bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Fatty Acid Composition of Liver Lipids from Rats Raised on Pork Rationsa,b
Authors: TINSLEY IAN J. 
Published: August 2006

SUMMARYThe liver lipid fatty acid composition of animals raised on pork rations was determined and compared with that of animals raised on a stock ration. The pork rations contained approximately 25% crude lipid, the proportion of oleic acid being 46–50%. The relation between the dietary and liver lipid fatty acid compositions was evaluated, with the most striking relationship being that between dietary and liver lipid oleate/linoleate ratios. The tissue levels of oleic, linoleic, and arachidonic acids provided supporting evidence for the existence of a competitive effect of oleic acid in the conversion of linoleic to arachidonic acid. The results suggest that the dietary oleate/linoleate ratio is of importance in essential fatty acid nutrition in rations containing appreciable quantities of oleic acid. The sex variable, as it applies to the relation between dietary and liver lipid, was also evaluated.
Organic Acids in Citrus Fruits. I. Varietal Differencesa
Authors: CLEMENTS ROBERT L. 
Published: August 2006

SUMMARYOrganic acids were determined in juices and peels of mature fruits of Washington Navel and Valencia oranges, grapefruit, lemon, tangerine, and Palestine sweet lime. Juices and peels were freeze‐dried, and organic acids were determined by silicic‐acid chromatography. Cation‐exchange resin in the hydrogen form was used for acidification of peel prior to extraction of acids with methanol. Citric acid predominated in all juices except that of the sweet lime (in which citrate level was so low that malate exceeded it). Malate occurred in all juices in low but measurable concentrations. Oxalate predominated in the peels, but in the lime, malonate appeared in equivalent amounts. Malonate appeared in all peels in measurable amounts, and in some peels was exceeded only by oxalate. Malic and citric acids were also determined in each peel. At least 15 peaks appeared with each peel, and paper chromatography of the effluents indicated the presence of more than one component in several peaks.
Isolation and Characterization of Low‐Density Lipoproteins in Native Egg Yolk Plasma
Authors: SAARI A. , POWRIE W. D. , FENNEMA O. 
Published: August 2006

SUMMARYThe composition of water‐washed yolk granules was different from that of yolk plasma. The lipid content of the granules was about 35%, in contrast to that of plasma (81%). Concentrations of phospholipid, phosphorus‐containing protein, and protein nitrogen were not the same for the granules and plasma. A method was developed for the isolation of two ultracentrifugally distinguishable fractions, LPL1, and LPL2, from yolk plasma by a differential flotation procedure. The differences in composition of LPL1 and LPL2 were small but significant. LPL1 contained about 89% lipid, whereas LPL2 was about 86% lipid. LPL1 and LPL2 behaved differently when treated by heat and a proteolytic enzyme. A major yolk steroid, isolated by digitonin precipitation, had a melting point and infrared spectrum similar to those for cholesterol.
Chromatographic Fractionation of Sarcoplasmic Proteins of Beef Skeletal Muscle on Ion‐Exchange Cellulosea,b
Authors: FUJIMAKI M. , DEATHERAGE F. E. 
Published: August 2006

SUMMARYSarcoplasmic proteins from beef skeletal muscle were fractionated by chromatography on ion‐exchange cellulose (cellulose phosphate and diethyl‐aminoethyl cellulose) at pH 5 and 9.3. From effluent diagrams of sarcoplasma from muscle immediately after slaughter, at least 14 fractions were recognized, and some of them were identified with known proteins by assays for enzymic activities. The numbers and levels of eluted peaks in the effluent diagram were found to decrease with storage (aging) of muscle and freeze‐drying of sarcoplasma; these decreases are perhaps due to denaturation. Proteins in solutions appear to be more completely separated by chromatography when different combinations of ion‐exchange cellulose are used.
Color Deterioration in Frozen French Beans (Phaseolus vulgaris)
Authors: WALKER G. C. 
Published: August 2006

SUMMARYExamination of 12 commercial frozen bean packs showed two forms of color deterioration. The first resulted in conversion of chlorophyll to pheophytin, and the second caused destruction of both chlorophyll and pheophytin. It is shown that both forms of degradation may be related to the process of fat peroxidation. The conversion of chlorophyll to pheophytin may occur during the anaerobic initiation stage of fat peroxidation. Destruction may occur during the aerobic propagation stage.
Apple Juice Volatilesa
Authors: MacGREGOR D. R. , SUGISAWA H. , MATTHEWS J. S. 
Published: August 2006

SUMMARYThirty compounds in the volatile fraction of McIntosh apple juice were isolated and identified. Material for gas chromatography was prepared by concentrating volatiles tenfold in a rising film evaporator and extracting with ethyl chloride. The compounds were identified by comparing retention volumes and infrared spectra with those of known compounds. Volatile components tentatively identified on the basis of their infrared spectra and retention data included 4 aldehydes, 1 ketone, 11 alcohols, 10 esters, and 4 fatty acids. In addition, 7 peaks were found but not identified. A variety of column packings and operating conditions were necessary to obtain reasonable separation of the components isolated.
The Long‐Term Effect of Electrical Stimulation on the Post‐Mortem Fall of pH in the Muscles of Landrace Pigs
Authors: HALLUND O. , BENDALL J. R. 
Published: August 2006

SUMMARYIt has been shown previously, in a series of experiments on the post‐mortem fall of pH in the muscles of Danish Landrace pigs, that the animals can be broadly divided into two groups, differing in rate of fall. One gives samples with low rates, called A, and the other with rates twice as high, called B.The present experiments show that the slow fall of pH in group A muscles can be converted to a quick fall by subjecting excised samples to a short tetanus. This accelerating effect of electrical stimulation lasts during the whole course of the pH‐time curves, and is easily distinguished from the well‐known short‐term effect, characteristic of this and many other types of muscle. Although the latter can be clearly demonstrated in rabbit muscle, for instance, the subsequent long‐term acceleration is entirely absent. The latter must therefore be considered a new and hitherto undescribed phenomenon, so far reported only for the pig. It is due to an induced higher ATP‐ase activity, although the mechanism is obscure.These findings open up a new approach in the search for the Cause of the rapid postmortem fall of pH characteristic of pig muscles which subsequently yield pale and watery pork.
The Growth and Persistence of Staphylococcus aureus in Milk and Broth Substrates
Authors: WALKER G. C. , HARMON L. G. 
Published: August 2006

SUMMARYThe growth of two strains of coagulase‐positive Staphylococcus aureus was measured in whole and skimmilk and in broth at 5, 10, 22, 30 and 37° There was a continuous decrease in population in all media at 5°. The medium had little effect on the duration of the logarithmic growth phase which varied from 12 hr at 37° to 20 days at 10°. Typical generation times in whole milk varied from 1642 min at 10° to 45 min at 37°. At 10 and 22° there was no statistically significant difference in the generation times among media or between strains. At, 30 and 37° there was no significant difference between the generation times in skimmilk and whole milk, but the generation time was significantly shorter (at the 5% level) in the broth than in the milks. The cultures maintained a longer stationary growth phase and were more persistent in broth and skimmilk than in whole milk. More rapid decreases in population in the whole milk were attributed to the toxicity of fatty acids released by the lipase of S. aureus. The decline in pH of the substrate was approximately proportional to the increase in population.
Enzymatic Reduction of Metmyoglobin by Ground Beef
Authors: STEWART MARGARET R. , HUTCHINS BOBBIE K. , ZIPSER MARELYNN W. , WATTS BETTY M. 
Published: August 2006

SUMMARYA method is described for estimating the ability of ground meat to reduce metmyoglobin enzymatically. The method involves a complete oxidation of all pigments to metmyoglobin by the addition of ferricyanide, followed by measurement of metmyoglobin reduction by the meat in 1 hr. The work was confined to beef rib eye muscle. Metmyoglobin‐reducing activity (MRA) showed great fluctuations in rib eyes from different animals. It was correlated with total pigment. In any one sample of meat, MRA increased with pH from pH 5.1 to 7.1 and with temperature from 3°C to 35°C. It declined only slightly in whole cuts of meat stored for several days in the refrigerator, but much more rapidly in stored ground meat. Chlortetracycline did not interfere with MRA, but 5% salt completely inhibited it. A possible reductive mechanism is discussed briefly.
Conversion of Valencene to Nootkatone
Authors: HUNTER G. L. K. , BROGDEN W. B. 
Published: August 2006

SUMMARYNootkatone, an important flavoring constituent in grapefruit, has been synthesized from the sesquiterpene hydrocarbon valencene. Valencene, which is isolated from orange oil, was oxidized with tert‐butyl chromate to yield a sesquiterpene ketone having the same physical properties as the natural nootkatone.
The Solubility of Intramuscular Collagen in Meat Animals of Various Ages
Authors: HILL F. 
Published: August 2006

SUMMARYThe percentage of total intramuscular collagen solubilized by heating in 1/4‐strength Ringer's solution, muscles from 98 cattle, 15 sheep, and 9 pigs at 77°C for 1 hour decreased as chronological age increased. Total intramuscular collagen was high in very young (8‐9 weeks) bo vines and in two of the three very old (7‐15 years) bovines studied. In the age range of 16 weeks to d1/2 years, variation in total bovine intramuscular collagen was wide. There was no indication of a systematic increase as age increased. The results provide strong presumptive evidence of an increase with age in the number or strength of the cross links of intramuscular collagen and furnish an acceptable explanation as to why total amounts of intramuscular collagen are inadequate to explain toughness associated with increasing chronological age.
Sensory and Chromatographic Analysis of Mixtures Formulated from Pure Odorants
Authors: KENDALL DAVID A. , NEILSON ANNE J. 
Published: August 2006

SUMMARYContinuing the leads from previously published studies of four chemicals having different odors hut similar molecular weights and boiling points, this work centers on sensory examinations of the vapors over essentially water solutions of GLC‐purified anethol, geranial, methyl salicylate, and safrol. Experienced profile‐trained panelists examined the odors from two‐ and four‐component mixtures of the odorants at multiple decimal fractions of odor‐recognition threshold concentrations in terms of molarity. Findings for the two‐component mixtures showed these possible phenomena: 1) intensification of one odorant with suppression of the other; 2) increase in total intensity of odor; 3) decrease in total intensity with development of a different odor character (i.e., blending); and 4) infrequently, no describable difference (i.e., no interaction). Interactions were also found for the four‐component systems, which, because of greater complexity, more frequently showed tendencies toward blending. Sucrose, salt, and mono‐sodium glutamate were added separately at their food‐use levels (respectively 10, 1, and 0.1%) to a quaternary mixture and were found to have different effects. Sucrose emphasized the mixture's lemon‐candy identity; salt clouded the solution and emphasized its root beer character; MSG disrupted the blend. In addition to these nonvolatiles, two odorous substances known to have odor‐blending or fixative properties were examined for recognition threshold and effect on the quaternary blend when added at 1/10 their threshold concentrations. Nonalactone, at 1/10 10−9 g/ml, increased the soapy‐oily character of the geranial. Exaltone, at 1/10 10−9 g/ml, blended the odor still further. The minimum change in concentration to give a detectable difference in odor strength (just noticeable difference) was determined for geranial at the profile intensity range of moderate. The jnd was found to he of the order of 100.2, representing about a 60% increase in concentration, which coincides with the 58% increase cited by other workers.
Pectin Methyl Esterases of the Banana. Purification and Properties
Authors: HULTIN H. O. , SUN BONNIE , BULGER J. 
Published: August 2006

SUMMARYEarlier, three fractions of pectin methyl esterase (PME) had been obtained from the pulp of the banana by differential extraction. The crude enzyme preparations have now been purified further by ammonium sulfate fractionation and ion‐exchange chromatography on columns of DEAE‐ and CM‐cellulose. Each fraction has a unique behavior on the ion‐exchange columns. Additional criteria have been established to differentiate the fractions. These include response to cations, inorganic phosphate, nucleotides, and sucrose, as well as differences in initial reaction kinetics, resistance to end‐product inhibition, and cold stabilities. The possibility of interconversion between fractions is discussed; Fractions I and II may be converted by treatment with 3.5 × 10−4M sodium dodecyl sulfate to forms resembling Fraction III as determined by pH‐activity spectra.
Surface Activity of Yolk, Plasma and Dispersions of Yolk Fractions
Authors: VINCENT R. , POWRIE W. D. , FENNEMA O. 
Published: August 2006

SUMMARYUndiluted yolk, plasma, and a 4.8% livetin solution had surface tensions of about 44 dynes/cm and interfacial tensions of around 5 dynes/cm. Extensive dilution of the yolk and plasma with either water or 10% NaCl did not bring about marked decreases in the activity of the surfaces. Rehydrated dried yolk had surface energy values similar to those for yolk. Granule suspensions, diluted with water and 10% Nail, had high surface and interfacial tensions. A yolk phospholipid fraction reduced the surface energy of sols to very low values. The contributions of proteins in a livetin fraction and of phospholipids to the surface properties of yolk are discussed.
Irradiation of Mangoes. I. Radiation‐induced Delay in Ripening of Alphonso Mangoes
Authors: DHARKAR S. D. , SAVAGAON K. A. , SRIRANGARAJAN A. N. , SREENIVASAN A. 
Published: August 2006

SUMMARYExtension of storage life of unripe and mature Alphonse mangoes could he achieved at an optimum dose of 25 krads when irradiated under air, nitrogen, or carbon dioxide. Nitrogen atmosphere during irradiation is of some advantage in minimizing changes in organoleptic quality, ascorbic acid, and carotenoids, and at the same time allowing the least spoilage of fruit. Judging from skin color and fruit firmness, a six‐day delay in ripening could be expected in fruits irradiated with 25 krads under nitrogen or air. Radiation effect on fruit skin is more prominent in terms of inhibition in chlorophyll disappearance and earotenoid formation than in ripening changes in the meat of the fruit.
Kinetic Behavior and Mechanism of Inhibition in the Maillard Reaction. I. Kinetic Behavior of the Reaction Between D‐Glucose and Glycine
Authors: SONG PILL‐SOON , CHICHESTER C. O. , STADTMAN F. H. 
Published: August 2006

SUMMARYThe kinetic behavior of the Maillard reaction between D‐glucose and glycine is discussed, and apparent rate constants–kl, from the induction period of the reaction, and Ka. t, from the steady‐phase formation of melanoidins– are estimated. The free energies of activation for two steps with corresponding rate constants K1 and ka t are respectively found to be 26.5 and 26.1 kcal mole‐1. Both steps have unfavorable negative entropy of activation. The overall rate expression is
image

where I represents intermediates, g and G respectively glycine and glucose, B the brown products, and k's the rate constants. On the basis of kinetic considerations, hydroxymethyl furfural is ruled out as a major intermediate in the Maillard reaction.
Composition of Raw and Roasted Lamb and Mutton I. Physical and Proximate Composition
Authors: MURPHY ELIZABETH W. , TOEPFER EDWARD W. , MARSH ANNE C. , HAGAN SUSIE N. 
Published: August 2006

SUMMARYSixty cuts each of raw and roasted rib‐loin and of raw and roasted leg of lamb and mutton, obtained from 118 carcasses, were separated into their physical components. Proximate composition was determined on the resulting separable lean, separable fat, and drippings. Correlation coefficients between weight of cut and each physical and proximate component were determined, and the effects of weight of cut and of roasting on the partitioning of nutrients among the separated portions were examined.With increasing weight of cut, percentage of separable fat and of drippings increased, and percentage of separable lean and of evaporation loss decreased. For rib‐loins, as weight of cut increased, the proportion of bone and waste, and the percentages of moisture, protein, and ash in all separable portions decreased, but the percentage of lipids increased. Relations were similar in leg cuts, except that percentage of bone and waste, percentage of protein in raw or roasted separable lean, and moisture content of drippings did not change significantly.Separable lean, raw or roasted, contained about 90% of the protein and moisture of the entire cut, but only about a quarter of the total lipids. Lean from raw cuts contained about 90% of the ash of the total cut, but lean from cooked cuts contained only about two‐thirds of the ash of the entire cut. As weight of cut increased, the amounts of proximate components in the lean decreased in proportion to those amounts in the total cut.
Volatile Components of Peach. II
Authors: SEVENANTS M. R. , JENNINGS W. G. 
Published: August 2006

SUMMARYA volatile‐essence concentrate isolated from the Red Globe variety of freestone peaches and already partially characterized, was further fractionated by newly developed gas chromatographic techniques of repetitive ultra micro collections and reinjections. An adapted micro‐cavity infrared cell permitted infrared analysis of these minute fractions, which were then identified by comparison with known compounds. Synthesis and ultra‐micro vapor‐phase hydrogenation were used to characterize compounds for which standards could not he obtained. Compounds identified include hexyl formate, hexyl acetate, tram‐2‐hexenyl acetate, hexyl alcohol, trans‐2‐hexenel‐01, isovaleric acid, ethyl benzoate, benzyl acetate, caproic acid, ganzma‐heptalactone, gamma‐nonalactone, hexyl benzoate, and an alpha‐pyrone.
Methyl Anthranilate Content of Citrus Honey
Authors: WHITE JONATHAN W. 
Published: August 2006

SUMMARYA photometric method for determination of methyl anthranilate (MA) was adapted for honey. Twenty‐one citrus honeys from 3 states and 5 crops averaged 2.87 μg/g (range 0.84–4.37). For 12 non‐citrus honeys, apparent MA content averaged 0.07 μg/g (range 0.00–0.28).
Factors Affecting Collagen Solubility in Bovine Muscles
Authors: HERRING H. K. , CASSENS R. G. , BRISKEY E. J. 
Published: August 2006

SUMMARY— Solubility of intramuscular collagen was studied as affected by chronological maturity in 15 bovine longissimus dorsi and 15 semimembranosus muscles and as affected by post‐mortem contraction state in the semitendinosus of 7 animals. Collagen solubility decreased significantly with each advancing maturity group in both longissimus dorsi and semimembranosus muscles. Collagen solubility was also higher (P < 0.05) in the longissimus dorsi than in the semimembranosus, except in the E maturity group. It was also related to panel tenderness in both muscles (r = 0.77 and 0.81 (P < 0.01) for longissimus dorsi and semimembranosus muscles, respectively. However, within‐maturity group correlations of solubility of collagen and tenderness were low and nonsignificent.Collagen content did not differ significantly in longissimus dorsi muscles of animals of A, B, and E maturity groups; however, the semimembranosus had more collagen (P < 0.05) in E than in A and B maturity groups. Collagen content was not related (P > 0.05) to panel tenderness in either muscle (r =−0.42 and −0.48 for longissimus dorsi and semimembranosus, respectively). Neither collagen solubility nor collagen content was significantly affected by post‐mortem contraction state. Furthermore, collagen solubility did not increase significantly with post‐mortem aging up to ten days.
A New Aroma‐Bearing Substance from Shiitake, an Edible Mushroom
Authors: WADA SHYOZO , NAKATANI HIROMI , MORITA KATSURA 
Published: August 2006

SUMMARY— Investigations on the physico‐chemical properties and a sensory evaluation as a component of Shiitake flavor were carried out with lenthionine, a substance which was isolated from dried Shiitake mushroom. Lenthionine is practically insoluble in water but soluble in non‐polar solvents. Its stability in an aqueous solution changes greatly with the pH of the solution.Lenthionine was identified as a significant component in the aroma of Shiitake mushroom and its detectable threshold level is at a concentration between 0.27 and 0.53 porn in water. This new aroma‐bearing substance will be used as a flavor additive in various foods.
Pectic Enzymes and Development of the Pear (Pyrus communis)
Authors: NAGEL C. W. , PATTERSON M. E. 
Published: August 2006

SUMMARY—Changes in firmness, protein, pectinesterase (PE) and polygalacturonase (PG) were followed during enlargement, maturation, and abnormal ripening of the Bartlett pear (Pyrus communis) on the tree. Although the PE activity per pear increased during maturation, with a good correlation with total weight (r= 0.93 and 0.87 for 1962 and 1963), the amount of activity per gram fresh weight and per milligram protein decreased. There was a high correlation between PE activity and protein (r= 0.84 and 0.91 for 1962 and 1963). The specific activity of the enzyme decreased during maturation. As the fruit matured and ripened on the tree, the percent recovery of PE decreased. The use of polyvinylpyrrolidone in the extraction procedure to adsorb the phenolic compounds counteracted this trend. It was concluded that the small changes in PE activity could not account for the changes in esterification of pectin observed by other investigators. Variable results were obtained with the PG assays. Weak PG activity was observed in the immature fruit in 1962 and 1963. No activity was observed in 1966, even in the presence of polyvinylpyrrolidone.