bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gel Strength of Kappa‐Carrageenan as Affected by Cations
Authors: ZABIK MARY E. , ALDRICH PEARL J. 
Published: August 2006

SUMMARY– Kappa carrageenan was ion‐exchanged with Al+3, NH4, +2, Ca+2, Fe+3, Fe+3, Mg+2, Na+2 and Sn+2. The gelling temperature and gel strength were determined for 1% exchanged kappa carrageenan gels prepared with 0.0375,0.075 and 0.15 N solutions of each of the exchanging cations; 1% exchanged kappa carrageenans with 0.0375, 0.075 and 0.15 N KCI, and non‐exchanged kappa carrageenan with the same concentrations of AlCl3, NH4Cl, CaCl2, FeCl2, FeCl3 MgCl2 KCl, NaCl and SnCl2.Ion‐exchange with Al, Fe+2, Fe+3 and Sn prevented gel formation. The other ion‐exchanged carrageenans had signicantly lower gel strength than the non‐exchanged carrageenan in a corresponding cation solution. Furthermore, the Mg‐ and Ca‐exchanged carrageenans had greater gel strengths than the NH4 and Na‐carrageenans. Use of KCI with the NH,‐, Ca‐, Mg‐ and Na‐exchanged carrageenan resulted in increased gel strength, but the Al, Fe+2, Fe+3 and Sn‐exchanged carrageenans still did not form a gel. The rank order of the gel strength of the NH4, Ca‐, Mg‐ and Na‐exchanged carrageenan dispersed in KCI was similar for the exchanged carrageenan in solutions of the exchanging cation, but the gelling temperatures and gel strength of the former approached that of the non‐exchanged carrageenan in similar concentrations of KCl.For the non‐exchanged carrageenan at the 0.075 N level of salt concentration, the effect of cation was K > Ca, Mg > Fe+2, NH4 < Na, Sn < Fe+3, Al (P < 0.001). Use of increasing concentrations of NH,Cl, NaCl, KCl and SnCl2 resulted in increased gel strength, whereas increasing concentrations of CaCl2, FeCl3 and MgCl2 decreased gel strength. These differences were reflected in a slightly different rank order for the 0.15 N level of salt.
Salt, Moisture and Aging Time Effects on the Viability of Trichinella spiralis in Pork Hams and Shoulders
Authors: GAMMON D. L. , KEMP JAMES D. , EDNEY J. M. , VARNEY W. Y. 
Published: August 2006

SUMMARY– Twenty‐four weanling pigs were infested with Trichinella spiralis, by dosing with trichina larvae. The hogs were raised to market weight and slaughtered. Lean samples from each ham and shoulder were digested in a pepsin‐HCI solution and microscopically examined. The samples contained respectively an average of 192 and 175 larvae per gram.The hams and shoulders were dry‐cured for 2 days per pound, using 8 pounds of cure per 100 pounds of meat. The mixture contained salt, sugar, potassium nitrate, and sodium nitrite. After being cured, the meat was hung for 30 days for salt equalization, rinsed, allowed to dry, smoked for approximately 24 hr at 90 to 100°F, and aged at 75°F.Cores were taken from randomly selected hams and shoulders at weekly intervals and analyzed for salt and moisture while part was digested and examined for live trichinae. Live trichinae persisted through the curing and salt equalization periods but began to be reduced in number after one week of aging. Samples taken from hams and shoulders aged for one month were found to be void of any live trichina larvae.Meat from similar samples was force‐fed to rats for 5 days. After 8 weeks the rats were sacrificed and the carcasses digested and examined. No trichina larvae were found.
Comparison of Sarcomere Length to Other Predictors of Beef Tenderness
Authors: HOWARD R. D. , JUDGE M. D. 
Published: August 2006

SUMMARY– Sarcomere length in the longissimus dorsi muscles of 20 bovine animals was compared to other variables in predicting tenderness (Allo‐Kramer shear) in two muscle positions (medial and lateral) and at four cooking temperatures (60, 64, 68 and 72°C). The medial muscle position was less tender, had shorter sarcomeres and had higher correlations between sarcomere length and tenderness than the lateral muscle position. In neither position did sarcomere length account for tenderness variation that was unaccounted for by combinations of other commonly‐used carcass variables indicating that a single measure of sarcomere length at a given position is of little value in predicting tenderness if certain carcass parameters are known.Comparison of sarcomere length with resistance to shear across the cross section of 5 additional longissimus dorsi muscles showed that very small differences in contraction state were associated with marked differences in tenderness in restricted muscle areas. The study emphasizes the importance of post‐rigor contracture to tenderness but indicates that several estimates are necessary to characterize a single muscle.
Salting and Drying Fish. 3. Diffusion of Water
Authors: VALLE F. R. DEL , NICKERSON J. T. R. 
Published: August 2006

SUMMARY– Drying of salted fish was studied in the falling rate period. It was found that this period consisted of two distinct phases, each of which was characterized by a Fickian diffusion coefficient. The coefficient for the first phase was, in all cases, greater than that for the second phase. The effect, on both diffusion coefficients, of the following variables was studied: degree of salting, drying temperature, and degree of hydration of ‐the muscle (varied by addition of acid, base and sodium trypolyphosphate to the muscle). The first diffusion coefficient was found to increase, pass through a maximum, and then decrease with degree of salting. The second coefficient was found to decrease with degree of salting within the range for which it was determined.The first diffusion coefficient was found to be directly correlated with the degree of hydration of the muscle; a plot of the coefficient versus water content of the muscle (expressed as pounds of water per pound of bone‐dry solids) yielded a straight line, the regression equation of which was found to be D = 0.16W + 0.09, where D is the diffusion coefficient in cm2/sec × 105 and W is the water content. Variations in the diffusion coefficient due to degree of salting and due to addition of acid, base, and phosphate could be explained by the hydration‐dependence of the coefficient. The temperature variation of both coefficients was found not to be great.
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.
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

SUMMARYAn 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

SUMMARYThe 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

SUMMARYProtein 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.
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

SUMMARYAging 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.
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.
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.
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.
Rapid Determination of Proline in Grapes and Wines
Authors: OUGH C. S. 
Published: August 2006

SUMMARY—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

SUMMARY—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

SUMMARY—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.