but to extrapolate from such laboratory effects to the commission of rape in real life is dubious. Studies of rapists' and nonrapists' immediate sexual reactions to presentations of pornography showed generally greater arousal to non-violent scenes, and no difference can be found in this regard between convicted rapists, nonsexual criminals and noncriminal males. In the second part of the paper an attempt was made to study the necessary precondition for a substantial causal relationship between the availability of pornography, including aggressive pornography, and rape--namely, that obviously increased availability of such material was followed by an increase in cases of reported rape. The development of rape and attempted rape during the period 1964-1984 was studied in four countries: the U.S.A., Denmark, Sweden and West Germany. In all four countries there is clear and undisputed evidence that during this period the availability of various forms of pictorial pornography including violent/dominant varieties (in the form of picture magazines, and films/videos used at home or shown in arcades or cinemas) has developed from extreme scarcity to relative abundance. If (violent) pornography causes rape, this exceptional development in the availability of (violent) pornography should definitely somehow influence the rape statistics. Since, however, the rape figures could not simply be expected to remain steady during the period in question (when it is well known that most other crimes increased considerably), the development of rape rates was compared with that of non-sexual violent offences and nonviolent sexual offences (in so far as available statistics permitted). The results showed that in none of the countries did rape increase more than nonsexual violent crimes. This finding in itself would seem sufficient to discard the hypothesis that pornography causes rape.(ABSTRACT TRUNCATED AT 400 WORDS)

Cross-Cultural Comparison↗

PubMed1990

The effects of glucocorticoids on the availability of L-tryptophan and tyrosine in the plasma of depressed patients.

There is evidence that a functional deficit of serotonin/noradrenaline and/or of their precursors L-tryptophan (L-TRP)/tyrosine and disorders in the hypothalamic-pituitary-adrenal (HPA) axis are linked to the pathophysiology of severe depressions. Several reports suggest a reciprocal relationship between these neurotransmitters and HPA axis activity. In order to investigate the effect of glucocorticoid excess on the availability of L-TRP and tyrosine to the brain, we measured urinary cortisol (UC) excretion in 24-h urine, and the availability of both amino acids before and after treatment with 1 mg dexamethasone in 26 depressed patients. We found no relationship between UC excretion and the availability of either amino acid. Dexamethasone significantly suppressed the availability of L-TRP (P less than 10(-5] and of tyrosine (P = 0.005). Major depressed patients with melancholia exhibited a significantly lower availability of L-TRP than minor depressives (P = 0.007).

Amino Acids↗

PubMed1975

Estimation of available methionine and cysteine in proteins of food products by in vivo and in vitro methods.

1. The available methionine and cysteine of proteins were determined by chemical methods after preliminary enzymic hydrolysis. 2. The values for the available methionine and cysteine contents of pure proteins (casein and bovine serum albumin) estimated by chemical methods were similar to those for the total content determined by the method of Moore, Spackman & Stein (1958). 3. Reductions of 15 and 11% respectively, when compared with unprocessed samples, were found in the available methionine contents of sweetened and unsweetened, condensed milks; of roller-dried milk and whey powders, and of mackerel sterilized at 126 degrees, the reductions were 22, 14 and 19% respectively. 4. The available cysteine content of sweetened, condensed milk was reduced by about 32%, whereas for mackerel sterilized at 115 and 126 degrees it was reduced by 64 and 75% respectively. 5. The contents of total sulphur amino acids for these food products did not differ from those for the unprocessed samples. 6. Values obtained for available S amino acid contents by rat bioassay confirmed the results of the in vitro estimations.

Animals↗

PubMed1977

An improved method for the microbiological assay of available amino acids in proteins using Tetrahymena pyriformis.

1. A standard microbiological procedure for the assay of available amino acids in proteins using Tetrahymena pyriformis has been modified by evaluating cell growth from the tetrahymanol content of the cultures by gas-liquid chromatography (GLC). 2. This modification improves the precision of the method compared with cell-counting techniques and provided automatic injection facilities are available for the GLC, the procedure is not excessively time-consuming. 3. It has been confirmed that enzymic predigestion is essential for all except the most soluble proteins and a satisfactory method using pronase has been incorporated into the microbiological procedure. 4. After enzymic digestion of the sample, growth of Tetrahymena with many proteins can be measured turbidimetrically, but particulate matter still persists with a proportion of samples, particularly those of plant origin, and the GLC method is therefore more widely applicable. It is also more precise. 5. Good agreement has been obtained between a chick bioassay and the modified Tetrahymena assay for available lysine in eight different proteins, including heat-damaged fish meals. 6. The modified procedure appeared to give good results for available tryptophan and methionine. 7. When cystine was omitted from the standard culture medium it was possible to test for available methionine plus cystine, but further work is required to assess the reliability of this particular assay.

Amino Acids↗

PubMed1979

Protein quality in cereals and pulses. 2. Influence of polyethyleneglycol on the nutritional availability of methionine in sorghum (Sorghum vulgar Pers.), field beans (Vicia faba L.) and barley.

1. Polyethyleneglycol (PEG 4000) was examined for its influence on relative nutritional value (RNV) and available methionine in sorghum (Sorghum vulgare Pers.), field beans (Vicia faba L.) and barley, as measured microbiologically with Streptococcus zymogenes. The results were assessed in relation to the content of tannins in the test samples. 2. In grain of hybrid sorghum the RNV averaged 87 (range 79--92) for six low-tannin varieties and 41 (30--53) for eleven high-tannin varieties. The corresponding available methionine values averaged 17.0 (15.7--18.9) and 8.9 (6.7--11.0) g/kg protein. Addition of PEG 4000 to the test samples increased the average RNV of the high-tannin varieties from 41 to 78, and the average available methionine content from 8.9 to 16.2 g/kg protein. 3. With seed of ten coloured flowered varieties of field beans, treatment with PEG gave a small but consistent increase in the available methionine content, which resulted from the inactivation of tannins in the testa. 4. In twenty-three samples of barley grain, treatment with PEG had no effect on the values obtained for available methionine. 5. Treatment of high-tannin sorghum grain with ammonia has been reported to inactivate the tannins and increase the nutritional value for rats and chicks. This finding was confirmed. The present study showed that ammonia and PEG 4000 were equally effective in enhancing the nutritional quality as measured in the microbiological tests.

Dietary Proteins↗

PubMed1977

Determination of zinc availability in foods by the extrinsic label technique.

The absorption of intrinsic 65Zn and extrinsic 65Zn from corn and liver was measured in rats. No significant difference between the absorption of intrinsic- and extrinsic-label was observed. These results indicate that endogenous zinc and exogenous 65Zn enter a common pool prior to being absorbed from the intestine. Since extrinsic 65Zn enters a common pool with intrinsic zinc, whole-body absorption of extrinsic 65Zn can be used to obtain an accurate estimate of the availability of zinc in food. The availability of zinc in human breast milk, in cow's milk, in infant formulas, and in reconstituted dry milk was analyzed by use of the extrinsic label. The zinc in human breast milk was most available (59%) while the zinc in the infant formulas was the least available (26 to 37%). Zinc from both raw and cooked corn was more available than zinc from either cooked or uncooked rat liver.

Absorption↗

PubMed1991

Reassessment of trans fatty acid availability in the US diet.

This report updates our 1984 estimate of the amount of trans fatty acids available for consumption in the US diet, namely 7.6 g.person-1.d-1, for 1989. Compared with 1984 data, we found essentially no change in 1989 for the per capita availability of trans fatty acids from total food service fats and oils. The 1989 value we obtained for industrial fats and oils is somewhat higher than the value we reported for 1984, in part because more complete data were available for 1989. In contrast, however, since 1984 the per capita availability of trans fatty acids from household salad and cooking oils, household shortenings, and all margarines and spreads (retail, food service, and industrial) has decreased. Overall, our reassessed (1989) value for total trans fatty acid availability is 8.1 g.person-1.d-1, which is similar to our original estimate. This total may increase slightly (approximately 0.3 g.person-1.d-1) as a result of the recent switch by many establishments from the use of tallow to partially hydrogenated vegetable oils for frying.

Dairy Products↗

PubMed1976

The availability of folates in man: effect of orange juice supplement on intestinal conjugase.

The mechanisms of the low availability of endogenous folates in orange juice and the inhibitory effects on the availability of pteroylheptaglutamate (PteGlu7) caused by orange juice supplements were investigated in man by the use of simulated orange juice (containing the principal components: citric acid, malic acid, etc.) with several different pHs. The endogenous folates in orange juice were identified as mainly 5-methyl reduced derivatives of pteroylpolyglutamates (40-45% pentaglutamate, 10-15% tetraglutamate, 30-40% monoglutamate, and the rest were tri-and diglutamates). The availability of PteGlu7 is decreased to 54% by supplementation with 600 g concentrated orange juice (pH 3.7) and to 39% and 66% by the supplement of 24 g and 12 g citric acid (pH 3.7), respectively. Neutralization of 12 g citric acid to pH 6.4 largely reverses the inhibitory effect. On the other hand, the availability of pteroylmonoglutamate (PteGlu) is not influenced by a supplement of orange juice or citric acid. The results suggest that the low availability of PteGlu7 is due to the inhibition of intestinal conjugase caused by the low pH. These observations suggest that pH of foodstuffs may be an important factor in the absorption of polyglutamate forms of folate.

Adult↗

PubMed1992

Forage availability x heifer phenotype interactions for Brahman-Hereford F1 yearling heifers grazing humid pasture and semiarid rangeland.

Yearling heifer growth data were obtained during 4 yr for 524 heifers allotted to either humid bermuda grass pastures (Overton) or semiarid rangeland (Uvalde). Each year, heifers were allotted on April 15 to four forage availability levels (400 to 2,800 kg of DM per 100 kg of BW at Uvalde and 80 to 260 kg of DM per 100 kg of BW at Overton) maintained by varying the stocking rate monthly until mid-October of each year. Forage availability and yearling heifer characteristics (weight, condition score, and height at hooks, taken on April 15) were treated as continuous variables in regression analyses. Final heifer weight, height, and condition responses to increased forage allowance were related to yearling phenotypes differently for the two locations. Generally, at Overton, forage availability influenced final characteristics to a greater extent than did yearling variables, whereas the trend was the opposite at Uvalde. At Uvalde, the yearling characteristic that had the largest effect on performance was height at hooks. Yearlings with large frames benefited from increased forage allowance by accumulating body fat at a faster rate than those with small frames. In contrast, at Overton, the yearling characteristic that had the largest effect on performance was condition. Fat heifers responded to increased forage availability to gain even greater advantages in fatness at the expense of potential growth in height and, thus, achieved early maturation. Yearling phenotypes were more broadly adapted to arrays of forage availability for humid, improved pastures than for semiarid rangeland.

Adipose Tissue↗

PubMed1976

Assessment of the quantity of biologically available phosphorus in yeast RNA and single-cell protein.

Two assays were conducted with chicks fed a phosphorus-deficient crystalline amino acid diet from day 8 to 17 posthatching to evaluate the phosphorus availability of purified torula yeast RNA and single-cell protein (Torula yeast). Tibia bone ash of the chicks was the criterion used in both assays, and regression analysis was used to evaluate bone ash as a function of phosphorus intake. A standard curve was established by feeding graded levels of KH2PO4 in each assay. Weight gain, tibia weight and tibia ash all responded to phosphorus supplementation whether provided by KH2PO4, RNA or single-cell protein. Weight of tibia ash provided the best linear fit when evaluated as a function of phosphorus intake. Availability in both assays estimated using the slope-ratio technique wherein milligrams of available phosphorus per gram of RNA or single-cell protein was calculated. In assay 1 the available phosphorus in RNA was found to be 93.2 mg/. In assay 2 the available phorphorus in single-cell protein was found to be 14.1 mg./g.

Animal Feed↗

PubMed1977

The available lysine requirements of 7-9 week old sexed broiler chicks.

The experiments were conducted to determine the available lysine requirement of broiler chicks during the 7-9 week growing period. The chicks were sexed at day old, and the sexes were reared in separate pens in the same facility. Commercial-type broiler rations were fed from day old to 7 weeks of age. At 7 weeks the sexing errors were removed and the pens equalized to 50 birds per pen. The eight dietary treatments were replicated three times per sex. Graded levels of L-lysine-HCL were added to the basal ration to give a stepwise increase of 0.07% lysine per level. The available lysine requirement for female during the 7-9 week period was 0.64% for both growth and feed conversion. When this was expressed as a function of energy, 0.187% available lysine per megacalorie of metabolizable energy (M.E) per kg. of diet was required. The available lysine requirement for males during this period was 0.69 and 0.66% for gain and feed conversion, respectively. Expressed as available lysine per megacalorie of M.E. per kg. of diet, the values would be 0.202 and 0.193%, respectively.

Age Factors↗

PubMed1977

Availability of oxidized sulfur amino acids for the growing chick.

In four trials, experimental diets were fed to one week old broiler cockerels for a period of 14 days to compare the availability of oxidized sulfur amino acids to DL-methionine on an equimolar basis. The data were analyzed by the slope-ratio technique. Chick weight gain per unit feed consumed was the dependent variable and dietary level of supplemental amino acid was the independent variable. There was no significant (P=.05) differences in availability of DL-, L-, and D-methionine. D-, DL-, and L-methionine sulfoxide were 52, 59 and 77%, respectively, as available as DL-methionine. The differences in availability between the three sulfoxides and DL-methionine were significant. Both DL- and D-methionine sulfoxide were significantly less available than L-methionine sulfoxide. No response was obtained from L-cysteic acid or DL-methionine sulfone.

Amino Acids, Sulfur↗

PubMed1992

The role of availability in the estimation of national populations.

In two parallel experiments, conducted 17 months apart, we examined the relations among population estimates, availability, and media coverage of the 100 countries with populations of 4 million or more. The results were consistent with the main hypothesis, that availability influences population estimates. Specifically, we found that (1) rated knowledge of each country (our measure of availability) was strongly correlated with estimated population for that country; (2) rated knowledge was more strongly correlated with estimated population than were other plausible predictors, such as land area; (3) a strong partial correlation between rated knowledge and estimated population remained even after true population and true land area were partialed out; and (4) longitudinal changes in rated knowledge predicted longitudinal changes in estimated population. Also as hypothesized, media coverage was positively related to availability and to population estimates. Further, we found that population estimates, rated knowledge, and amount of media coverage that each country received were very stable over the year-and-a-half period. These results led us to consider when availability is most likely to be relied upon heavily in quantitative estimation and how it may be integrated with other knowledge to derive quantitative estimates.

Adult↗

PubMedDate not supplied

Clinical comparison of the anticalculus efficacy of three commercially available dentifrices.

A three-month, double-blind, parallel and unsupervised clinical study was conducted to compare the effects on supragingival calculus formation of the following four dentifrices: 1) A placebo dentifrice containing 0.243% sodium fluoride in a silica base. 2) A commercially available anticalculus dentifrice containing 5.0% soluble pyrophosphate in a 0.243% sodium fluoride silica base. 3) A commercially available anticalculus dentifrice containing 1.3% soluble pyrophosphate and 1.5% of a Gantrez copolymer in a 0.243% sodium fluoride silica base. 4) A commercially available anticalculus dentifrice containing 3.3% soluble pyrophosphate and 1.0% of a Gantrez copolymer in a 0.243% sodium fluoride silica base. The three-month results indicated that the three commercially available anticalculus dentifrices provided statistically significant reductions (at the 99% level of confidence) in supragingival calculus formation of 43.87%, 46.60%, and 51.32% respectively, as compared to the placebo dentifrice. There was no statistically significant difference among the three commercially available anticalculus dentifrices.

Adult↗

PubMed1988

Estimating reduced availability due to first pass elimination from relative total clearance and renal clearance.

A simple formula is presented for estimating the systemic availability of an orally administered drug from the relative total clearance (oral clearance) when renal clearance forms an important part of total clearance. Hepatic plasma flow is used in the equation and is represented by an average value taken from the literature. The formula is applied to data for cimetidine discussed in the literature. A further application is demonstrated for a drug under development for which an intravenous formulation was not available. It is possible to estimate the upper and lower limit of availability if some information on the amount of drug absorbed is available.

Administration, Oral↗

PubMed1991

Extent of damage to amino acid availability of whey protein heated with sugar.

The effect of heat treatments, at various water activities (aW), on digestibility and on the availabilities of amino acids of whey protein samples in the presence of lactose was estimated by an in vitro digestion method with continuous dialysis. Four aW (0.3, 0.5, 0.7 and 0.97), three temperatures (75, 100 and 121 degrees C) and three heating periods (50, 500 and 5000 s) were selected. The initial lysine:lactose molar ratio was 1:1. Amino acid profiles showed that excessive heating of whey (121 degrees C, 5000 s) destroyed a significant proportion of cystine at all aW, lysine at aW 0.3, 0.5 and 0.7, and arginine at aW 0.5 and 0.7. At aW 0.3, 0.5 and 0.7, protein digestibility decreased (P less than 0.05) as the temperature increased from 75 to 121 degrees C for a heating period of 5000 s, and as the heating time was prolonged, from 500 to 5000 s at 121 degrees C. Excessive heating also decreased (P less than 0.05) the availabilities of all amino acids at aW 0.3, 0.5 and 0.7. The availabilities of lysine, proline, aspartic acid, glutamic acid, threonine, alanine, glycine and serine were particularly affected. Severe heating at aW 0.97 did not seem to favour the Maillard reaction, but the availabilities of cystine, tyrosine and arginine were decreased, probably as a result of structural modifications of the protein upon heating. Heating whey protein concentrates in the presence of lactose not only affected lysine, but also impaired enzymic liberation of other amino acids, according to the severity of heat treatments and aW.

Amino Acids↗

PubMed1992

The effect of dairy products on iron availability.

Many researchers report substantial reductions in iron availability when dairy products are consumed with solutions of iron. Yet other studies indicate that dairy products have little effect on iron availability when added to complex meals. The conflicting data may be due to differences in the technique used to measure availability, species of animal used, form of iron in the diet, and meal composition. Human studies show superior bioavailability of iron in human milk when compared with cow's milk. Definitive causes for the differences between human and cow's milk have not been identified. Human milk contains lower amounts of casein, phosphate, and calcium, components thought to inhibit iron absorption. More work is needed to identify the factors that influence iron-dairy interactions. The nutritional benefits provided by dairy products outweigh the slight inhibitory effect they may have on iron availability.

Animals↗