bluuebunny/crossref_metadata_2025 huggingface dataset:
Cysteine Inhibition of Enzymatic Blackening with Polyphenol Oxidase from Potatoes
Authors: MUNETA PAUL , WALRADT J.
Published: August 2006

The possible sites of cysteine inhibition of enzymatic blackening using polyphenol oxidase from potatoes were studied. The initial site of cysteine inhibition of enzymatic blackening caused by tyrosine oxidation occurred at the oxidation of tyrosine to 3,4‐dihydroxyphenylalanine (dopa). Following the initial induction period, the oxygen uptake paralleled those treatments with no cysteine. Concentrations of cysteine (9.5 × 10‐3M) which inhibited tyrosine oxidation for 100 min did not inhibit dopa oxidation significantly. However, higher concentrations (1.9 × 10‐2M) inhibited dopa oxidation. Cysteine did not inhibit chlorogenic acid oxidation under the conditions of our study. Oxygen uptake with chlorogenic acid plus cysteine was higher than in the absence of cysteine. Cysteine concentrations which effectively inhibited tyrosine oxidation did not inhibit oxidation in the presence of tyrosine plus chlorogenic acid.
Tenderness and Maturity in Relation to Certain Muscle Components of White Leghorn Fowl
Authors: WANGEN R. M. , SKALA J. H.
Published: August 2006

Tenderness of roasted and stewed pectoralis major and biceps femoris muscles (estimated by shear values) from White Leghorn female birds was studied in relation to maturity and composition at 4, 8, 12 and 18 months of age. Shear values of pectoralis major muscles did not change significantly with age or differ significantly between cooking methods. Shear values of biceps femoris muscles increased significantly with age of roasted specimens. No similar significant change occurred in stewed specimens. Roasted biceps femoris had significantly higher (P < 0.01) shear values than stewed samples at 12 months and more markedly at 18 months of age. No association was noticed between either intramuscular fat or moisture content and shear value trends. Hydroxyproline content (HOP) was determined in biceps femoris samples only. Total HOP content was significantly higher in more mature samples with a significant difference only at 12 months of age between cooking methods. Residual HOP content as a measure of collagen not converted to gelatin during cooking, showed a tendency to increase with age and differed significantly between cooking method only at 18 months of age. Total and residual HOP content of roasted biceps femoris were significantly correlated with shear values (r = 0.64 and 0.79, P < 0.01). The marked increase in residual HOP content at 18 months seemed to explain more satisfactorily the divergence in shear values.
Partial Purification of Salmon Muscle Cathepsins
Authors: TING CHAO‐YUN , MONTGOMERY M. W. , ANGLEMIER A. F.
Published: August 2006

Salmon muscle cathepsins hydrolyzed denatured hemoglobin optimally at pH 3.7 with two minor pH optima noted at pH 7.0 and 8.5. Cathepsins optimally active at pH 3.7 and extracted with 0.2 N KCI, were partially purified by (1) precipitation of inactive protein at pH 5.5, (2) (NH4)2SO4 fractionation, and (3) column chromatography on DEAE‐cellulose. Two cathepsins appeared to be separated by this procedure; one was purified 27‐fold with 17% recovery and the other was purified 116‐fold with 6.8% recovery.
Adsorption of Volatile Organic Compounds in Dehydrated Food Systems. 1. Measurement of Sorption Isotherms at Low Water Activities
Authors: ISSENBERG P. , GREENSTEIN G. , BOŠKOVIĆ M.
Published: August 2006

Removal of water vapor during food dehydration results in losses of volatile compounds that contribute to flavor. The relative importance of diffusion and adsorption to retention of volatile components by solid food constituents during dehydration processes is not well known.

A frontal analysis gas chromatographic apparatus has been developed to measure vapor‐solid adsorption at low adsorbate concentrations. Volatile compound is sorbed from the gas stream by an adsorbent in a system designed to minimize diffusion and kinetic effects. The system includes saturator chambers, which maintain constant concentration of adsorbate in the carrier gas stream, and a flame ionization detector.

Data collected are presented as sorption isotherms. With microcrystalline cellulose powder as adsorbent and hexane and acetone vapors as adsorbates partial pressures in the range of 1 millitorr were produced and maintained. Resulting concentrations measured were in the range of micrograms adsorbate per gram adsorbent (ppm), orders of magnitude encountered in real dehydrated food systems.
The Volatile Alcohols of Ripe Bananas
Authors: MURRAY K. E. , PALMER J. K. , WHITFIELD F. B. , KENNETT B. H. , STANLEY G.
Published: August 2006

The volatile alcohols in ripe bananas were identified in preparation for the study of their biosynthesis. The following 13 alcohols were identified by gas chromatography‐mass spectrometry supported in some cases by IR spectral data: ethanol, propan‐l‐01, P‐methylpropan‐l‐01, butan‐l‐01, pentan‐2–01, 3‐methylbutan‐l‐01, hexan‐l‐01, heptan‐2–01, cis and tram hex‐3‐en‐l‐01, cis and traws hex‐4‐en‐l‐01, and cis pent‐2‐en‐l‐01 (tentative). 2‐Methylbutan‐l‐01 was shown to be associated with 3‐methylbutan‐l‐01 in a ratio of 1:200.
Effect of Feeding and Withdrawal of Menhaden Oil on the w3 and w6 Fatty Acid Content of Broiler Tissues
Authors: MILLER DAVID , LEONG KAM C. , SMITH RESTON
Published: August 2006

SUMMARY– Analysis was made of the fatty acid composition of liver, adipose fat, thigh and breast muscles of broilers fed corn‐soy commercial‐type of diets containing one of two levels of fish oil (2.5 or 5.0%). The oil was subsequently continued, withdrawn or replaced with yellow grease 2, 3 or 4 weeks before termination of the experiment at the 8th week. The tissue contents of four w‐3‐type fatty acids (20:4, 20:5, 22:5 and 22:6) were increased in relation to the number of weeks menhaden fish oil was included in the diet. (The first number indicates the chain length of carbons, the second indicates the number of double bonds. The number following w (omega) indicates the carbon position of the first double bond as counted from the terminal methyl group.)

Of the four tissues studied, the liver had the highest total content of the w3 fatty acids; the adipose fat, the least. The muscles had intermediate values; the breast containing more than the thigh. Withdrawal of fish oil at the 4th week resulted in favorable organoleptic evaluation. A more favorable evaluation was obtained if yellow grease was substituted in place of fish oil for the last 4 weeks. The organoleptic scores were highly significantly correlated with the content of 20:5 03, 22:5 w3 and 22:6 w3 but it was less significantly correlated with the content of 20:4 w3. An inverse relation existed between the content of the w3 with that of the w6 fatty acids.
Tenderization of Chicken Muscle: The Stability of Alkali‐Insoluble Connective Tissue During Post‐Mortem Aging
Authors: de FREMERY DONALD , STREETER IVA V.
Published: August 2006

SUMMARY— The relation between tenderness of breast and thigh muscles from chicken broilers and stability of connective tissue therein was measured during post‐mortem aging. Tenderness was determined with a Warner‐Bratzler shear‐force apparatus and with a trained taste panel. Maximum shear‐resistance values occurred in breast muscles 3 to 4 hr post‐mortem; minimum values were reached 12 hr post‐mortem and did not change significantly during aging for 8 days. Maximum shear‐resistance values occurred in thigh muscles 3 hr post‐mortem; in these muscles tenderization continued during 8 days of aging.

In contrast, alkali‐insoluble connective tissue determined in either raw or cooked muscle (as measured by alkali‐insoluble hydroxyproline) did not change significantly as a function of post‐mortem aging time (1 hr vs 24 hr for breast meat, 1 day vs 8 days for thigh meat). Cooking solubilized considerable amounts of the connective tissue. Post‐mortem tenderization of chicken meat is not related to changes in connective tissue but must be ascribed to some other fraction (or fractions) of muscle tissue.
Changes in Molecular Weight of Pectin During Methylation with Diazomethane
Authors: SMIT CHRISTIAN J. B. , BRYANT EDWIN F.
Published: August 2006

SUMMARY– Acid and enzymatic demethylation procedures suggest that the change in molecular weight during methylation is a result of depolymerization and that a change in the percent methoxyl groups probably has very little effect on the change in molecular weight during methylation or demethylation with pectins having an ester content between 60% and 95%.

Samples of a commercially prepared citrus pectin were acid washed, dissolved and neutralized to different levels with dilute NaOH. These samples were treated with isopropanol to yield an open gel‐like precipitate, the alcohol was replaced with ether and the pectin treated with diazomethane at < −30°C. The samples methylated to 70%, 85% and 95% had molecular weight values which decreased with increasing degrees of esterification. Molecular weight was determined by measuring the viscosity of a 0.1 % sol in 1 % Calgon.
Characterization of Israel Lemon Oil and Detection of its Adulteration
Authors: LIFSHITZ ABRAHAM , STEPAK Y. , BASKER H. B.
Published: August 2006

Samples of genuine Israel lemon oil were examined by the usual standard methods and by gas‐liquid chromatography. The variations obtained are discussed, and were evaluated statistically. Chi‐square equations were computed for the evaluation of samples of doubtful origin. Sophisticated adulterations of the other of 10% were clearly detectable.
Taste Thresholds of Butter Volatiles in Deodorized Butteroil Medium
Authors: SIEK T. J. , ALBIN INGA A. , SATHER LOIS A. , LINDSAY R. C.
Published: August 2006

—Taste thresholds of 31 volatile compounds found in butter were measured in deodorized butteroil and thresholds of seven volatiles were measured in fresh butter. Thresholds of mixtures of each of the major classes of volatile compounds (free fatty acids from C2 through C12, gamma‐lactones from C7 through C11, even‐numbered deltalactones from C8 through C14 and methyl ketones from C3 through C13 except C12 were determined as well as thresholds of single compounds of these classes. Butyric acid, diacetyl, delta‐decalactone, 2‐nonanone, gamma‐undecalactone and n‐hexanal, oftreported constituents of milk fat, had thresholds in butteroil of 0.66, 0.055, 1.4, 7.7, 0.95 and 0.19 ppm, respectively. The threshold of a mixture of free fatty acids from C2 through C12 was 0.55 ppm. Synergistic interactions among methyl ketones and free fatty acids were pronounced and interactions among aldehydes were weak, while interactions among lactones were not apparent.
Distribution of Arsenic Residues by Activation Analysis
Authors: GEISMAN J. R. , CAREY W. E. , GOULD W. A. , ALBAN E. K.
Published: August 2006

—Arsenic bearing compounds have been used as insecticides, fungicides and herbicides. Wide‐spread use of these chemicals could lead to build‐up in the soil. Detection of arsenic requires special apparatus and sophisticated techniques. A method using neutron activation analysis was developed that required only drying of samples and encapsulation. Using activation analysis, it was found that arsenic was concentrated in the root of tomato plants. Data indicated a discrimination within the plant between fruit, stems and leaves, and root. Thus, it was concluded that soil concentrations of arsenic would have to be at the level that causes a reduction in fruit size and/ or yield before fruit concentration of arsenic would exceed the tolerance. This situation is not likely to occur at concentrations used for defoliation of horticultural crops prior to mechanical harvest. Activation analysis could be used to detect microgram quantities of arsenic in milligram size samples. The method was precise and repeatable and did not require elaborate sample preparation techniques.
Reaction at Limited Water Concentration 1. Sucrose Hydrolysis
Authors: SCHOEBEL T. , TANNENBAUM S. R. , LABUZA T. P.
Published: August 2006

—To enable development of a model describing reaction kinetics in dehydrated foods, we studied sucrose hydrolysis at limited water concentration. Saturated sucrose solutions containing various acids and inert solid materials gave identical rate constants and energy of activation as predicted from dilute solutions. Reaction rates in freeze‐dried systems humidified to low moisture contents indicated that any equation describing the rate of hydrolysis must include a term for the velocity of dissolution of solid sucrose into the surface water. The rate of hydrolysis was a pseudo first‐order reaction obeying the same kinetics as in dilute solution; the rate of dissolution became rate‐limiting when the initial supply of dissolved sucrose was exhausted.
Determining Glucose and Glycogen from a Single Sample of Meat
Authors: HEFFERAN P. M. , GOODNIGHT K. C.
Published: August 2006

A method was developed determining glucose and glycogen as separate entities from a single sample of meat. This method is based on the quantitative separation of glycogen from glucose by precipitation of the former species with an inert organic solvent. During this separation care must be exercised not to allow the temperature of the meat extract to rise above 5°C. After separation the two carbohydrate species may be analyzed by existing methods. The accuracy of this method was tested by comparing its results with those of established methods for the determination of glucose and glycogen. The error caused by the formation of Maillard addition products was evaluated.
The Influence of Tension on Pre‐Rigor Excised Bovine Muscle
Authors: GILLIS W. A. , HENDRICKSON R. L.
Published: August 2006

—The influence of four levels of tension in two pre‐rigor excised bovine muscles on fiber diameter, sacromere length, percent kinkiness, and shear value were studied. Fiber diameter was found to be smaller with 1,000‐g pull treatment than when there was no tension, but no significant change was found with succeeding increases in tension. Sarcomere length was found to increase to the 2,500 g pull treatment and then level off. Both muscles exhibited less kinkiness to the 1,000‐g pull treatment. However, after this level the semitendinosus muscle increased whereas the semimembranosus decreased. In like manner, a considerable decrease was noted in shear force to the 1,000‐g pull treatment for both muscles, but after this point a small increase was noted for the semitendinosus muscle whereas the semimembranosus muscle did not change.
Enzymic and Acid Hydrolysis of Sucrose as Influenced by Freezing
Authors: LUND D. B. , FENNEMA O. , POWRIE W. D.
Published: August 2006

—Sucrose hydrolysis catalyzed by invertase was studied over the temperature range 12 to −22°C in solutions of various concentrations. Freezing resulted in a marked decrease in invertase activity. Factors considered as having a possible role in the inhibition of invertase by freezing were: (1) the presence of ice crystals, (2) the increased concentration of solutes resulting from ice formation, and (3) a temperature effect in excess of that predicted from the Arrhenius equation (secondary temperature effect). It was shown that ice crystals formed at the rate used in this study had no effect on invertase activity, and that the decrease in invertase activity at sub‐zero temperatures was quantitatively accounted for by the concentration effect and the secondary temperature effect. High levels of sucrose and buffer (ionic strength) were found to inhibit invertase activity. Sucrose hydrolysis catalyzed by acid (HCI) was studied over the temperature range 12 to –16.5°C, and an Arrhenius plot of the data was linear between 12 and ‐7°C. Once the solution was frozen (below –6.8°C), the effect of temperature on the reaction rate constant no longer obeyed the Arrhenius equation, and the reaction rate constant was found to exhibit a maximum between –8.5 and –16.5°C. The rate of sucrose hydrolysis catalyzed by acid was influenced by cooling and conventional freezing in a manner quite different from that observed with invertase‐catalyzed hydrolysis.
Some Sensory Effects of Hydrocolloid Sols on Sweetness
Authors: VAISEY M. , BRUNON R. , COOPER J.
Published: August 2006

SUMMARY: Sweetness‐texture interactions in cornstarch, guar and carboxymethylcellulose were assessed by a trained sensory panel. Viscosity curves over a range of sucrose levels from 2.5 to 5.5% in the three gums were determined using a Brookfield viscometer. The relationship between viscosity curves and sweetness perception determined by rates of sweetness recognition, matching of equisweetness in different gums, apparent levels of sweetness and ranking of series of gums in order of sweetness indicated that gums with less viscosity drop as shear rates increase tend to mask sweetness perception.
Formation of a Green Pigment from Tuna Myoglobins
Authors: GROSJEAN OK‐KOO , COBB BRYANT F. , MEBINE BRUCE , BROWN W. DUANE
Published: August 2006

SUMMARY: A green pigment was produced when yellowfin (and other) tuna myoglobins, trimethylamine oxide (TMAO), and cysteine were heated together in 0.1 M phosphate buffer pH 5.7. The green product could not be produced with mammalian myoglobins, which contain no cysteine residues. The roles of myoglobin, cysteine, and TMAO in the production of off‐color (green) cooked tuna were investigated. Denaturation of myoglobin, apparently exposing a sulfhydryl group, was necessary for the greening reaction to occur. TMAO acted as a mild oxidizing agent to promote the formation of a disulfide bond between cysteine and the sulfhydryl group on the denatured myoglobin. TMAO could be replaced by oxygen (air), but cysteine appeared to be specific for the reaction. The green color could be reversed by sodium sulfite, but not by other reducing agents tested.
Serendipity Berries–Source of a New Intense Sweetener
Authors: INGLETT G. E. , MAY JOANN F.
Published: August 2006

SUMMARY: The fruit of Dioscoreophyllum cumminsii, Serendipity Berries, contains an intensely sweet principle. Chromatography of water extracts of the berry on G‐50 and G‐200 Sephadex indicated that the sweetener was bound to fruit protein. Degradation of the fruit extract with bromelain, a proteolytic enzyme, yielded a lower, molecular weight material with intense sweetness of excellent quality. Functional group tests indicated that this material was not proteinaceous, but rather a carbohydrate type substance. Threshold taste response gave a sweetness value of 1500 times sweeter than sucrose.
Microbiology of Fresh Apple and Potato Plugs Preserved by Gas Exchange
Authors: KAFFEZAKIS J. G. , PALMER S. J. , KRAMER AMIHUD
Published: August 2006

SUMMARY: Gas exchange as a means of preservation of fresh disk‐shaped plugs of apples and potatoes at ambient temperatures was studied. Death kinetics of the microorganisms E. coli, St. aureus and CL botolinum were determined. The concurrent effects of the gas on the browning enzyme systems of the products was followed. Gram negative rods in the environment of the test materials were rapidly killed when exposed either to a mixture of ethylene oxide (10%) and carbon dioxide (90%) or to pure sulfur dioxide and sulfur dioxide (50%) air mixtures. Gram positive cocci and the spores of the anaerobes showed somewhat slower rates of destruction under the same conditions. Treatment with pure carbon monoxide, nitrogen or packaging in vacuum achieved considerable freedom from color changes but had no appreciable effect on microorganisms.
Production of Enterotoxin‐B in Cured Meats
Authors: GENIGEORGIS C. , RIEMANN H. , SADLER W. W.
Published: August 2006

SUMMARY— A variety of laboratory cured hams were inoculated with 103−106 cells of S. aureus strain S‐6 and incubated at 10, 22 and 30°C anaerobically for up to 16 weeks. Enterotoxin‐B was detected by gel‐diffusion in hams with original pH over 5.30, up to 9.2% NaCl (brine) and 0.54 ppm undissociated nitrous acid. There was better toxin production at 30° than at 22° or 10°C. Toxin was detected at 10°C after at least 2 weeks incubation and in most samples after 8 weeks when pH was greater than 5.6. Toxic hams had more than 4 × 106 cells/g. Contaminants were always less than 105/g. Tween 80 inhibited toxin production at 30° but not at 10°C. Toxic hams looked normal even after 2 months incubation at 10°C.
EFFECT OF SUCROSE ON CRISPNESS OF EXPLOSION‐PUFFED APPLE PIECES EXPOSED TO HIGH HUMIDITIES
Authors: STROLLE E. O. , CORDING J. , MCDOWELL P E. , ESKEW R. K.
Published: August 2006

SUMMARY— Explosion‐puffed apple pieces, because of their hygroscopicity, rapidly lose their crispness under humid conditions. A major cause of the loss of crispness is softening of the sugars, present in the glassy or amorphous state, as moisture is adsorbed. Of these sugars, sucrose has the highest softening point. Materials higher in sucrose content can tolerate more moisture at a given temperature before they soften than materials higher in monosaccharides. The sucrose content of apple pieces is 20—30% of the total sugars. The sucrose content of pieces for puffing was increased to 86% of the total sugars by the following treatment before puffing: The pieces were first soaked in tap water 3—6 hr to reduce monosaccharide content, then soaked in 20—40% sucrose solutions several hours to increase sucrose content by osmosis and counter‐diffusion of sucrose. The pieces were then partially dried, puffed and finally dried by conventional hot‐air drying to 2% moisture content. Comparison of untreated and treated pieces revealed that the untreated pieces lost their crispness at 4.3% moisture and the treated pieces at 6.6%. When exposed to 75% R.H. and 72°F the untreated pieces remained crisp between 1 and 2 hr; at 75% R.H. and 90°F these pieces softened in less than 1 hr. However, the treated pieces exposed to 75% R.H. remained crisp 4—5 hr at 72°F and 2 hr at 90°F.
Ph ADJUSTMENT CONTROL OF OXIDATIVE OFF‐FLAVORS DURING GRINDING OF RAW LEGUME SEEDS
Authors: KON SAMUEL , WAGNER JOSEPH R. , GUADAGNI D. G. , HORVAT R. J.
Published: August 2006

SUMMARY—

Grinding dry California Small White beans or Lee soybeans under acid conditions inhibited lipoxidase in the seeds and resulted in bland legume slurries and “milks.” Sensory evaluation and gas chromatography were used to determine the effect of processing method on flavor. Off‐flavor development was suppressed at pH 3.85 and below; acidification to about pH 2.0 was necessary to obtain maximum protein extraction in the preparation of legume “milk.” Acceptable bland products were obtained from the slurries by neutralization after heating.
EFFECTS OF MALVIDIN‐3,5‐DIGLUCOSIDE AND CYANIDIN CHLORIDE ON FOUR SALMONELLA SEROTYPES
Authors: PAGENKOPF ANDREA L. , WOODBURN MARGY
Published: August 2006

SUMMARY— Reductions in numbers but no depression of respiration of 4 Salmonellaserotypes over a 7.0‐hr period was noted when they were incubated in the presence of anthocyanin pigments, malvidin‐3.5diglucoside or cyanidin chloride. At certain concentrations of these pigments in the presence of glucose, stimulation of the respiration of some serotypes was evident. Slight reductions in cell numbers were noted as concentrations of malvidin‐3,5‐diglucoside increased. Comparable counts were obtained upon plating the cells on minimal and complete media, indicating lack of metabolic damage to those cells present. An enzyme assay utilizing the respiration of Saccharomyces cerevisiae var. ellipsoideus indicated the possibility of an anthocyanase in the cells which had been preincubated in the presence of the diglucoside of malvidin without glucose but not with glucose. If this observation were substantiated, it would indicate the production of a glucose‐repressible anthocyanase. No evidence was obtained to indicate utilization of the aglycone by any of the 4 serotypes.
SMOKE‐FLAVORED CHICKEN ROLLS
Authors: BRECLAW E. W. , DAMSON L. E.
Published: August 2006

SUMMARY— Boned Leghorn fowl meat was seasoned and prepared as all light or all dark meat 2‐lb rolls. 6 smoke‐flavor treatments were applied to both the light and dark meat rolls. These treatments were liquid brine smoke, concentrated liquid smoke, smokehouse, oil‐base smoke, oil‐base smoke and cure, and dry smoke. Products were held up to 14 days at 1°C and 5 weeks at — 18°C. Light meat contained more moisture, gave a higher yield, was more tender and exhibited better binding characteristics than dark meat. Cured samples contained less moisture than the uncured. A taste panel gave a higher preference for the products which received the oil‐base smoke, oil‐base smoke plus cure, and smokehouse. Light meat was preferred to dark, although dark meat was rated more juicy. No significant changes occurred due to freezing or storage, or both.
APPLYING PROTEOLYTIC ENZYMES ON SOYBEAN. 6. Deodorization Effect of Aspergillopeptidase A and Debittering Effect of Aspergillus Acid Carboxypeptidase
Authors: ARAI SOICHI , NOGUCHI MASATOSHI , KUROSAWA SHUKUKO , KATO HIROMICHI , FUJIMAKI MASAO
Published: August 2006

SUMMARY— A proteolyzate obtained by treating an isolated soybean protein preparation with Molsin, a crude preparation of aspergillopeptidase A (APase A), was less bitter and contained larger amounts of free amino acids, especially hydrophobic amino acids. A proteolyzate obtained by treating this protein preparation with crystallized APase A was much more bitter and contained smailer amounts of free amino acids, mainly consisting of hydrophilic amino acids. The latter was richer in peptides than the former, bearing hydrophobic amino acid residues near the C‐termini. Difference in N‐terminal amino acid composition apparently has not been found between the 2 proteolyzates. These results indicate that Molsin per se contains a certain carboxypeptidase which decomposes the C‐terminal structures and, consequently, lessens the bitterness (debittering effect). This carboxypeptidase was found to be identical with aspergillus acid carboxypeptidase (AACPase). Abase A, as well as MO/sin, was effective in removing odor ants, i.e., n‐hexanal, n‐hexanol and n‐heptanol, from the isolated soybean protein preparation Ideodorization effect). AACPase seemed to have no deodorization effect. A method was suggested to prepare a deodorized and debittered proteolyzate by a combination use of APase A and AACPase.
PARTIAL THERMAL REVERSAL OF GELATION IN THAWED EGG YOLK PRODUCTS
Authors: PALMER H. H. , IJICHI K. , ROFF H.
Published: August 2006

–The effects of storage temperature. additives and heat treatment after thawing on the gelation of yolk, as determined by measurement of viscosity, are quantitatively compared Commercially separated egg yolks were thawed at 21°C (70° F) and tested for gelation after storage at temperatures from –78 to −12°C Laboratory‐separated white‐free yolks and commercially separated plain. sugared and salted yolks were heated after thawing. then cooled to 21°C to determine the effectiveness of heat treatment in reducing gelation. Heat treatment at 45 to 55°C for 1 hr reduced their viscosity more than 50%. Plain commercial yolks became pourable at ambient temperature after treatment, and their whipping performance improved. Higher temperatures caused protein coagulation and viscosity increase.
EFFECT OF SOME PHYSICAL AND CHEMICAL TREATMENTS ON THE BINDING QUALITY OF POULTRY LOAVES
Authors: MAESSO E. R. , BAKER R. C. , BOURNE M. C. , VADEHRA D. V.
Published: August 2006

SUMMARY— The effect of several physical and chemical treatments on the binding of poultry meat pieces was studied. Both NaCl, Ken a FP‐28 (sodium tripolyphosphate, tetrasodium pyrophosphate and sodium acid pyrophosphatel and hexametaphosphate were found to enhance binding. Kena increased binding more than hexametaphosphate. When combining Natl and Kena, there was a significant additive effect. Mechanical beating of meat released the intracellular content of broken muscle cells and caused a significant increase in binding. Alternate freezing and thawing with removal of intracellular material (drip) significantly decreased binding of meat. However, single freezing treatments with no drip loss did not differ significantly from the control (no freezing). Drip was shown to have binding properties. The amount of binding between meat pieces was increased with poultry meat emulsion and albumen. Poultry meat emulsion increased binding more than albumen.
MOLECULAR PROPERTIES OF POST‐MORTEM MUSCLE. 9. Effect of Temperature and pH on Tropomyosin‐Troponin and Purified α‐Actinin from Rabbit Muscle
Authors: ARAKAWA NOBUHIKO , GOLL DARREL E. , TEMPLE JOANNE
Published: August 2006

SUMMARY– A study was done on the effects of in vitro storage of purified α‐actinin, troponin, tropomyosin, and the tropomyosin‐troponin complex on the activity of these protein fractions in the ATPase and superprecipitation assays. Storage was done at various combinations of temperatures between 0 and 40°C and pH values between 5.7 and 7.0. Even after 40 hr of storage, activities of purified tropomyosin and the tropomyosin‐troponin complex were not affected by any combination of temperature and pH included in this study, but activities of purified α‐actinin and troponin were almost completely lost after 16 hr at 40°C and pH 5.7. Storage for 40 hr at low pH (5.7) and low temperatures (0°C) did not affect the activity of either α‐actinin or troponin, but 40 hr of storage at high temperatures (40°C) and neutral pH caused some loss in activity for both these proteins. This loss of activity caused by 40°C, pH 7.0 storage was much more noticeable in the case of troponin than in the case of α‐actinin. Storage periods of 40 hr or longer were required before any loss of α‐actinin activity could be detected at pH 7.0 and 40°C. Since most meat animal carcasses are chilled soon after exsanguination and attain muscle temperatures of 25°C or lower before the pH falls below 6.2, it is probable that α‐actinin and tropomyosin‐troponin activity remain almost unchanged in meat handled through normal market channels. However, myofibrillar tissue in those porcine animals whose musculature undergoes a very rapid post‐mortem decline in pH so that values of 5.7 or less are reached while muscle temperatures are still 37°C or higher may lose much of its α‐actinin and tropomyosin‐troponin activity during the first 24 hr post‐mortem.
FLAVOR QUALITY IN EXPLOSION PUFFED DEHYDRATED POTATO. 1. A Gas Chromatographic Method for the Determination of Aldehydes Associated with Flavor Quality
Authors: SAPERS G. M. , SULLIVAN J. F. , TALLEY F. B.
Published: August 2006

SUMMARY– Explosion puffed dehydrated potatoes may develop a characteristic off‐flavor during puffing. An objective method, based on the analysis of headspace vapor by GLC, was developed to measure peak heights of components associated with this off‐flavor. Ground potatoes and an internal standard, ethylbutyrate, were added to boiling water, and the mixture was equilibrated for 10 min at 98°C. A vapor sample was then withdrawn and analyzed chromatographically on a Carbowax 20M packed column at 100°C using an inlet splitter. Heights of peaks corresponding to 2‐methylpropanal plus acetone, 2‐methylbutanal plus 3‐methylbutanal, hexanal, and ethylbutyrate were determined and peak ratios calculated. The method was found to be precise, accurate, and rapid. Comparisons of a number of potato samples by sensory evaluation and the objective method showed that the intensity of the off‐flavor is associated with the heights of the 2‐methylpropanal plus acetone and 2‐methylbutanal plus 3‐methylbutanal peaks.
FLAVOR QUALITY IN EXPLOSION PUFFED DEHYDRATED POTATO. 2. Flavor Contribution of 2‐Methylpropanal, 2‐Methylbutanal and 3‐Methylbutanal
Authors: SAPERS G. M.
Published: August 2006

SUMMARY– Headspace vapor components previously associated with the intensity of an off‐flavor in explosion puffed dehydrated potatoes were added to potatoes lacking the off‐flavor to determine the flavor contribution of these compounds. 2‐Methylpropanal produced a characteristic wet fur flavor note while 2‐ and 3‐methylbutanal modified this flavor and contributed burnt flavor notes. While these flavor notes resembled some elements of the puffing off‐flavor, the total off‐flavor at its normal intensity could not be simulated by combinations of these compounds in potato at realistic concentrations. Acetone, which is also present in the headspace vapor of explosion puffed dehydrated potatoes, was found as a major headspace component of fresh boiled potatoes. This compound and smaller amounts of 2‐ and 3‐methylbutanal were produced in overcooked fresh potatoes which lacked the puffing off‐flavor.
DISC GEL ELECTROPHORESIS OF PROTEINS IN NATIVE AND HEAT‐TREATED ALBUMEN, YOLK, AND CENTRIFUGED WHOLE EGG
Authors: CHANG P. , POWRIE W. D. , FENNEMA O.
Published: August 2006

SUMMARY– Polyacrylamide disc gel electrophoresis was an effective technique for resolving the proteins of albumen, yolk, and centrifuged whole egg into distinct bands. Albumen proteins including ovalbumins, conalbumins, and globulins were separated into 12 bands. Ovomucoid could not be detected and lysozyme did not migrate into the gel. With yolk, 19 bands including livetins and lipovitellins but not low‐density lipoproteins were formed. When centrifuged whole egg was subjected to electrophoresis, livetin and albumen protein bands were detected, but no evidence was obtained for the formation of new protein complexes. Alterations of gel patterns were observed when albumen, yolk, and centrifuged whole egg were heated to pasteurization temperatures of 61.7°C and above.
EFFECTS OF FOUR SPECIES OF BACTERIA ON PORCINE MUSCLE. 1. Protein Solubility and Emulsifying Capacity
Authors: BORTON R. J. , BRATZLER L. J. , PRICE J. F.
Published: August 2006

SUMMARY– A technique was used to obtain aseptic porcine muscle, portions of which were inoculated with cultures of Pediococcus cerevisiae, Micrococcus luteus, Leuconostoc mesenteroides and Pseudomonas fragi. The inoculated samples were compared with aseptic controls throughout a 20‐day storage period at temperatures of 2 and 10°C. All 4 organisms grew at 10°C, but only P. fragi and L. mesenteroides grew at 2°C. The solubilities of the various protein fractions were affected by inoculation treatment. This was exemplified by correlation coefficients ranging from —.37—0.50. The coefficients indicated the interrelationships affected by storage conditions and bacterial growth. Protein solubility studies revealed a loss in the water‐soluble fraction during storage of the controls and the M. luteus‐ and L. mesenteroides‐treated samples. Samples inoculated with P. fragi evidenced an initial loss, followed by an increase. The solubility of meat proteins in a salt solution increased during the first 8 days of storage, then decreased or remained relatively constant for all samples. In comparison with controls, samples inoculated with P. fragi increased in salt‐soluble protein solubility during the first 8 days, whereas those inoculated with L. mesenteroides decreased during the latter part of storage. Insoluble protein generally increased except for P. fragi‐inoculated samples, which decreased. Nonprotein nitrogen (NPN) increased for all treatments and controls during the 20‐day storage period. NPN extracted from the samples inoculated with P. fragi increased greatly. The pH increased with growth of M. luteus and P. fragi and decreased with growth of P. cerevisiae and L. mesenteroides. The emulsifying capacity was not influenced by the growth of M. luteus or P. cerevisiae. However, the emulsifying capacity of samples inoculated with L. mesenteroides decreased, whereas that of samples inoculated with P. fragi increased.
EFFECT OF GAMMA RADIATION ON WHEAT STARCH AND ITS COMPONENTS
Authors: ANANTHASWAMY H. N. , VAKIL U.K. , SREENIVASAN A.
Published: August 2006

SUMMARY– Studies on the susceptibility of irradiated wheat starch, amylose and amylopectin to alpha‐ and beta‐amylolysis reveal that they are more susceptible to enzyme actions, compared to their unirradiated controls; however, irradiated amylose seems to be comparatively more vulnerable. From irradiated starch, series of oligosaccharides of the maltose series are discernible, while glucose appears only above 200 Krad dose level. Quantitative analysis of the radiolytic breakdown products of starch reveal that at high dose levels (1 Mrad) maltose, maltotriose and maltotetrose are the main products. Results on the separation of radiolytic breakdown products suggest they resemble those produced by alpha‐amylolysis of starch.
EXPLORING AIRBORNE SOUND IN A NONVACUUM FREEZE‐DRYING PROCESS
Authors: MOY JAMES H. , DiMARCO G. ROBERT
Published: August 2006

SUMMARY– A study was made to determine if sound energy could be used to enhance freeze‐drying rates of foods and to analyze the kinetics in such a system. A prototype pilot freeze‐dryer with airborne sound was designed and built to freeze‐dry liquid foods, e.g., tea and coffee extracts. The sound source was a stem‐jet whistle producing 10.8–12.2 kcps with a maximum sound intensity level of 149 db. Desiccated compressed air at 70° to 90°F served as the driving force of the whistle as well as the carrier of the sublimed moisture. Experimental results showed this to be a feasible process. Sample temperature, inlet air pressure, the freeze‐dryer tube size, and the sound source, all had significant effects on the freeze‐drying rates. Freeze‐drying rates were 11–100% higher in the stem‐jet whistle runs than in the dummy whistle runs; 7% of this improvement was attributed to the thermal effect on the air resulting from friction and adiabatic compression. The remaining increase was due to the sound pressure energy, the increase in heat and mass transfer coefficients, and the “reduced‐pressure” effect in the sweeping air stream during the rarefaction cycle of the sonic vibration. The flaking action of the sound waves on near‐dried tea and coffee was considered a processing advantage because of the ease in product recovery and because a new surface was continuously being exposed for sublimation.
DEVELOPMENT OF A NEW PRODUCT FOR THE CIVIL DEFENSE PROGRAM
Authors: TATE J. N. , MATHEWS RICHARD D. , STONE HERBERT
Published: August 2006

SUMMARY– Development of a new cereal‐based product—proposed as a replacement for existing rations now used in the Civil Defense Ration Program—is described. Major emphasis was placed on developing a product containing adequate amounts of protein (46 g/day vs 14 g/day for existing rations) and at a competitive cost. Selection of raw materials, nutritive value and processing conditions were developed to meet these and other criteria of the Office of Civil Defense. Major ingredients were whole wheat flour, casein and lard. The finished product cost was 20c/lb vs 23c/lb for the existing rations. Application of these efforts to other civilian areas is discussed.
PREMORTEM STRESS AND POSTMORTEM BIOCHEMICAL CHANGES IN SKIPJACK TUNA AND THEIR RELATION TO QUALITY OF THE CANNED PRODUCT
Authors: CRAWFORD LADELL , IRWIN ENID J. , SPINELLI JOHN , BROWN W. D.
Published: August 2006

SUMMARY– Live skipjack were caught, brought to shoreside and held in tanks 24–48 hr. At this time some were exercised to simulate stress during commercial capture, sacrificed, held at 74 or 32°F for 6 hr, sampled for chemical analyses, then canned. Unstressed (rested) skipjack were treated similarly. Some autolytic degradation products post‐mortem were measured and the differences noted. Organoleptic evaluation was made on canned fish from the various treatment groups. While there were differences in various organoleptic parameters among the groups subjected to different treatments, there was no overwhelming evidence connecting stress or temperature of holding to quality in the canned product.
EFFECT OF HEAT TREATMENT ON VISCOSITY OF YOLK
Authors: CHANG P. K. , POWRIE W. D. , FENNEMA O.
Published: August 2006

SUMMARY– Apparent viscosity readings at different shear rates for yolk or albumen‐containing yolk in the native or heated conditions were obtained by a Wells‐Brookfield microviscometer. The viscosity‐shear rate curves for these yolk samples are typical for a pseudoplastic, non‐Newtonian fluid. The apparent viscosity of native yolk with a solids content of 52.5% dropped gradually from 23 to 18 poises with an increase in shear rate from 1.9 to 76.8 sec‐1. The apparent viscosity of pasteurized yolk (65.6°C for 3 min) dropped drastically from 200 to 100 poises with an increase in shear rate from 1.9 to 19.2 sec‐1. Addition of thin albumen at levels of 5, 10 and 20% to native yolk brought about a considerable decline in the viscosity. The heat damage to the albumen‐containing yolk as reflected by viscosity increase was reduced as the content of thin albumen increased. The viscosity increase of urea‐treated yolk and yolk with 5 and 10% thin albumen was related to the temperature of heat treatment prior to urea addition.
CHEESE COLORS FROM PLANT SOURCES. 1. Preparation and Properties of Color from Pepper and Safflower
Authors: EL‐SHIBINY S. , EL‐SALAM M. H. ABD
Published: August 2006

SUMMARY–A cheese color was prepared from the extract of pepper (Capsicum frutescens var. California wonder) and safflower (Carthamus tinctorius) pigments. The prepared color had a good keeping quality, slightly affected by temperature and sunlight. The prepared color proved successful in cheese coloration and resisted the biochemical changes in cheese during ripening. However, a slight loss in the color of cheese was observed during storage.
POLYPHENOLS OF CASHEW KERNEL TESTA
Authors: MATHEW A. G. , PARPIA H. A. B.
Published: August 2006

SUMMARY: The chemical nature of the polyphenols of cashew kernel testa has been determined by means of 2‐dimensional paper chromatography and specific reactions. Presence of (+) catechin and (‐) epicatechin as the major polyphenols has been confirmed by co‐chromatography with authentic samples. Proanthocyanidins have been studied by treatment with hot acid and identification of the resultant anthocyanidins. Leucocyanidins and leucopelargonidins have been noticed as monomeric components, whereas polymeric proanthocyanidins contain in addition small quantities of leucodelphinidin. Individual components have been quantitatively estimated colorimetrically with Folin‐Denis reagent, after separation by fractional extraction using solvents of increasing polarity and paper chromatography. The characteristic bluish‐black discoloration noticed in cashew‐nuts has been identified as an iron‐polyphenol complex formed during processing. The polypnenols were found to be derived from the testa.
BENZO(A)PYRENE IN SMOKED MEAT PRODUCTS
Authors: RHEE KI SOON , BRATZLER L. J.
Published: August 2006

SUMMARY: A procedure was established for analyzing benzo(a)pyrene (BaP) in smoked meat products, which involves extraction, solvent partition, column chromatography and spectrophotofluorometric measurement. Studies were then made as to the effect of artificial casings on the content of BaP, penetration of BaP through a meat product in smoking, possible presence of the hydrocarbon in unsmoked meats and distribution of the compound after cooking smoked meat. Bologna was used in most experiments except for the one on cooking effect, in which bacon was used. Artificial cellulose casings caused a noticeable reduction in the concentration of BaP. Regardless of whether the smoke was generated in a small‐scale or in a larger‐scale generator, bologna smoked in casings had much less BaP than that smoked without casings. BaP was concentrated in the outer part of bologna. In smoking with or without casings, the hydrocarbon did not penetrate farther, in most cases, than 1.4–1.6 mm from the surface of the bologna. Several unsmoked meats of beef and pork were analyzed and none seemed to have endogenous BaP, since the detected amount was similar in magnitude to that of the solvent control. More than half the amount of BaP in smoked bacon was found in the fat drippings following cooking.
SEROLOGIC IDENTIFICATION OF SPECIES OF ORIGIN OF SAUSAGE MEATS
Authors: KARPAS ARTHUR B. , MYERS WALTER L. , SEGRE DIEGO
Published: August 2006

SUMMARY: A partially purified immunoglobulin G (lgG) solution prepared from the serum of species to be tested was heated to the specifications for sausages. The resulting supernatant fluid was decanted and the precipitate washed with saline and used to immunize rabbits. The supernatant fluid was used to sensitize tanned sheep red blood cells. The immune serum was rendered monospecific by absorptions with heterologous, heated lgG precipitates. A sample of monospecific immune serum was absorbed with a washed homogenate of sausage. Aliquots of the monospecific immune serum, both untreated and sausage absorbed, were tested with cells sensitized with the homologous heated lgG supematant fluid. A significant reduction of titer by sausage absorption indicated that the sausages contained the meat homologous to the immune serum.
BIOCHEMISTRY OF TEA FERMENTATION: CONVERSION OF AMINO ACIDS TO BLACK TEA AROMA CONSTITUENTS
Authors: CO H. , SANDERSON G. W.
Published: August 2006

SUMMARY: 14C‐amino acids were added to fresh tea‐leaf homogenate undergoing conversion to black tea. After conversion (30 min, 25°C), the volatile compounds present in the headspace over the reaction mixture were collected and analyzed by gas chromatography. Results showed that leucine, isoleucine, valine and phenylalanine were partially converted to the aldehydes expected from a Strecker degradation. These aldehydes are constituents of black tea aroma. Further, drying of the fermented mixture caused an additional amount of the aldehydes to be formed. In contrast, no detectable volatile compounds were formed from aspartic acid, glutamic acid, glutamine, arginine, threonine. serine or theanine under the same conditions. Production of aldehydes from amino acids was shown to be dependent on the enzymic conversion process: Tea leaf which had been inactivated by steam treatment was not effective in causing formation of volatile aldehydes from the amino acids. Identical results were obtained in a model tea fermentation system composed of a crude soluble enzymes extract from tea leaves, purified epigallocatechin gallate and 14C‐amino acids. Ascorbic acid was found to inhibit formation of aldehydes from amino acids in this model tea fermentation system; dehydroascorbic acid by itself was found to be effective in causing formation of volatile aldehydes from amino acids.
LOW‐TEMPERATURE, LONG‐TIME HEATING OF BOVINE MUSCLE 3. Collagenolytic Activity
Authors: LAAKKONEN E. , SHERBON J. W. , WELLINGTON G. H.
Published: August 2006

SUMMARY: Naturally occurring collagenolytic activity was found in the water‐soluble fraction of bovine muscle. General proteolytic activity determined with Azocoll indicated that this total activity was much greater than the collagenase activity specifically determined according to the method of Wünsch and Heidrich. The collagenase fraction was concentrated by polyacrylamide gel electrophoresis and the activity of the enzyme was studied under various pH and temperature conditions. This collagenase could remain active in the meat at cooking temperatures experienced in long‐time, low‐temperature cooking, < 60°C. With faster heating and higher internal temperatures, > 70‐80°C, the collagenase observed in this study is inactivated.