bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Electrodialysis to Improve the Protein Stability of Frozen Skim Milks and Milk Concentrates
Authors: LONERGAN D. A. , FENNEMA O. , AMUNDSON C. H.
Published: August 2006

Removal of calcium from skim milk by electrodialysis was logarithmically related to the extent of demineralization (log% calcium removed = 0.18% ash removed + 0.53). This removal of calcium caused a logarithmic dissociation of micellar to serum (sub‐micellar) casein (log% total casein in serum = 0.020% calcium removed + 0.70). Increases in protein stability for skim milk and concentrated skim milk were related to this dissociation of micellar casein, and the initial degree of dissociation persisted throughout frozen storage. Protein stability was > 53 wk at –8°C when 80% of the casein in unconcentrated skim milk was dissociated. Concentrated skim milk was stable for > 30 wk at –8°C when 45% of the casein was dissociated. Control samples (7–9% casein dissociated) were stable for only 4–8 wk at –8°C.
Effect of Chemical Modifications on Some Physicochemical Properties and Heat Coagulation of Egg Albumen
Authors: MA CHING‐YUNG , HOLME JOHN
Published: August 2006

Egg albumen was modified with succinic anhydride and a water‐soluble carbodiimide, 1‐ethyl‐3(3‐dimethylaminopropyl) carbodiimide. The chemically modified proteins exhibited only minor conformational changes, but were altered in their responses to heat treatment. Heat‐induced coagulation was retarded by both modifications suggesting that thermocoagulation requires a balanced electrostatic attraction between protein molecules. Hydrophobicity measurements and pH‐titration data suggest the involvement of hydrophobic and ionic interactions in heat aggregation and gelation of egg white proteins. The soluble fraction of the heat‐coagulated proteins contained mainly monomers, while under conditions where a gel or coagulum was not formed, the heat‐treated egg albumen solutions contained high M.W. soluble aggregates. A scheme for the thermal coagulation of egg albumen is proposed.
Timed Emulsification Studies with Chicken Breast Muscle: Whole Muscle, Low‐Salt Washed Muscle and Low‐Salt Soluble Proteins
Authors: GASKA MARILYN T. , REGENSTEIN JOE M.
Published: August 2006

Emulsion formation with chicken breast muscle was investigated using timed emulsification. Emulsions were made at a fixed oil/water ratio of 2:1 by Omni‐mixing for various lengths of time between 0 and 5 min; then the emulsions were centrifuged and the aqueous layer analyzed for protein. Emulsions formed using whole muscle or muscle washed with low molarity salt solution and suspended in buffered (10 mM sodium phosphate, pH 7.0) 0.6M NaCl were superior in stability upon centrifugation to those made with muscle in distilled water, buffered 0.025M NaCl or buffered 0.05M NaCl. Size of insoluble protein pellets from the centrifuged emulsions decreased as emulsification time increased. Little emulsifying effect of the low‐salt soluble (sarcoplasmic) protein, defined as those proteins extracted with buffered 0.05M NaCl, was observed in the presence or absence of high‐salt solubilized protein.
Composition and Physiological Properties of Several Sources of Dietary Fiber
Authors: SOSULSKI F. W. , CADDEN A. M.
Published: August 2006

Dietary fiber sources containing 31 – 99% of neutral detergent fiber were evaluated for functional properties and physiological effects on rats. The high water hydration capacity of mucilage‐containing psyllium seeds and flax hulls were associated with low digestibility, high volume and weight of feces, and low serum triglycerides. Mustard hulls and sunflower heads, which contained less mucilage or pectin, were intermediate in water hydration capacity and as bulking agents in the gastrointestinal tract. Fiber sources rich in hemicellulose and lignin (wheat bran, sunflower hulls) had high fat absorption properties, digestibility and serum triglycerides. Pea hulls and cellulose showed less strong functional properties as sources of dietary fiber.
Partial Separation and Characterization of Papaya Endo‐ and Exo‐Polygalacturonase
Authors: CHAN HARVEY T. , TAM STEVEN Y.T.
Published: August 2006

Exo‐ and endo‐polygalacturonases (EC 3.2.1.40 and EC 3.2.1.15) in papayas were extracted, purified 20‐ and 90‐fold, respectively, and characterized. Both enzymes functioned optimally at pH 4.6 and 45°C. Heat inactivation of the papaya PGases was biphasic and both phases followed first order kinetics. Decreasing the pH from 4.6 to 3.6 decreased the time required for their heat inactivation. The activation energies for the thermal inactivation at pH 3.6 and 4.6 were 85 and 92 kcal/mol, respectively, for endo‐PGase (PG I) and 140 and 102 kcal/mol, respectively, for exo‐PGase (PG II). The apparent molecular weight was determined by gel filtration to be 164,000 daltons for PG I and 34,000 daltons for PG II.
Thermal Destruction of Vitamin B6 Vitamers in Buffer Solution and Cauliflower Puree
Authors: NAVANKASATTUSAS S. , LUND D. B.
Published: August 2006

Thermal degradation rates of pyridoxal (PL‐HCl), pyridoxine (PN‐HCl) and pyridoxamine (PM‐2 HCl) in 0.1 M phosphate buffer (pH 7.20) were determined over the temperature range 110‐145°C using HPLC procedures. Thermal degradation of PM‐2 HCl was modelled by a pseudo‐first order rate constant. Thermal degradation of PN‐HCl and PL‐HCl was modelled by a 1.5 order and second order model, respectively. The temperature dependence of all three rate constants could be described by the Arrhenius equation. None of the degradation products from any of the vitamers exhibited antivitamin activity. Thermal degradation rates of vitamin B6 in cauliflower puree were measured over the temperature range 106‐138°C and found not to be described by a first‐order model. The activation energy was markedly lower in this food system than in the model system and emphasizes the importance of conducting experiments on real food systems. The activation energy is in the range reported for several other water soluble nutrients.
A Computer Assisted Analysis of Some Theoretical Rate Effects in Mastication and in Deformation Testing of Foods
Authors: PELEG M. , NORMAND M. D.
Published: August 2006

Simplified rheological models, with relaxation times comparable to those of solid foods, were used to simulate stress strain relationships at rates comparable to those in mastication and in common deformation tests (linear velocities on the order of 100 and 1 cm min−1 respectively). The simulations included the regimes of constant deformation and strain rates and a sinusoidal deformation pattern. They demonstrated that the information in sensory perception and mechanical testing can be different in both kind and magnitude largely due to the rheological character of the food and its relaxation time and to a lesser extent, to the exact deformation regime.
Factors Influencing the Production and Activity of a Streptococcus thermophilus Lipase
Authors: DeMORAES JOSE , CHANDAN R. C.
Published: August 2006

The cells from 32 strains were disrupted by pressure. All the strains except two showed lipase activity. Optimum temperature for lipase production was 44°C. Production of lipase was inhibited by addition of butter oil (29%), milk (41%) and casein (12%) and stimulated by soybean oil (39%), cream (27%) and corn oil (21%) to the medium. The enzyme was stable when stored at 37°C and 45°C for 1 wk. The enzyme was partially inactivated by pasteurization treatment (65°C/30 min). Optimum temperature and pH for lipase activity was 45°C and 9.0, respectively. The enzyme was relatively more active toward tributryin than toward natural lipids.
Inhibition of Pseudomonas fluorescens by Hydroxycinnamic Acids and Their Alkyl Esters
Authors: BARANOWSKI JOHN D. , NAGEL CHARLES W.
Published: August 2006

Alkyl esters of six hydroxycinnamic acids and cinnamic acid were evaluated in a liquid medium for their effectiveness in inhibiting the growth of Pseudomonas fluorescens, a bacterium commonly implicated in food spoilage. Compounds were tested at concentrations of 0–250 ppm, using turbidity as a measurement of growth. At 125 ppm, esters of p‐coumaric and caffeic acids were more inhibitory than either methyl or propyl paraben. Methyl esters of methoxylated cinnamic acids were much less inhibitory than the methyl esters of the corresponding positional hydroxylated cinnamic acids. The results indicate that esters of certian of these naturally occurring hydroxycinnamic acids may be useful as food additives to extend shelf life by inhibiting microbial growth.
Bone and Plasma Protein Extracts in Sausages
Authors: CALDIRONI H. A. , OCKERMAN H. W.
Published: August 2006

Proteins from bones were extracted (4°C) at pH 10 and emulsifying capacity (EC) of bone protein extracts (BPE) were compared with beef muscle (BMP) and blood plasma (PP) proteins. PBE showed the lowest EC (ml oil/g total protein) values but they were similar to BMP when the EC was calculated on a soluble protein basis. EC values from BPE were enhanced by mixing those proteins with BMP. Sodium‐pyrophosphate improved EC values primarily at low protein concentrations. Water‐holding capacity (WHC) of the BPE, BMP and PP were obtained and a close correlation (r = 0.99) was found between WHC and the fat/protein ratio of the samples. Up to 10% BPE plus 5% PP and both plus 0.4% of sodium pyrophosphate were included in the manufacture of cooked sausages. These products were ranked as acceptable by a sensory panel.
Effect of Sodium Nitrite Concentration, Sodium Erythorbate and Storage Time on the Quality of Franks Manufactured from Mechanically Deboned Turkey
Authors: WESLEY ROGER L. , MARION WILLIAM W. , SEBRANEK JOSEPH G.
Published: August 2006

The effects of sodium nitrite (0‐156 ppm), sodium erythorbate (0 or 550 ppm) and storage time (up to 10 wk at 4°C) were measured on the chemical and sensory properties of turkey franks formulated largely from mechanically deboned turkey (MDT), Residual nitrite in the finished product was proportional to that incorporated at time of formulation and was reduced by using small initial amounts in combination with the maximum allowable erythorbate (550 ppm). Acceptable cured color in turkey franks was achieved with the incorporation of 50 ppm of nitrite. Erythorbate effectively increased cured color development and stability, particularly with smaller amounts of nitrite. Rancidity development in turkey franks was not of major significance. Even so, the presence of erythorbate imposed further control of oxidative changes in lipids. Maximum cured flavor development occurred with 50–100 ppm nitrite.
Dried Pork as Influenced by Nitrate, Packaging Method and Storage
Authors: OCKERMAN H. W. , KUO J. C.
Published: August 2006

A new technique was developed to produce high quality, uniform and attractive thin sliced, cured dried pork. The effects of nitrate, packaging method and storage time on residual nitrite, TBA values, sensory properties and microbiological counts were determined. Residual nitrite decreased with increased storage time at 3 ± 1°C. The addition of nitrate plus vacuum packaging caused a greater residual nitrite level and a lower TBA value during storage. Nitrite and/or nitrate acted as an antioxidant to retard oxidative rancidity (TBA value). Dried pork manufactured by the technique described had no major rancidity problem and had an acceptable shelf life. Total aerobic plate counts, lactic acid producing microbial counts and total anaerobic counts were not affected by nitrate or packaging methods. Coliforms, molds and yeasts were not found in this dried pork.
Effect of Changes in Intermuscular and Subcutaneous Fat Levels on Cholesterol Content of Raw and Cooked Beef Steaks
Authors: RHEE KI SOON , DUTSON THAYNE R. , SMITH GARY C.
Published: August 2006

Muscle, intermuscular (seam) fat and subcutaneous fat dissected from boneless rib steaks (U.S. Choice quality grade; USDA yield grade 1 to 5) were analyzed for cholesterol content. For raw steaks, the cholesterol content (wet basis) in the fat fractions was greater than 150% of that in the muscle fraction; the difference diminished greatly when steaks were cooked to an internal temperature of 70°C. On an average of all yield grades, cooked intermuscular fat and subcutaneous fat contained about 108 and 122%, respectively, of the cholesterol content in cooked muscle. The percentage of total cholesterol in raw and cooked steaks that was contributed by the combined fat fractions increased significantly with numerical increases in the USDA yield grade. However, the amount of cholesterol per gram of the whole steak was not significantly different among the five yield grades.
Sampling Methods for Detection of Salmonella in Raw Chicken Carcasses
Authors: D'AOUST J. Y. , STOTLAND P. , BOVILLE A.
Published: August 2006

Detection of Salmonella in thaw water, pericloacal skin and whole carcass rinse samples from naturally contaminated broiler chickens was compared. Of 100 birds tested, 70 were found to contain salmonellae by the three sampling techniques combined; the median level of contamination was 0.27 salmonellae/100g eviscerated carcass weight. Recovery with the whole carcass rinse technique (93%) was significantly greater than that obtained with thaw water (63%) and skin (74%) methods; performance of the latter two methods was not statistically different. Thaw water does not provide a reliable index of Salmonella contamination and therefore is not a suitable method for the nondestructive analysis of poultry carcasses. Selective enrichment in tetrathionate brilliant green broth and plating on bismuth sulfite agar identified the greatest number of contaminated carcasses under all sampling conditions.
Effect of High Doses of High and Low Intensity UV Irradiation on Surface Microbiological Counts and Storage‐Life of Fish
Authors: HUANG YAO‐WEN , TOLEDO ROMEO
Published: August 2006

Ultraviolet (UV) irradiation at 254 run and doses of 300 mWs/cm2 from a photochemical reactor (16.6 min at 300 μW/cm2) or 4.8 Ws/cm2 from a high intensity UV‐C lamp (40 sec at 120–180 mW/cm2 reduced surface microbial count on mackerel by two to three log cycles. UV treated mackerel wrapped in 1 mil polyethylene and packed in ‐1°C ice had at least a 7 day longer shelf life than conventional ice‐packed untreated controls. Spray washing with water containing 10 ppm chlorine by itself or in combination with UV irradiation was necessary to reduce surface counts on rough surfaced fish to the same extent as that on smooth surfaced fish. When UV irradiated and packed in 0°C ice, surface microbial counts on vacuum packaged mackerel lagged by 4 days those on mackerel wrapped in 1 mil polyethylene.
Microwave Processing to Destroy Salmonellae in Corn‐Soy‐Milk Blends and Effect on Product Quality
Authors: BOOKWALTER G. N. , SHUKLA T. P. , KWOLEK W. F.
Published: August 2006

Enriched corn‐soy‐milk (CSM) blends were inoculated with Salmonella senftenberg and packed in 50‐lb (22.7 kg) bags. The inoculated product and CSM bags containing natural salmonellae contamination were heated from 21° to 56.7°C through 82.2°C in 3.9 – 10 min, respectively, using a 60 Kw (2450 MHz) continuous microwave tunnel, and then palletized with and without 4‐cm spacers between rows. Spacer palletized bags cooled to 43°C after 9.7 hr with moving air and after 23.3 hr without moving air, but 60 hr was required with no spacers. Initial most probable numbers (MPN) of 4 × 102 cells/g for S. senftenberg were reduced 102‐fold to 105‐fold after processing at 56.7° through 82.2°C, respectively. Nutritional damage occurred at process temperatures of 77.8° and 82.2°C. At 61.1° and 67.2°C, MPN were reduced 2 × 103‐fold with no significant change in rheology, moisture, color, vitamins A and B1, available lysine, and protein efficiency ratios.
Properties and Uses of Horny and Floury Endosperms of Corn
Authors: KIKUCHI K. , TAKATSUJI I. , TOKUDA M. , MIYAKE K.
Published: August 2006

Ordinary corn kernel endosperm is composed of horny and floury portions. Corn varieties having different endosperm were investigated. Their chemical composition was almost identical, but in tissue structure the floury endosperm is soft and the horny endosperm is hard. The starch isolated from floury endosperm is easier to gelatinize, and higher in viscosity, swelling value, and α‐amylase digestibility than the starch from horny endosperm. The floury endosperm is superior to the horny endosperm in such baking products as bread and cookies.
The Standard Scales of Texture: Rescaling by Magnitude Estimation
Authors: CARDELLO ARMAND V. , MATAS ALINA , SWEENEY JAMES
Published: August 2006

Food items comprising the six “standard scales” of texture [Szczesniak et al., J. Food Sci. 28: 397 (1963)] were rescaled using the psychophysical method of modulus‐free magnitude estimation. The category scale position of each food item on the standard scales was plotted against the geometric mean magnitude estimate for that item. The category (interval) scale data were concave downward relative to the magnitude (ratio) scale data. These results underscore the differences that can be obtained by using either interval or ratio procedures and suggest that the attributes of “hardness,”“chewiness,”“fracturability,”“viscosity,”“gumminess,” and “adhesiveness” can be classified as “prothetic” continua.
GLC‐MS Analysis of Fatty Acids From Five Black Walnut Cultivars
Authors: SENTER S. D. , HORVAT R. J. , FORBUS W. R.
Published: August 2006

The lipids from kernels of five black walnut cultivars were extracted by solvent extraction and the fatty acids were analyzed as their methyl esters by GLC‐MS analyses. Twenty‐one fatty acids were identified in each cultivar. Five acids, palmitic, stearic, oleic, linoleic and linolenic, were present in quantities greater than 1% of total lipids present. Quantities of the individual fatty acids varied significantly among cultivars (P > 0.05) except for palmitic. Linoleic was the predominant fatty acid in all cultivars. Oleic and linoleic comprised greater than 85% of the lipids present in the walnut kernels.
Development and Use of A Proficiency Test Specimen for Paralytic Shellfish Poisoning
Authors: ARES JOHN A. , DYMSZA HENRY A.
Published: August 2006

A proficiency test specimen was developed for evaluating laboratory precision in paralytic shellfish poisoning bioassays. Such a specimen is needed since much of health and economic consequence depends on an analyst's precision in measuring the toxin. Therefore, after testing clams, mussels, and mashed potato matrices, a test specimen composed of saxitoxin dihydrochloride and hydrated potato flakes was selected. Samples containing two toxin levels were sent to 14 collaborating laboratories. Analysis of results identified errors arising from poor dilution techniques. Recovery percentages and variances of mashed potato were comparable to those previously reported with shellfish matrices. Use of the potato matrix appears to offer cost and convenience advantages.
Centralized Packaging of Beef Loin Steaks with Different Oxygen‐Barrier Films: Microbiological Characteristics
Authors: VANDERZANT C. , HANNA M. O. , EHLERS J. G. , SAVELL J. W. , SMITH G. C. , GRIFFIN D. B. , TERRELL R. N. , LIND K. D. , GALLOWAY D. E.
Published: August 2006

Vacuum packaged beef strip loins (n = 72) were stored (2° 1°C) for either 0,12 or 24 days before fabrication; steaks were packaged and displayed (2°C or 7°C) up to 6 days in oxygen‐permeable film or up to 30 days in vacuum packages (medium or high oxygen‐barrier film). For steaks displayed in oxygen‐permeable film, Pseudomonas spp. were a considerable (25–49%) or dominant (>50%) part of the microflora. The microflora of vacuum‐packaged steaks from 0 day loins was dominated by a combination of hetero‐ and homofermentative Lactobacillus spp.; when vacuum‐packaged steaks were from 12 and 24 day loins, the microflora was in most cases dominated by the heterofermentative Lactobacillus cellobiosus.
Safety and Sensory Evaluation of Canned Rice
Authors: SHARP R. N. , KATTAN A. A. , SHARP C. Q. , COLLINS J. A.
Published: August 2006

Rice, thermally canned as an acid food, was studied to determine if the process would provide a product which was safe and acceptable. Heat penetration studies showed that heat transfer was initially by convection and then by conduction as the rice imbibed sufficient water to restrict the convection currents. Although heat penetration studies indicated that a temperature of 180°F (82°C) was reached in 8 min and inoculated packs processed for 20 minutes in actively boiling water did not support bacterial growth, 30 minutes processing time was required to attain optimum quality. Canned rice, rice with textured vegetable protein (TVP®), Spanish rice, and Spanish rice with TVP were rated acceptable in general appearance, texture and taste. Experimental Spanish rice was rated superior to one and equal to two commercial Spanish rice products in general appearance and flavor.

THESE DATA indicate that the process described by Sharp et al. (1981) produced an adequately processed canned rice product. Processing in actively boiling water for 20 min was adequate to destroy the vegetative cells in an inoculated pack while a pH of 4.4 prevented spores from germinating. The potential of the processing method was demonstrated by the development of four products that were rated acceptable.
Corn Distillers' Dried Grains with Solubles and Corn Distillers’Dried Grains: Dry Fractionation and Composition
Authors: WU Y. VICTOR , STRINGFELLOW ARTHUR C.
Published: August 2006

Corn distillers' dried grains with solubles (CDGS) and corn distillers' dried grains (CDG) at various moisture and fat contents were pin milled and screened. Fractions of CDGS and CDG contained from 11.4–45.7% and 12.5–49.6% protein, respectively (dry basis), compared with 30% for CDGS and 25% for CDG. The highest protein shifts were obtained when CDGS at initial moisture of 21% was ground twice at 14,000 rpm and CDG at initial moisture of 21% was ground once at 14,000 rpm. Fat, ash, dietary fiber contents, and amino acid composition of CDGS and CDG fractions were also determined.
Sulfur Amino Acid Stability. Effects of Processing on Legume Proteins
Authors: MARSHALL H. F. , CHANG K. C. , MILLER K. S. , SATTERLEE L. D.
Published: August 2006

Four legume protein sources: peanuts, dry beans, alfalfa and soybeans were processed in laboratory, pilot plant and commercial processing facilities. Raw ingredients, intermediate and final protein products were analyzed for total and reactive cysteine/cystine (Cys), total methionine, methionine sulfoxide and methionine sulfone. Lysine, total and reactive, was determined on each legume protein sample. Processing of soybeans, peanuts and alfalfa into protein products caused no significant loss of lysine or the sulfur amino acids. The production of a protein concentrate from dry beans resulted in a significant loss of Cys. One commercial soy isolate was found to contain 51% of its total methionine as methionine sulfoxide, yet its Cys was unaffected.
Perception of Texture by Trained and Consumer Panelists
Authors: CARDELLO ARMAND V. , MALLER OWEN , KAPSALIS JOHN G. , SEGARS RONALD A. , SAWYER F. MILES , MURPHY CLAIRE , MOSKOWITZ HOWARD R.
Published: August 2006

Four experiments were conducted to assess the relationships between judgments of the perceived texture of foods by trained and consumer panelists. In Experiment 1, no differences were observed between trained texture profile panelists and naive consumers in a similarities scaling task. In Experiments 2 and 3, good linear correlations were observed between scalar judgments of texture, although a broader perceptual range was evidenced for trained panelists. In Experiment 4, psychophysical exponents of texture were found to be larger for trained than for consumer panelists, and judgments of acceptability also differed between the two groups. It was concluded that, through experience, trained texture profile panelists develop a broader perceptual range of textures, but that regression equations can be developed to relate these data to consumer data.
Surface Tension and Foaming of Protein Solutions
Authors: KITABATAKE NAOFUMI , DOI ETSUSHIRO
Published: August 2006

The relationship between surface tension and foamability of protein solutions was examined. Proteins including egg albumin, soybean protein, casein, milk whey protein and gelatin were used. Foamability was expressed as “foaming power” which corresponded to the ratio of gas volume to the liquid volume in the foam. The absolute surface tensions of protein solutions were not correlated to foamability, but the rate constant of surface tension decay of protein solutions was significantly correlated to foamability of protein solution.
Detection of Microbial Contamination Utilizing an Infrared CO2 Analyzer
Authors: THRELKELD C. H.
Published: August 2006

Infrared (IR) analysis of headspace gas for the presence of CO2 was evaluated as a method of nondestructively sampling and segregating microbiologically contaminated products. Approximately 1.8 million 7‐oz bottles containing citrus juices and fruit drinks were inspected and segregated based on IR CO2 analysis. Comparison of IR analysis with conventional plating methods indicated 89% of the samples determined to be positive by conventional methods were also detected by IR analysis. False negatives were found to be the result of nonfermentative microorganisms in over 80% of the contaminated samples not detected by IR analysis. Nonfermentative organisms were identified and effects on product were evaluated. The expected contamination rate was 5.3% compared to 6.3% contamination detected by IR analysis.

IN SUMMARY, an IR CO2 analyzer was utilized successfully to inspect 100% of product suspected of microbial contamination. When proper procedures were followed, contaminated product was detected and removed for destruction while good product was recovered for subsequent shipment to consumers. This system is advantageous because it allows for a 100% nondestructive inspection, is comparable to conventional plating methods in determining the presence of microbial contamination, and can be automated to a high degree. It is probable that automated container handling would have resulted in fewer false positives due to tilting of bottles as well as elimination of false negatives containing CO2 which were the result of insufficient time of analysis. Disadvantages include the requirement of an IR detectable microbial product, a container or package adaptable to an IR transmission or reflection type analysis, and a considerable cost for equipment. Any product contaminated by fermentative microorganisms and packaged in glass containers having a headspace of approximately 0.5 inch could be inspected by the methods described here. Justification for the cost of equipment would depend on the amount of contaminated product and the expected recovery rate. It is quite possible that future application of IR analysis could include monitoring food process streams for indicators of microbial contamination.
Determination of D‐Amino Acids in Some Processed Foods and Effect of Racemization on In Vitro Digestibility of Casein
Authors: BUNJAPAMAI S. , MAHONEY R. R. , FAGERSON I. S.
Published: August 2006

Several processed foods and controls were analyzed by gas chromatography for the presence of D‐amino acids. The concentration of each of the D‐amino acids detected in the processed foods was approximately the same as that in the controls except that D‐aspartic acid was significantly higher in dark toast surface and extruded soy flour. In vitro digestibility of casein which was alkali‐treated to cause racemization, but without lysinoalanine (LAL) formation, was essentially the same as that of racemized casein containing LAL, but was lower than that of nonracemized control casein.
A Model System for Curd Formation and Melting Properties of Calcium Caseinates
Authors: HOKES JOANNE C. , MANGINO M. E. , HANSEN P. M. T.
Published: August 2006

A lipid‐free model system was developed to aid in the study of melting and other functional properties of calcium caseinates in their application to imitation processed cheese. The model system was formed by the controlled addition of water to an alcohol suspension of the protein. At a critical water concentration, a curd was formed spontaneously. The recovered curd was melted and the area of the melt determined (melt area index). The amount of water added, rate of water addition and the source of caseinate affected the melt area index. A protein fraction, recovered from the supernatant, was rich in γ‐casein and also contained minor amounts of β‐, αs‐ and k‐caseins.
Diffusional Behavior of Tripaimitin in a Freeze‐Dried Model System at Different Water Activities
Authors: NAESENS W. , BRESSELEERS G. , TOBBACK P.
Published: August 2006

The diffusional behavior of tripalmitin (TP) in a low moisture model system composed of microcrystalline cellulose and gum arabic was found to be very dependent on the water activity (aw), the temperature and the presence of paraffin oil (PO). The complex mechanism of mobilization of food components in dry systems, particularly that of TP in our system, has been discussed in detail. Such knowledge is especially important in relation to the reactions that occur hi foodstuffs during dehydration and subsequent storage. As a typical example, the results on TP diffusion indicate that the restriction of enzymatic activity in dry systems may not solely be due to the diffusional limitations of the reactants.
Effect of Bile Salts and Bile Salt Mixtures on the Recovery of Yersinia enterocolitica
Authors: YU C. L. , HARMON M. C. , SWAMINATHAN B.
Published: August 2006

The effect of sodium salts of cholic, deoxycholic, chenodeoxycholic, glycocholic and taurocholic acids and of Bacto‐bile salts, Bacto‐bile salts #3 and Bacto‐oxgall on the recovery of nine strains representing seven serotypes (0:3, 0:8, 0:9, 0:11, 24, 0:12, 25, 0:16, 0:17) of Yersinia enterocolitica was determined. Serotypes 0:3, 0:8, 0:9 and 0:17 were resistant to 3% sodium taurocholate, 3% Bacto‐bile salts or 3% Bacto‐oxgall. Serotypes 0:11, 23, 0:12, 25, 0:16 and 0:17 were significantly inhibited by 3% sodium deoxycholate, 2.5% chenodeoxycholate and 3% Bacto‐bile salts #3. Differences in the inhibitory effects of bile salt mixtures could not be explained only on the basis of their bile acid composition as determined by gas‐liquid chromatography.
Air Classification of Peas (Pisum sativum) Varying Widely in Protein Content
Authors: REICHERT R. D.
Published: August 2006

Four samples of field peas, ranging in protein content from 14.5–28.5% (dry, dehulled seed basis), were pin milled and air classified yielding protein concentrates and starch concentrates containing 33.6–60.2 and 3.8–11.3% protein, respectively. The protein content of the dehulled peas were negatively correlated with their starch content (49.7–59.8%), lipid content (3.0–4.1%) and cell wall material (CWM) content (7.1–9.6%). The % protein in all air classified fractions was positively correlated to % protein in the dehulled peas, whereas, lipid and CWM content was negatively correlated. Air classification at lower air flows (smaller cut sizes) resulted in protein and starch fractions containing higher levels of protein. Starch separation efficiency and protein separation efficiency generally increased with increasing protein content.
Effect of Drip Irrigation of Pecan Quality and Relationship of Selected Quality Parameters
Authors: HEATON E. K. , DANIELL J. W. , MOON L. C.
Published: August 2006

The effect of four drip irrigation rates 0, 22.7, 45.4, and 68.1 L/hr/tree (LHT) on several quality parameters of ‘Stuart’ pecans were investigated along with values calculated from inshell weights, volumes, and kernel weights. Irrigation significantly increased kernel yield/tree, nut weight, diameter, kernel specific gravity, fill of nut, oil content, and appearance rating. Values calculated by computer analyses from weights and volumes were useful for evaluating the quality of nuts from the different irrigation treatments. This technique should be useful for researchers engaged in quality evaluations of inshell pecans. Nut size and % fill, and kernel color are the best parameters to estimate quality and value of pecans before actual shelling and processing. Additionally processing costs are partially dependent on nut size (no./kg) and kernel yield.
Ultrastructural Analysis of a Soybean Protein Isolate
Authors: DIECKERT JULIUS W. , DIECKERT MARILYNE C.
Published: August 2006

Various fixation techniques were employed in an effort to prepare a dry protein isolate from soybeans for analysis using transmission electron microscopy. A number of fixation schemes proved successful, and different properties of the material were brought out by the various treatments. Comparisons of electron micrographs of the isolate fixed and extracted in different ways yielded an effective means for determining the distribution of fat and protein in the sample and the effect of moisture on that distribution. Analysis of the isolate demonstrated the occluding effect of dry protein for fat located in walls of the protein shells of the isolate.
Concentration of Creatine Phosphate, Adenine Nucleotides and Their Derivatives in Electrically Stimulated and Nonstimulated Beef Muscle
Authors: CALKINS C. R. , DUTSON T. R. , SMITH G. C. , CARPENTER Z. L.
Published: August 2006

The concentration of creatine phosphate (CP), adenosine tri‐, di‐ and monophosphate (ATP, ADP and AMP, respectively), inosine monophosphate (IMP) and inosine in longissimus muscle removed from electrically stimulated (ES) and nonstimulated (NS) beef sides was enzymatically determined. After aging the carcass 7 days, steaks were removed for flavor evaluation. R values (absorbance ratios) were obtained from muscle samples removed over time from both sides. Data indicate more rapid catabolism of CP, ATP, and ADP in ES samples, with subsequent fluctuations in IMP and inosine concentration. At 12 and 24 hr post‐stimulation, ES samples had more inosine; however, this difference did not exist after aging. Flavor differences were not observed after the 7‐day aging period. R values parallel the degradation of adenine nucleotides and indicate rapid onset of rigor mortis in ES muscle.
Influence of Type (Wooled or Hair) and Breed on Growth and Carcass Characteristics and Sensory Properties of Lamb
Authors: OCKERMAN H. W. , EMSEN H. , PARKER C. F. , PIERSON C. J.
Published: August 2006

Comparisons were made between 12 Barbados Blackbelly and 12 St. Croix ram lambs (hair types) and 10 Florida Native and 12 crossbred ram lambs (wooled types) for growth, carcass characteristics and sensory panel evaluation scores. In addition, 14 predominantly hair and 14 predominantly wooled crossbred ram lambs were compared for carcass characteristics and sensory panel evaluation scores. The hair sheep had a lower rate of gain than the wooled types. The wooled breeds and predominantly wooled crossbreds were heavier and graded higher than the hair breeds and predominantly hair types. The sensory panel found the meat acceptable (tenderness, juiciness, flavor and acceptability) from all breeds.
Incidence of Salmonella in Fresh Pork Sausage in 1979 Compared with 1969
Authors: JOHNSTON R. W. , GREEN S. S. , CHIU J. , PRATT M. , RIVERA J.
Published: August 2006

A Salmonella survey was conducted to determine its incidence in fresh pork sausage. Retail size samples representing different days of production were collected from 40 federally inspected plants and analyzed for the presence of salmonellae. The results obtained during the 1979 survey were compared to results obtained in a similar 1969 survey. Salmonellae were isolated from 162 of the 566 (28.6%) samples analyzed in 1969. For the samples analyzed in 1979, 74 of 603 samples (12.4%) were positive for salmonellae. The reduction of 16.2% over 1969 indicates a reduction in the incidence of Salmonella in this product for the firms tested.
Composition of Guinea Keet Breast and Thigh Meat
Authors: HAMM D. , ANG C. , HUGHES B. L. , JONES J. E.
Published: August 2006

Guinea keets, reared to 12 wk on a modified turkey starter and grower diet, were processed like broilers and thigh and breast meat samples analyzed. Proximate analysis for breast and thigh meat without skin was: dry matter 25.4 and 24.0%; protein 22.7 and 19.4%; hexane extractables 0.86 and 2.2%; and ash 1.06 and 1.05% respectively. Total cholesterol in breast meat was 40.6 mg/100g raw tissue, and 62.1 mg in the thigh. Also included were analyses for Na, K, Ca, Mg, P, thiamin, riboflavin, niacin, pantothenic acid and the fatty acid profiles of the meat and skin. Guinea meat was found to be lower in fat, sodium and cholesterol and higher in potassium, phosphorus, thiamin, riboflavin, niacin and vitamin B6 than broiler meat.
Maillard Browning Reaction of Sugar‐Glycine Model Systems: Changes in Sugar Concentration, Color and Appearance
Authors: REYES FELIX G. R. , POOCHAROEN BOONTHONG , WROLSTAD RONALD E.
Published: August 2006

The reactivities of glucose, fructose, and sucrose with glycine (1:1 molar ratio) at 60°C and pH 3.5, were compared over 280 hr. While fructose initially browned at a faster rate, it was overtaken by glucose after 80 hr. Initially more fructose than glucose was consumed, but the reverse was true after 60 hr. Sucrose was readily hydrolyzed under these reaction conditions and underwent Maillard browning reactions, its color and appearance being similar to the glucose solutions at the later stages of the experiment. Glucose and sucrose solutions developed considerable haze while the fructose‐glycine solution remained clear.
Effect of Extractable Lipid on the Viscosity Characteristics of Yam Tuber Flours
Authors: OSAGIE A. U. , MOLOGOHME A. O. , OPUTE F. I.
Published: August 2006

Extractable lipids comprised below 2% of the flours made from yam tubers. This small amount of lipid was best extracted by water‐saturated‐butanol compared to 80% methanol and chloroform‐methanol (2:1) mixtures. The fatty acid composition in each lipid extract was not significantly affected by the method of extraction. Defatting yielded flours which gelatinized at higher temperatures and possessed increased overall viscosities compared with undefatted flours. It is suggested that the particular uses of the yam flours may be influenced by the lipids present.
Effects of Various Kitchen Heat Treatments, Ultraviolet Light, and Gamma Irradiation on. Mirex Insecticide Residues in Fish
Authors: CIN DAVID A. , KROGER MANFRED
Published: August 2006

Concentrations of the chlorinated hydrocarbon insecticide mirex (C10C112) were determined in brown trout from a defined contaminated area of Spring Creek, Centre County, PA, using electron‐capture gas chromatography. Conventional heat treatments, namely, baking, frying, poaching, and baking without skin, did not cause significant decreases of the contaminant. Ultraviolet irradiation led to significant reductions (p < 0.05) in mirex concentration in muscle tissue. Exposures of 24, 48, and 72 hr led to degradations of 30.0%, 42.8%, and 45.6%, respectively, of the initial mirex concentration. Gamma irradiation also led to significant reductions (p < 0.05) in mirex concentration in muscle tissue. Following absorption of 1, 3, and 5 Mrad, degradations of 9.8%, 23.1%, and 37.5%, respectively, of the initial mirex concentration were observed.
Effect of Packaging Film and Vacuum Level on Regular and Sorbate‐Cured Bacon
Authors: AMUNDSON C. M. , SEBRANEK J. G. , KRAFT A. A. , RUST R. E. , WAGNER M. K. , GEHRKE W. H.
Published: August 2006

Bacon was produced with either 40 ppm NaNO2/0.26% potassium sorbate, or 120 ppm NaNO2. Slices were packaged in either nylon/Surlyn or nylon/Saran/Surlyn pouches and sealed at either a high or intermediate vacuum level. At 0, 10, 21 and 28 days after packaging, residual nitrite, rancidity, pH, residual salt and pigment conversion were measured. Residual nitrite and pH were lower while nitrosopigment conversion was higher in bacon packaged with the high‐barrier film. Vacuum level, however, had no effect on any measured characteristic. The sorbate/reduced nitrite cure resulted in lower pigment conversion, lower residual nitrite, and a higher TBA number.
Computer‐Assisted Identification of Bacteria on Hot‐Boned and Conventionally Processed Beef
Authors: LEE C. Y. , FUNG D. Y. C. , KASTNER C. L.
Published: August 2006

Mesophilic and psychotrophic bacteria (706 isolates) obtained from hot‐boned and conventionally processed beef at the time of fabrication and after 14‐day vacuum storage at 2°C were analyzed by computer‐assisted numerical taxonomy (108 attributes per isolate). There was no significant difference in terms of the number of phenons between hot‐boned and conventionally processed beef both at the time of fabrication and after storage. Before storage, 24 mesophilic phenons and 11 psychrotrophic phenons were characterized. After storage in vacuum bags, there were 13 mesophilic phenons and 6 psychrotrophic phenons. The after storage flora consisted mainly of Streptococcus and Lactobacillus from both hot‐boned and conventionally processed beef.
Microbiological Quality of Vacuum Packaged Poultry With or Without Chlorine Treatment
Authors: KRAFT A. A. , REDDY K. V. , HASIAK R. J. , LIND K. D. , GALLOWAY D. E.
Published: August 2006

Dry packed broilers were cut up or kept as whole carcasses and vacuum packaged in a high barrier or low barrier film or stretch wrapped in a tray package. In an additional study, chicken was treated with 20 ppm chlorine in a chilled water dip; control chicken had no chlorine added to the water. The poultry was then packaged as previously indicated. The chicken was stored in a display case at about 5°C and examined for various bacteria and odor development at intervals up to 10 days. Vacuum packaging dry packed broilers resulted in significantly lower bacterial counts and longer keeping time compared with stretch wrapped chicken. Longest shelf life was obtained with a high barrier film, and chlorine as a dip did not provide increased storage life compared with vacuum packaged broilers maintained in the dry state.
Effect of Thermal Processing on the Survival of Foot‐and‐Mouth Disease Virus in Ground Meat
Authors: BLACKWELL J. H. , RICKANSRUD D. , McKERCHER P. D. , McVICAR J. W.
Published: August 2006

Foot‐and‐mouth disease virus was examined for its stability during cooking in tissues from infected cattle. The 01 (CANEFA 2) serotype of foot‐and‐mouth disease virus survived in lymph node tissues after heating for 2 hr at 69°C, for 1 hr but not for 2 hr at 82°C, and for 15 min but not for 0.5 hr at 90°C. Incorporation of 1% NaCl into suspensions of infected lymph nodes enhanced viral survival after heating for 0.5 hr but not for 1 hr at 90°C. The virus did not survive in either ground beef or meatballs contaminated with infected lymph node tissue, when processed to internal temperatures of 93.3, 96.1 or 98.8°C using commercial thermal processing procedures. Accurate temperature measurements were achieved with a temperature sensitive indicator disc developed in this study.
Effects of Mixing and Thermal Processing on Shelf‐Stable Sectioned and Formed Beef
Authors: WIEBE W. R. , SCHMIDT G. R.
Published: August 2006

Sectioned and formed roast beef, vacuum mixed and heat processed in either retortable pouches or cans, had a lower cook yield than its nonvacuum mixed counterpart. Vacuum mixing had no significant influence on increasing particle‐to‐particle cohesion (binding strength). Sectioned and formed roast beef cooked in retortable pouches at 121°C (Fo= 6.0) had a higher cook yield and binding strength than product processed at 110°C (Fo= 6.0). Processing the canned product at 121°C (Fo= 6.0) as opposed to 110°C (Fo= 6.0) resulted in no improvement of cook yield or binding strength. Overall, product processed in retortable pouches had a higher binding strength, but a lower cook yield than product processed in cans.
Storage Stability of Orange Juice Concentrate Packaged Aseptically
Authors: KANNER JOSEPH , FISHBEIN JACOB , SHALOM PAULETTE , HAREL STELA , BEN‐GERA ITAMAR
Published: August 2006

Orange juice concentrates were packaged aseptically by a “Dole” aseptic canning machine using 6 oz metal cans. The final juice products (11°, 34°, 44°, 58° Brix) were stored between −18° and 36°C and tested periodically for nonenzymatic browning, ascorbic acid destruction, furfural and sensory changes. Nonenzymatic browning, the main deterioration phenomena in these products, was satisfactorily retarded at 12°C or lower. Ascorbic acid destruction rate constant was dependent on temperatures between 5 and 25°C, and was affected by degree of juice concentration. Furfural accumulation in juice was higher than that in 58° Brix concentrate. Orange juice concentrate of 58° Brix did not show flavor changes after storage at 5°C or 12°C for 17 or 10 months, respectively, when evaluated after reconstitution to 11° Brix.
Estimation of Fungal Contamination in Tomato Products by a Chemical Assay for Chitin
Authors: BISHOP R. H. , DUNCAN C. L. , EVANCHO G. M. , YOUNG H.
Published: August 2006

A chemical method for the quantitative measurement of fungal chitin was used to estimate the level of mold contamination in tomato products. The alkaline degradation of chitin results in a polyglucosamine which is measured calorimetrically and the results expressed as μg of fungal glucosamine. Addition of fungal mycelium to tomato products gave recoveries of 97 ± 3% of the expected level of glucosamine. Analysis of various types of tomato products showed a significant correlation (P < 0.01) between fungal glucosamine content and the Howard mold count.
Effect of Postharvest Holding Conditions on the Quality of Salt‐Stock Pickles
Authors: LEE J. P. , UEBERSAX M. A. , HERNER R. C.
Published: August 2006

Quality changes of green‐ and salt‐stock cucumbers held at 5, 20, and 30°C up to 6 days prior to brining were evaluated. Cucumbers held at 5°C showed firm texture, low respiration rates, minimum weight loss, and good quality stock after fermentation. Increasing postharvest holding temperatures and times prior to brining resulted in loss of firmness, high respiration rates, increased weight loss, and a decrease in salt‐stock quality. Salt‐stock pickle defects increased dramatically under high temperature long time holding periods due to textural degradation and internal softening. Brining directly after harvest yielded the highest quality salt‐stock. Cucumbers held 2 days at 20°C or 6 days at 5°C resulted in good salt‐stock quality.
Changes in Roasted Peanut Flavor and Other Quality Factors with Seed Size and Storage Time
Authors: PATTEE HAROLD E. , PEARSON JACK L. , YOUNG CLYDE T. , GIESBRECHT FRANCIS G.
Published: August 2006

Peanut seed size and time in storage have been investigated as to their influence on roasted flavor, peanut butter color. Blanchability of roasted peanuts, oxidative stability and iodine value of raw peanuts. Seed size had a significant effect on roasted flavor and peanut butter color with constant roasting time and with roasting to a uniform peanut butter color. Blanchability of the seed after roasting was also significantly affected by seed size as well as storage time. Oxidative stability of the raw peanuts showed a general tendency to decrease with seed size and storage time. Iodine values were significantly higher in the smallest seed size but storage time did not affect iodine values. The data suggest that inferior quality is being introduced into marketing channels through use of a 5.95 mm screen size as a minimum for grading U.S. No. 1 Virginia‐type peanuts.
Characteristics of Frozen Desserts Sweetened with Xylitol and Fructose
Authors: ABRIL J. RUBEN , STULL J. WARREN , TAYLOR RALPH R. , ANGUS ROBERT C. , DANIEL TERRY C.
Published: August 2006

Combinations of xylitol, fructose and 24 DE corn syrup solids (CSS) were the sweetening agents in ice cream‐type frozen desserts. A 23 factorial experimental design evaluated the most acceptable combinations of xylitol (4% or 6%), fructose (4% and 6%) and CSS (10% and 12%). Based on chemical, physical and sensory analyses of the eight experimental combinations it was demonstrated that a formulation involving 6% xylitol, 6% fructose and 10% CSS gave product acceptability similar to that of an ice cream with conventional ingredient array and composition.