bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability of α‐Tocopherol, Thiamin, Riboflavin and Retinol in Pork Muscle and Liver during Heating as Affected by Dietary Supplementation
Authors: LEONHARDT MONIKA , GEBERT STEFAN , WENK CASPAR
Published: August 2006

The α‐tocopherol (Vit E) and ascorbic acid (Vit C) supplementation of pig diets increased (P<0.05) liver α‐tocopherol concentrations. After heating, the liver samples of both treated groups and the longissimus dorsi muscle samples of the vitamin C group showed increased riboflavin retention (P<0.05). The supplemented and control groups did not show differences regarding retention of α‐tocopherol, retinol and thiamin in heated liver and longissimus dorsi. Dietary vitamin C resulted in higher liver vitamin E and was most effective in protecting riboflavin against loss during heating of liver or longissimus dorsi.
Low‐fat Margarine Spreads as Affected by Aqueous Phase Hydrocolloids
Authors: CLEGG STUART M. , MOORE ADELE K. , JONES SYLVIA A.
Published: August 2006

The effects of gelatin, maltodextrin, modified starch, sodium alginate and sodium caseinate on the physical, structural and sensory properties of low‐fat spreads were systematically evaluated. Stability at 34°C and stability on centrifugation decreased, while microscopy revealed an increase in aqueous phase droplet size and more open emulsion structures after inclusion of hydrocolloids. These effects were accompanied by changes in sensory (texture and flavor) properties, with the spreads becoming less waxy/greasy but having faster, more intense flavor characteristics after addition of hydrocolloids. Gelatin and maltodextrin had a slight effect, modified starch and sodium alginate were intermediate and sodium caseinate had the greatest destabilizing effect on structural characteristics of the emulsion.
HPLC Method for Cyst(e)ine and Methionine in Infant Formulas
Authors: TORAN A. ALEGRÍA , BARBERÁ R. , FARRÉ R. , LAGARDA M.J. , LÓPEZ J.C.
Published: August 2006

Cyst(e)ine and methionine were converted into cysteic acid and methionine sulfone by oxidizing with performic acid. The oxidized samples were then subjected to acid hydrolysis (6N HCl, 105–110°C/24 hr). After derivatization with phenylisothiocyanate, reverse phase HPLC separation was carried out at 48°C and with UV detection. Different gradients and pH values in the eluent were assayed to determine the best resolution. Analytical parameters, detection and quantification limits, linearity, precision and accuracy, were determined. The method was reliable and accurate for measuring cyst(e)ine and methionine in infant formulae.
Heat‐Induced Gelation of Myofibrillar Proteins and Myosin from Fast‐ and Slow‐Twitch Rabbit Muscles
Authors: BOYER C. , JOANDEL S. , ROUSSILHES V. , CULIOLI J. , OUALI A.
Published: August 2006

Heat‐induced gelation of myofibrillar proteins and myosin (0.6M; pH 6.0) from rabbit fast‐ and slow‐twitch muscles was analyzed by thermal scanning rheometry. Proteins from slow‐twitch muscle exhibited higher thermostability and lower gel strength than those from fast‐twitch muscle. Purifying myosin from myofibrillar proteins changed heat‐gelation profiles and generally increased gel rigidity at 80°C. However, the effect of some proteins on the gelation of myosin was muscle dependent. Complete elimination of actin decreased the heat‐gelling ability of slow myosin and increased that of fast myosin. Also, elimination of C‐protein led to a greater increase in rigidity of gels from slow myosin than from fast myosin. The heat‐behavior of the different protein fractions was related to the degree and type of aggregation in the gel.
Protein Extractability of Turkey Breast and Thigh Muscle with Varying Sodium Chloride Solutions as Affected by Calcium, Magnesium and Zinc Chloride
Authors: NAYAK RAJESH , KENNEY P. BRETT , SLIDER SUSAN
Published: August 2006

Ground turkey breast and thigh muscle were extracted with various NaCl solutions with or without added CaCl2, MgCl2, or ZnCl2 (0.05%). Protein solubility was increased by CaCl2 and decreased by ZnCl2 in each muscle type. At 4% NaCl, MgCl2 increased thigh myosin solubility by 30%, compared to the control, whereas CaCl2 had no effect. At 2% and 4% NaCl, breast myosin was not affected by MgCl2 or CaCl2. Myosin was not detected for either muscle type when ZnCl2 was used. All three salts increased breast actin solubility but only MgCl2 increased thigh actin solubility. The CaCl2 resulted in the highest overall protein solubility and MgCl2 resulted in the highest thigh myosin and actin solubility at 4% NaCl.
Continuous Spectrophotometric Method for Determining Monophenolase and Diphenolase Activities of Pear Polyphenoloxidase
Authors: ESPÍN JUAN CARLOS , MORALES MERCEDES , VARÓN RAMÓN , TUDELA JOSÉ , GARCÍA‐CÁNOVAS FRANCISCO
Published: August 2006

A continuous spectrophotometric method was based on the coupling reaction between 3‐methyl‐2‐benzothiazolinone hydrazone (MBTH) and the quinone product of the oxidation of p‐hydroxyphenyl propionic acid (PHPPA) or 3,4‐dihydroxyphenyl propionic acid (DHPPA) in the presence of polyphenol oxidase. The monophenolase activity of pear PPO was characterized for the first time. Solubility and stability of the adduct formed at the optimum pH (4.3) enabled the system to reach steady‐state, making it possible to determine monophenolase activity with short lag periods. This, together with the value of ε for the MBTH‐quinone adduct, makes this method more sensitive than other continuous methods for assaying monophenolase and diphenolase activities.
ACC Oxidase in Papaya Sections After Heat Treatment
Authors: CHAN HARVEY T. , MAINDONALD JOHN M. , LAIDLAW W.G. , SELTENRICH M.
Published: August 2006

The effect of heat treatment on 1‐aminocyclopropane‐1‐carboxylate (ACC) oxidase in excised sections of papaya (Carica papaya L). ‘Kapoho’ fruit immersed in hot water baths was analyzed as kinetics of a set of consecutive reactions. Treatments were at 23, 28, 33, and 38°C which would be encountered during initial treatments of whole fruits during heating to fruit‐center temperatures of 47°C and above. The response of ACC oxidase was considered as two consecutive reactions, one for production and one for degradation. Activation energies were compared to those reported at 43°C to 51°C. The implications of the analyses were confirmed by results for a whole‐fruit hot‐water dip.
Optimizing Low Fat Peanut Spread Containing Sucrose Polyester
Authors: SHIEH CHWEN‐JEN , AKOH CASIMIR C. , KOEHLER PHILIP E.
Published: August 2006

Mixture experimental design was used to model the formulation of a low fat peanut spread based on textural profile analysis. Emulsifier was the important factor affecting physical properties of the low fat peanut spread. Sucrose polyester (SPE) contributed only the oily attribute to the product and did not significantly affect physical properties. The optimum combination was 1% salt, 6% corn syrup solids, 2.6% emulsifier, 23.9% SPE, and 66.5% ground defatted peanuts adjusted to 40% peanut oil. The fat content of the optimum sample was 26.6%.
Transglutaminase from Streptoverticillium ladakanum and application to minced fish product
Authors: TSAI GUO‐JANE , LIN SHANG‐MAY , JIANG SHANN‐TZONG
Published: August 2006

The transglutaminase (TGase) from Streptoverticillium ladakanum was purified to electrophoretic homogeneity after ammonium sulfate fractionation and Blue Sepharose Fast Flow chromatography. The molecular weight of the purified TGase was 30.5 kDa estimated by Superdex 75HR gel filtration, and 37.5 kDa by SDS‐PAGE. This enzyme, with optima at pH at 6.0 and 50°C was very stable at pH 5.0–7.0. It was strongly inhibited by PCMB, PMSF, Pb2+, Zn2+ and Cu2+, but not affected by EDTA and Ca2+. This suggested that the purified TGase was calcium‐independent and its active center contained cysteine. It catalyzed the crosslinking of fish myosin heavy chain and substantially increased the gel strength of mackerel surimi.
Biogenic Amines in Dry Sausages as Affected by Starter Culture and Contaminant Amine‐Positive Lactobacillus
Authors: EEROLA SUSANNA , MAIJALA RIITTA , SAGUÉS ARTUR‐XAVIER ROIG , SALMINEN MAIJA , HIRVI TIMO
Published: August 2006

The effect of an amine‐negative starter culture, containing Pediococcus pentosaceus and Staphylococcus carnosus, on the growth and amine formation of an amine‐positive contaminant lactic acid bacterium (G 106) was studied in dry sausages. Levels of biogenic amines, precursor amino acids, pH, water activity and microbial counts were measured. Levels of phenylethylamine and tyramine increased in the sausages inoculated with the amine‐positive strain. The starter culture did not prevent growth of G 106 or its amine formation capability. However, levels of histamine remained low although G 106 could produce histamine in vitro.
Tuna Protein Nutritional Quality Changes after Canning
Authors: CASTRILLÓ N ANA M. , NAVARRO M. PILAR , GARCÍA‐ARIAS M. TRINIDAD
Published: August 2006

Albacore tuna (Thunnus alalunga) was steamed and canned in soy bean oil and sterilized at 115°C for 55 or 90 min. Proximate composition, total amino acid and available lysine content were determined during different phases of the process. Water and protein were lost in all phases and fat content increased. There was a decrease in available lysine during cooking but no loss in total amino acids. Nutritional evaluation of the protein showed differences in biological value and net protein utilization when the canned tuna was mixed with bread flour.
Odorants Contributing to Warmed‐Over Flavor (WOF) of Refrigerated Cooked Beef
Authors: KERLER JOSEF , GROSCH WERNER
Published: August 2006

A systematic study was performed to determine the odorants contributing to the warmed‐over flavor (WOF) of cooked beef patties. The most potent odorants of the freshly cooked patties and of the cooked, refrigerated and reheated patties showing WOF were screened by dilution experiments. Eleven odorants were selected for quantification by stable isotope dilution assays. Three aroma models were prepared on the basis of the results. A sensory comparison of the models indicated that WOF was the result of a combination of a loss of desirable odorants, e.g. 4‐hy‐droxy‐2,5‐dimethyl‐3(2H)‐furanone and 3‐hydroxy‐4,5‐dimethyl‐2(5H)‐furanone, along with an increase in lipid peroxidation products, in particular n‐hexanal and trans‐4,5‐epoxy‐(E)‐2‐decenal.
Low‐Fat Ground Beef from Desinewed Shanks With Reincorporation of Processed Sinew
Authors: CAMPBELL R.E. , HUNT M.C. , KROPF D.H. , KASTNER C.L.
Published: August 2006

Six shank treatments (one at 7% and five at 10% fat) and two ground round controls (10 and 20% fat) were used to compare sensory properties of low‐fat ground beef from shanks with and without sinew reincorporated. Five shank treatments were desinewed with a commercial de‐sinewer; the other was whole ground shank. Four desinewed shank treatments had 7% flaked sinew reincorporated; the fifth had none. Patties with flaked sinew had more (P < 0.05) collagen than controls or those with desinewed shank only. Control patties had lower pH (P < 0.05) than shank patties (5.80 vs 6.07). Desinewed‐shank patties had fewer (P < 0.05) connective tissue particles and were more (P < 0.05) juicy than whole‐ground‐shank patties. Shank patties were lighter red but less stable in color than the controls.
Characteristic Anthocyanin Pattern from Onions and other Allium spp
Authors: FOSSEN TORGILS , ANDERSEN ØYVIND M. , ØVSTEDAL DAG OLAV , PEDERSEN ATLE T. , RAKNES ÅSE
Published: August 2006

Three red onion (Allium cepa) cultivars, top onion (A. cepa var. vivi‐parum), A. altaicum and chive (A. schoenoprasum) contained several or all of the following anthocyanins: 3‐(6′‐malonyl‐3′‐glucosylglucoside), 3‐(3′,6′‐dimalonylglucoside), 3‐(6′‐malonylglucoside), 3‐(3′‐malonyl‐glucoside), 3‐(3′‐glucosylglucoside) and 3‐glucoside of cyanidin. Trace amounts of two pelargonidin derivatives and the 3,5‐diglucosides of cyanidin and peonidin were for the first time reported in red onion. Carbon NMR data showed that the sugars of the 3‐(6′‐malonyl‐3′‐glu‐cosylglucoside), 3‐(6′‐malonylglucoside) and 3‐glucoside of cyanidin were pyranoses. Substitution either by sugar or acid in the sugar 3‐position of an anthocyanin has never been reported outside the genus Allium.
Gelation of Beef Heart Surimi as Affected by Antioxidants
Authors: SRINIVASAN SUBRAMANIAN , XIONG YOULING L.
Published: August 2006

Oxidation of proteins (carbonyls) and lipids (TBARS) in beef heart surimi‐like materials during preparation and storage (2°C) was inhibited by propyl gallate (0.02%) or α‐tocopherol (0.2%). Inhibition of oxidation did not affect surimi gel property (storage modulus, G'). Storage promoted oxidation of proteins in 0.2% ascorbate‐washed mince, leading to increases in peak (∼ 55°C) and final (70°C) G' of thermally induced surimi gel. Protein carbonyls in stored surimi and its sol (salted), as well as TBARS of the sol, strongly correlated with both peak and final G of gels. Incorporation of tripolyphosphate into washed mince promoted gelation whether the surimi‐like material was oxidized or not.
Composition of Surimi‐like Material from Beef or Pork
Authors: PARK S. , BREWER M.S. , McKEITH F.K. , BECHTEL P.J. , NOVAKOFSKI J.
Published: August 2006

A surimi‐like material was made from finely minced beef or pork by water washing followed by screening to remove connective tissue. Changes in component proteins, amino acid composition and vitamin, mineral and cholesterol content occurring during preparation were investigated. Total amino acid nitrogen contents of water‐washed beef and pork were higher than those of the respective muscle by 7% and 6.5%. Among 16 amino acids measured, histidine and glycine decreased in both water‐washed beef and pork, while others increased compared to original muscle. Thiamin content decreased after washing. Surimi‐like beef and pork had less cytoplasmic minerals (K, Na, Mg) but more minerals associated with proteins or subcellular organelles (Ca, Cu, Zn, Fe). Fat content decreased, although cholesterol concentration was not changed by washing.
Chemical Changes After Irradiation and Post‐Irradiation Storage in Tilapia and Spanish Mackerel
Authors: AL‐KAHTANI HASSAN A. , ABU‐TARBOUSH HAMZA M. , BAJABER ADNAN S. , ATIA MOHAMED , ABOU‐ARAB ATIF A. , EL‐MOJADDIDI MOHAMED A.
Published: August 2006

Influence of gamma irradiation (1.5–10 kGy) and post‐irradiation storage up to 20 days at 2 ± 2°C on some chemical criteria of tilapia and Spanish mackerel were studied. Total volatile basic nitrogen formation was lower in irradiated fish than in the unirradiated. Irradiation also caused a larger increase in thiobarbituric acid values which continued gradually during storage. Some fatty acids decreased by irradiation treatments at all doses. Thiamin loss was more severe at higher doses (≥4.5 kGy), whereas riboflavin was not affected. Alpha and gamma tocopherols of tilapia and alpha, beta, gamma, and delta tocopherols, in Spanish mackerel, decreased with increased dose and continued to decrease during 20‐day post‐irradiation storage.
Glutathione Peroxidase Activity During Storage of Fish Muscle
Authors: WATANABE F. , GOTO M. , ABE K. , NAKANO Y.
Published: August 2006

Activity of fish muscle glutathione peroxidase, which presumably protects muscle from oxidative deterioration during storage and processing, was found in both Japanese jack mackerel and skipjack tuna. Activity of the peroxidase and level of reduced glutathione (enzyme substrate) decreased during 5 days storage at 4°C. Lipid hydroperoxides were substantially formed in the fish muscles during the storage.
Supercritical Carbon Dioxide Extraction Efficiency for Carotenes from Carrots by RSM
Authors: VEGA P.J. , BALABAN M.O. , SIMS C.A. , O'KEEFE S.F. , CORNELL J.A.
Published: August 2006

Increasing demand for β‐carotene has resulted in a growing interest in its extraction from natural sources. Carotenes were extracted from carrot pulp (press cake) using SC‐CO2. Three levels of pressure (20.7, 27.6, and 34.5 MPa), temperature (40, 55, and 70°C), and ethanol co‐solvent (0, 5, 10% wt) were studied. Percentages α‐, β‐ and total carotenes extracted were determined by HPLC and spectrophotometric methods. A maximum of 99.5% of β‐carotene was extracted using 10% ethanol. Concentration of ethanol and temperature were the most important factors in increasing extraction yield. A response surface model was developed from the results: %β‐carotene extraction = 8.4558 + 0.8816 T– 10.7650 E + 0.1843 T*E + 1.9019 E2– 0.0261 E2*T, where T = temperature (°C), E = ethanol (%). R2= 0.973.
Dynamics of Solidification in 2% Corn Starch‐Water Mixtures: Effect of Variations in Freezing Rate on Product Homogeneity
Authors: MASHL STEPHEN J. , FLORES ROLANDO A. , TRIVEDI ROHIT
Published: August 2006

Directional solidification studies of gelatinized corn starch‐water mixtures were undertaken in order to examine, in situ, the freezing behavior of this food model. The solidification rate was controlled by varying sample cell velocity as it moved from a 25°C hot stage to a ‐25°C cold stage. While freezing at cell velocities ≤7.5 μm/sec, starch granules were alternately pushed or entrapped by the advancing solid‐liquid interface producing a segregated structure consisting of alternating high‐starch and low‐starch bands. At a cell velocity of 10 μm/sec, the frozen product was homogeneous. The relationship between the solid‐liquid interface velocity and segregation behavior was quantified and compared to an existing model of particle‐interface interactions.
Glass Transition Temperatures Determined using a Temperature‐Cycling Differential Scanning Calorimeter
Authors: BELL LEONARD N. , TOUMA DERGHAM E.
Published: August 2006

Glass transition temperatures, Tg, of polystyrene, polyvinylpyrrolidone, polydextrose, gelatin, corn flakes, pasta, and aqueous glucose/glycine solutions were determined using a differential scanning calorimeter which cycled the temperature while the net temperature increased at a constant rate. Operating conditions of the modulated differential scanning calorimeter(tm) (MDSC(tm)) for optimizing the endothermic baseline shift associated with the glass transition were a scan rate of 5°C/min with an amplitude of ± 1°C over a modulation period of 60 or 100 sec. The MDSC successfully separated the glass transition from other irreversible thermal changes in simple food ingredients. While the MDSC did not distinctly determine Tg of complex food systems at low moisture contents, glass transitions were observed for solutions and food systems at higher moisture contents. Tg values from MDSC were reproducible and similar to those from standard DSC.
Disulfide‐mediated Polymerization Reactions and Physical Properties of Heated WPI‐stabilized Emulsions
Authors: MONAHAN F.J. , McCLEMENTS D.J. , GERMAN J.B.
Published: August 2006

Heating a 19 wt% corn oil‐in‐water emulsion stabilized by 1 wt% whey protein isolate from 30 to 70°C and then cooling to 25°C for at least 15 hr, brought about minimal changes in droplet aggregation, apparent viscosity and susceptibility to creaming. At 75°C, droplet aggregation occurred but this decreased on heating to 90°C. The apparent viscosity and susceptibility of droplets to creaming increased as the degree of droplet aggregation increased. Inclusion of the sulfhydryl blocking agent N‐ethylmaleimide to inhibit thiol/disulfide interchange reactions did not affect droplet aggregation but resulted in higher apparent viscosity values and susceptibility to creaming at 85 and 90°C and not at lower temperatures. The results suggest that droplet aggregation results from noncovalent interactions between unfolded protein molecules adsorbed on different droplets and that the interactions are strengthened by disulfide bonds.
Membrane Packaging System to Permit Safe Hydration of Freeze‐Dried Contents with Impure Water
Authors: SCHIMMEL KEITH A. , WURIE ALIEU , ILIAS SHAMSUDDIN , PEGRAM JAN E.
Published: August 2006

We tested the feasibility of using polymer membranes for a self‐hydrating packaging system to reconstitute freeze‐dried foods using nonpurified water. Several commercial membranes were screened according to (1) hydration rate, (2) water permeability, (3) passage of microorganisms, (4) salt rejection, and (5) strength. The most promising membranes were used for developing and testing prototype packaging systems. A feasible self‐contained rehydration system was a nylon‐6 polyamide membrane that rehydrated the freeze‐dried food within 30 min while passage of microorganisms was prevented. The temperature was 37°C, and the food contained 0.5g/5g of a low molecular weight solute (salt). Such self‐contained membrane rehydration systems must be designed to accommodate expected environmental conditions such as temperature, relative humidity, and nature of the product.
Optimization of Hexametaphosphate‐Assisted Extraction of Flaxseed Proteins Using Response Surface Methodology
Authors: WANASUNDARA P. K. J. P. D. , SHAHIDI F.
Published: August 2006

Total proteins of defatted low‐mucilage flaxseed meals were isolated by extraction with aqueous sodium hexametaphosphate (SHMP). A composite central rotatable design was used to study effects of pH (X1), meal‐to‐solvent ratio (X2) and concentration of SHMP (X3) on nitrogen extractability (Y1) and protein recovery (Y2). Using RSM, quadratic polynomial equations were obtained for Y1and Y2by multiple regression analysis. All three variables significantly affected nitrogen solubility and protein extractability. The pH was the most effective factor and meal‐to‐solvent ratio was least. Verification experiments confirmed validity of predicted models. Stationary points for response surfaces were characterized as maxima and they were Y1=77.6% at X1= 8.90, X2= 1:33.6 and X3=2.75% and Y2=57.5% at X1=9.00, X2=1:33.3 and X3=2.85%, for nitrogen extractability and protein recovery, respectively.
Optimizing Water Washing Process for Sunflower Heads before Pectin Extraction
Authors: SHI X.Q. , CHANG K.C. , SCHWARZ J.G. , WIESENBORN D. , SHIH M.C.
Published: August 2006

Most pigment in sunflower heads is water soluble, but is strongly associated with extractable pectin. Washing sunflower heads before pectin extraction is necessary to remove pigment and improve pectin quality. An undesirable side effect is loss of water‐soluble pectin. Response Surface Methodology (RSM) was applied to determine effects of variables and to optimize washing conditions for minimum pectin loss with maximum pigment removal. Benchscale washing experiments were carried out at 70‐80°C for 10‐30 min at water/solid ratios (v/w) of 20:1 to 40: 1, respectively. Both removal of water‐soluble pigments and loss of pectin from sunflower tissue increased with increasing temperature, washing time, and water/solid ratio. Optimum conditions were 74.8°C for 25 min at a 25:1 water/solid ratio. This resulted in removal of 56.47% of the pigment, but loss of 2.90% of the pectin, which is practicable for the sunflower pectin industry.
Mathematical Modeling of Temperature and Gas Composition Effects on Visual Quality Changes of Cut Endive
Authors: VANKERSCHAVER K. , WILLOCX F. , SMOUT C. , HENDRICKX M. , TOBBACK P.
Published: August 2006

Quantitative descriptive analysis was used to evaluate the influence of different temperature (1‐16°C) and gas conditions (air, 11% and 19% CO2) on visual quality changes in cut endive. Based on the coefficient of determination (R2), the residuals, the estimated intercept and the variance‐stabilizing characteristics of a logarithmic transformation, a first order model was selected to represent quality deterioration kinetics. The influence of temperature and gas composition on quality deterioration rate was modeled using a combined temperature (Arrhenius)‐gas composition (exponential relation)‐quality deterioration (first order) model. The model was validated under dynamic temperature conditions showing limitations of the Time‐Temperature‐Tolerance‐concept.
Microwave Heating Uniformity of Ready Meals as Affected by Placement, Composition, and Geometry
Authors: RYYNÄNEN S. , OHLSSON T.
Published: August 2006

The importance of chemical and physical modifications in a ready meal on microwave heating uniformity was investigated. Experimental materials were four‐component chilled ready meals which were heated in a domestic microwave oven. The experiment was set up by using 25 factor design and data were evaluated by analysis of variance. Temperatures during and after microwave heating were measured. Heating uniformity could be mainly modified by arrangement and geometry of components and type of tray. In contrast, chemical modifications had no effect or some combined effects with other factors.
Milk Proteins Affect Yield and Sensory Quality of Cooked Sausages
Authors: ELLEKJÆR MARIT RISBERG , NÆS TORMOD , BAARDSETH PERNILLE
Published: August 2006

Sausages were produced with seven different mixtures with skim milk powder, sodium caseinate and whey protein (1.5, 3, 5%) according to a simplex‐centroid design, where the proportion of each ingredient varied from 0 to 100%. Principal component analysis (PCA) identified that sausages with 1.5% milk protein were most similar in sensory quality to the controls and had minimum cooking loss. PCA was effective to reduce the number of attributes to five to describe the main variation among the 1.5% milk protein sausages. A mixture of 1:1 blend of skim milk powder and whey protein resulted in the product with lowest cooking loss.
Foaming and Emulsifying Properties of Whey Protein Concentrates As Affected by Lipid Composition
Authors: VAGHELA M.N. , KILARA A.
Published: August 2006

Freeze‐dried WPC, containing 35 and 75% protein were manufactured by pretreating whey with calcium chloride and heat. These and commercial WPC were subjected to proximate analysis and lipid classes, phospholipid classes, free fatty acids (FFA), and monoacylglycerols (MAG) composition were determined. Solubility, thermal, foaming, and emulsifying properties of the WPC were studied. Pretreatment increased calcium and phosphorus contents and decreased the contents of all other minerals. The pretreatment had no effect on solubility, denaturation enthalpy, and onset temperature of denaturation of WPC. These values were comparable to those of commercial WPC. Foaming capacity and emulsion stability were unaffected, but foam stability increased and emulsifying capacity decreased due to pretreatment. Overall, total lipids and lipid class contents of experimental WPC were too low to affect surface properties of WPC.
Antistaling Additives, Flour Type and Sourdough Process Effects on Functionality of Wheat Doughs
Authors: ARMERO ENRIQUE , COLLAR CONCEPCIÓN
Published: August 2006

Antistaling additives—distilled monoglycerides (MGL), diacetyl tartaric ester of monodiglycerides (DATEM), sodium stearoyl lactylate (SSL), carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC) and fungal α‐amylase—were studied for effects on rheological and fer‐ mentative properties of white/whole wheat bread doughs, made following straight/sour dough processes. A fractionated factorial design (L32) was used to evaluate single additive effects and interactions. Single addition of DATEM, followed by SSL, α‐amylase and hydrocolloids improved oven rise and final volume. In presence of DATEM, synergistic (MGL) and antagonistic (SSL) effects of additional emulsifiers were found on gassing power. SSL was the only effective conditioner for enhancement of mixing properties. Dough plasticity was negatively affected by MGL addition and by CMC/HPMC in white/whole flours respectively. Some combinations resulted in detrimental dough handling properties.
Low O2 Atmospheres Affect Storage Quality of Zucchini Squash Slices Treated with Calcium
Authors: IZUMI HIDEMI , WATADA ALLEY E. , DOUGLAS WILLARD
Published: August 2006

Calcium chloride treated or nontreated zucchini squash slices were stored in air or low O2 (0.25, 0.5 and 1%) at 10°C. Respiration rate, ethylene production, and development of browning/decay were reduced under low O2. Slices stored under 0.25% O2 had less weight loss and browning/decay, and greater shear force and L‐ascorbic acid content than those stored in air. Microbial count, pH, and color at the end of storage were improved by low O2. Calcium treatment had no additive effect on maintaining quality of zucchini squash slices stored in 0.25% O2 atmosphere.
Methods of Antibiotic Applications as Related to Microbial Quality of Lamb by PCA and Bioluminescence
Authors: BAŞOL MUSTAFA SACIT , GÖĞÜŞ UĞUR
Published: August 2006

The effects of different methods of application of chlortetracycline and oxytetracycline on microbial properties of lamb meat were studied. A significant antibacterial effect of antibiotic was found on total mesophilic bacteria count. The mesophilic bacteria level was determined by two methods: the conventional method using Plate Count Agar and bioluminescence. Correlation curves of the CFU and RLU values proved two methods were highly related. Thus for the microbiology quality of meat hygiene the bioluminescence method may be used as a fast and alternative method to PCA. Note that bioluminescence requires a higher degree of skill and attention.
Gelation of Proteins from Washed Muscle of Threadfin Bream (Nemipterus japonicus) under Mild Acidic Conditions
Authors: CHAWLA S.P. , VENUGOPAL V. , NAIR P.M.
Published: August 2006

Gelation of proteins of washed mince of threadfin bream was induced by the organic acids: acetic, lactic, tartaric, and citric. Washing of mince was essential for gelation. The strength of acetic acid‐induced gel was affected by setting conditions and heat treatment. Gelation was associated with degradation of myosin heavy chain and appearance of a new protein band of about 160 kDa. Solubility studies of the gel in various solvents suggested structural changes. Gelation was also associated with oxidation of sulfhydryl groups. Salts negatively influenced gelation.
Glass Transition Explanation for the Effect of Polyhydroxy Compounds on Protein Denaturation in Dehydrated Solids
Authors: BELL LEONARD N. , HAGEMAN MICHAEL J.
Published: August 2006

Dehydrated proteins are frequently subjected to thermal stress in the presence of other components. The effect such substances may have upon protein structure, and therefore function, has not been fully investigated. Thus, the effect of added polyhydroxy components on the denaturation of lyophilized β‐lactoglobulin, ovalbumin, and ribonuclease, as determined by differential scanning calorimetry, was evaluated. The denaturation temperature, Tm, of the globular proteins decreased in the dry state after the addition of sucrose, sorbitol, or glycerol. The thermal stability (based on Tm) of the dehydrated proteins appeared to correlate with the glass transition temperature (Tg) of the polyhydroxy component, which was assumed to be related to the Tg of the mixture. The lower the Tg of the component, the greater was the degree of protein destabilization. Thus, glass transition data may be used to predict the effect that a component would have on denaturation of dehydrated proteins at elevated temperatures.
Pulsed Ultra High Pressure Treatments for Pasteurization of Pineapple Juice
Authors: ALEMÁN GIOVANNA D. , WALKER MARCIA , FARKAS DANIEL F. , TORRES J. ANTONIO , TING EDMUND Y. , MORDRE SIGURD C. , HAWES ADRIAN C.O.
Published: August 2006

Sinusoidal and step‐pressure pulses were compared with static pressure treatments for the inactivation of Saccharomyces cerevisiae 2407‐1a in pineapple juice. No inactivation was observed after 40–4,000 fast sinusoidal pulses (10 cycles/s) at 4–400 sec in the 235–270 MPa range. Static 270 MPa treatments at 40 and 400 sec resulted in 0.7 and 5.1 decimal reductions, respectively. Slower 0–270 MPa step pulses at 0.1 (10 pulses), 1 (100 pulses), and 2 (200 pulses) cycles/s with 100 sec total on‐pressure time resulted in 3.3, 3.5, and 3.3 decimal reductions, respectively. A comparable static pressure treatment resulted in 2.5 decimal reductions. Changing the on‐pressure/off‐pressure time ratio (3:1, 3:3 and 1:3) showed that treatments with longer on‐pressure time, e.g., 0.6 sec on‐pressure and 0.2 sec off‐pressure were significantly more effective showing nearly a 4 decimal reduction in 100 sec.
Storage of Spinach Under Low Oxygen Atmosphere Above the Extinction Point
Authors: KO N.P. , WATADA A.E. , SCHLIMME D.V. , BOUWKAMP J.C.
Published: August 2006

The extinction point of spinach was <0.4% but above 0.2% O2 at 0° and 5°C. Respiration rates were ∼2.3 times greater at 5°C than at 0°C and were similar among cultivars. In 0.8% O2 atmosphere, O2 uptake of three cultivars was reduced by an average of 53% and CO2 production was reduced by 35% relative to those stored in air. Deterioration of leaves was reduced by 30 to 54%, while weight loss, color and chlorophyll content were not affected by the 0.8% O2 atmosphere. Thus O2 could be allowed to be depleted to 0.8% in modified atmosphere packaging without quality loss due to anoxia.
Fatty Acid Distribution and Its Effect on Oxygen Permeability in Laminated Edible Films
Authors: PARK J.W. , TESTIN R.F. , VERGANO P.J. , PARK H.J. , WELLER C.L.
Published: August 2006

Lipid contents, distributed fatty acid concentrations and oxygen permeability of laminated methylcellulose/corn zein‐fatty acid films and methylcellulose films separated from the laminate were investigated. Total lipid contents ranged from 0.056 to 0.157 g/cm3 for the laminated edible film structure, and distributed fatty acid contents ranged from 0.062 to 0.220 g/cm3 in the methylcellulose layer. Fatty acid distribution increased with chain length and fatty acid concentration. Oxygen permeabilities of both laminated methylcellulose/corn zein‐fatty acid films and methylcellulose films separated from the laminate increased as chain length of fatty acid decreased and concentration of fatty acid increased. Scanning electron microscopy and Soxhlet extraction appeared to show distribution of fatty acids from the corn zein layer into and through the methylcellulose layer.
Empirical Model for Water Uptake and Hydration Rate of Food Powders by Sorption and Baumann Methods
Authors: ELIZALDE B.E. , PILOSOF A.M.R. , BARTHOLOMAI G.B.
Published: August 2006

The empirical model q = Q t/B + t, where q is the amount of water taken up at time t was useful to describe water uptake of several food powders determined either by the Baumann or the sorption isotherm method at 75.6 and 100% RH. The equilibrium values (Q) and the specific rate constant (K) derived from this model as (QB)‐1 could be used to characterize food materials for hydration capacity and rate. Large differences were observed in Q values between methods and between food powders. The Baumann Q values and sorption isotherm Q values at 100% RH ranked similarly water takeup of food powders (R = 0.97, p < 0.001). Baumann K values and sorption isotherm K values at 100% RH also correlated highly. However, little differences were observed among the K and Q values of different food powders determined by the sorption isotherm method at 75.6% RH.
Corn Zein Packaging Materials for Cooked Turkey
Authors: HERALD T.J. , HACHMEISTER K.A. , HUANG S. , BOWERS J.R.
Published: August 2006

Mechanical and barrier properties of corn zein films with butylated hydroxyanisole (BHA), bacterial enzyme, and emulsifier additives were investigated and compared to those of polyvinylidine chloride (PVDC) films. No significant differences (P < 0.05) occurred in elongation, tensile strength, or Young's modulus among corn zein films. PVDC had the lowest apparent water vapor permeability (WVPapp), and no significant differences in WVPapp were found between zein films and PVDC. Cooked turkey breast was packaged, evaluated by a trained sensory panel, and analyzed for hexanal content. Turkey breast wrapped in corn zein film with antioxidant and emulsifier had lower hexanal content than samples packaged in PVDC.
Quality of Broiled Beef Patties Supplemented with Wheat Germ Protein Flour
Authors: ROCHA‐GARZA ANA E. , ZAYAS JOSEPH F.
Published: August 2006

Quality characteristics of ground beef patties, supplemented with hydrated wheat germ protein flour (WGPF) at levels 2.0, 3.5, and 5.0% were studied. Water‐holding capacity decreased and pH increased with addition of WGPF. Water activity was not affected. Supplemented beef patties had lower cooking losses and changes in diameter and higher yields than control patties. Supplemented beef patties exhibited lower shear force and compression values than all‐meat patties. No differences were found in wheat‐like aroma and flavor. WGPF has potential for use as an extender in ground meat products.
Process and Characteristics for a Surimi‐like Material Made from Beef or Pork
Authors: PARK S. , BREWER M.S. , NOVAKOFSKI J. , BECHTEL P.J. , McKEITH F.K.
Published: August 2006

Beef or pork was chopped, screened, and washed; water was removed by centrifugation to make surimi‐like, water‐washed beef or pork. Processing parameters were evaluated to develop the optimum processing techniques to yield the most functional material. Regardless of fat content in the starting material, water‐washed beef or pork contained <1% fat. Water‐washed muscle was lighter (reduced redness and yellowness) than the original starting material but had more color than fish surimi. Washed beef or pork formed gels with greater hardness than commercial fish surimi above 55°C after heating at 0.5°C/min. Salt soluble protein of water‐washed beef or pork was higher than that of commercial fish surimi.
Attachment of Salmonella typhimurium to Poultry Skin as Related to Cell Viability
Authors: KIM K.Y. , LILLARD H.S. , FRANK J.F. , CRAVEN S.E.
Published: August 2006

3H‐labeled S. typhimurium cells inactivated by gamma‐radiation (60Co) and by formaldehyde (5%) were used to determine if cell viability affected attachment to poultry skin. Both gamma‐irradiated and formal‐dehyde‐treated cells attached like live cells. There was no difference in attachment between cells grown in a chemically defined medium (SCDM) or in brain heart infusion broth (BHI). Live and gamma‐irradiated cells and BHI‐grown and SCDM‐grown cells had similar surface hydrophobicity. Live and gamma‐irradiated cells had similar cell surface charges, whereas BHI and SCDM‐grown cells had different surface charges. Differences in cell surface charge did not affect attachment rate.
Potential Inoculum Sources for Decay of Fresh‐cut Celery
Authors: ROBBS P.G. , BARTZ J.A. , SARGENT S.A. , McFIE G. , HODGE N.C.
Published: August 2006

Bacteria responsible for decay of precut celery (Apium graveolens) appear to be residents on the plants at harvest. Bacterial genera isolated from equipment in a fresh celery packinghouse were similar to those found on plants sampled at the packinghouse entrance. Population densities and array of genera were highest on unwashed plants, whereas certain genera were no longer detected on the washed plants. Fluorescent Pseudomonas spp. predominated, but strains of Pantoea agglomerans (=Erwinia herbicola), Enterobacter agglomerans, Aeromonas, Arthrobacter, and Aureobacterium were frequently isolated. Members of the coliform group such as Citrobacter, Klebsiella, and Escherichia were rare.
‘Flavor‐fade’ and Off‐Flavors in Ground Roasted Peanuts As Related to Selected Pyrazines and Aldehydes
Authors: WARNER K.J.H. , DIMICK P.S. , ZIEGLER G.R. , MUMMA R.O. , HOLLENDER R.
Published: August 2006

Headspace volatiles from ground roasted Florunner medium peanuts, stored at 65°C for 1–68 days, were separated and identifled by GC/MS. Selected pyrazines, resulting from Maillard browning and selected aldehydes from autoxidation were evaluated to determine their mechanistic contributions to peanut ‘flavor‐fade.’ The 2,6‐dimethylpyrazine, 2‐methylpyrazine, 2‐ethyl‐5‐methyl or 6‐methylpyrazine, 2,3,5‐trimethylpyrazine, and pentanal remained constant during storage (p < 0.05). Flavor scores for ‘roasted peanut’ decreased slightly, then leveled off and hex‐anal, heptanal, octanal and nonanal increased during storage (p < 0.05). Oxidative ‘rancid’ flavor scores and thiobarbituric acid values also increased during storage (p < 0.05). Based on results, the ‘flavor‐fade’ of stored roasted peanuts is due to masking of pyrazines and other ‘roasted peanut’ flavor compounds by large quantities of low‐molecular weight aldehydes from lipid autoxidation, and not due to polymerization and/or degradation of the pyrazines.
Emulsifying Properties of Low‐fat, Low‐cholesterol Egg Yolk Prepared by Supercritical CO2 Extraction
Authors: BRINGE NEAL A. , HOWARD DAVID B. , CLARK DEANE R.
Published: August 2006

Comparisons were made with native egg yolk, dried egg yolk and a commercial yolk substitute (soy lecithin). Aqueous emulsions were prepared by sonicating water containing 0–5% NaCl, 20% peanut oil, HC1 or NaOH as needed for pH adjustment, and 1–3% emulsifier expressed as the total of phospholipids, glycolipids and proteins contributed by yolk ingredients or soy lecithin. The median diameters of fat particles in the emulsions with and without dispersing fat droplet floes using Triton X‐100, were evaluated by laser light diffraction. The emulsifying properties of low‐fat, low‐cholesterol egg yolk were similar to or better than those of native yolk and dried egg yolk. Soy lecithin had less effective emulsifying properties than yolk ingredients with respect to coalescence of fat droplets during storage and separation during 70°C treatment.
Composition and Structure of Fat Globule Surface Layers in Recombined Milk
Authors: SHARMA RANJAN , SINGH HARJINDER , TAYLOR MICHAEL W.
Published: August 2006

Protein coverage, composition and structure of surface layers of fat globules in recombined milk were determined. Average protein load was ∼6 mg/m2 fat surface. Both casein and whey proteins were present in the fat globule surface layer, with casein adsorbed in preference to whey proteins and αs (αsl+αs2)‐casein adsorbed in preference to β‐casein. Transmission electron microscopy showed that the surface layer of fat globule was made up of casein micelles, fragments of casein micelles and a thin layer of protein, possibly whey proteins. Experiments with surface layers that had been dispersed in EDTA showed that the extent of dissociation of caseins followed the order: β‐casein > αs‐casein ≦ K‐casein, suggesting that most of the K‐casein was probably associated directly with the fat surface.
Oxidative Stability of Anhydrous Milkfat Microencapsulated in Whey Proteins
Authors: MOREAU D.L. , ROSENBERG M.
Published: August 2006

The chemical stability was studied on anhydrous milkfat (AMF) encapsulated in whey protein isolate (WPI) and WPI combined with lactose (1:1 w/w WPI/L). AMF‐containing microcapsules, as well as bulk milkfat, were stored at 20°C with light, 40°C without light, and 50°C with and without light for up to 12 mo. Milkfat oxidation was monitored by oxygen uptake in headspace and hexanal accumulation. In all cases, AMF oxidation was significantly limited by microencapsulation in WPI or WPI/L. Whey proteins are effective microencapsulating agents.
Viscoelastic Behavior of Whey Protein Isolates at the Sol‐Gel Transition Point
Authors: LABROPOULOS A.E. , HSU SHAN‐HUI
Published: August 2006

The flow behavior of whey protein isolates (WPI) was studied in systems processed under different conditions. Experiments were undertaken to study effects of heating conditions (temperature/time), pH, solid content, calcium chloride, and guanidinium hydrochloride addition on the gelation of whey protein isolate solutions. The rheological data demonstrated a power‐law frequency dependence of the viscoelastic functions G″ (ω) and G″ (ω) and a frequency‐independent tan δ determined from a multi‐frequency scan of tan δ vs gelling time at the gel point. The power‐law exponents (n) obtained from these dynamic measurements for determining the sol‐gel transition point were between 0.62 and 0.69. Those values suggest a percolation mechanism for the gelation process.
Permeability Properties of Fruit Puree Edible Films
Authors: McHUGH T.H. , HUXSOLL C.C. , KROCHTA J.M.
Published: August 2006

The potential of fruit purees as edible mass transfer barriers was studied. Water vapor and oxygen permeabilities (WVP and O2P) of peach puree films were evaluated at different relative humidities (RH) and temperatures (T). Peach puree was not a good water barrier. Peach and apricot films exhibited lower WVPs than pear and apple films. Calcium addition, RH increases and T decreases resulted in increased WVP values for peach puree edible films. WVPs of peach films were compared with other edible and synthetic films. Peach puree films were good oxygen barriers. RH increases resulted in exponential increases in O2P. Most edible and many synthetic polymers showed higher O2Ps at equivalent conditions.
Occurrence and Flavor Properties of Sinigrin Hydrolysis Products in Fresh Cabbage
Authors: CHIN H.‐W. , ZENG QIAOLING , LINDSAY R.C.
Published: August 2006

Contrary to a published report, allyl isothiocyanate was confirmed as a major volatile sulfur compound along with 1‐cyano‐2,3‐epithiopropane in dichloromethane extracts of freshly disrupted cabbage tissues resulting from thioglucosidase hydrolysis of allyl glucosinolate (sinigrin). Compared to authentic allyl isothiocyanate which had characteristic sharp, black mustard‐like aroma notes, authentic 1‐cyano‐2,3‐epithiopropane had weak, musty, sulfurous, and mustard‐like aromas. Based on calculations of odor units (Uo) using data from the analysis of disrupted cabbage tissues, allyl isothiocyanate would contribute appreciably (to 245 Uo) while 1‐cyano‐2,3‐epithiopropane would not likely contribute notably (<0.8 Uo) to fresh cabbage flavors.
Determination of Sorbic Acid Diffusivity in Edible Wheat Gluten and Lipid Based Films
Authors: REDL A. , GONTARD N. , GUILBERT S.
Published: August 2006

Edible films using wheat gluten as the structural matrix with or without different lipid components and pure lipid films were tested for sorbic acid retention properties. A diffusion mechanism following Fick's first law was identified. An experimental procedure was developed for determining the diffusivity coefficient of sorbic acid in edible films immersed in an aqueous medium. The effect of film composition and temperature was investigated. The diffusion coefficient of sorbic acid in a gluten based film was 7.6 × 10−12 m2/sec. The addition of a lipid component such as acetylated monoglyceride led to a 50% reduction in diffusivity. In a pure lipid film such as beeswax the diffusion coefficient of sorbic acid was 2.7 × 10 −16m 2/sec. The effect of temperature could be described by an Arrhenius type model, with activation energy ranging from 30.0 to 39.8 kJ/mole.
Immersion Chilling and Freezing: Phase Change and Mass Transfer in Model Food
Authors: LUCAS T. , RAOULT‐WACK A.‐L.
Published: August 2006

The influence of immersion chilling and freezing process variables (temperature, concentration, agitation) on phase change and salt gain, was studied on a gelatin gel dipped into a NaCl solution, with particular emphasis on unsteady state (first hour). Under freezing conditions, water loss was <2 g/100g initial gel and salt gain remained low (<1 g/100g initial gel). Salt penetration was hindered by formation of an ice barrier, which was favored by high concentration and low temperature. Under chilling conditions, salt gain was higher (up to 2 g/100g initial gel), and was enhanced when temperature or concentration increased.
Accelerated Postmortem Aging of Beef Utilizing Electronbeam Irradiation and Modified Atmosphere Packaging
Authors: LEE MOOHA , SEBRANEK J. , PARRISH F.C.
Published: August 2006

The combined effects of electron‐beam irradiation and modified atmosphere packaging (MAP) with 25% CO2 and 75% N2 were examined. Steaks from prerigor beef longissimus (lumborum and thoracis) were prepared, placed in MAP, irradiated with 2 kGy, and stored at 15°C or 30°C. Postrigor longissimus steaks from the other half of each carcass were vacuum‐packaged and stored at 2°C. Analysis for tenderness, lipid oxidation, color, and microbial growth were conducted over 2 wk. Aging irradiated prerigor beef at 30°C for 2 days with MAP resulted in similar Warner‐Bratzler shear values as conventional wet aging at 2°C for 7 or 14 days, and steaks did not show discoloration, lipid oxidation, or microbial spoilage.