bluuebunny/crossref_metadata_2025_split huggingface dataset:
Headspace Evaluation of Methanethiol and Dimethyl Trisulfide in Aqueous Solutions of Soy‐protein Isolates
Authors: Boatright W.L. , Lei Q. 
Published: July 2006

ABSTRACT Volatile compounds from 2 samples of aqueous soy‐protein isolates (SPI) (7%) were analyzed using both static and dynamic headspace methods. Based on dynamic headspace analyses, the most powerful odorants were (1) dimethyl trisulfide, (2) methanethiol, (3) hexanal, (4) an unidentified charred, sweaty feet‐like odor, (5) 2‐pentyl furan, (6) 2,3‐butadione, and (7) an unknown burnt‐like odor. The most powerful odorants by static headspace analyses were (1) dimethyl trisulfide, (2) hexanal, (3) methanethiol, and (4) 2‐pentyl furan. Using deuterium labeled DMTS as an internal standard, DMTS was quantified at 60.1 and 45.5 ppb in the SPIs. This corresponds to odor values of 6014 and 4554, respectively. Using a cool, on‐column technique, direct injection of concentrated‐headspace volatiles and solvent‐recovered volatiles with an internal standard of d6‐DMTS detected both methanethiol and DMTS at similar levels as with the traditional injection methods.
Improved Peanut Flour for a Reduced‐Fat Peanut Butter Product
Authors: Lima I.M. , Guraya H.S. , Champagne E.T. 
Published: July 2006

ABSTRACT A commercial peanut flour (12% fat) was mixed with water (30% w/w), homogenized and drum‐dried in a double drum dryer. The drum clearance was adjusted to result in thin dried sheets which on milling resulted in a very fine, single banded particle size flour. The flour was no longer gritty and was used to dilute fat by mixing with full fat (52.5%) paste to obtain a 30% fat reduction in the peanut butter product. Response surface methodology, RSM, was used to optimize drum temperature (T), speed (S), and clearance (C) in order to minimize stickiness and hardness, maximizing oil separation and particle size. Based on surface responses and contour plots, optimum conditions were: T = 135 °C, S = 1 rpm and C = 0.33 mm. Optimum values predicted by RSM for peanut flour particle size, peanut butter stickiness, hardness, and oil separation were: 49.65 μm, 12347 N, 311.4 N and 6.87% respectively. Close agreement between experimental and predicted values was obtained.
Thawing Prior to Cooking Affects Sensory, Shear Force, and Cooking Properties of Beef Patties
Authors: Bigner‐George M.E. , Berry B.W. 
Published: July 2006

ABSTRACT:Patties from 6 commercial formulations were cooked to 71°C from either the frozen state or after thawing for 24 to 27 h at 4 °C to eliminate the pink/red color exhibited when cooked to 71 °C from the frozen state. Thawed patties had shorter cooking times, higher cooking yields, and lower shear force peak load and peak energy values. Patties cooked from the thawed state increased in thickness during cooking, while patties cooked from the frozen state decreased in thickness during cooking. Thawing prior to cooking increased sensory evaluation scores except for patties made with carrageenan. Thawing not only eliminated the problem of pink/red color after cooking but also improved sensory, shear force, and cooking properties of beef patties.
The Effects of Antioxidants on Browning and on Degradation Products Caused by Dehydroascorbic Acid
Authors: Sawamura M. , Nakagawa T. , Katsuno S. , Hamaguchi H. , Ukeda H. 
Published: July 2006

ABSTRACT:The efficiency of L‐cysteine (cysteine) and sodium sulfite as antioxidants was examined in the browning of an aqueous solution of 100 mM dehydroascorbic acid (DHA). The browning was suppressed at 100 mM cysteine and at 40 mM and higher concentrations of sodium sulfite, but it increased in the presence of 10 mM of those agents. These agents did not allow the reduction of DHA to L‐ascorbic acid (AA). These results suggest that the suppression or acceleration of browning is likely to be related to some degraded intermediates of DHA. The two colorless intermediates, which during DHA breakdown eventually transform into browning pigments, were discussed with regard to the browning regulation mechanism.
Headspace Volatiles of Sockeye and Pink Salmon as Affected by Retort Process
Authors: Girard B. , Durance T. 
Published: July 2006

ABSTRACT:Sockeye and pink salmon were canned according to constant and variable temperature retort processes. A total of 102 volatile constituents were detected by gas chromatography‐mass spectrometry. Based on principal component analysis (PRIN) applied to the different classes of volatiles, PRIN1 explained 72.2% of variation and was significant (P < 0.0001) for species differentiation. PRIN2 and PRIN4 extracted smaller variations (14.5% and 3.1%, respectively) but were significant (P < 0.05 and P < 0.01, respectively) for differences in retort regimes. However, sensory panelists did not find flavor differences between retort modes. Olfactometry revealed that aldehydes, sulfurs, and ketones constituted the major volatile classes of aroma‐impact constituents in canned sockeye salmon.
Proteolytic Degradation of Tropical Tilapia Surimi
Authors: Yongsawatdigul J. , Park J.W. , Virulhakul P. , Viratchakul S. 
Published: July 2006

ABSTRACT:Proteolytic degradation of tropical tilapia surimi was biochemically and rheologically characterized to identify a group of proteinase(s) responsible for its textural degradation. Proteolysis of tilapia surimi occurred as the temperature increased and attained the highest activity at 65 °C. Smaller proteins with molecular weight of 116‐97 kDa were noted as a result of myosin heavy chain (MHC) degradation. MHC completely disappeared when incubated at 65 °C for 4 h. Proteolysis was significantly inhibited by soybean trypsin inhibitor (SB) and leupeptin (LE). Storage modulus (G′) of surimi gels mixed with either SB or LE was higher than other inhibitors indicating that serine type proteinase(s) were involved in proteolysis of tropical tilapia surimi.
Microbiological and Color Quality Changes of Channel Catfish Frame Mince During Chilled and Frozen Storage
Authors: Suvanich V. , Marshall D.L. , Jahncke M.L. 
Published: July 2006

ABSTRACT:Microbial counts and color values of channel catfish frame mince were determined during storage at ‐20, 0, and 5 °C. Aerobic plate counts increased from 5.5 to greater than 8 log10 CFU/g by 3 d at 0 and 5 °C. Total coliform counts increased 1 log during refrigerated storage for 5 d. Both microbial populations declined during 3 mo frozen storage. Washed mince was lighter in color, less red, and less yellow than unwashed mince. Color of both mince types did not change during storage. Microbial results suggested that prepared catfish frame mince should be stored no longer than 3 d at 0 to 5 °C. Frozen mince remained acceptable for at least 3 mo at 20 °C. Key Words: catfish, mince, quality, microorganisms, color
Antioxidant Activity of Nontocopherol Hazelnut (Corylus spp.) Phenolics
Authors: Yurttas H.C. , Schafer H.W. , Warthesen J.J. 
Published: July 2006

ABSTRACT:Hazelnuts were investigated for the presence of antioxidant compounds other than tocopherol. Hazelnuts from 2 regions were extracted with methanol:water (2:1; v/v). Extracts were subjected to either acid or alkaline hydrolysis but neither improved the separation quality during high pressure liquid chromatography (HPLC) analysis. Nonhydrolyzed extracts of hazelnut had greater antioxidant activity in comparison to hydrolyzed extracts. The 1st 10 minute eluent in the HPLC had greater antioxidant activity relative to the later eluting fractions. Gallic acid, p‐hydroxyl benzoic acid, caffeic acid and/or epicatechin, sinapic acid, and quercetin were tentatively identified using HPLC.
Moisture Loss and Lipid Oxidation for Precooked Beef Patties Stored in Edible Coatings and Films
Authors: Wu Y. , Rhim J.W. , Weller C.L. , Hamouz F. , Cuppett S. , Schnepf M. 
Published: July 2006

ABSTRACT:Edible/biodegradable wheat gluten (WG), soy protein (SP), carrageenan (CA) and chitosan (CH) films and coatings were used on precooked beef patties. After 3 d of refrigerated storage, no difference was found in moisture loss between WG, SP, and CH film‐wrapped patties and unpackaged patties (control‐A). All coatings were as effective as polyvinyl chloride film (control‐B) in reducing moisture loss. CA film decreased moisture loss but not as effective as control‐B. WG, SP, and CA coatings and CA film reduced thiobarbituric acid‐reactive substances and hexanal values compared to control‐A. WG‐coated patties had lower hexanal values than control‐B samples. WG, SP, and CH films were not effective in controlling lipid oxidation.
Effect of Cottage Cheese Whey Pretreatment and 2‐phase Crossflow Microfiltration/Ultrafiltration on Permeate Flux and Composition
Authors: Martínez‐Hermosilla A. , Hulbert G.J. , Liao W.C. 
Published: July 2006

ABSTRACT:The effect of chemical pretreatment with calcium chloride and ethylene diamine tetraacetic acid (EDTA) in combination with 2‐phase crossflow microfiltration and ultrafiltration was studied. Solutions of untreated and chemically treated whey were microfiltered at 3 flow rates, with 0%, 10%, and 20% air injection. Significant increases (p < 0.05) in flux were found for untreated and EDTA treated whey at 10 L/min when 20% air was applied. Microfiltration permeates also had a higher (p < 0.05) protein concentration at this flow rate when air was used. Ultrafiltration of the microfiltration permeates resulted in no difference (p < 0.05) between the flux of untreated permeate ultrafiltered with 20% air and calcium chloride treated whey permeate with 0% air injection. This suggests that 2‐phase flow with air injection could be used to increase the efficiency of both the microfiltration and ultrafiltration of whey and chemical pretreatment could be minimized.
A Fluorescent Lectin Test for Mold in Raw Tomato Juice
Authors: Potts S.J. , Slaughter D.C. , Thompson J.F. 
Published: July 2006

ABSTRACT:Fungal (mold) contamination is an important indicator of low quality raw product in the processing tomato industry. A quantitative lectin assay was developed that was less expensive, faster, and more precise than the industry standard Howard mold count. This assay, based on a fluorescent‐labeled lectin isolated from wheat germ, had a selective affinity for the chitin in fungal cell walls. Assay values were correlated with mold contamination for 4 fungal species: Alternaria alternata (r2= 0.91), Cladosporium herbarum (r2= 0.75), Fusarium oxysporum (r2= 0.97), and Stemphylium botryosum (r2= 0.99). Combining all 4 species, the lectin assay had a strong correlation (r2= 0.76) with a linearized Howard mold count.
Evaluation of Genistin and Genistein Contents in Soybean Varieties and Soy Protein Concentrate Prepared with 3 Basic Methods
Authors: Pandjaitan N. , Hettiarachchy N. , Ju Z.Y. , Crandall P. , Sneller C. , Dombek D. 
Published: July 2006

ABSTRACT:The contents of genistein and its β‐glucoside form, genistin, in 13 soybean varieties were determined. Soybean variety (Var‐1) with high genistein and genistin contents (0.019 mg/g and 0.420 mg/g) was used to evaluate the 3 basic soy protein concentrate (SPC) production methods (acid, alcohol, and hot‐water leach) for genistin and genistein retention on a total weight basis. The acid leach method gave the highest total genistin + genistein content (0.742 mg/g) compared to SPCs prepared with the hot‐water leach method (0.671 mg/g), and the alcohol leach method (0.070 mg/g). The acid leach, hot‐water leach and alcohol leach methods had 20.3%, 24.2%, and 91.2% losses of total genistin + genistein, respectively.
Ability of Various Dairy Proteins to Reduce Pink Color Development in Cooked Ground Turkey Breast
Authors: Slesinski A.J. , Claus J.R. , Anderson‐Cook C.M. , Eigel W.E. , Graham P.P. , Lenz G.E. , Noble R.B. 
Published: July 2006

ABSTRACT:Dairy proteins were evaluated for their ability to reduce pink color in ground turkey samples. Sodium nitrite and nicotinamide were added to induce pink color formation. Nonfat dry milk (NFDM) and 1 of the whey protein concentrates (WPC) reduced CIE a* values in samples containing 10 ppm sodium nitrite. All of the dairy proteins tested reduced CIE a* values in nicotinamide‐treated samples. In samples prepared without nicotinamide or nitrite, only WPC reduced CIE a* values, while the other proteins tested had no effect or increased redness. NFDM or specific WPC proteins could be used to reduce the pink color defect and increase yield.
Response Surface Methodology for Reduction of Pinking in Cooked Turkey Breast Mince by Various Dairy Protein Combinations
Authors: Slesinski A.J. , Claus J.R. , Anderson‐Cook C.M. , Eigel W.E. , Graham P.P. , Lenz G.E. , Noble R.B. 
Published: July 2006

ABSTRACT:Nonfat dry milk (NFDM), sodium caseinate (SC), whey protein concentrate (WPC), and combinations of each were evaluated for abilities to reduce pink color development in cooked, ground, uncured turkey breast. Protein treatments were also evaluated in the presence of pink‐color‐generating ligands (nicotinamide, 1%, sodium nitrite, 10 ppm, and sodium nitrate, 50 ppm) with and without ethylenedinitrilo‐tetraacetic acid disodium salt (200 ppm). NFDM and WPC at levels as low as 1.5% were effective in reducing CIE a* values (P < 0.05) regardless of ligand treatment; SC was not. EDTA reduced pink color within all protein and ligand treatments. Poultry producers can reduce pink color development in further‐processed products by selective addition of dairy proteins.
Preservation of Microstructure in Peach and Mango during High‐pressure‐shift Freezing
Authors: Otero L. , Martino M. , Zaritzky N. , Solas M. , Sanz P.D. 
Published: July 2006

ABSTRACT:A histological technique was used to evaluate modifications on the microstructure of peach and mango due to classical methods of freezing and those produced by high‐pressure‐shift freezing (HPSF). With the high‐pressure‐shift method, samples are cooled under pressure (200 MPa) to ‐20°C without ice formation, then pressure is released to atmospheric pressure (0.1 MPa). The high level of supercooling (approximately 20°C) leads to uniform and rapid ice nucleation throughout the volume of the specimen. This method maintained the original tissue structure to a great extent. Since problems associated with thermal gradients are minimized, high‐pressure‐shift freezing prevented quality losses due to freeze‐cracking or large ice crystal presence.
Oil Absorption During Frying of Frozen Parfried Potatoes
Authors: Aguilera J.M. , Gloria‐Hernandez H. 
Published: July 2006

ABSTRACT:A tracer method was used to assess the uptake of oil by commercial frozen parfried potatoes fried (180 °C, 150 s) in colza oil (CO) involving a short post‐frying immersion in hot coconut fat (CF). CO and CF were determined directly in the crust by differential scanning calorimetry (crystallization temperature and enthalpy −42.7 °C/50 J/g and 10 °C/71 J/g, respectively). Oil uptake by the crust during frying in CO or CF was similar (average 25.3%). Potato samples transferred immediately after frying in CO to the CF bath had most of the CO absorbed replaced by CF after a 10 s post‐frying, meaning that CO was readily accessible in the crust structure. Samples fried in CO and cooled for up to 60 s before transfer to hot CF showed only partial replacement of CO. Oil wetting the surface of the sample at the end of frying was estimated as 70 to 80% of the total oil uptake. Formation of the crust (frying time > 1 min) was required for oil to migrate into intercellular spaces that are dynamically formed during frying and thus accessible to CF and solvents.
Effect of High Pressure Processing at Different Temperatures on Protein Functionality of Porcine Blood Plasma
Authors: Parés D. , Saguer E. , Toldrà M. , Carretero C. 
Published: July 2006

ABSTRACT:Samples of porcine blood plasma were treated by high hydrostatic pressure at 450 MPa, for 15 min at 5 and 40 °C. The effects of these treatments on the structure and the solubility of plasma proteins and on the water‐holding capacity, the strength, and the microstructure of heat‐induced gels were compared.Although the calorimetric and solubility data showed that structural protein modifications had occurred as a consequence of pressurization, the functional properties of heat‐induced gels were not significantly affected. The water‐holding capacity and the hardness of the gels from pressurized plasma were similar to those from the nontreated plasma (control). There were no differences between the microstructure of pressurized plasma gels related to the processing temperature, but their appearance was always different from that of the untreated plasma gels.
Efficacy of the Antimicrobial Peptide Nisin in Emulsifying Oil in Water
Authors: Bani‐Jaber A. , McGuire J. , Ayres J.W. , Daeschel M.A. 
Published: July 2006

ABSTRACT:Nisin is an amphiphilic, antimicrobial peptide that has found application as a preservative in the food industry. Evaluation of nisin as an emulsifier was accomplished by measuring its ability to stabilize dispersed oil droplets in water. This was achieved by monitoring the time‐dependent electrical conductivity of the dispersion. Nisin solutions at concentrations of 0.1, 0.5, 1, 5, and 10 mg/ml were used to prepare emulsions, by homogenization of a volume of nisin solution and corn oil. While nisin showed significant emulsifying capacity in comparison to Tween® 80 and β‐casein, its emulsifying properties were found to be highly concentration‐ and pH‐dependent.
Quality Comparison of Hydroponic Tomatoes (Lycopersicon esculentum) Ripened On and Off Vine
Authors: Arias R. , Lee T.‐C. , Specca D. , Janes H. 
Published: July 2006

ABSTRACT:There is a general belief that the quality of tomatoes ripened on vine is better than tomatoes ripened off the vine, influencing among other parameters, the price of this commodity. We compared the quality of hydroponic tomatoes ripened on and off vine by chemical, physical, and sensory evaluation to find what attributes are affected and to what extent. Lycopene, β‐carotene, total and soluble solids, moisture content, ascorbic acid, acidity, pH, texture, and color were analyzed. Tomatoes ripened on vine had significantly more lycopene, β‐carotene, soluble and total solids, higher a* and lower L*, and were firmer. However, a 100‐judge panel rated only the color and overall liking of the vine‐ripened tomatoes as more intense than the fruit ripened off vine. Therefore, the chemical and physical differences were mostly not large enough to influence the panelist's perception. The characterization of tomatoes ripened on and off vine may help to guide post‐harvest handling and treatment and to improve the quality of tomatoes ripened off vine.
Detection of Residues of Genetically Modified Soybeans in Breaded Fried Turkey Cutlets
Authors: Stram Y. , Vilk A. , Klinger I. 
Published: July 2006

ABSTRACTThe presence of genetically modified organisms (GMOs) in food products is usually ascertained by the polymerase chain reaction (PCR) or nested PCR if sensitivity has to be increased. Since most, if not all, GMO products are of plant origin, the target sequences are the 35S promoter or NOS terminator. The extreme sensitivity of nested PCR can be misleading if the results are not interpreted correctly, since contamination of non‐GMO products with residual amounts of GMO may be positive. We report that breaded turkey breast cutlets labeled as containing GMO soybean products were actually prepared from wheat flour that had been contaminated with transgenic soybean.
Effects of Antioxidants and Packaging on Lipid and Cholesterol Oxidation and Color Changes of Irradiated Egg Yolk Powder
Authors: Du M. , Ahn D.U. 
Published: July 2006

ABSTRACTElectron‐beam irradiation significantly increased the oxidation of docosahexaenoic, arachidonic and linolenic acids, and cholesterol in egg yolk powder. Arachidonic‐acid content was reduced from 4.58% to 3.07%, and total cholesterol oxidation products increased from 11 μg/g to 467 μg/g after 5.0 kGy irradiation. Further oxidation occurred during storage. Vacuum‐packaging significantly reduced, but the use of antioxidants had no effect on the fatty acids and cholesterol oxidation during irradiation and storage. Irradiation caused color change in egg yolk powder. The Hunter color a‐ (redness) values decreased from 3.89 to 2.48 and 1.94, respectively, after 2.5 and 5.0 kGy irradiation. Hunter color a‐ and b‐values were also decreased during storage. Vacuum‐packaging and antioxidants significantly reduced color changes.
Effect of Temperature of Milk Acidification on Rennet Gel Properties
Authors: Renault C. , Gastaldi E. , Cuq J.L. , De La Fuente B. Tarodo 
Published: July 2006

ABSTRACTChanges in mineral solubilization and rennet reaction rate were investigated after decreasing milk pH to 6.3 by lactic acid addition at a temperature of acidification (TAC) of 25 or 35 °C with a short period of equilibration. With increasing TAC, casein micelles retained higher amounts of Ca and P, and at a given temperature of coagulation, rennet clotting time was increased, and dG'/dt decreased. This effect was confirmed by the microstructure of casein micelles during the first stage of the enzymic coagulation indicating that the aggregation of para‐k‐casein was observed later at higher TAC. The effect of TAC on rennet milk gel formation could be attributed to the nature of the micellar mineral content and the conformational state of casein micelles before rennet action.
High Hydrostatic Pressure for Accelerating Ripening of Goat's Milk Cheese: Proteolysis and Texture
Authors: Saldo J. , Sendra E. , Guamis B. 
Published: July 2006

ABSTRACTHigh hydrostatic pressurization is proposed for cheese ripening acceleration. Several treatments were used for accelerating ripening of goat's milk cheese: 50 MPa / 72 h, 400 MPa / 5 min and 400 MPa / 5 min followed by 50 MPa / 72 h all at 14 °C. Moisture content and pH were higher in 400 MPa treatments compared to the others. By measuring proteolysis indexes, 400 MPa treatments were found to accelerate ripening (14 d in contrast to 28 d conventionally) due to enhanced enzyme activity from inoculated starter culture. Sensory analysis indicated bitter notes in the accelerated ripened cheese. Pressurized cheeses were less crumbly and more elastic than control.
Cholesterol and Lipid Oxidation Products in Cooked Meat as Affected by Raw‐Meat Packaging and Irradiation and by Cooked‐Meat Packaging and Storage Time
Authors: Du M. , Nam K.C. , Ahn D.U. 
Published: July 2006

ABSTRACT:Aerobic packaging significantly increased cholesterol oxidation products (COPs) and thiobarbituric acid reactive substances (TBARS) in cooked turkey, pork, and beef patties after 7‐d storage, but vacuum packaging was very effective in preventing cholesterol and lipid oxidation. Packaging of meat after cooking had a much stronger effect on COPs formation than before cooking, and irradiation had only a minor effect. The amount of total COPs correlated well with TBARS in cooked meat. Turkey had the highest rates of COPs and TBARS formation and beef had the lowest rates after 7‐d storage, which were closely related to the fatty acid composition of meats. 7a‐hydroxycholesterol, 7p‐hydroxycholesterol, and 7‐ketocholesterol were the major COPs detected in all 3 cooked meat patties.
Monitoring Chemical Changes in Some Foods Using Fourier Transform Photoacoustic Spectroscopy
Authors: Irudayaraj J. , Sivakesava S. , Kamath S. , Yang H. 
Published: July 2006

ABSTRACT:The potential of Fourier transform infrared photoacoustic spectroscopy (FTIR‐PAS) to characterize some common foods was studied. Lard, peanut butter, mayonnaise, and whipped topping were heated to 60 and 90 °C separately, and the spectra were obtained periodically for a period of up to 32 and 16 d, respectively. Key bands in the mid‐infrared spectral region were examined to monitor changes presumably due to lipid oxidation. Spectral data were analyzed, using principal component analysis (PCA) correlation, and linear discriminate analysis (LDA) techniques with Mahalanobis distances to estimate the extent of deterioration attributable to oxidation. The PAS was found to be simple, rapid, and nondestructive. It required limited sample preparation, and proved highly desirable for analyzing low‐moisture samples.