bluuebunny/crossref_metadata_2025 huggingface dataset:
Milk Plasmin Activity Influence on Cheddar Cheese Quality during Ripening
Authors: FARKYE N.ANA Y. , LANDKAMMER C.HRISTINA F.
Published: August 2006

Up to six‐fold increase in plasmin activity in milk did not significantly (p<0.05) affect the composition (moisture, protein, NaCl) of cheese, although a slight increase in moisture and decrease in protein content of the cheese was noted. Proteolysis in cheese increased with plasmin activity, resulting in improved flavor and overall quality of the cheese after 3 and 6 months ripening. Consistently, increasing the plasmin activity in milk about three‐fold resulted in cheese of superior sensory quality.
Evaluation of Frying Oil Filtration Systems
Authors: ZHANG W.B. , ADDIS P.B.
Published: August 2006

Three heated oil filtration systems were evaluated: (1) paper filter; (2) paper filter plus diatomaceous earth (DE); and (3) depth filtration with a filter pad under positive pressure. Methods 1 and 2 are traditional methods. Results on tallow‐cottonseed oil (90:10) and hydrogenated soybean shortening indicated that depth filtration was more effective at maintaining lipid oxidation products at low levels than methods 1 and 2. Levels of free fatty acids did not appear to differ markedly between treatments in both comparisons of depth filtration with traditional methods. Mineral analysis of both heated oil filtrate and residue removed from oil by filters revealed that depth filtration was more effective at removal of pro‐oxidant transition metals than were methods 1 and 2.
Evaluation of Ultrafiltration and Adsorption to Debitter Grapefruit Juice and Grapefruit Pulp Wash
Authors: HERNANDEZ E. , COUTURE R. , ROUSEFF R. , CHEN C. S. , BARROS S.
Published: August 2006

Grapefruit juice and grapefruit pulp wash were ultrafiltered and debittered with a pilot system. The flow rate through the membrane increased with the transmembrane pressure up to 137.8 kPa. Limonin in grapefruit juice and grapefruit pulp wash was completely removed. The debittering process was tested at 13, 27 and 48°C. Limonin removal efficiency was independent of temperature between 13 and 48°C. However the resin column was exhausted more rapidly for na‐ringin, narirutin, hesperidin, and neohesperidin particularly at 13°C. Taste panel results suggested that debittering of grapefruit pulp wash appreciably increased its flavor acceptability.
Solid State Ethanol Fermentation of Apple Pomace as Affected by Moisture and Bioreactor Mixing Speed
Authors: NGADI M.O. , CORREIA L.R.
Published: August 2006

Solid state ethanol fermentation was conducted on apple pomace in a 40 L capacity horizontal batch reactor at 30°C using apple pomace moisture contents of 77 and 85% wb, mixing speeds of 2, 20 and 40 rpm and Saccharomyces cerevisiae ATCC 24702. A higher mean maximum ethanol concentration of 19.26% db was obtained at 85% wb moisture, whereas a mean ethanol of 18.10% db was produced at 77% wb pomace moisture. Mean ethanol concentrations during fermentation of 10.79 and 10.27% db, at bioreactor mixing speeds of 2 and 20 rpm, respectively, were significantly higher than the corresponding value of 9.30% db obtained at 40 rpm mixing speed. Maximum ethanol concentrations were attained earlier at 2 and 20 rpm than at 40 rpm. A linear regression model for fermentation efficiency was fitted as a function of initial glucose and moisture.
Controlled Fermentation of Caperberries
Authors: SÁNCHEZ A.NTONIO H. , DE CASTRO A.NTONIO , REJANO L.UIS
Published: August 2006

The effects of concentration (0, 4, 7 and 10% NaCl) and buffering of brines on the fermentation of caperberries were studied. In all cases, lactic acid bacteria were the main microorganisms responsible for the processes. The evolution of the samples in water and 4% salt was similar, while 7 and 10% levels delayed fermentation depending on concentration. The buffered series fermented more strongly than unbuffered treatments. Color and texture were similar in all treatments. An increase of salt level up to 10% NaCl at equilibrium was found to be suitable for bulk storage.
Changes in Volatile Flavor Components of Guava Puree during Processing and Frozen Storage
Authors: YEN G.OW‐CHIN , LIN H.SIN‐TANG , YANG P.AT
Published: August 2006

The changes in volatile flavor components of guava puree during processing (85–88°C, 24 sec) and storage at 0°C, ‐ 10°C and ‐20°C for up to 4 months was evaluated by Likens‐Nickerson distillation and capillary GC‐MS. Pasteurized guava puree showed increases in aldehydes and hydrocarbons with decrease in esters when compared with unpasteurized puree. There was only a slight decrease in alcohols and hydrocarbons of pasteurized guava puree stored at ‐ 20°C for 4 mo. Remarkable increases in ethyl alcohol, n‐hexanal, decanoic acid, dodecanoic acid and ethyl acetate in pasteurized guava puree were observed when stored at 0°C and ‐ 10°C for 2 and 4 mo, respectively.
Demethylation of Pectic Substances: Relationship to Methylesterase Activity during Brine Storage of Cherries
Authors: TAILLAN E. , AMBID C. , PECH J.C. , RAYNAL J.
Published: August 2006

Residual pectin methylesterase activity (60% of initial activity) was present in cherry fruit stored 12 mo in brine. The specific activity of pectin methylesterase increased during the first 4 mo (195% of initial specific activity) but remained relatively stable thereafter. Methanol concentration increased (+144.5%) indicating that pectic substances underwent continuous demethylation during 12 mo storage. Pectin deesterification was probably of enzymatic origin since notable chemical deesterification occurred only at a pH lower than that found in fruit during storage. Residual pectin methylesterase activity introduces the possibility of improving fruit texture by manipulating physico‐chemical conditions prior to blanching and candying.
Staphylococcus aureus Growth and Enterotoxin Production in Mushrooms
Authors: BRUNNER K.EVIN G. , WONG A.MY C. L.
Published: August 2006

An enterotoxin A (SEA) producing strain of Staphylococcus aureus was inoculated onto mushrooms and incubated under simulated pre‐and post‐canning conditions. S. aureus grew and produced SEA in mushrooms incubated at 25°C in 10% to 20% NaCl. Growth and SEA production occurred when mushrooms were stored in plastic bags at 37°C, but not at 25°C. Mushrooms heat‐processed at 121.1°C supported S. aureus growth and SEA production. No SEA was recovered from mushrooms inoculated with 1 or 10 ng SEA/g and heated at 121.1°C for 4.5 min. At higher inoculated SEA levels (100 and 1,000 ng/g), SEA was detectable after 10 min of heating. Staphylococcal enterotoxin could be present in canned mushrooms as a result of pre‐, but more likely post‐processing contamination.
Optimal Sterilization Temperatures for Conduction Heating Foods Considering Finite Surface Heat Transfer Coefficients
Authors: SILVA C. , HENDRICKX M. , OLIVEIRA F. , TOBBACK P.
Published: August 2006

Optimal sterilization temperatures are defined as the processing temperatures which result in a minimum surface cook‐value after achieving the desired degree of sterility. They were calculated as a function of product heating rate, surface heat transfer coefficient, initial food temperature, heating medium come‐up‐time, z‐value for the quality factor and target Fo‐value. Different one‐dimensional heat transfer shapes were considered. Compared to the other variables, initial temperature and heating medium come‐up‐time had little influence on optimal processing temperature. Regression equations were developed relating optimal temperatures with all relevant variables.
Anthocyanin Pigments of Sweet Potatoes–Ipomoea batatas
Authors: SHI Z.ULIN , BASSA I.A. , GABRIEL S.L. , FRANCIS F.J.
Published: August 2006

The anthocyanin pigments of red sweet potato roots (Impomoea batatas) were isolated, purified and identified by HPLC and conventional paper chromatographic, spectral and chemical methods. Two major pigments and two minor pigments were present in fresh tissue slices extracted with boiling 1% HAc methanol. Tissues extracted cold yielded 11 or more pigments probably from degradation of the two major pigments. One major pigment was identified as peonidin‐3‐diglucoside‐5‐glucoside with three molecules of ferulic acid and one molecule of caffeic acid. The other major pigment was peonidin‐3‐diglucoside‐5‐glucoside with two molecules of ferulic acid and one caffeic acid.
Reduction of Flatulence‐Causing Sugars by High Temperature Extrusion of Pinto Bean High Starch Fractions
Authors: BOREJSZO Z.BIGNIEW , KHAN K.HALIL
Published: August 2006

Pinto bean high starch fractions were extruded using a Wenger TX‐52 twin screw extruder. The effect of process temperature and moisture in the barrel on flatulence‐causing sugars was investigated. Levels of flatulence causing sugar were lower in extruded compared to non‐extruded samples with higher reduction at higher process temperature. Sugar content decreased from 5.29% in nonextruded samples to 3.69% in samples extruded at 163°C. Moisture content in the extruder barrel did not significantly affect sugars in the samples. Raffinose and stachyose contents were reduced 47 to 60% by extrusion.
Subcellular Membrane Integrity of Atlantic Cod (Gadus morhua) Myotomal Tissue: Effects of Frozen Storage
Authors: ABLETT R.ICHARD F. , GOULD S.TEPHEN P.
Published: August 2006

The influence of frozen storage on the ultrastructural integrity of Atlantic cod muscle tissue membranes was investigated following three methods of freezing and retention for 12 wk at ‐ 12°C and ‐ 35°C. In comparison to controls (0 wk), extensive membrane condensation associated with sarcoplasmic reticulum was apparent in samples stored for 12 wk at ‐ 12°C. The effects were observed to a much lesser extent in samples retained for 12 wk at – 35°C. It was apparent that cryogenic, plate or blast freezing techniques showed no measurable influence on the observed membrane condensation and that such ultrastructural changes resulted as a consequence of relatively high (–12°C) subfreezing temperatures.
Properties of Low‐Fat Ground Beef Containing Potassium Lactate During Aerobic Refrigerated Storage
Authors: EGBERT W.R. , HUFFMAN D.L. , BRADFORD D.D. , JONES W.R.
Published: August 2006

Low‐fat patties containing water, carrageenan, encapsulated salt and hydrolyzed vegetable protein (carrageenan‐based patties) with 0, 1, 2 or 3% potassium lactate were compared to low‐fat all‐beef patties with no additives. Carrageenan‐based patties had enhanced (P<0.05) sensory properties (juiciness, tenderness, mealiness and beef flavor intensity) compared to all‐beef patties. The bacterial populations of low‐fat, carrageenan‐based patties did not differ (P<0.05) from low‐fat all‐beef patties. Bacterial growth in low‐fat, carrageenan‐based patties was reduced through the use of 2 or 3% potassium lactate with no deleterious effects on the sensory properties of the low‐fat, ground beef. However, low‐fat, carrageenan‐based patties underwent greater (P<0.5) discoloration and lipid oxidation during aerobic refrigerated storage than all‐beef patties.
Fat, Soy and Carrageenan Effects on Sensory and Physical Characteristics of Ground Beef Patties
Authors: BREWER M. SUSAN , McKEITH FLOYD K. , BRITT KRISTI
Published: August 2006

Sensory and physical characteristics of beef patties containing 20% fat, 8% fat, or 8% fat plus 20% soy protein isolate (SI), soy flour (SF), soy concentrate (SC), or a mixture (MIX) of carrageenan (0.5%), starch (0.5%), and phosphate (0.2%) were compared after 0, 4, 8, and 12 wks storage at ‐ 18°C. MIX had higher Hunter a* values than other treatments. Cook loss was lowest for MIX and highest for all beef patties. Soy extenders decreased beefy flavor and increased off‐flavor scores. Time in frozen storage increased off‐flavor, rubbery texture, and TBA value, and decreased red color and Hunter b* value of ground beef patties. Quality may be lowered in frozen‐stored high fat, or low‐fat‐soy extended beef patties.
Analysis and Thermal Stability of Porcine Thyroglobulin‐Binding Lectins in the Major Phaseolus vugaris L. G2/Albumin Groups
Authors: BONORDEN WILLIAM R. , SWANSON BARRY G.
Published: August 2006

Porcine thyroglobulin (PTG)‐binding lectins from cultivars representing the five major G2/albumin groups of Phaseolus vulgaris L. were quantified and assayed for thermal stability with PTG‐Sepharose affinity chromatography and the Folin‐Ciocalteau protein assay. Lectin concentrations of the five cultivars were 30, 25, 21, 21 and 15 mg g−1 dry flour, for Jamapa (MG2), ICA‐Pijao (BG2), California Light Red Kidney (TG2), Black Turtle Soup (VG2) and Sanilac (SG2), respectively. Heat stabilities of the five major lectin‐containing G2/ albumin groups were MG2= BG2<VG2<SG3<TG2. Thermally processing whole beans at 89°C for 60‐130 min inactivated the lectins in all G2/albumin groups.
Fatty Acid Profiles of Lipid Depots and Cholesterol Concentration in Muscle Tissue of Finishing Pigs Fed Ractopamine
Authors: ENGESETH N.J. , LEE K.‐O. , BERGEN W.G. , HELFERICH W.G. , KNUDSON B.K. , MERKEL R.A.
Published: August 2006

Ractopamine (RAC) enhances lipolysis and depresses lipogenesis in pigs. We hypothesized that depression of fatty acid (FA) formation from six carbon precursors may enhance enrichment of depot lipids from long chain FA in corn‐soybean meal finishing diets. We tested that hypothesis as well as the effect of RAC on muscle cholesterol concentration. Finishing pigs were fed 16% protein corn‐soybean diets containing 0 or 20 ppm RAC. RAC feeding had only a minor effect on fatty acid profiles (FAP) of lipid depots of finishing pigs. Adipose tissue lipids of pigs fed RAC had lower 18:0 (wk 4) and higher 18:3 (wk 4) and 18:2 (wk 6) compared to controls. Muscle lipid effects were quite variable. Total cholesterol concentration of muscle was not significantly affected by RAC feeding.
Intermittent Tumbling Affects Quality and Yield in Prerigor Sectioned and Formed Ham
Authors: BEDINGHAUS A.J. , OCKERMAN H.W. , PARRETT N.A. , PLIMPTON R.F.
Published: August 2006

Intermittent tumbling of prerigor porcine muscle maximized quality and yield in sectioned and formed ham when compared to a postrigor tumbled control. Intermittent tumbling affected precook salt‐soluble protein, precook water‐binding potential, tumbling yield, Instron bind, and sensory panel cohesion and tenderness scores. Tumbling did not affect sensory color distribution scores or cooked yield. A 3 hr intermittent tumbling cycle was adequate for producing prerigor and postrigor cured hams. Intermittent tumbling of prerigor or postrigor cured muscle tissue beyond 3 hr had no additional beneficial effect.
Ovalbumin thermal Gelation Prediction by Application of Temperature‐Time History
Authors: HARTE J.B. , ZABIK M.E. , OFOLI R.Y. , MORGAN R.G.
Published: August 2006

A model for characterizing changes in viscosity of soy protein during extrusion was adapted to predict apparent viscosity ratio of gelling ovalbumin. For ovalbumin (87% purity) the temperature time histories of 3,5, and 7% gel formation were determined at 85, 90 and 95°C. A back‐extrusion method was used to determine apparent viscosity ratios during gelation. Activation energy for denaturation/gelation was estimated at 159 kJ/mol. The model parameter a (degree of molecular entanglement) was 0.75, 0.75, and 1.0 for 3, 5, and 7% gels, respectively. Reaction rate constants were similar for samples with different protein concentrations. Maximum apparent viscosity ratio increased as protein concentrations increased. The mathematical model was verified by determining apparent viscosity ratios at 86 and 93°C and water holding at 90°C, resulting in R2‐0.93. This model may be useful in predicting ovalbumin thermal gelation apparent viscosity ratios.
Near Infrared Spectroscopic Measurement of Protein Content in Oil/Water Emulsions
Authors: KAMISHIKIRYO HIROMI , HASEGAWA KIYOZO , TAKAMURA HITOSHI , MATOBA TERUYOSKI
Published: August 2006

The regression coefficient (slope) of the calibration for determination of the protein content decreased as oil content increased. A corrected equation for the effect of oil was derived using optical intensities at 2170 nm (protein) and 2306 nm (oil). The accuracy of the corrected calibration was tested against separate data sets with each oil content. Standard errors of the corrected calibration were comparable to the standared regression equation over a wide range of oil content, suggesting that this corrected calibration is useful for determination of the protein content in oil/water emulsions.
Dietary Fiber Binding of Bile Acid through Mineral Supplementation
Authors: PANDOLF T. , CLYDESDALE F. M.
Published: August 2006

Iron and/or calcium were added to psyllium, guar gum, locust bean gum, citrus rag, high methoxy pectin, and low methoxy pectin. This mixture was then incubated with either cholic acid, deoxycholic acid, glycocholic acid, or taurocholic acid to evaluate the effect of minerals on fiber‐bile acid binding. The addition of iron with or without calcium increased the binding of deoxycholic acid to all fibers (p≤0.01 and p≤0.025) except low methoxy pectin. Iron and calcium caused increased binding of high methoxy pectin to all bile acids (p≤0.01 and p≤0.025). Dietary fiber's ability to bind certain bile acids may be maximized through mineral supplementation.
Predicting Thermophilic Spore Population Dynamics for UHT Sterilization Processes
Authors: SAPRU V. , TEIXEIRA A.A. , SMERAGE G.H. , LINDSAY J.A.
Published: August 2006

A mathematical model of Bacillus stearothermophilus spore populations during lethal heating treats activation of dormant spores and inactivation mechanisms affecting dormant/activated spores. Rate constants of activation/inactivation processes were determined from isothermal survivor curves of experiments in 105, 110, 115, and 120°C and corresponding simulations with the model. Variations of rate constants with temperature were incorporated by Arrhenius equations responding to general temperature regimes. Tests demonstrated high correspondence between experimental survivor curves and those generated by simulations with the model for isothermal and dynamic, lethal heating. Tests also indicated Arrhenius rate constants at low lethal temperatures (105‐120°C) and the model may apply to ultra high temperature. The new model was more effective than the traditional model in representing and predicting spore population dynamics during lethal heating.
Hydrolysis and Maillard Reactions During Ripening of Iberian Ham
Authors: VENTANAS J. , CÓRDOBA J. J. , ANTEQUERA T. , GARCIA C. , LÓPEZ‐BOTE C. , ASENSIO M. A.
Published: August 2006

Thirty‐eight hams from Iberian breed were processed by the traditional dry‐curing procedure. Active proteolysis and autooxidation occur during the first period, as revealed by the accumulation of peptide, nitrogen and carbonyl compounds. In the second step a strong increase in amino acid nitrogen was observed, whereas the content of all the aldehydes studied decreased notably. This could be due to condensations between carbonyls and free amino acids during the summer period. While hams were kept in the cellar, the overall increase of amino acid nitrogen was in contrast to the slow rate of accumulation of some individual amino acids. This was presumably due to degradation to volatile derivatives, where Maillard reactions could be involved.
Glucose and Internal Cooking Temperature Effects on Low Fat, Pre‐ and Post‐Rigor, Restructured Beef Roasts
Authors: GOLL S.J. , KASTNER C.L. , HUNT M.C. , KROPF D.H.
Published: August 2006

Muscles were excised pre‐rigor (hot‐boned, HB) or post‐rigor (conventionally boned, CB), chunked, and were subjected to four ingredient treatments: (SPE) 2% NaCl, 0.5% NaCl, 0.5% phosphate, 2% glucose (SP 2% NaCl, 0.5% phosphate (SG) 2% NaCl, 2% glucose and (PG) 0.5% phosphate, 2% glucose to produce low fat, restructured, beef roasts, which were cooked to an internal temperature of 63 or 93°C. Addition of glucose to a salt and phosphate (LEM‐O‐FOS1) ingredient treatment as well as cooking to 93°C helped maintain low warmed‐over flavor (WOF) scores and kept thiobarbituric acid values below threshold (< 1.0) while maintaining desirable consumer acceptability scores.
Interactions Between Lipids and Milk Proteins in Emulsion
Authors: AYNIÉ S. , MESTE M. LE , COLAS B. , LORIENT D.
Published: August 2006

The interactions between nitroxide homologs of fatty acids and purified components of milk proteins in a model food emulsion were studied using electron spin resonance. The importance of the interactions in emulsions decreased in the order αs1‐casein > β‐lacto‐globulin > β‐casein β whole casein. αs1‐Casein resulted in a better organization of the lipid monolayer. Neither the flexibility nor the tertiary structure of the proteins explained this result. It appeared that the interactions occurred through lipid polar heads and protein polar side chains due to hydrogen bonds and/or electrostatic interactions.
Infrared Processing of Dry Peas, Canola, and Canola Screenings
Authors: McCURDY SANDRA M.
Published: August 2006

Dry peas, canola and canola fine screenings were heated to various temperatures using infrared energy, then selected characteristics were compared with those of unprocessed commodities. Processed dry peas exhibited dehulling and air classification characteristics similar to raw peas. Bitterness and protein solubility in raw pea protein were reduced by infrared heating. Infrared processed canola seed exhibited lower crude fibre content and lower yields in dehulling compared to raw seed. Processing the seed did not affect crude oil quality, except for sulfur and phosphorus content. Inactivation of canola and screenings myrosinase by infrared heating was related to commodity moisture content. Infrared heating to 105°C inactivated weed seed viability in screenings.
Orange Flavor Absorption Into Various Polymeric Packaging Materials
Authors: CHARARA Z.N. , WILLIAMS J.W. , SCHMIDT R.H. , MARSHALL M.R.
Published: August 2006

Citrus oil components (from cold‐pressed and terpeneless oils), which contribute substantially to flavor of orange juice, were shown to be absorbed into various polymeric materials [low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), and surlyn (S)] used in aseptic packaging. Equilibration of absorption took place within 4 days, while extraction of the oil constituents occurred in 24 hr when higher temperatures were used. Substantial absorption of oil constituents by LDPE and S occurred while highly crystalline polymers (PP and HDPE) did not absorb much. The degree of absorption also depended on the nature of the oil constituents. Absorption was higher for terpene constituents followed by sesquiterpenes and aldehydes. Swelling factors showed that highly crystalline polymers (HDPE and PP) swelled less than crystalline polymeric materials. Citrus oil affected the crystallinity of the polymers by lowering their melting point and percent crystallinity.
Fluorometric Peroxygenase Assay for Lipid Hydroperoxides in Meats and Fish
Authors: MIYAZAWA TERUO , KASHIMA MINORU , FUJIMOTO KENSHIRO
Published: August 2006

A fluorometric assay for lipid hydroperoxide in meats and fish was developed using pea peroxygenase, a hydroperoxide‐dependent hy‐droxylase. The freeze‐dried microsome fraction of germinating pea seed was used as a peroxygenase source. Linear relationships between the hydroperoxide added (25 to 150 nmol) and fluorescence were observed with methyl linoleate hydroperoxide, linoleic acid hydroperoxide, triglyceride hydroperoxide, and phosphatidylcholine hydroperoxide. α‐Tocopherol at levels equivalent to those in meats and fish did not affect the peroxygenase reaction. The assay was specific for hydroperoxides. The method enables determination of total lipid hy droperoxides in sample homogenates without extracting total lipids from retail meats and fish.
Validity of Descriptive and Defect‐oriented Terminology Systems for Sensory Analysis of Fluid Milk
Authors: LAWLESS HARRY T. , CLAASSEN MICHELLE R.
Published: August 2006

Fluid milk defects were evaluated by 2 trained sensory panels, one generating their own associative descriptive terms (PG) and the second using traditional dairy judging terminology (TT). The same samples were evaluated by a consumer acceptance panel. The trained panels had equal levels of discriminative ability as shown by ratings of untreated, oxidized and rancid milks. The PG system had as good or better correlation with consumer acceptability ratings as the TT system, as determined by multiple regression, especially when more than one defect was present. Discriminant analysis showed that descriptive profiles obtained by either trained panel could be used to identify defects by their actual root causes, and that the classification accuracy of the descriptive panel surpassed that of the defect‐oriented group.
Properties of Acidic Whey Protein Gels Containing Emulsified Butterfat
Authors: YOST RUTH A. , KINSELLA J. E.
Published: August 2006

Changes in physical properties of whey protein gels following addition of emulsified fat were investigated. Gels were made by heating mixtures of dialyzed whey protein isolate at pH 4.60 with and without emulsified fat droplets. Addition of emulsified fat improved the gel‐like qualities of these systems. Gel strength progressively increased upon addition of emulsified fat up to 30.00% by weight. Mean droplet size 1.85 km produced the greatest reinforcement of gel strength. Gels made with intermediate concentrations of protein were most sensitive to the effect. The elastic moduli and viscosities of whey protein gels at pH 4.60 increased with fat content, whereas syneresis decreased upon addition of fat.
Viscoelastic Properties of Myofibrillar Protein‐Polysaccharide Composite Gels
Authors: XIONG YOULING L. , BLANCHARD SUZANNE P.
Published: August 2006

The influence of polysaccharide gums on thermal gelation of chicken salt‐soluble protein (SSP) was studied by determining changes in dynamic: viscoelasticity and aggregation of the protein‐gum composites in 0.6M NaCl at pH 6.0. Xanthan gum increased the storage modulus (G') of SSP up to 45°C, but decreased Cl'and inhibited the sol – gel transition at > 45°C. Alginate generally hindered SSP gelation. SSP‐gum composite gels cooled to 23°C were weaker but held more water than gels made from SSP alone. Neither gum altered the SSP aggregation pattern, nor the SSP absorption spectra. The inhibition of SSP gelation by both gums appeared mainly due to physical entanglement rather than chemical interactions.
Factors Influencing Ellagic Acid Precipitation in Muscadine Grape Juice During Storage
Authors: GARRIDO V.M. , SIMS C.A. , MARSHALL M.R. , BATES R.P.
Published: August 2006

Ellagic acid sedimentation in white muscadine grape juice was monitored following different processing treatments and storage temperatures. High storage temperatures (40°C) greatly accelerated sediment formation, and pasteurization (100°C, 10 min) resulted in a faster sediment formation than sterile filtration. Sediment also increased substantially after juice was hydrolyzed (121°C and pH 2 for 10 min). Ultrafiltration of juice through a 10,000 or 30,000 dalton membrane resulted in significantly less sediment formation in the juice. Treatment of juice with polyvinylpolypyrrolidone (0.1– 0.2 g/L juice), egg albumen (6–10 mg/L juice) or gelatin (0.05 – 0.4 g/L juice) resulted in a significant reduction of juice phenolics and sediment formation. A commercial pectinase added to the grapes increased sediment formation and total phenolics in the juice. Levels of ellagic acid in juice were very low and did not correlate well with amount of sediment formed.
Oxygen Availability Affects Prooxidant Catalyzed Lipid Oxidation of Cooked Turkey Patties
Authors: AHN D.U. , AJUYAH A. , WOLFE F.H. , SIM J.S.
Published: August 2006

The catalytic effect of free ionic iron, hemoglobin and/or NaCI, and the effect of total lipid, class of lipid, and fatty acid composition on lipid oxidation of precooked refrigerated meat patties were highly significant only when oxygen was freely accessible to the patties during storage. With limited oxygen contact (cold vacuum‐packaging) after cooking, the 2‐thiobarbituric acid reactive substances (TBARS) values of patties were much lower than the values for patties with free oxygen contact (loose packaging) and did not increase substantially during storage. However, the TBARS values of cold packaged patties were higher (P<0.05) than those of hot packaged patties which had almost no oxygen contact after cooking. Elimination of oxygen during storage (hot or cold vacuum‐packaging after cooking) resulted in prooxidants, fat content, fatty acid composition or the class of lipids having no effect on lipid oxidation.
Prevention of Lipid Oxidation in Precooked Turkey Meat Patties with Hot Packaging and Antioxidant Combinations
Authors: AHN D. U. , WOLFE F. H. , SIM J. S.
Published: August 2006

The effects of antioxidants or hot packaging and their combination on lipid oxidation were quite variable depending on the additives in turkey meat. The TBARS values of cooked patties were greatly affected by the degree of oxidation in the raw meat, and the effectiveness of antioxidants varied with added prooxidants. Ascorbate and free radical terminators had stronger antioxidant effects than iron chelators, and chelating iron alone could not eliminate lipid oxidation in either raw or cooked meat with added NaCl. The combination of hot packaging and antioxidants provided cooked patties with better protection from lipid oxidation than either treatment alone.
Thermal Stability of Some Metabolically Conjugated Potential Precursors of Flavor Components in Meat and Milk
Authors: LOPEZ V. , LINDSAY R.C.
Published: August 2006

The stability of selected metabolic conjugates (phenylphosphate, phenylglucuronide, naphthylglucuronide, and naphthylsulfate) was evaluated in model systems. Phenylphosphate was less stable than the glucuronides and the sulfate, especially under neutral (pH 6.8) and acidic conditions (pH 1.5). Phenylphosphate was completely degraded after 1.7 hr at 100°C, and after 0.3 hr at 150°C at pH 6.8. The glucuronide and sulfate conjugates were especially stable under neutral conditions (pH 6.8) requiring > 5 hr for complete hydrolysis at 100°C. All conjugates were quite stable to hydrolysis under alkaline conditions (pH 11). The presence of certain organic solvents (ethyl acetate or ethyl ether) caused rapid hydrolysis of conjugates under very mild conditions (40°C for 30 min). This information may improve under‐standing of flavor production from animal products.
In vitro Digestibility of Whey Protein/K‐Casein Complexes Isolated from Heated Concentrated Milk
Authors: SINGH HARJINDER , CREAMER LAWRENCE K.
Published: August 2006

The disulfide‐linked complex of K‐casein and whey proteins that forms when concentrated milk is heated was isolated by centrifugation and column chromatography on Sephacryl S‐1000. The rate of hydrolysis of β‐lactoglobulin and K‐casein in the complex and the reduced and carboxymethylated components of the complex were measured by polyacrylamide gel electrophoresis. The rates of hydrolysis at pH 2.0 (pepsin) and pH 8.0 (trypsin and chymotrypsin) were similar for k‐casein in the complex and its reduced form. β‐Lactoglobulin hydrolysis was faster for the reduced complex than for the complex which was much faster than for the native protein for all three enzymes. The results suggest that heating milk increases the digestibility of whey proteins, despite the formation of large protein complexes between the whey proteins and K‐casein.
Pericarp Thickness and Other Kernel Physical Characteristics Relate to Microwave Popping Quality of Popcorn
Authors: MOHAMED A.A. , ASHMAN R.B. , KIRLEIS A.W.
Published: August 2006

The popping performance of 18 popcorn hybrids was studied using 2 microwave treatments, with and without salt, and 1 conventional method. Differences in popping quality indices between the 2 microwave treatments, indicated a negative effect of salt on popping for the majority of hybrids. Pericarp thickness, kernel volume, sphericity, diameter ratio, thousand kernel weight, hardness, and density were investigated. Pericarp thickness gave highest correlation with expansion volume in microwave and conventional popping while sphericity correlated slightly better in unsalted microwave popping. Regression models, which predict expansion volume in terms of pericarp thickness and kernel shape and size, were developed for both microwave and conventional popping.
Changes in Phenolic Content in Fresh Ready‐to‐use Shredded Carrots during Storage
Authors: BABIC I. , AMIOT M.J. , NGUYEN‐THE C. , AUBERT S.
Published: August 2006

Phenolic compounds of shredded carrots were characterized and quantified by HPLC and their concentrations were measured during storage in air at 4°C. Trans 5′‐caffeoylquinic acid amounted to 60% of total phenolic content and accumulated rapidly. Para‐hydroxybenzoic acid and p‐hydroxybenzoic esters were not found in freshly prepared shredded carrots and their content increased after the first day. Patterns of accumulation varied, between samples from the same carrot cultivar grown in different geographical areas. When shredded carrots were stored in polypropylene film pouches or in controlled atmospheres containing 30% CO2 and/or 0% 02, phenolic compounds accumulated very slowly. The increase in phenylalanine ammonialyase activity was consistent with accumulation of phenolic compounds and may relate to microbial spoilage.
Vacuum Infiltration of Polyamines Increases Firmness of Strawberry Slices Under Various Storage Conditions
Authors: PONAPPA TILAK , SCHEERENS JOSEPH C. , MILLER A. RAYMOND
Published: August 2006

Strawberry slices were vacuum infiltrated with polyamines and changes in firmness during storage were determined. Spermine and spermidine at 10 mM or 100 mM significantly increased firmness, whereas pu‐trescine was not as effective at increasing firmness of slices stored at 1°C. The firming effect of the polyamines was similar to that of calcium chloride, and may have been due to their ability to bind to cell walls and membranes. In ripe receptacles of various cultivars which differed in firmness, putrescine (12–38 nmol/g fresh weight) and spermidine (19–33 nmoI/g fresh weight) were the predominant polyamines, while only low levels of spermine (<10 nmol/g fresh weight) were present. There was no discernible relationship between endogenous polyamine levels and fresh fruit firmness for the cultivars studied.
Enzymatic Browning Inhibited in Fresh and Dried Apple Rings by Pineapple Juice
Authors: LOZANO‐DE‐GONZALEZ PATRICIA G. , BARRETT DIANE M. , WROLSTAD RONALD E. , DURST ROBERT W.
Published: August 2006

Sliced apple rings were treated with water (control), canned pineapple juice, frozen pineapple juice, ion‐exchanged pineapple juice, frozen orange juice, ascorbic acid, a commercial antibrowning preparation or sodium bisulfite. The rings were either left exposed to air, vacuum packaged, or dehydrated. Browning was measured calorimetrically and by visual examination over extended periods of time. Pineapple juice was an effective browning inhibitor in both fresh and dried apples. Pineapple juice was fractionated using various size and charge separation procedures. All fractions inhibited enzymatic browning of crude apple extracts by at least 26%. Results indicate that the inhibitor is a neutral compound of low molecular weight.
Gelatinization and Retrogradation Characteristics of Hydroxypropylated and Cross‐linked Rices
Authors: YOOK CHEOL , PEK UN‐HUA , PARK KWAN‐HWA
Published: August 2006

Chemically modified rices were prepared by treating with propylene oxide and epichlorohydrin. Gelatinization and retrogradation characteristics of these modified rices were investigated by using DSC and amylograph. Hydroxypropylation of rice caused an extreme decrease in gelatinization temperature from 62°C to 50°C and reduced the retrogradation rate of cooked rice. In rice treated by both hydroxypropylation and cross‐linking the retrogradation was reduced more than for hydroxypropylated rice.
Pediococcus acidilactici PO2 Bacteriocin Production in Whey Permeate and Inhibition of Listeria monocyfogenes in Foods
Authors: LIAO CHII‐CHERNG , YOUSEF AHMED E. , RICHTER EDWARD R. , CHISM GRADY W.
Published: August 2006

Growth of Pediococcus acidiluctici PO2 and production of associated bacteriocin (pediocin PO2) were demonstrated in whey permeate (WP) supplemented with 0.5–4% yeast extract (YE). Initial pH 6.5 (without PH regulation during fermentation) wag optimal for production of uediocin PO2 in WP containing 2% YE. A pediocin‐rich dairy ingredient (PRDI) powder was made of the fermented WP and applied in heat‐treated whole milk and pasteurized liquid whole egg. PRDI in‐hibited Listeria monocyfogenes in milk. L. monocytogenes was inhib‐ited by untreated liquid whole egg and PRDI appeared to contain a factor that offsets the inherent antilisterial action of the egg product.
Physical and Sensory Characteristics of Low Fat Ground Beef Patties
Authors: MILLER M. F. , ANDERSEN M. K. , RAMSEY C. B. , REAGAN J. O.
Published: August 2006

Ground beef patties with combinations of 0 and 10% added water and 0 and 0.25% added phosphate were compared with controls (22% fat and 0% added water and phosphate). Added water increased thaw and cooking losses but improved objective texture measurements and sensory panel ratings (P < 0.05). Added water and phosphate increased the percentage of water, decreased protein and did not affect fat. Added water and/or phosphate resulted in higher (P < 0.05) juiciness, tenderness and overall palatability scores. Low fat patties with added water were similar to 22% fat patties. Water and/or phosphate also improved sensory ratings for texture and flavor of 10% fat patties to equal those for 22% fat patties.
National In‐Home Consumer Evaluation of Pork Roasts From Pigs Administered Porcine Somatotropin (pSt)
Authors: PRUSA K.J. , FEDLER C.A. , MILLER L.F.
Published: August 2006

Boneless pork loin (longissimus) or ham (semimembranosus) roasts from 60 control and 60 porcine somatotropin‐produced (pSt) pigs (3 mg daily) were analyzed for composition and evaluated by 120 families in each of three major cities. In San Antonio and Portland each family received a loin roast from a control pig and a pSt‐treated pig. In Buffalo, each family received a fresh ham roast from a control pig and a pSt‐treated pig. Consumers were asked to evaluate the roasts during conventional in‐home meal preparation and consumption. Overall, pSt roasts contained less intramuscular fat and no differences were noted in acceptability scores when control loin or ham roasts were compared with pSt‐produced loin or ham roasts. No differences were noted in the preference scores for the loin roasts; however, consumers preferred the tenderness, juiciness and flavor of the control ham roasts.
Sodium Tripolyphosphate Stability and Effect in Ground Turkey Meat
Authors: LI WEI , BOWERS JANE A. , CRAIG JEAN A. , PERNG SHIAN K.
Published: August 2006

Ground turkey meat, cooked and uncooked, was prepared with and without 0.5% sodium tripolyphosphate (SIP) and stored at 5°C for different periods of time. STP stability was evaluated by determining soluble orthophosphate. Water‐holding capacity (WHC), pH, and mi‐crobial count were also measured. STP hydrolyzed rapidly in uncooked samples. Refrigerated storage time (up to 6 days) did not affect STP hydrolysis in cooked turkey meat. Heating accelerated the rate of STP hydrolysis. End point temperatures (65, 75, and 85 °C) did not affect the extent of STP hydrolysis. STP increased WHC in both cooked and uncooked samples. STP did not inhibit total microbial growth in cooked or uncooked ground turkey meat.
Oat Gum and β‐Glucan Extraction from Oat Bran and Rolled Oats: Temperature and pH Effects
Authors: DAWKINS N. L , NNANNA I. A.
Published: August 2006

The extractability of oat gum from oat bran and rolled oats was studied using 12 treatment combinations in a factorial design (2x3x4x2) i.e. 2 oat products; 3 pH (8.0–10.5); 4 temperatures (5O–70°C); 2 replications. The extraction procedure involved: (a) alkaline treatment of flour and removal of starch residue; (b) isoelectric precipitation of protein residue [namely, protein concentrates (PC)]; (c) and alcohol precipitation of oat gum/β‐glucan and collection of gum by centrifu‐gation. Extracted oat gum ranged from 2.99–6.28% for oat bran and 1.82–5.24% for rollcd oats whereas β‐glucan (in gum) ranged from 70–89% and 50–68%, respectively. Protein contents of the PC from oat bran was 69–91% and rolled oats 66–89%. Correspondingly, starch content of residues ranged from 30–63% and 61–47%. Oat gum/β‐glucan extracted at pH 9.2/50°C or pH 10.5/50/55°C showed little or no starch contamination.
Soybean Flour Lipoxygenase lsozyme Mutant Effects on Bread Dough Volatiles
Authors: ADDO K. , BURTON D. , STUART M.R. , BURTON H.R. , HILDEBRAND D.F.
Published: August 2006

Lipoxygenases are implicated in improvement of bread quality after addition of enzyme active soy flour. However, differences among the three major isozymes in soybeans in terms of impact on bread characteristics are not known. Differences exist among soybean lipoxygenase isozymes in terms of stability and generation of volatile flavor and aroma. Soybean flour with different lipoxygenase isozymes present might affect bread dough volatiles or defatting may affect activity of the isozymes. Full fat or defatted soy flour could be added to bread dough. Defatting selectively reduced lipoxygenase 2 activity with little effect on lipoxygenases 1 and 3. Addition of full fat soy flour from mutant isolines indicated that as with soybean homogenates, lipoxygenase 2 is mostly responsible for undesirable aroma compounds. Much higher levels of volatile alcohols were found in soy flour amended bread dough than in soy flour homogenates alone.
Flavor Modifying Characteristics of the Intense Sweetener Neohesperidin Dihydrochalcone
Authors: LINDLEY M. G. , BEYTS P. K. , CANALES I. , BORREGO F.
Published: August 2006

Addition of l–4 ppm neohesperidin dihydrochalcone to sweet and nonsweet food products modified the intensity of some flavor attributes in all products evaluated, as determined by a panel of trained assessors during a series of descriptive attribute analyses. Flavor enhancements were perceived in all products, although no consistent pattern of enhancement was observed across the product range. Fruit flavors were enhanced across all fruity products, as were some odor attributes. Intensity reductions of some sharp or spicy flavor attributes were also recorded. The great majority of flavor modifications induced were considered to bring about improvements in product sensory quality.
4‐Hexylresorcinol, a Potent Inhibitor of Mushroom Tyrosinase
Authors: DAWLEY RUTHELLEN M. , FLURKEY WILLIAM H.
Published: August 2006

4‐hexylresorcinol (4HR) was a potent inhibitor of mushroom tyrosinase in crude extracts, causing 90% loss of activity at 100 μM. The concentration of 4HR needed to cause 50% inhibition (I50) was = 5 μM. Partially purified tyrosinase was inhibited by lower concentrations of 4HR and was characterized with an I50 of = 1 μM. Electro‐phoretic analysis, coupled with isoenzyme staining in the presence and absence of 4HR, showed inhibition of tyrosinase isoforms but not of laccase isoforms.
Gluconic Acid Influences Texture and Color of Canned Asparagus
Authors: McGLYNN W.G. , DAVIS DR. , HONARMAND F.
Published: August 2006

The color and texture of canned asparagus spears were measured using a shear‐press and a Gardner color difference meter. Canning spears with 1% gluconic acid reduced pH of asparagus tissue to = 4.1 within 24 hr. After 5 mo storage, the 1% acidified pasteurized spears were lighter, less green, and more yellow than nonacidified retorted spears. Acidification with a milder thermal process almost doubled firmness of the acidified spears.
Packaging Effects on Growth of Listeria innocua in Shredded Cabbage
Authors: OMARY M.B. , TESTIN R.F. , BAREFOOT S.F. , RUSHING J.W.
Published: August 2006

Freshly shredded white cabbage was treated with citric acid and sodium erythorbate, inoculated with Listeria innocua (in lieu of Listeria monocytogenes), and packaged in 230g lots in four types of retail bags with oxygen transmission rates (OTRs) of 5.6, 1,500, 4,000, and 6,000 cc O2/m2/24 hr, then stored 21 days at 11°C. After 14 days, L. Innocua decreased in cabbage stored in three films. After 21 days, Listeria population increased in all packages, but the increase was less (p<0.05), for cabbage packaged in film with the highest OTR (commercial film).
Resistant Starch in Foods: Modified Method for Dietary Fiber Residues
Authors: SAURA‐CALIXTO F. , GOÑI I. , BRAVO L. , MAÑAS E.
Published: August 2006

In a modified method for measuring Resistant Starch (RS) in dietary fiber residues all operations for obtaining fiber residues and determination of RS were performed in a 50 mL centrifugation tube. This minimized error sources and simplified previous methodology.
Cholesterol Autoxidation Inhibition Varies Among Several Natural Antioxidants in an Aqueous Model System
Authors: RANKIN S. A. , PIKE O. A.
Published: August 2006

Inhibition of cholesterol autoxidation by several natural materials was examined in an aqueous meat model system at pH 5.50 and 80°C. Antioxidant effectiveness was measured using the induction period for 7‐ketocholesterol. An industrial rosemary oleoresin, quercetin, myr‐icetin and BHA (included for comparison) had no antioxidant properties for cholesterol. All tocopherol treatments delayed cholesterol oxidation. The γ‐ and δ‐ treatments were most effective and α‐toco‐pherol was least effective. No synergistic effects were observed with tocopherol blends. Antioxidants effective against unsaturated fatty acid autoxidation may not inhibit cholesterol autoxidation.
Tocopherol Micro‐Extraction Method with Application to Quantitative Analysis of Lipophilic Nutrients
Authors: ABDOLLAHI ABBAS , ROSENHOLTZ NEAL S. , GARWIN JEFFREY L.
Published: August 2006

A method proposed for determining vitamin E consists of extraction with n‐hexane/2‐propanol and separation by normal‐phase HPLC. It was used to monitor tocopherol content of eggs metabolically enriched with vitamin E. It accurately evaluated nutritional uniformity of many samples in a relatively short time. Chromatographic resolution showed alpha‐tocopherol as the only major peak in the enriched eggs. Quantification with HPLC or GC demonstrated that the extraction technique could also be used to determine cholesterol and fatty acids. Results from eggs containing varied ratios of fatty acids indicate that the method did not differentially extract different types of fatty acids.
Component Analysis of Disaggregation of Pectin During Plate Module Ultrafiltration
Authors: HOAGLAND P.D. , KONJA G. , FISHMAN M.L.
Published: August 2006

Concentration of commercial lime and citrus was carried out by plate module ultrafiltration with a 300K cut‐off membrane with small changes in intrinsic viscosity and 48 and 55% recoveries. Subsequent ultrafiltration of permeates with a 100K cut‐off membrane yielded pectins from retentates with lower viscosities and recoveries of 34 and 39%. Component analysis was applied to concentration and viscosity response curves from high performance size exclusion chromatography. Results suggested viscosity loss was due to passage through the membrane of small pectin molecules and/or aggregates released from breakdown of larger pectin aggregates during 300K ultrafiltration. Concentration of pectin with minimum loss of viscosity requires ultrafiltration which insures retention of small pectin aggregates. Improved component analysis was developed for characterizing solution behavior of pectin during processing.