bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat Denaturation of the Ovomucin‐Lysozynie Electrostatic Complex‐A Source of Damage to the Whipping Properties of Pasteurized Egg White
Authors: GARIBALDI J. A. , DONOVAN J. W. , DAVIS J. G. , CIMINO S. L.
Published: August 2006

SUMMARY– A longer whip time is usually required to obtain a meringue of the same specific gravity from pasteurized egg white as from unpasteurized egg white. We have determined the rate at which this change in whipping properties occurs as a function of heating time and pH. The rate of damage is minimal at neutral pH. The activation energy for whipping property damage at pH 7.5 is 140 kcal. Experiments in which either ovomucin or lysozyme concentration of egg white was increased and decreased showed that the reaction producing damage to the whipping properties is first order with respect to both ovomucin and lysozyme concentration. Since an increase of 0.33 in the ionic strength of egg white produces a ten‐fold decrease in the rate of whipping property damage, the reactants are probably present as the ovomucin‐lysozyme electrostatic complex. The product appears to be an irreversibly denatured ovomucin‐lysozyme aggregate or network. Removal of the product restores the whipping properties of the egg white. The whipping property damage is a decrease in the mechanical stability of the foam. For this reason a longer time is needed to whip pasteurized egg white to a satisfactory meringue. Whipping aids such as triethyl citrate or triethyl phosphate compensate for the damage to the whipping properties, but do not appear to reverse the reaction producing damage to the whipping properties of the egg white.
Alcohol: NAD Oxidoreductase (E. C. 1.1.1.1.) from Peas
Authors: ERIKSSON C. E.
Published: August 2006

SUMMARY– The substrate specificity of the enzyme alcohol: NAD oxidoreductase from seeds and pods of the pea plant (Pisum sutivum) was investigated. The enzyme catalyzes the oxidation of primary aliphatic alcohols especially 2‐alken‐1‐01s e.g., trans‐2‐hexen‐1‐01, under the conditions used. It also catalyzes the reduction of aliphatic aldehydes especially ethanal, hexanal and unsaturated nonanals. The reaction product was routinely identified by mass spectrometry.

The enzyme activity was found to be inhibited competitively by fatty acids, methanol, imidazol and L‐histidine.

The enzyme was used as a catalyst in experiments for determining equilibrium constants and the calculation of the free energy change of some alcohol‐aldehyde systems in the presence of oxidized and reduced coenzyme. On the basis of the equilibrium constants determined, the composition of various alcohol‐aldehyde mixtures were calculated for different NAD+2NADH ratios and different pH values.

The enzyme preparation could not be separated into fractions with altered substrate specificity by ammonium sulfate precipitation or by ion exchange chromatography.
Gamma Irradiation and Enriched CO2 Atmosphere Storage Effects on the Light‐induced Greening of Potatoes
Authors: ZIEGLER R. , SCHANDERL S. H. , MARKAKIS P.
Published: August 2006

SUMMARY – Michigan‐grown Kennebec and Sebago potato tubers were exposed to gamma irradiation in the dose range of 0 to 400 Krad and subsequently stored in atmospheres containing 0.03% to 15% CO2. Upon illumination with 3,000 lux for periods up to 20 days while maintaining the atmosphere, all tubers developed some greening. The tubers exposed to 200 and 400 Krad were inhibited from greening to the highest degree but suffered general quality loss. The levels of 10 to 20 Krad, which are suitable for the sprout inhibition of potatoes, did not cause significant inhibition of greening under any of the conditions of this experiment. Storage in enriched CO2 atmospheres inhibited the greening to the extent of 50% at 15% CO2, only upon prolonged illumination (12 days), while irradiation (40 Krad) was only effective after a short period (4 days) of illumination. Irradiation in the O–40 Krad range did not increase the inhibition caused by CO2. The inhibition of potato greening by irradiation was effective through a period of 5 weeks storage in the dark prior to illumination.
Biological Degradation of Chlorophyll in a System Using Bell Peppers (Capsicum frutescens)
Authors: McFEETERS ROGER F. , SCHANDERL S. H.
Published: August 2006

SUMMARY– A degradation system was developed based on the incorporation of radioactive chlorophyll into a ripening bell pepper carpel.

Pure chlorophyll a in aqueous triton X‐100 injected into green bell peppers (Capsicum frutescens) variety 035 was degraded up to 50% by the end of ripening, versus a control in buffer pH 5.4 not exceeding 7% loss in 2 weeks. Variety and stage of ripeness affected the amount of degradation.

Labeled chlorophyll a with a specific activity of 7 to 8 × 105 dpm/mg was then prepared from young wheat plants, fed 14Cob and injected in amounts of 0.2 to 0.3 mg. The distribution of activity in pepper extracts after pigment degradation was evaluated. The acetone water extract remaining after transfer of lipid material to petroleum ether acquired activity within 2 days of injection, but the amount remains fairly constant for 12 days. The activity of the extraction residue, and of an 80% ethanol extract thereof, increased throughout the experiment. The residue containing increasing amounts of protein had the largest amount of radioactivity of the three fractions at the conclusion of the experiment.

Preliminary chromatography did not yield isolated radioactive products.

Extracts of pepper show no activity when substituted for soybean extract in a system containing chlorophyll and linoleic acid.

The degradation of chlorophyll by ripening bell peppers provides a tool for further studies for degradation in a physiological system.

Labeling facilitates isolation, identification, and establishment of origin of small amounts of breakdown products.
Cellulase Activity during the Maturation and Ripening of Tomato Fruit
Authors: HOBSON G. E.
Published: August 2006

An enzyme that attacks carboxymethyl cellulose may be extracted efficiently from tomato fruit by salt solutions. From a high initial value in small green fruit, activity fell gradually during fruit swelling. With incipient ripeness, the activity increased again and continued to rise to the full red condition. The green areas of “blotchy” ripened fruit showed 40% less activity than the adjacent red tissue. Fruit of tomato species in the sub‐genus Eriopersicon contained considerably more activity than examples from the sub‐genus Eulycopersicon. Firmness measurements on fruit from both sub‐genera were not significantly correlated with the cellulase activities, and from this and other evidence it is concluded that is is not a major factor controlling the softening of at fruit, at least during the ripening period.
Characterization of Water‐Soluble Wheat Flour Pentosans
Authors: LIN FANG MING , POMERANZ Y.
Published: August 2006

The yield and protein contents of water‐soluble pentosan preparations ranged from 0.67 to 0.84% and 15.4 to 24.2%, respectively. After soluble‐starch was removed, total yield of water‐soluble gums was 0.38 to 0.58%, and their protein contents ranged from 16.9 to 22.6%.

Pentosans were fractionated on diethyl aminoethyl cellulose columns. Based on carbohydrate contents, fraction II, eluted with 0.0025 M borate was the largest. Fraction I (eluted with water) was generally the smallest and contained no protein. Fraction III (eluted with 0.025 M borate) was the second smallest and was richest in protein. Effects of amylase, protease, and of pentosanases, and of column fractionation on composition of pentosans were followed by infrared spectroscopy.
Post‐Mortem Changes in Extractability of Myofibrillar Protein from Chicken Pectoralis
Authors: SAYRE R. N.
Published: August 2006

Protein extractability from chicken pectoralis was measured after the muscle had aged in ice for various periods from 30 min to 24 hr post‐mortem. The extraction solution was KCl in phosphate buffer at pH 7.0 and ionic strength 1.0. Residue from the salt extraction was treated with 0.1 N NaOH to remove additional myofibrillar proteins and the remainder was considered stromal protein.

Sarcoplasmic protein, non‐protein nitrogen and stromal protein remained constant for all aging periods at 33%, 16% and 7% of the total nitrogen, respectively, Myosin extractability decreased rapidly during the first 3–4 hr of aging while the alkali soluble protein increased and actomyosin was extracted at a low, constant level. Following 4–6 hr of aging the alkali soluble protein became constant, and actomyosin appeared in the extract in increasing quantities as myosin continued to decline. The sum of myosin, actomyosin and alkali soluble protein was constant for all aging times at 44% of ihe muscle nitrogen. Actomyosin formation was accompanied by increased hydration of the myofibrillar proteins as indicated by increased swelling of the residue from salt extraction with greater aging time.

The initial accumulation of alkali soluble protein and subsequent release of actomyosin correspond to the time course of toughening and tenderization in chicken muscle. Both of these observations may reflect initial binding of myosin to the nonextractable thin filaments, followed by disintegration or detachment of these filaments from the Z membrane.
Petals of Aztec Marigold, Tagetes erecta, as a Source of Pigment for Avian Species
Authors: ALAM A. U. , CREGER C. R. , COUCH J. R.
Published: August 2006

SUMMARY—The deposition of the pigments of Aztec marigold petal was determined in the egg and tissue of laying hens fed 33–66 and 99 mg of the pigments per kg of low pigment diet. Thirty‐three mg pigment per kg of feed produced yolk color which is considered acceptable to the consumer. With an increase in the amount of pigment in the feed, color deposition in the organs increased, but efficiency of utilization was lowered.
Role of Flavin Adenine Dinucleotide in Stabilization of Cytoskeleton of Chicken Muscle Cell
Authors: STANLEY D. W. , SAWYER F. M. , HULTIN H. O.
Published: August 2006

Aging of muscle had previously been shown in our laboratory to increase the propensity of properly treated muscle cell segments to empty on extraction with water. It has been suggested that this emptying is caused by breakdown of a cytoskeleton, and, further, that this cytoskeleton is stabilized by flavin adenine dinucleotide (FAD). Due to the possible relationship of cytoskeletal breakdown to quality changes in meat post‐mortem, the role of FAD in the preservation of cytoskeletal structure in chicken breast muscle was studied. No significant differences in FAD decomposition or extraction were found between samples handled in a manner such as to produce very large differences in the extent of emptying, the measure of cytoskeletal breakdown. Similarly, adding FAD to suspensions of muscle cell segments could not inhibit emptying under conditions where the supernatant fraction of a muscle homogenate could. It was concluded that FAD plays no role in the stabilization of the cytoskeleton of chicken breast muscle.
Dynamic Viscoelastic Characterization of Solid Food Materials
Authors: MORROW C. T. , MOHSENIN N. N.
Published: August 2006

SUMMARY—There currently exists a large demand for objective methods to be used in the evaluation of food texture. A very logical approach to the evaluation of some of the parameters of texture would appear to be the use of engineering parameters for the characterization of mechanical response of materials used in processing or direct consumption. Considering the changeability of living materials, dynamic tests in which information is derived in a relatively short time appear to be highly desirable. Dynamic methods currently available include direct stress‐strain measurements, transducer methods, resonance methods and wave propagation. Results from any of these tests may be presented in the form of storage and loss moduli. Interpretation of results is dependent upon the final use of the product. In most cases, a relation between the structural mechanics of the food material and the observed mechanical behavior appears to be desirable both as an aid in quality control and as a guide to the development of synthetic foods.
Connective Tissues from Normal and PSE Porcine Muscle. 1. Chemical Characterization
Authors: McCLAIN P. E. , PEARSON A. M. , BRUNNER J. R. , CREVASSE G. A.
Published: August 2006

SUMMARY– The epimysial connective tissue from normal and PSE (pale, soft and exudative) porcine muscle was chemically characterized. Samples from PSE muscles exhibited markedly lower turbidity values (P < 0.01) than those from normal muscles. No significant differences were found in ultimate pH values. The epimysium from PSE muscles contained significantly higher (P < 0.05) quantities of salt soluble tropocollagen and a greater amount of heat labile collagen (P < 0.01) than that from normal tissues. No significant differences in α‐ and β‐subunit composition, plasma hydroxy‐proline levels or amino acid composition were evident between the two sources of epimysial connective tissues.
Comparative Rates of IMP Degradation in Unfrozen and Frozen‐and‐Thawed (Slacked) Fish
Authors: KEMP BARBARA , SPINELLI JOHN
Published: August 2006

SUMMARY— The comparative rates of IMP degradation between fresh and frozen‐and‐thawed (slacked) fish were compared on six different species of fish. Several factors that could contribute to a rate change of IMP degradation were evaluated. These included freezing temperatures, time in frozen storage, pre‐ and post‐rigor freezing, and method of killing the fish.

English sole and rainbow trout showed slight increases in the rate of IMP degradation when they were frozen and then thawed within 48 hr. Silver salmon and halibut that were frozen and then thawed within 48 hr showed no change in the rate of IMP degradation. Halibut, however, that was frozen and stored at −20°F for 3 months showed a slight decrease in the rate of IMP degradation after it was thawed; but king salmon handled under the same conditions did not.

The method of kill or freezing the fish either pre‐ or post‐rigor did not alter the rate of IMP degradation after the fish was thawed.

No loss of IMP occurred in fish (halibut) stored at −20°F. Over one‐third of the original IMP content was lost in halibut stored at +15°F after 3 months of storage.

These results show that there is no significant difference in the rate of IMP degradation between fresh and slacked fish. The flavor‐contributing effect of IMP in slacked fish therefore should be the same as in fresh fish, provided the fish was frozen and stored at or near a temperature of −20°F.
Relative Differences in Tenderness of Breast Muscle in Normal and Two Dystrophic Mutant Strains of Chickens
Authors: PETERSON D. W. , LILYBLADE A. L.
Published: August 2006

SUMMARY– Cooked samples of Pectoralis major muscles from one normal and two mutant dystrophic lines of chickens were compared for tenderness using a mechanical device. The muscles from one of these lines, characterized by partial atrophy, were found to be significantly more tender than normal muscles, whereas the muscles from the second mutant line, characterized by hypertrophy were much tougher than normal muscles. Cooking‐weight losses were much greater in both of the dystrophic mutant lines than in the normal line. Some relationships between composition of the three muscle types and their textural qualities are discussed.
A Study of the Sarcoplasmic Proteins of Porcine Muscle by Starch Gel Electrophoresis
Authors: BORCHERT L. L. , POWRIE W. D. , BRISKEY E. J.
Published: August 2006

SUMMARY– Extensive investigations were conducted on numerous variables in order to establish the most ideal conditions for the starch gel electrophoresis of the proteins of porcine skeletal muscle sarcoplasm. This technique was used to evaluate the characteristics of the sarcoplasm extracted from (a) muscles at various times post‐mortem, (b) muscles which ultimately remained normal in color and gross morphology as well as muscles which became extremely PSE and (c) muscles which had altered color and gross morphology due to post mortem treatment (i.e., normal color and gross morphology due to surface treatment with L‐N2 and PSE characteristics due to post‐mortem incubation at 37°C for 4 hr).

There were no discernible differences between the starch gel electrophoretograms of sarcoplasmic proteins extracted from pre‐ and post‐rigor muscle. Likewise, there were no visually detectable differences between the starch gel electrophoretograms of sarcoplasmic proteins extracted from naturally occurring normal and PSE muscles. Furthermore, the preservation of normal color and gross morphology through L‐N, treatment did not give rise to electrophoretic differences when compared with either naturally occurring normal or PSE muscle.

Although sarcoplasmic protein solubility diminished in naturally occurring PSE muscle, this loss in soluble protein did not necessarily manifest itself in the preferential denaturation of a specific sarcoplasmic protein. However when muscles were incubated at 37°C for 4 hr to induce the PSE condition they yielded sarcoplasmic extracts with marked electrophoretic reductions in creatine kinase, phosphoglucomutase, triosephosphate isomerase and F‐protein (Scopes, 1965). Although there were no apparent differences in creatine kinase isozymes between samples of muscle which ultimately remained normal or became PSE, the minor (fastest moving) creatine kinase band, as well as the phosphoglucomutase bands, appeared more labile during incubation at 37°C than the major (slowest moving) creatine kinase band.
Sarcolemmae from Chicken Skeletal Muscle. 2. Properties
Authors: HULTIN H. O. , WESTORT C.
Published: August 2006

SUMMARY– Sarcolemmae are usually identified solely by morphological characteristics. We have determined several chemical and enzymic properties of sarcolemmae from chicken breast muscle prepared by homogenization of aged muscle in dilute CaCl2 solution, washing 4 times in NaCl‐histidine at pH 7.4, extraction with water buffered to pH 7 and isolation by differential centrifugation on a discontinuous sucrose gradient. The phospholipid content of the sarcolemmae was low, representing only 2 to 3% by weight compared with the 20 to 35% usually found in membraneous systems. This discrepancy may be due to the relatively small proportion of plasma membrane in the sarcolemma.

Analyses indicate little contamination by nuclei or mitochondria. The sarcolemmae have, like the microsomal fraction, high contents of RNA and glucose‐6‐phosphatase activity. The sarcolemma is either rich in these elements or is contaminated by other subcellular elements, such as the transverse tubules (T system), which are. The sarcolemmae display a Mg+2‐ activated ATPase activity which is typical for membraneous systems. Lactate dehydrogenase was shown to be associated with the sarcolemmae. Whether this represents the situation in vivo or is an artifact of preparation is not clear. The sarcolemmae are capable of binding soluble LDH.
The Use of Cryoscopy in Enzymatic Studies
Authors: SHIPE W. F. , BREDDERMAN SUSIE H.
Published: August 2006

SUMMARY— The feasibility of cryoscopy for measuring changes in water‐soluble components of five enzyme‐substrate mixtures was investigated. Cellulase, pectinase, pectin esterase, alpha‐amylase and beta‐amylase were studied. Viscosity measurements were run simultaneously with freezing points as a conventional method for determining enzymatic activity. Measurements taken at periodic intervals revealed changes in both viscosity and freezing‐point values. A comparison of the two sets of values can be useful in assaying the purity of commercial enzyme preparations.
Molecular Properties of Post‐Mortem Muscle. 6. Effect of Temperature on Protein Solubility of Rabbit and Bovine Muscle
Authors: CHAUDHRY H. M. , PARRISH F. C. , GOLL D. E.
Published: August 2006

SUMMARY– Studies were conducted to investigate the effect of temperature on the actin‐myosin interaction of rabbit and bovine muscle during rigor and post‐rigor shortening. Muscle was stored at four different temperatures (2°, 16°, 25° and 37°), corresponding to three types of post‐mortem muscle shortening: cold, minimal and high temperature. These three types of shortening are presumably related to different states of the actin‐myosin interaction in post‐mortem muscle. Post‐mortem tenderization may be the result of either actin‐myosin dissociation or F‐actin depolymerization.

To detect the occurrence of either of these possible changes, two salt solutions, differing widely in their myofibrillar protein extracting abilities, were used to compare post‐mortem myofibrillar protein solubility after different times of post‐mortem storage and to provide information about the actin‐myosin complex. Myofibrillar protein solubility of both rabbit and beef muscle in 0.5M KCl, 0.1M phosphate, pH 7.4, increased markedly with increasing post‐mortem storage at temperatures up to 25deg;. Similar solubility changes were obtained with 1.1M Kl, 0.1M K phosphate, pH 7.4, but these changes were much smaller in magnitude. Solubility in both salt solutions, in general, decreased for muscle stored at 37°.

Although time and temperature of post‐mortem storage caused appreciable alterations in protein solubility, these alterations could not be directly related to changes in tenderness or sarcomere length or to species differences in the effects of temperature on post‐mortem shortening. Viscosity, analytical ultracentrifugation, and ATPase assays all indicated the absence of “normal” actomyosin in all myofibrillar protein extracts in this study. It was suggested that the 1.1 M KI extracts contained G‐actomyosin, but the available evidence indicated the presence of only myosin in 3‐hr, 0.5 M KCI extracts.
Molecular Properties of Post‐Mortem Muscle. 7. Changes in Nonprotein Nitrogen and Free Amino Acids of Bovine Muscle
Authors: PARRISH F. C. , GOLL D. E. , NEWCOMB W. J. , de LUMEN B. O. , CHAUDHRY H. M. , KLINE E. A.
Published: August 2006

SUMMARY– Proteolysis and its relationship to tenderness were studied by measuring nonprotein nitrogen (NPN), free amino groups, and shear resistance during post‐mortem aging of bovine muscle. Both NPN and free amino groups increased during post‐mortem aging, indicating some degradation of proteins and/or peptides. However, neither the increase in NPN nor free amino groups was related to post‐mortem tenderization since these quantities increased only after most of the improvement in tenderness had occurred. Much of the increase in NPN or free amino groups may originate from degradation of sarcoplasmic proteins or peptides. It is suggested that weakening or breaks at crucial points in the sarcomere, such as at the junction of the Z‐line with the thin filaments, occur within the first 48‐72 hr post‐mortem and that this weakening or cleavage is responsible for tenderization. Cathepsin D may be responsible for this weakening but most of the available evidence is against proteolysis as the primary cause of post‐mortem tenderization.
The Detection and Enumeration of Clostridium perfrinqens in Foods
Authors: HALL W. M. , WITZEMAN J. S. , JANES R.
Published: August 2006

SUMMARY— A method that uses SPS agar and incorporates an improved egg yolk agar and nitrate motility medium has been developed for the enumeration and confirmation of vegetative cells and/or spores of Clostridium perfringens in foods. The method is based upon several diagnostic criteria and can be completed within 48 hr.
Rapid Determination of Proline in Grapes and Wines
Authors: OUGH C. S.
Published: August 2006

—An improved method for the rapid determination of free proline in grapes and wine is given. No significant interference from other amino acids in amounts found in grapes and wine would normally be expected. The method is applicable to most biological material as long as lysine, hydroxyproline, tryptophan and glutamine are not present in total amounts greatly exceeding that of proline. Lysine caused greatest interference and this was only 6% error on equal mole amounts. A direct dilution technique instead of the usual extraction of reaction product by benzene increased accuracy and speed of this method. The relative standard deviation between pairs of samples of grape juice averaged about 3% and for wine about 4%.
Occurrence and Properties of Enzymes Associated with Mevalonic Acid Synthesis in the Orange
Authors: POTTY V. H.
Published: August 2006

—Active enzyme preparations were obtained from mature orange fruit in a quest for the various enzymes associated with terpenoid synthesis. These preparations were examined systematically for the presence of enzymes involved in the biosynthetic pathway to mevalonic acid. Orange fruit was shown to contain acetyl‐CoA synthetase (EC.6.2.1.1) forming acetyl coenzyme A from acetate. It also contained the iodoacetamide‐sensitive acetoacetyl‐CoA thlolase (EC.2.3.1.9) the enzyme responsible for the synthesis of acetoacetyl coenzyme A. Hydroxymethylglutaryl‐CoA synthase (EC.4.1.3.5) and the corresponding reductase (EC.1.1.1.34), however, were not found in preparations from orange fruit. Nonetheless, acetoacetyl coenzyme A, formed by the thiolase, was further metabolized in the mature fruit via 3‐hydroxybutyryl‐CoA dehydrogenase (EC.1.1.1.35), a constituent enzyme in lipid biosynthesis. These results suggest that mature orange fruit derives mevalonic acid or other necessary basic intermediates for terpenoid biosynthesis from other sources.
Enzymic Activity during Growth of Vanilla Fruit 1. Proteinase, Glucosidase, Peroxidase and Polyphenoloxidase
Authors: WILD‐ALTAMIRANO CARLOS
Published: August 2006

—A preliminary study has been made of these enzymic activities along the growth of vanilla pods looking for information about biochemical reactions which lead to the production of the aroma. Proteinase activity decreases with pod age. The activities of glucosidase, peroxidase and polyphenoloxidase increase with stage of growth reaching a maximum near or at ripening. Possibly these enzymes play some role in reactions taking place in curing vanilla, either directly or indirectly supplying the initial products to be transformed into those responsible for color and odor. Partially purified polyphenoloxidase shows a ration catecholase‐cresolase activity of 8.9.
Ascospore Production by Byssochlamys fulva
Authors: SPLITTSTOESSER D. F. , CADWELL MARK C. , MARTIN MARSHA
Published: August 2006

—The effect of different variables on ascospore production was studied quantitatively. Maximal populations were obtained in 5% malt extract broth, pH 2‐3, after an incubation of 7‐14 days at 30°C. Tests on nine different fruit and vegetable juices showed that eight afforded good sporulation. Prune, grape and pineapple yielded the greatest numbers. Plating methods were found to underestimate the true ascospore populations because of spore dormancy and because a majority of the asci, each containing eight ascospores, remained intact.
Heat of Respiration of Fresh Produce as Affected by Controlled Atmosphre
Authors: TOLEDO R. , STEINBERG M. P. , NELSON A. I.
Published: August 2006

—The heat of respiration of fresh produce in controlled atmosphere (CA) storage was determined with a calorimeter to provide information on the refrigeration load imposed. The heat of respiration in air at the same temperature was also measured to enable direct comparison with the heat of respiration in CA. The calorimeter was a heavily insulated Dewar flask and the product was continuously flushed with either air or CA.

The values obtained for the heat of respiration in air were in good agreement with those reported in the literature for these products. The heat of respiration (Btu/Ton‐24 hr) in optimum CA with the ratio in CA to that in air given as a percent was as follows: Wando peas at 48°F—6,690, 31%; Thorogreen lima beans—2,290, 30%; cut Victory Golden sweet corn—3,810, 32%; Red Delicious apples—525, 28%. It was concluded that the heat of respiration of fresh produce in CA can be estimated by assuming that it is about 30% that in air.
Incidence and Growth of Some Health‐Related Bacteria in Commercial Freshwater Crayfish (Genus Procambarus)
Authors: LOVELL RICHARD T. , BARKATE JOHN A.
Published: August 2006

—Collections of freshwater crayfish were obtained from 22 sources representing the major commercial crayfishing areas in Louisiana, and analyzed for coliforms, Escherichia coli, fecal streptococci, coagulase‐positive staphylococci, Salmonella and Clostridium botulinum type E. Growth patterns for E. coli, Staphylococcus aureus, Streptococcus faecalis and Salmonella typhimurium in raw and cooked crayfish flesh, and in a crayfish‐containing commercial‐type substrate were determined at 5, 25, and 37°C. C. botulinum type E toxin production was determined at intervals of storage in ice pack and at 5 and 30°C.

Coliforms, E. coli, fecal streptococci, coagulase‐positive staphylococci, Salmonella, and C. botulinum type E were found in 100, 92.6, 94.1, 3.0, and 0%, respectively, of the samples analyzed. Staphylococcus aureus and Salmonella typhimurium grew well in all three of the substrates at 25 and 37°C. Streptococcus faecalis and possibly E. coli showed suppressed growth in the raw flesh, but both grew well in cooked flesh and the commercial‐type substrate. None of these four organisms grew at 5°C. C. botulinum type E produced toxin in all three of the substrates within 48 to 72 hours at 30°C and after 33 days at 5°C.

Toxin was not produced at 56 days in ice‐pack. The pH increased in the raw and cooked flesh, with extended storage time, to above 8.0 and the toxin became inactive. In the commercial‐type substrate, the pH decreased to 5.7 and the toxin remained active. When the pH of the commercial‐type substrate was adjusted to 8.5 with NaOH, the toxin was inactivated.
Sensory Evaluation of Lamb and Yearling Mutton Flavors
Authors: BATCHER OLIVE M. , BRANT A. W. , KUNZE MARION SIMONE
Published: August 2006

—Differences in flavor attributable to age of animal and to sex were detected when broth from samples of lamb and yearling mutton meat were served to panel members in triangle tests. No differences were detected in slices of roasted, broiled, or braised meat scored by the panel. Broth from the lean meat of lamb (7 to 8 months) was preferred to that prepared from lean of 15. to 16 month old yearling mutton carcasses. Differences in flavor intensity of wether and ram meat served as patties in triangle tests were present only in patties containing 20% added fat. Full natural flavor of slices of cooked meat was not associated with elther the cover fat thickness of the cut or with the fat content of the muscle.
Free Amino Acids and Other Nitrogenous Substances of Table Grape Varieties
Authors: KLIEWER W. MARK
Published: August 2006

—The concentration of eight amino acids, total free amino acids, total nitrogen and free amino acid fraction nitrogen in the juices of 28 table varieties of grapes was determined at both early and a late stage of fruit maturity. Arginine, proline, glutamic acid and alanine were the most prominent amino acids. The varieties were classified into four groups according to which of these acids predominated. Total free amino acids at early and late fruit maturity ranged from 1.04 to 5.53 and 1.24 to 6.45 nM/100 ml juice, respectively in the various varieties. The eight amino acids analyzed accounted for 74 to 96% of the total free amino acids. The amino acid fraction nitrogen in the juices ranged from 60 to 90% of the total nitrogen. The eight amino acids accounted for 60 to 96% of the amino acid fraction Kjeldahl nitrogen and 37 to 85% of the total Kjeldahl nitrogen. Argining accounted for 15 to 50% of the total nitrogen in the juices of the various fruits.
Classification of Some Esterases of the Green Bean (Phaseolus vulgaris L.)
Authors: PUTNAM TERYL B. , MONTGOMERY M. W.
Published: August 2006

Aqueous extracts of green beans hydrolyzed the acetyl, propionyl, and n‐butyryl esters of glycerol, phenol, sodium 2‐naphthol‐6‐sulfonate and choline. Triolein and soluble long‐chain esters of sodium 2‐naphthol‐6‐sulfonate were not hydrolyzed. Optimum esterase activity occurred at pH 7.2. Three esterases were classified by studylng the effects of the organophosphorus compounds, diethyl p‐nitrophenyl thioposphate (parathion), tetraethyl pyrophosphate (TEPP) and diisopropyl phosphorofluoridate (DEP), on the hydrolysis of nine substrates, One esterase, resistant to organophosphorus compounds, was classified as an arylesterase (EC 3. 1. 1. 2). The two esterases inhibited by organophosphours compounds were classified as carboxylesterases (EC 3. 1. 1. 1).
Carotenoid Degradation in Bleached Paprika
Authors: MAR ROSALITA R. DE LA , FRANCIS F. J.
Published: August 2006

—Commercial samples of bleached and normal paprika were extracted with acetone, separated by countercurrent distribution fractionation, purified by column chromatography and identified by spectral and chemical methods.

The bleaching treatment of the paprika samples resulted in a loss of nearly 96% in total extractable pigment expressed as beta‐carotene.

The fractionation of the cartenoid extracts revealed a great variation in the distribution patterns of the pigments. Most grades of paprika showed a predominace of diolpolyol carotenoids, but one grade had a far greater amount of hydrocarbons.

There were 54 and 37 pigments isolated from bleached and unbleached Domestic paprikas, respectively. Of the 54 and 37 pigments, only 33 and 21, respectively, were completely or tentatively identified. Sixteen of the known pigments in unbleached paprika were also observed in the bleached sample.

It is evident that the bleached paprika gave more isomers and oxicative products than did the unbleached sample. Most of the compounds appearing with the capsanthin and capsourbin fractions seemed to be isomers of more fully oxygenated derivatives of these two major pigments. Most of the more oxygenated products appeared to possess ketonic group(s).
Capillary Distribution and Fiber Characteristics in Skeletal Muscle of Stress‐Susceptible Animals
Authors: COOPER C. C. , CASSENSand R. G. , BRISKEY E. J.
Published: August 2006

Muscle from stress‐susceptible and stress‐resistant pigs was studied for capillary distribution and fiber characteristics. More capillaries were associated with red fibers than white fibers and there was a greater capillary to fiber ratio in red than white muscle. There was no difference in capillary fiber ratio between normal (from stress‐resistant pigs) and PSE (from stress‐susceptible pigs) muscle. Muscle from stress‐susceptible animals had more intermediate fibers than did muscle from stress‐resistant animals. Certain intermediate fibers from stress‐susceptible animals had a high amylophosphorylase and ATPase activity. It was postulated that such fibers are important in the drastic post‐mortem muscle behavior in stress‐susceptible animals and may represent the characteristic which causes muscle to become PSE.
Turbidity, Viscosity and ATPase Activity of Fibrillar Protein Extracts of Rabbit Muscle
Authors: WEINER P. D. , PEARSON A. M. , SCHWEIGERT B. S.
Published: August 2006

Results suggest that actomyosin from muscle in rigor is more easily dissociated than actomyosin from prerigor muscle. The addition of MgCl2 decreased the rate of ATP hydrolysis and extended the clear phase of the fibrillar protein extract. Pyrophosphate in the presence of magnesium was as effective as ATP in clearing actomyosin. As the ATP was hydrolyzed, the viscosity of the solution returned to values greater than those obtained before the addition of ATP. However, samples cleared with pyrophosphate retained their low viscosity characteristics indefinitely.
Studies on Natural Actomyosin: Survey of Experimental Conditions
Authors: HERRING H. K. , CASSENS R. G. , FUKAZAWA T. , BRISKEY E. J.
Published: August 2006

—Natural actomyosin was prepared from the longissimus dorsi of both bovine and rabbit. Rabbit actomyosin had about two times the ATPase activity of bovine muscle actomyosin. However, both types of natural actomyosin behaved in a similar manner with respect to ionic conditions. They were activated by Mg++ at low KCI (20–50 mM), inhibited by Mg++ at high KCI (100 mM) and activated by Ca++ at high KCI (100 mM). Bovine actomyosin, in contrast to rabbit actomyosin, did not show activation at low Mg++ (0.01 mM) in the alkaline pH range. Maleate, when used as Tris‐Maleate buffer, inhibited superprecipitation of natural actomyosin from rabbit and bovine muscle. It was hypothesized that the low ATPase activity and the non‐activation at low Mg++ in the alkaline pH range of bovine compared to rabbit actomyosin was a species difference.
Potentiometric Determination of Fluoride in Beverages by Means of the lon Selective Solid State Electrode
Authors: FERREN WILLIAM P. , SHANE NORMAN A.
Published: August 2006

—A method employing the fluoride ion‐selective solid‐state membrane electrode has been developed to determine the presence and amount of free fluoride ion in carbonated and noncarbonated beverages. Representative carbonated and non‐carbonated beverages containing known amounts of added fluoride were used to relate electrode activity measurements to fluoride concentration in parts per million. Calibration curves were constructed for each system wherein fluoride concentration (ppm), was plotted as a function of potentiometric measurements (millivolts); using the fluorideion‐activity‐electrode as the indicator electrode and a saturated calomel electrode (SCE), as the reference electrode. Beverages studied were selected to represent a range of pH values and complexity of organic and inorganic constituents present in order to demonstrate the ability of the fluoride‐ion‐electrode to selectively determine free‐fluoride ion.
Lethality of Radio‐Frequency Energy upon Microorganisms in Liquid, Buffered, and Alcoholic Food Systems
Authors: CARROLL D. E. , LOPEZ ANTHONY
Published: August 2006

This work was done to determine if 60 mc/sec R‐F energy has a selective killing effect on microorganisms other than that attributable to heat. The organisms studied were Saccharomyces cerevisiae, Escherichia coli, and Bacillus subtilis, An aqueous buffer medium was used to suspend the microorganisms for the irradiation treatments. No killing effect of the R‐F energy per se on the organisms was observed at any of the various buffer pH values, nor was there an obsevable synergistic killing effect of R‐F energy and heat on the microorganisms in any of the buffer. However, a synergistic killing effect of ethanol and heat at 48.8°C was demonstrated on S. cerevisiae. Irradiating S. cerevisiae and E. coli in several liquid foods also failed to show a selective killing effect of R‐F energy.
Some Properties of Mitochondria from Irradiated Tomato Fruit
Authors: PADWAL‐DESAI S. R. , AHMED E. M. , DENNISON R. A.
Published: August 2006

—Homestead tomato fruit were irradiated with 300 Krad of 60Co gamma rays at three stages of maturity–mature‐green, 2 and 6 days from color break. Though oxygen consumption by mitochondrial preparations was greatly suppressed immediately after irradiation it increased to a maximum during the following 2 days and then declined similarily to nonirradiated fruit. Oxygen consumption was reduced considerably during ripening of the nonirradiated and irradiated 6 day breakers. Mitochondria from irradiated fruit exhibited lower P/O ratios than from nonirradiated fruit. A considerable reduction was less pronounced with the 2 and 6 day breakers. In vitro irradiation of mitochondrial preparations indicated no differences in activity with doses up to 100 Krad, but at 150 and 300 Krad, the activity decreased by 50 and 90%, respectively.
The Volatile Components of Irradiated Beef and Pork Fats
Authors: CHAMPAGNE J. R. , NAWAR W. W.
Published: August 2006

Samples of beef and pork fats were irradiated under vacuum at seven doses ranging from 0.5 to 6.0 megarads. Of the components produced by irradiation, 41 were identified by gas chromatography and mass spectrometry. These include a series of n‐alkanes, 1‐alkenes, internally unsaturated alkenes and alkadienes. The latter two groups of compounds have not been reported previously in meats or meat fats. In addition, hexadecanal, octadecanal and octadecenal were found to be produced in relatively large quantities by irradiation. Quantitative data showed that a definite relationship exists between the volatile pattern and ther fatty acid composition of the irradiated material. Flavor thershold values of the unsaturated classes of hydrocarbons vary widely among themselves but are much lower than those of the n‐alkanes.
Identification and Characterization of the Pectic Enzymes of the McFarlin Cranberry
Authors: ARAKJI OMAR A. , YANG H. Y.
Published: August 2006

Endo‐polygalacturonase activity was found in cranberry proteins. Viscosity measurements showed that the hydrolysis of pectins with both high and low methoxyl content occurred on addition of a protein dialysate to pectin solutions. The use of a phenol binding agent in the enzyme preparation was necessary to obtain a high hydrolytic activity. Higher activity was noted with citrus pectins than cranberry pectins. Optimum activity was found at pH 5.0 for cranberry polygalacturonase. Activity was destroyed after 35 min of heating at 100°C. Up to 0.6 M NaCl gave no significant effect on cranberry polygalacturonase activity at pH 5.0. Cranberry pectin esterase activity was low when compared to strawberry and tomato pectin esterase. The optimum pH value for pectin esterase was 7.5, and the enzyme was inactivated when heated for 5 min at 100°C. When pectin solutions were treated with NaCl, optimum pectin esterase activity occurred at 0.15 M concentration.
Chemical Composition and Heat Resistance of Bacillus stearothermophilus Spores
Authors: ROTMAN Y. , FIELDS M. L.
Published: August 2006

—Heat resistance measurement demonstrated that the rough variant was more heat tolerant than the smooth variant. Spores of the two variants were analyzed for DPA, calcium, manganese, magnesium and zinc. No direct relationship was found between DPA, mineral concentrations and heat resistance.
Colorimetry of Foods. 1. Correlation of Raw, Transformed and Reduced Data with Visual Rankings for Spinach Puree
Authors: CLYDESDALE F. M. , FRANCIS F. J.
Published: August 2006

—Freshly processed spinach puree and stored processed puree were mixed in proportions varying from O to 100% in increments of 10% to provide three different sets of 11 samples each. These sets simulated the range of color values actually obtained with samples in storage after processing. Color measurements were performed by means of a General Electric Recording Spectrophotometer, a Hunterlab Model D25 Color Difference Meter, and a Colormaster Differential Colorimeter, Model V. Experiments were carried out on each set of samples to obtain tristimulus values from each instrument. These values were mathematically transformed to the tristimulus values of the other two color systems. Tristimulus values from the instruments also were reduced to common color functions, and all data were correlated with visual rankings. Good correlations of instrument versus visual rank were obtained. Absolute values obtained from the transformation equations were very different from instrumental values. However, the transformations resulted in only a slight decrease in correlation with visual preference. Reduced data calculated from instrumental read‐out correlated well with visual rank. However, conversion of Colormaster data to Adams data and resultant reduction produced poor correlations.
Quantitative Determination of Formic, Acetic, Propionic and Butyric Acids in Frozen Whole Eggs by Gas‐Liquid Chromatography
Authors: STEINHAUER J. E. , DAWSON L. E.
Published: August 2006

—Whole eggs containing known amounts of formic, acetic, propionic and butyric (C1‐C4) acids were evaluated using gas‐liquid chromatography (GLC) and AOAC (1960) procedures. Acetic, propionic and butyric acids were recovered from whole egg samples and chromatographed as the acids per se, along with an internal standard. Formic and acetic acids were recovered from whole egg samples and chromatographed as their butyl ester derivatives without an internal standard. Quantitation of butyl formate and butyl acetate was accomplished by comparing the chromatogram peak heights of the butyl esters recovered from the egg samples with the chromatogram peak heights of a known concentration of butyl ester standards. The recovery of acids from whole egg samples by GLC procedures was as accurate, and generally less variable, than by AOAC (1960) procedures. The percentage recovery of acids from whole egg samples using GLC procedures depended on the concentrations of the acids present and was as follows: acetic acid varied from 114 to 100% (low to high concentration); propionic acid varied from 101 to 100% (low to high concentrations); and butyric acid varied from 103 to 99% (low to high concentration). The recovery of formic acid as its butyl ester derivative varied from 104 to 96% (low to high concentration), while the recovery of acetic acid as its butyl ester derivative varied from 102 to 98% (low to high concentration).
Enzyme‐Catalyzed Reactions as Influenced by Inert Gases at High Pressures
Authors: BEHNKE J. R. , FENNEMAand O. , POWRIE W. D.
Published: August 2006

—The activities of tyrosinase, invertase, trypsin and chymotrypsin were studied after exposure to one or more of the following high‐pressure inert gases: N2O at 600 psig or N2 or Ar each at 5000 psig. Exposure to high‐pressure nitrogen or argon failed to significantly inhibit the rate of tyrosinase activity in fluid systems. However, the rates of tyrosinase‐catalyzed reactions in shell‐cast gelatin gels were significantly depressed by exposure to high‐pressure nitrogen, and even more so by high‐pressure nitrous oxide. This inhibition proved to be oxygen dependent and reversible. Pressurization experiments with invertase, trypsin and chymotrypsin indicated that high‐pressure N2O did not significantly inhibit these enzymes. This lends support to the hypothesis that high‐pressure inert gases inhibited tyrosinase activity in nonfluid systems by decreasing the availability of oxygen, rather than by physically altering the enzyme. It must be concluded that there is little hope that the enzymes in food systems can be effectively inhibited by brief exposure to inert gases at pressures of 5000 psig or less.
Degradation of DDT and DDE by Cheese Microorganisms
Authors: LEDFORD R. A. , CHEN J. H.
Published: August 2006

Representative microorganisms of the diverse flora associated with several varieties of surface‐ripened cheese were isolated. Species of streptococci, micrococci, yeasts and Gram‐positive rods accounted for most of the isolates. These were incubated at 32°C in media containing 0.5 ppm lindane, p‐p DDE, and p‐p DDT. The pesticides were dissolved in a small amount of ethanol to facilitate incorporation into the media. Following incubation for 10 days, the concentrations of residual pesticides were determined by electron capture gas chromatography. The growth of streptococci and micrococci isolates did not apear to produce any changes in pesticide levels, though they apparently were uninhibited by the pesticides. However, the growth of other isolates dechlorinated p‐p DDT. Moreover, aerobic growth of geotrichum species caused almost complete disappearance of the p‐p DDT and p‐p DDE peaks from the gas chromatograms. These results suggest the possibility that residues of DDT and DDE might be degraded if they are present in certain types of surface‐ripened cheeses.