bluuebunny/crossref_metadata_2025_split huggingface dataset:
Viscoelastic Properties of Storage Tissues from Potato, Apple, and Pear
Authors: SOMERS G. FRED 
Published: August 2006

SUMMARYSlices of potato tubers were subjected to cyclic elongation, stress relaxation, and breaking in an Instron materials‐testing instrument. Cubes of such tissues and of ripe, fruits of pears and apples were subjected to cyclic compression and stress relaxation. The time required for 20% relaxation of the stress was progressively longer with each of 3 cycles. Cycling increased the apparent values of Young's modulus,E, for slices treated in acetone, treated in acetone and rehydrated, and frozen and then thawed, but decreased values for slices soaked overnight in H2O at 6°C. With potato slices and cubes, treatments which wilted them resulted in shorter times for a 20% relaxation of stress. Cubes of pear and apple soaked 3 hr in H2O tended to disintegrate and also showed much shorter times for relaxation of stress than cubes treated in 0.5Msucrose. The general features of all curves were qualitatively similar, except that compressing cubes of potato tubers beyond a stress of about 0.9 Kg/cm2resulted in a sharp, reversible increase in apparent values ofE.
Separation and Partial Characterization of the Peroxidases of Ficus glabrata Latex
Authors: KON SAMUEL , WHITAKER JOHN R. 
Published: August 2006

SUMMARYThree protein components with peroxidase activity were separated from Ficus glabrata latex by chromatography on diethylaminoethyl cellulose at pH 7.0. Purification was aided by carboxymethyl cellulose adsorption and ammonium sulfate precipitation. These three components were identical to horse‐radish peroxidase II with respect to molecular weights, absorption spectra, and activity‐pH relationships. They differed markedly from horseradish peroxidase II with respect to isoelectric points [at pH 4.25–4.45 (acetate buffer), vs. pH 7.2]. They were more heat‐stable than horse‐radish peroxidase II. While one of the F. glabrata peroxidases had Vmax values similar to those of horse‐radish peroxidase II on hydrogen peroxide and guaiacol, the other two F. glabrata peroxidases had quite different kinetic parameters. The three F. glabrata peroxidases differed in chromatographic, electrophoretic, heat stability, and kinetic properties (components B and C, vs. A), but all other properties measured were identical or similar for the three peroxidases.
The Identification of Methylcyclopentenolone and Other Compounds in Maple Sirup Flavor Extract
Authors: FILIPIC V. J. , UNDERWOOD J. C. , WILLITS C. O. 
Published: August 2006

SUMMARYA number of compounds in the flavor‐containing chloroform extract of maple sirup have been isolated and identified. A major constituent not previously isolated by gas chromatography was acetol. Other constituents present in lesser concentrations which have not previously been reported were acetoin, ethyl vanillate, syringoyl methyl ketone, and methyleyclopentenolone.
Release of Cellular Constituents During Heat Inactivation of Endospores of Aerobic Bacilli
Authors: WALKER HOMER W. , MATCHES JACK R. 
Published: August 2006

SUMMARYRelease of dipicolinic acid from spores of some species of Bacillus during heating at 100°C was determined. The total amount and rate of release of dipicolinic acid from these spores varied between species and strains, the most resistant spores releasing the least. Studies were made on Bacillus polymyxa and B. megaterium to determine the influence of buffers and pH on the liberation of dipicolinic acid, carbohydrate, and nitrogen. Release of these materials was usually least at pH 7.0 and greatest under conditions that favored thermal inactivation. Some of the amino acids and carbohydrates released were identified.
Studies in Meat Tenderness II. Proteolysis and the Aging of Beef
Authors: DAVEY C. L. , GILBERT K. V. 
Published: August 2006

SUMMARYThe proteolytic changes which occur in the longissimus dorsi muscles of beef carcasses during 30 days' aging at 2°C give rise to a mean increase of nonprotein nitrogen of 0.045mM/g meat, representing a degradation of 2.3% of the meat protein. The tenderizing and proteolysis which occur during aging are not related, for differences in the rates of tenderizing among carcasses arc not paralleled by similar differences in the rates of proteolysis. Bacterial action is not responsible for the observed proteolytic and tenderizing changes.
Solubility and Electrophoretic Behavior of Some Proteins of Post‐Mortem Aged Bovine Muscle
Authors: ABERLE E. D. , MERKEL R. A. 
Published: August 2006

SUMMARYThe solubility characteristics and starch gel electrophoretic properties of intracellular bovine muscle proteins from the longissimus dorsi and semitendinosus muscles were investigated during a 336‐hr post‐mortem aging period. The relationship of solubility and electrophoretic behavior to post‐mortem tenderization was also investigated. In the semitendinosus muscle, the solubility of sarcoplasmic protein was highest at slaughter and decreased as post‐mortem aging proceeded, but no change was observed in the longissimus dorsi muscle. Fibrillar protein was least ex‐tractable at 24 hr post‐mortem, but its solubility was significantly higher at 168 and 336 hr than at 24 hr post‐mortem in both muscles studied. The amount of extractable fibrillar nitrogen was negatively related to Warner‐Bratzler shear values as post‐mortem aging proceeded. The increase in amount of soluble fibrillar nitrogen during the post‐mortem aging periods of 24‐168, 24‐336, and 168‐336 hr was positively related to the decrease in shear value for the respective periods. Fifteen zones were definable in the starch gel electrophoretic patterns of the sarcoplasmic proteins. At the pH used in this experiment, most of the zones were anionic. These anionic zones exhibited more discrete boundaries in the latter stages of aging, and certain new zones appeared or increased in intensity as aging progressed.
The Precursors of Chocolate Aroma: Changes in the Sugars During the Roasting of Cocoa Beans
Authors: ROHAN T. A. , STEWART T. 
Published: August 2006

SUMMARYThe destruction of reducing sugars during the roasting of cocoa beans was investigated and found to be almost complete. The significance of this observation is discussed in relation to the possible role played by the reducing sugars in the deamination of the free amino acids of the cocoa bean, and to flavor development.
Chemical Studies on Concentrated Pineapple Juice 1. Carotenoid Composition of Fresh Pineapples
Authors: MORGAN R. C. 
Published: August 2006

SUMMARYThe carotenoid composition of fresh pineapples was examined by counter‐current distribution and column chromatography. The number of different compounds found, not including isomers, was 21. The major constituents of the carotenoid mixture were violaxanthins (50%), luteoxanthins (13%), beta‐carotene (9%), and neoxanthins (8%). Less abundant carotenoids included zeta‐carotene, hydroxy alpha‐carotene, cryptoxanthins, lutein, auroxanthins, and neochromes.
Tentative Identification of Carbonyl Compounds In Wood Smoke by Gas Chromatography
Authors: LOVE SUZANNE , BRATZLER L. J. 
Published: August 2006

SUMMARYIsolation, separation, and partial identification of 21 carbonyl compounds found in wood smoke are described. Isolation was by precipitation of carbonyls by 2,4‐dinitrophenyl‐hydrazine. Separation was by gas cbromatography using Carbowax ZOM and diisodecylphthlate as the liquid phase. Tentative identification of the eluted components was based upon retention times of the unknowns compared with those of authentic compounds on the two columns used. Sixteen of the twenty‐one components were tentatively identified: formaldehyde, acetaldehyde, propanal, acetone, acrolein, isobutyraldehyde, butanal, 2‐butanone, diacetyl, isovaleraldehyde, J‐methyl‐Z‐butanone, crotonaldehyde, pinacolone, 4‐methyl‐3‐pentanone, α‐methylvaleraldehyde, and tiglic aldehyde. Trace amounts of 3‐hexanone and 2‐hexanone were found. Also present were 1‐3 five‐carbon compounds, but no separation could by. achieved to identify them.
Microbial Growth Patterns of Rehydrated Freeze‐Dried Foods. II. Chicken
Authors: PABLO IGNACIO S. , SILVERMAN GERALD J. , GOLDBLITH SAMUEL A. 
Published: August 2006

SUMMARYMicrobial growth patterns in rehydrated freeze‐dried chicken at 4, 20, 30, and 37°C are similar to those of rehydrated freeze‐dried shrimp, and are greatly influenced by storage temperature, time, and initial number of microorganisms present. Lag time was shortest at 37 and 30°C, four times as long at 20°C as at 37°C, and 120 times as long at 4°C as at 37°C. At 37°C, the maximum population was 300,000 times the initial population, while at 30°C it was 115,000 times wafter 26 hr. The microbial population increased 100,000‐fold at 55 hr at 20°C, and 500‐fold at 15 days at 4°C.A natural contaminant in the freeze‐dried chicken examined, eoagulase‐positive Staphylococcus aureus, was found to be at a level of 3040 organisms per gram, out of a total population of 10° organisms per gram. Fecal enterococci were also present in the freeze‐dried material at a level of about 10° to 10° per gram.Rehydration studies show that Staphylococcus aureus and “fecal enterococci” as natural contaminants in freeze‐dried chicken can grow in competition with the natural flora at 20 °C or above and that the competition may be due to the nature of the microbial distribution on the chicken surface. Refrigeration temperatures in the vicinity of 4°C completely suppressed the growth of S. aureus and greatly extended the shelf life of rehydrated chicken.
Studies in Meat Tenderness. I. Sensory and Objective Assessments of Tenderness
Authors: MARSH B. B. , WOODHAMS PAMELA R. , LEET N. G. 
Published: August 2006

SUMMARYAs an introduction to a long‐term investigation of meat tenderness, seven series of comparisons were made between sensory and objective evaluations of the tenderness of roasted lamb rib‐loins. Using a tenderometer based on that of Volodkevich, high coefficients of correlation (0.68‐0.94) were found despite the occasional occurrence of large variations in tenderness within single muscles and the detection of slight panel fluctuation in three of the more prolonged series. Sensory assessment of tenderness was shown to be more nearly linearly related to either the reciprocal or the square root of shear force than to shear force itself.
Effect of Freeze‐Drying on Denaturation of Myosin horn Rabbit Skeletal Muscle
Authors: YASUI TSUTOMU , HASHIMOTO YOSHIO 
Published: August 2006

SUMMARYThe effect of freeze‐drying on the denaturation of myosin A and myosin B prepared from rabbit skeletal muscle and of heavy meromyosin derived from trypsin‐treated myosin A was investigated by measurement of adenosine tri‐phosphatase activities and by solubilities. The results show that the myosins undergo denaturation through the process of freeze‐drying. Factors involved in the denaturation are the pH and ionic strength of the solution and the dehydration. The denaturation is inhibited by the addition of sucrose to the system.
Changes in Aldolase Activity in Cod and Haddock During Frozen Storage
Authors: CONNELL J. J. 
Published: August 2006

SUMMARYThe aldolase activity of cod and haddock flesh is significantly reduced by freezing and thawing, and falls progressively during storage at ‐14°. During both rigor mortis and frozen storage at ‐14°, much of the aldolase activity becomes inextractable in water.
Separation of a Polyphenol Oxidase for Anthocyanin‐Degradation in Eggplant
Authors: SAKAMURA S. , SHIBUSA S. , OBATA Y. 
Published: August 2006

SUMMARYThe anthocyanin‐decolorizing enzyme which was previously found to he a polyphenol oxidase in eggplant fruits was further purified by DEAE‐cellulose column chromatography. At least two different enzymes were prepared, both of which equally oxidized catechol to its o‐qui‐none as a primary product, indicating their polyphenol oxidase nature, but differed from each other in substrate specificity. One of the two enzymes showed higher activity toward the eggplant anthocyanin and catechol than toward chlorogenic acid. When the anthocyanin was used as a substrate, the pH of maximum enzyme activity was 6.5. The second enzyme was more active on chlorogenic acid, with maximum activity near pH 5.0, and less active on the anthocyanin.
Microbial Growth Patterns of Rehydrated Freeze‐Dried Foods. I. Shrimp
Authors: PABLO IGNACIO S. , SILVERMAN GERALD J. , GOLDBLITH SAMUEL A. 
Published: August 2006

SUMMARYMicrobial growth patterns of rehydrated shrimp were investigated at 4, 20, and 37°C. Storage temperature greatly influenced the growth rates. The lag period was longest at 4°C and shortest at 37°C. The maximum population, almost a million times that of the initial population, was reached twice as fast at 37°C as at 20°C. Samples stored at 4°C increased 10,000‐fold in total aerobic counts but required two weeks to do so.Growth patterns indicate a shift in microbial spectrum in response to temperature. This was pronounced when rehydrated shrimp was stored at 4°C, the essentially mesophilic population becoming a minority.It is apparent that, in common with other types of perishable food products, rehydrated shrimp can have a storage life significantly extended by low temperatures. The shrimp storage life was 7 times as long at 4°C as at 20°C, and 20 times as long as at 37°C.
Deterpenation of Citrus Essential Oils by Solvent Partition with Dimethyl Sulfoxide
Authors: NORMAN SHIRLEY , CRAFT C. C. 
Published: August 2006

SUMMARYA comparison of deterpenation of cold‐pressed lemon and orange oils by silicic acid, steam distillation, and dimetbyl sulfoxide (DMSO) partition is presented. The recoveries by each method for lemon and orange oils and the ultraviolet absorbance of the orange oil fractions are given. Deterpenation by DMSO compared favorably with the steam‐distillation and silicic acid methods. The recoveries of 34 naturally occurring citrus constituents from aqueous DMSO after solvent partition with pentane are presented to indicate the separation capabilities of DMSO for flavor and aroma studies in citrus and citrus products and possible application to residue analyses.
Seasonal Variation of Naringin and Certain Other Flavanone Glycosides in Juice Sacs of Texas Ruby Red Grapefruit
Authors: HAGEN R. E. , DUNLAP W. J. , WENDER S. H. 
Published: August 2006

SUMMARYA recently developed chromatographic‐fluorometric method was used for individual quantitative determination of naringin, neohesperidin, poncirin, naringeuin‐7‐β‐rutinoside, hesperidin, and isosakuranetin‐7‐β‐rutinoside in juice sacs of Texas Ruby Red grapefruit harvested in late July and late September, 1964, and monthly thereafter through late April, 1965. The concentrations of the six glycosides in these juice sacs were found to decrease rapidly and approximately porportionally during the period from late July through late November. In December–April, the concentrations of all six glycosides tended to decrease, although the monthly changes were slight. These results are compared with data obtained from the same samples by the Davis method for “naringin” determination and with taste‐panel evaluations of grapefruit juice bitterness.
Lemon Oil Analysis. I. Two‐Dimensional Thin‐Layer Chromatography
Authors: MacLEOD WM. D. , BUIGUES NELIDA M. 
Published: August 2006

SUMMARYRecent refinements in thin‐layer chromatography (TLC) provide the analytical chemist with an inexpensive, convenient, and rapid method for obtaining basic information on the condition of cold‐pressed citrus oil samples. Simple TLC distinguished lemon and lime oils from all other citrus oils. Two‐dimensional TLC was used to distinguish between lemon and lime oils. Distilled lemon oils were characterized by their deficiency of UV fluorescence.
Further Study on the Immunogenicity of Farm‐Processed Cocoa
Authors: LEVANON YEHUDA , O.ROSSETINI STELA M. 
Published: August 2006

SUMMARYBeans and pulp from cocoa were subjected to laboratory fermentation reproducing farm‐processing conditions. A parallel was noted between the gradual decrease of the sugars content and the progressive disappearance of immunological activity when unfermented, in. completely‐fermented, and fully‐fermented bean extracts were compared. The saccharidic nature of the antigens was evidenced through staining with Schiff's reagent on gel electrophoretogram, paper chromatography, and acid hydrolysates.One of the two antigens, Fraction A, is present in unfermented bean extracts; both antigens yield glucose only when they are subjected to an acid hydrolysis.Dialysis showed that the only antigen (Fraction E) found in incompletely fermented bean extracts is a molecule smaller than that of the Fraction B found in unfermented extracts. Beans adequate for the chocolate industry did not show an immunogenic component. A rapid and simple ring test is proposed for determining the degree of fermentation (quality of the farm product) of cocoa beans.
Effect of Antioxidants on Lipoxidase Activity in Model Systems and Pea (Pisum sativum) Slurries
Authors: RHEE KI SOON , WATTS BETTY M. 
Published: August 2006

SUMMARYThe antioxidants BHA, propyl gallate, quercetin, gallic acid, turnip green extract, and sodium tripolyphosphate were tested for their inhibitory effect on linoleate oxidation catalyzed by purified soybean lipoxidase or crude pea lipoxidase, and on lipid oxidation occurring in blending of peas. In artificial lipoxidase‐linoleate systems, most phenolic inhibitors, especially BHA and propyl gallate, were very effective, but sodium tripolyphosphate was ineffective. The effectiveness of antioxidants decreased with increase in lipoxidase concentration. The relative effectiveness of the various antioxidants was quite different in pea slurries from that in artificial systems. Higher concentrations of propyl gallate, turnip green extract, and sodium tripolyphosphate retarded the pea lipid oxidation, but no significant inhibitory effect was found with other antioxidants tested. Factors which might contribute to variations in the behavior of antioxidants in pure model systems versus raw pea slurries are discussed. Hydrogen peroxide at concentrations of 0.005% or higher rapidly destroyed lipoxidase activity.
Post‐Rigor Changes in Selected Physicochemical Properties of Myosin B Fraction of Turkey Muscle
Authors: SCHARPF L. G. , MARION W. W. , FORSYTHE R. H. 
Published: August 2006

SUMMARYChanges in selected physicochemical properties of the myosin B fraction of turkey muscle were followed during a 44‐hr post‐rigor aging period. Sedimentation patterns of myosin B fractions prepared 48 hr after death indicated a decrease in a high‐molecular‐weight component thought to he myosin B gel. It is concluded that myosin B fractions lose gel‐forming ability with resolution of rigor. Density‐gradient centrifugal patterns showed small increases in slowly sedimenting components of myosin B fractions with aging. These components were. high in ATP‐ase activity in the presence of calcium ions and showed no reduction of viscosity with addition of ATP. Some evidence favors the concept of dissociation of myosin B into myosin A and actin with resolution of rigor. This dissociation, however, may also represent disruption of myosin R gel formed during and after extraction from muscle.
Consideration of Selected Agricultural Products as Viscoelastic Materials
Authors: MORROW C. T. , MOHSENIN N. N. 
Published: August 2006

SUMMARYA demand currently exists for information on the mechanical behavior of foods and agricultural products during handling, processing and quality evaluation. Many of the older subjective tests have now been replaced by various techniques from which empirical and partially objective measurements may he obtained; however, the majority of these measurements are not well‐defined in terms of accepted physical constants, thereby making their interpretation difficult. To provide consistency between various investigations, all mechanical properties may be evaluated in terms of common engineering parameters as the first approximation. From the point of view of mechanics, many products such as fruits, vegetables, and cereal grains in their natural state may be considered as convex bodies for which classical solutions can be applied for evaluation of compression, shear and tension properties.In this paper previous and current investigations in which the engineering approach to mechanical property evaluation has been used are reviewed. In all of these investigations, the common methods for product testing are hydrostatic and uniaxial compression. Instrumentation and techniques are described for obtaining and interpreting data from these tests in terms of physical constants.The mechanical behavior of most agricultural products is time dependent. Therefore, characterization of mechanical behavior requires the application of viscoelasticity principles in which both viscous and elastic responses are combined. The fundamental principles of viscoelasticity are presented briefly and analogies are developed for relating the observed behavior to well‐established mechanical systems.To illustrate the application of the engineering approach to mechanical property evaluation, a study on McIntosh apple fruits is described. This study demonstrates that many of the principles of classical mechanics are applicable to selected agricultural materials.
The Texture of Ice Cream 2. Rheological Properties of Frozen Ice Cream
Authors: SHAMA F. , SHERMAN P. 
Published: August 2006

SUMMARYThe creep behavior of frozen ice cream can be represented satisfactorily by a six‐element model. The parameters involved are the instantaneous elasticity (E0), two elastic moduli (E1 and E2), and two viscosity components (η1 and η2) associated with retarded elasticity, and a Newtonian viscosity (ηN). From the effect of fat, overrun, and temperature on the magnitude of these parameters it is suggested that E0 is affected primarily by the ice crystals, E1 and η2 by the weak stabilizer‐gel network, η1 by protein‐enveloped air cells, η1 by the fat crystals, and ηN by both fat and ice crystals. When ice cream mix is whipped and frozen, the fat globules undergo some coagulation from rupture of the protective protein‐emulsifier layer around the globules. Coagulation is hindered by the simultaneous conversion of water to ice.
The Texture of Ice Cream 3. Rheological Properties of Mix and Melted Ice Cream
Authors: SHERMAN P. 
Published: August 2006

SUMMARYFat coagulation begins when ice cream mix is frozen and whipped. The effect is hindered by the simultaneous conversion of water to ice. When frozen ice cream thaws, the ice crystals disappear so that coagulation is able to continue. It leaves a melt with a weak structure which differs from the fat network present in the original mix. This is snbstantiated by the eomparative creep behavior of mix and melt at low rates of shear. The creep behavior of melted ice cream is represented by a mechanical model containing 4 elements: instantaneous elastic compliance, J0; a retarded elastic compliance, J1, comprising an elastic modulus, E1 and a viscosity, π1; and a Newtonian compliance, t/πN, where t is time and πN is the Newtonian viscosity. Ice cream mix requires 6 elements since an additional elastic modulus, E2, and a second viscosity, π2, are associated with retarded elasticity. These additional elements are attributed to globules of 0.5 μ or less, which are separated by only a few Angstroms after flocculation rather than the 50 Å or more separating larger globules. Structure recovery in mix after it has been subjected to high shear indicates pronounced flocculation in the static emulsion. Weak forces of attraction hold the globules together within the flocculate.