bluuebunny/crossref_metadata_2025 huggingface dataset:
Viscoelastic Properties of Storage Tissues from Potato, Apple, and Pear
Authors: SOMERS G. FRED
Published: August 2006

Slices 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

Three 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

A 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

Release 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

The 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

The 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

The 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

The 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

Isolation, 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

Microbial 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

As 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

The 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

The 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

The 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

Microbial 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

A 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

A 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

Recent 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

Beans 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

The 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

Changes 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

A 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

The 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

Fat 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.
Gas Chromatographic Determination of Pentachlorophenol and Sodium Pentachlorophenate Residues in Fruits
Authors: CHENG KIN WA , KILGORE WENDELL W.
Published: August 2006

A sensitive procedure for the determination of pentachlorophenol and sodium pentachlorophenate residues on fruits by electron‐capture gas chromatography is described. In this method sodium pentachlorophenate is converted to pentachlorophenol in acid solution prior to analysis. The pentachlorophenol is then methylated with diazomethane, and is analyzed as the methyl ether by electron‐capture gas chromatography. As little as 0.01 ppm can be detected, with recovery values ranging from 76 to 90%.
Evaluation of Objective Methods of Measuring Differences in Texture of Freeze‐Dried Chicken Meat
Authors: BELE LINDA MAY , PALMER HELEN H. , KLOSE ALVIN A. , IRMITER THEODQRE F.
Published: August 2006

Breast and thigh meat of nine‐week‐old fryers from a commercial source was processed as frozen or freeze‐dried raw or cooked meat. Objective methods were compared with sensory evaluation of texture and juiciness differences in the meat. The effect of freezing temperature (‐23° and ‐191°C) on the quality of freeze‐dried poultry meat and the differing effect of freeze drying on raw and cooked breast and thigh meat were also determined.

Freeze‐dried chicken meat was readily distinguished from frozen. Freeze‐dried meat had poorer texture and less juiciness, higher shear resistance, and more expressible liquid than frozen. Cooked chicken meat had significantly higher shear resistance (Allo‐Kramer and Instron) after freeze‐drying than after freezing. The shear resistance tests agreed well with panel judgments of texture and could be substituted for them. However, for meat that was frozen or freeze dried before cooking, the differences in shear resistance were not consistently significant. Freeze‐dried breast meat had larger amounts of expressible liquid (Succulometer) than the frozen. For breast meat this objective test agreed well with panel judgments of juiciness and could he substituted for them. Although the panel consistently distinguished differences between frozen and freeze‐dried thigh meat, little or no liquid could be expressed from any of the thigh meat; thus the test could not be substituted for the panel judgments. No significant differences in “water‐holding capacity” (Grau‐Hamm press) were found between frozen and freeze‐dried meat; this test could not be substituted for the panel tests under the conditions used.

Freezing temperature (‐23° and ‐191°C) had no significant effect on meat freeze‐dried before cooking. The freezing temperatures resulted in detectable differences in meat freeze dried after cooking, but the differences were too small to be of practical importance.

Freeze drying adversely affected breast more than thigh. The breast meat was less tender and juicy, and had higher shear resistance, and more expressible liquid.

Meat cooked after freeze drying had better texture and juiciness, lower shear resistance, and less expressible liquid than meat cooked before freeze drying.
Enzymatic Reducing Pathways in Meat
Authors: WATTS BETTY M. , KENDRICK JEAN , ZIPSER MARELYNN W. , HUTCHINS BOBBIE , SALEH BASSIMA
Published: August 2006

Methods for measuring reducing capacity of meats are described. These include changes in oxidation‐reduction potentials of ground meat and changes in oxygen tension of meat slurries, as well as reduction of metmyoglobin. Except for a small residual utilization of oxygen in meat slurries (ascribed to nonenzymatic oxidation), all reductive activity in meat can be stopped by inhibitors of DPNH oxidation via the electron transport chain. Added DPN accelerates all reductive activity. Metmyoglobin reduction does not occur until oxygen has snbstantially disappeared from the meat.

Meat contains little or no snccinate. Added succinate greatly accelerates oxygen utilization, but affects metmyoglobin reduction only indirectly by establishing anaerobic conditions more rapidly. It is concluded that both oxygen utilization and metmyoglobin reduction in meat are normally mediated through DPN.
Irradiation of Mangoes. II. Radiation Effects on Skin‐coated Alphonso Mangoes
Authors: DHARKAR S. D. , SAVAGAON K. A. , SRIRANGARAJAN A. N. , SREENIVASAN A.
Published: August 2006

The respiratory patterns of skin‐coated and uncoated Alphonso mangoes, either unirradiated or irradiated under gaseous atmospheres like air, nitrogen, or carbon dioxide, were studied. The skins were coated with an emulsion made of an acetylated monoglyceride preparation. Skin‐coated fruits show physiological damage presumably due to too much inhibition of respiration. This defect is rectified by a spurt in respiratory activity when fruits are irradiated in air or nitrogen. Irradiation in carbon dioxide, which also retards respiration, shows physiological damage which is reversible, the recovery of organoleptic qualities being possible to some extent. Suppression of respiration beyond an optimum level seems to be responsible for irreversible damage to the fruit. Organoleptic evaluation, analysis for fruit constituents, skin color, and pressure tests showed that storage life of the fruit can be increased by combining skin‐coating with irradiation under either air or nitrogen.
Autoxidation of Methyl Linoleate in Freeze‐Dried Model Systems. II. Effect of Water on Cobalt‐Catalyzed Oxidation
Authors: LABUZA THEODORE P. , MALONEY JOHN F. , KAREL MARCUS
Published: August 2006

The oxidation of methyl linoleate catalyzed by various salts of cobalt was studied in a model system based on microcrystalline cellulose. The freeze‐dried model system was adjusted to various water activities, and the effect of water on the oxidation kinetics was determined using manometric measurements and measurements of diene conjugation.

It was found that water had an inhibitory effect on the metal‐catalyzed oxidation of the fatty ester, as well as on oxidation in the absence of added metals. The kinetics of the reactions were evaluated in terms of the previously established hydroperoxide decomposition mechanisms. The effect of water on the metal‐catalyzed oxidation was found to exist in the monomolecular decomposition period as well as in the more rapid phase of the reaction, during which the hydroperoxide decomposition is known to follow bimolecular decomposition kinetics.

The inhibition of the reaction by water is interpreted as due to deactivation of added, as well as of originally present, metal catalysts by hydration of the coordination shells; and also possibly as due to hydrogen bonding between hydroperoxides and water, and therefore to interference with the normal bimolecular decomposition reaction.
The Fluoride Content of Some Foods and Beverages–a Brief Survey Using a Modified Zr‐SPADNS Method
Authors: MARIER J. R. , ROSE DYSON
Published: August 2006

An analytical method is described that estimates up to 2.0 ppm of fluoride in a 10‐g sample of food, with a standard deviation of 0.093 ppm F per test. A brief survey of beverages and canned vegetables indicates that the use of fluoridated water (i.e., 1.0 ppm F‐) by food or beverage processors will increase the fluoride content of the products by 0.34– 0.75 ppm (av. increase: 0.50 ppm). On the basis of food analyses and a concomitant study of the fluid intake of laboratory personnel, it is estimated that the total ingestion of fluoride per day by healthy “indoor” workers will range from 2 to 5 mg per day. Implications of these findings are discussed.
The Analysis of Volatile Components of Jamaica Rum
Authors: MAARSE H. , ten NQEVER de BRAUW M. C.
Published: August 2006

The application of combined capillary‐column gas chromatography and mass spectrometry in analysis of the volatile components of a heavy‐body Jamaica rum is described. Pre‐fractionation of the complex essencew ontaining components in widely differing concentrations—was performed on a packed column previous to further analysis on the capillary column. A large number of esters, aldehydes, acetals, and alcohols were identified.
Gas Chromatographic Determination of Anthocyanins and Other Flavonoids as Silyl Derivatives
Authors: KEITH ELIZABETH S. , POWERS JOHN J.
Published: August 2006

Gas chromatographic methods were developed for the separation of apigeninidin compounds, pelargonidin, cyanidin, delphinidin, petunidin, and malvidin. Protocatechuie, p‐hydroxybenzoic, gallie, vanillie, and syringic acids–which are useful for the identification of particular anthocyanidins–were also amena‐able to gas chromatographic analysis. Phlorglucinol could likewise he measured. Separation of rhamnose, ribose, xylose, fructose, ga‐lactose, and glucose was good. Except for fructose, the others are common glycosidie sugars and aid in differentiating anthocyanins. Retention times were determined for the monogluco‐sides of delphinidin, petunidin, pelargonidin, and malvidin; for a delphinidin glycoside extracted from wild grape hyacinths; and for arhutin, hesperidin, rutin, and quercitrin. Betanin likewise was volatile as the silyl ether. Rhamnetin, catechin, and quercetin yielded good gas chromatographic waves. Phenolphthalein and naphthorescoreinol were sometimes used as internal standards. The silyl ethers or esters above were prepared in pyridine or dimethyl sulfoxide. The data suggest that gas chromatography might he used for preparative as well as for identification purposes.
Chemical Changes During Frozen Storage of Pomphrets, Mackerel, and Sardines
Authors: PAWAR S. S. , MAGAR N. G.
Published: August 2006

The effects of quick and slow freezing processes, with and without glazes, on the storage life of three commercially important fish from the Bombay Coast were studied. During storage, moisture content decreased, resulting in an apparent increase in total crude proteins. Glazing showed a definite advantage over control fish in the retention of moisture during storage. Sarcoplasmic ATP‐ase activity decreased very slowly during storage. Total ribose decreased, whereas Ba‐acetate alcohol nonprecipitable ribose increased to a different extent in all three fish. The ratio of Ba‐acetate alcohol nonprecipitable ribose to total acid‐soluble ribose (denoted as R) was found to be higher in slowly as against quickly frozen fish, indicating a greater extent of cell damage in the former. Large quantities of trimethyl‐amine, nonprotein nitrogen and ribose were lost from the fish on thawing. Of all the glazes used, that containing citric acid was most effective in preserving the color of the fish. All glazes prolonged storage life by protecting from rancidity and desiccation.
Apple Polyphenol Oxidase Activity in Relation to Various Phenolic Compounds
Authors: SHANNON CHRISTINE T. , PRATT DAN E.
Published: August 2006

SUMMARY— The role of various polyphenolic compounds in oxidations catalyzed by apple polyphenol oxidase (PPO) was investigated. Quercetin, quercitrin, rutin, cyanidin chloride, phloroglucinol, and resorcinol were neither substrates nor inhibitors of apple PPO. Phloroglucinol and resorcinol increased the rate of PPO catalyzed oxidation of chlorogenic acid.

Esculetin and dihydroquercetin were found to be substrates of PPO. No synergistic effect was detected in the browning rates of an esculetinchlorogenic acid mixture or a dihydroquercetin‐chlorogenic acid mixture. Ferulic acid, fisetin, and p‐coumaric acid were generally non‐competitive inhibitors, although ferulic acid inhibited competitively in one test. It was hypothesized that the conjugated system in flavones prevents these compounds from being apple PPO substrates.
Isolation and Characterization of Ether Soluble Sugar‐Amino Acid Interaction Products
Authors: LANGNER ERNST H. , TOBIAS JOSEPH
Published: August 2006

SUMMARY— A procedure is described for isolating compounds formed during the heating of solutions containing sugars and amino acids. It consists of solvent partition into ethyl ether, concentration of the solvent, high vacuum distillation in an isolated system and a final concentration. Model systems were employed, consisting of one sugar and one source of amino acids from the group: dextrose, lactose, glycine, lysine, valine, and casein. The flavor concentrate had a strong caramel odor.

A total of 38 non‐acidic and 5 acidic gas chromatographic components were observed, but none of the systems gave rise to all of these. The differences in the gas chromatographic patterns of extracts containing both sugars and amino acids and those containing sugars alone, were more quantitative than qualitative.

While many of the components remain unidentified, those positively identified were largely sugar dehydration and degradation products. One nitrogen‐containing component was identified as 2‐acetylpyrrole.
Cellular Distribution of Lactate Dehydrogenase in Chicken Breast Muscle
Authors: HULTIN H. O. , SOUTHARD J. H.
Published: August 2006

SUMMARY— The distribution of lactate dehydrogenase (LDH) in chicken breast muscle was studied by preparing subcellular fractions by homogenization and differential centrifugation under conditions known to cause the enzyme to be associated with the particulate structures. The LDH was widely distributed among the subcellular fractions with the outer cell membrane and the mitochondrion having especially high activities associated with them.

A 4‐hr aging period of the whole, excised muscle had only a minor effect on the subcellular distribution of the enzyme. The major change in aged muscle was an increase of enzymic activity in the soluble, supernatant fractions. Although certain possible artifacts have been ruled out, it is not completely certain that the particle‐associated LDH is a true reflection of the situation in vivo. There is at least, however, a reproducible pattern to the binding of LDH to the individual subcellular fractions when chicken breast muscle is homogenized under the specified conditions.
Studies on the Nutritional Value of Tempeh
Authors: MURATA KIKU , IKEHATA HIDEO , MIYAMOTO TEIJIRO
Published: August 2006

SUMMARY— Protein, fat, ash, fiber content, amino acid composition, and fatty acid composition including free fatty acids and some B vitamins (thiamine, riboflavin, vitamin B6, nicotinic acid, and pantothenic acid) of tempeh and unfermented soybeans were compared.

The following observations, which are significant for evaluation of the nutritional value of tempeh, were made:

 There were no large differences in protein and ash content between tempeh and unfermented soybeans.

 Fiber was slightly increased during fermentation.

 The fat content of tempeh was slightly lower than that of soybeans, but the acid value was noticeably higher.

 Free amino acids were increased during fermentation. The amount of different free amino acids in the palatable tempeh was from 1 to 8.5 times as much as that of unfermented soybeans.

 Riboflavin, vitamin B6, nicotinic acid, and pantothenic acid were increased during fermentation, although thiamine was little altered.
Nutritional Value of Protein from a Soybean Milk Powder
Authors: DE OLIVEIRA J. E. DUTRA , SCATENA L.
Published: August 2006

SUMMARY— Soybean milk powder was prepared from de‐hulled soybeans by standard milk plant equipment. The product was tested biologically in young growing rats. When soymilk or skim milk combined with different amounts of corn starch to give a range of dietary protein levels was fed to rats, the nutritive value of the vegetable milk compared favorably with that of animal milk at the highest level of protein intake. The growth response was generally less with soymilk at low protein levels and this could be corrected by supplementation with methionine. Mixing cow's milk and soymilk in different proportions did not improve significantly the nutritional value of the protein, although such mixtures might have advantages for palatability, industrial feasibility, or consumer acceptability.
Deformation Testing of Foods. 2. A Simple Spring Model of Deformation
Authors: BOURNE M. C.
Published: August 2006

SUMMARY— A model system is described which closely represents the deformation of a food as it is squeezed in the hand. The model consists of a set of true springs of differing heights and with differing Hooke's constants arranged in parallel. One or more springs are required to represent a given food depending upon the degree of curvilinearity of the force‐compression curve of the food. No dashpots are needed in this simple model. The one restriction on the model is that it is intended to represent the physical response of the food to a single compression. A graphical method for measuring the number, size and Hooke's constants of the springs in the model is described. The spring model shows that with some foods at least, small compression forces measure differences in softness better than large forces.
Precursors of Chocolate Aroma: Studies in the Degradation of Amino Acids during the Roasting of Accra Cocoa Beans
Authors: ROHAN T. A. , STEWART T.
Published: August 2006

SUMMARY— A preliminary study of the Strecker degradation of amino acids by reducing sugars in cocoa beans has revealed an unexpected temperature effect on the extent of the reaction which might influence the flavor of the product. Model amino acid/sugar systems were studied and the results support the hypothesis that there exists a relationship between the temperature of reaction, the extent of amino acid degradation and the production of flavor volatiles during the roasting of cocoa beans. A factory experiment, in which Accra cocoa beans were roasted at three different temperatures, provided supporting evidence of the influence of temperature on total flavor and on the strength of basic chocolate flavor.
Apparent Diffusivity in Honey‐Water System
Authors: FAN L. T. , TSENG J. T.
Published: August 2006

SUMMARY— A laser interferometric micro diffusion cell was used to measure the apparent diffusivity of water‐honey system. The results show that the apparent diffusivity of water in honey is very much dependent on the concentration.
Composition of Lipids in Some Beef Muscles
Authors: HORNSTEIN I. , CROWE P. F. , HINER R.
Published: August 2006

SUMMARY— The lipids extracted from five different muscles of four Angus steers were separated into phospholipids, free fatty acids, and a fraction containing the triglycerides. The phospholipid concentration for a given muscle was relatively constant in all four animals. The concentration of total lipids varied considerably more than that of phospholipids. The diaphragm had the highest total lipid and phospholipid content. The diaphragm also differed from the other muscles studied in the palmitic and steak acid concentration of the phospholipids. The free fatty acid concentration varied from muscle to muscle, however, two distinct patterns of free fatty acid distribution were observed in the four animals. The triglycerides and phospholipids differed in the qualitative composition of their fatty acids. Approximately 20% of the phospholipid fatty acids, but only a trace of triglyceride fatty acids, were above C20. The phospholipids contained a much greater amount of polyunsaturated acids than the triglycerides.
Some Volatile Components of Vitis Vinifera Variety White Riesling.
Authors: VAN WYK C. J. , WEBB A. DINSMOOR , KEPNER RICHARD E.
Published: August 2006

SUMMARY— Volatile components of the grape Vitis vinifera var. White Riesling were isolated by reduced pressure steam distillation followed by solvent extraction and fractionation by gas‐liquid chromatography. Individual components were identified by a combination of the techniques of functional group analysis, gas‐chromatographic relative retention times, and infrared spectroscopy. Major components are: ethanol, isobutanol, 2.methylbutanol, 3‐methylbutanol, 2‐hexenal, n‐hexanol, trans‐2‐hexen‐1‐01, and 2.Dhenethanol. Alcohols oresent in relatively smaller amounts are: methanol, n‐butanol, n‐pen‐tanol, n‐heptanol, linaloöl, n‐octanol, n‐decanol, and benzyl alcohol. Acids constitute only a small part of the total volatiles of White Riesling, the maior acids being: acetic, n‐caproic, 2‐hexenoic, n‐caprylic, n‐pelargonic, and n‐capric. Acids present in trace amounts are: propionic, isobutyric, n‐butyric, 2‐methylbutyric, isovaleric, isocaproic, n‐heptanoic, n‐undecanoic, succinic, and ethyl acid succinate. The only esters detected were trace quantities of ethyl acetate and isoamyl acetate.
Changes in Fish Proteins Caused by Storage in Saline Solution and Their Inhibition by Phosphates.
Authors: NIKKILA O. E. , KUUSI TAINA , KYTOKANGAS RIITTA
Published: August 2006

SUMMARY— It is known that even small concentrations of sodium chloride cause a loss in the solubility of actomyosin in fillets of Baltic herring. This change is prevented by the simultaneous presence of a sufficient amount of phosphates. To date, the mode of action of phosphates is unsettled. This problem has here been studied by the aid of radioactive pyrophosphate.

The fillets were kept in solutions containing sodium chloride, pyrophosphate, or both, at +4°C. The migration of tracer pyrophosphate was followed by application of the auto‐radiographic method; at the same time, changes in the solubility of actomyosin were checked. To avoid losses of soluble compounds, the sections for autoradiogaphy were prepared by freeze‐drying and paraffin impregnation techniques. It was found that the migration was very rapid: in 24 hr the fillets were completely marked. The rate of migration was also estimated by counting of the sections.

Studies were also made of the changes in the phosphorus fractions of the fillets during the course of standing using 1% pyrophosphate and maximal standing time of 5 days. Initially, there occurred a rapid loss of phosphorus compounds from the fillets; this related to the lipid and nucleic acid phosphorus. The tracer migrated rapidly into the fillets during the first day, and more slowly after this. The bulk of the tracer was in the acid‐soluble fraction. Apparently, there also occurred some incorporation into the lipids and nucleic acids.
Atypical Intrafascicular Accumulation of Fat in Porcine Striated Muscle
Authors: ALLEN E. , CASSENS R. G. , BRAY R. W.
Published: August 2006

SUMMARY—

Intrafascicular fat‐like cells were observed in striated porcine muscle. Post‐mortem muscle appeared normal in color, texture, and visible fat, but Sudan IV staining revealed that certain intrafascicular cells did contain fat.
Relation of Phospholipids to Other Tissue Components in Two Beef Muscles
Authors: TURKKI PIRKKO R. , CAMPBELL ADA MARIE
Published: August 2006

SUMMARY—

The relation of phospholipids to other tissue components was studied in the extensor carpi radialis and psoas major muscles of beef. Total lipid, phospholipid, desoxyribonucleic acid (DNA), and total nitrogen were determined in each muscle. The distribution of total N among the fibrillar protein N, sarcoplasmic protein N, nonprotein N (NPN), and stroma N was determined. Phospholipids were separated from neutral lipids and fractionated into lecithin, cephalins, and sphingomyelin by thin‐layer chromatography. The quantity of each class was estimated by phosphorus analysis.

The concentrations of total lipid and phospholipid were higher in the psoas than in the extensor muscle. The amount of phospholipid per unit weight of‘DNA, total N, protein N, and fibrillar protein N also was higher in the psoas major than in the extensor carpi radialis. In terms of sarcoplasmic protein N, the concentration of phospholipid was similar in the 2 muscles.

In both muscles, lecithin accounted for about 62%, cephalins 30%, and sphingomyelin less than 10% of the lipids recovered.