bluuebunny/crossref_metadata_2025 huggingface dataset:
Volatile Profiles of Raw and Cooked Turkey Thigh as Affected by Purge Temperature and Holding Time Before Purge
Authors: Ahn D. U. , Jo C. , Olson D. G.
Published: July 2006

Effects of purge temperature and sample holding time on volatile profiles were determined using a purge‐and‐trap/gas chromatography unit with autosampler. Purge temperature and sample holding time before purge influenced the profile of volatiles in raw and cooked meat. The most notable changes were observed when the purge temperature was increased from 60°C to 80°C. Many of the changes in volatiles were related to oxidation of lipids. We recommend that meat should be purged at 40°C or 50°C (temperature at sensory analysis) to minimize heat‐induced production of volatiles and sample purge should be done within 3h after sampling to reduce oxidative changes during sample holding time.
Color Stability of Strawberry Jam as Affected by Cultivar and Storage Temperature
Authors: García‐Viguera C. , Zafrilla P. , Romero F. , Abellán P. , Artés F. , Tomás‐Barberán F.A.
Published: July 2006

The stability of three strawberry cultivars was evaluated for changes in jam color quality during processing and storage at 20°, 30° and 37°C for 200 days. Anthocyanin content was determined by HPLC. The effect of cultivar, processing and storage on jam pigments, instrumental color (L*, a*, b*) and consumer preference were also determined. ‘Oso grande’ jam had the lowest anthocyanin concentration (110 mg/g f.w), higher monomeric pigment degradation during processing and storage, highest pH, least desirable color score from the sensory panel and shortest shelf‐life. Similarities were found between jams prepared with ‘Chandler'and Tudla’ cultivars, as well as initial differences in total anthocyanin concentrations (195 and 130 mg/g f.w.).
Butter Microencapsulation as Affected by Composition of Wall Material and Fat
Authors: Pauletti M. S. , Amestoy P.
Published: July 2006

A second‐order central composite design was used to evaluate the influence of capsule wall materials on yield (MEY) and efficiency (MEE) of the spray‐drying butter microencapsulation process. Variables were: maltodextrin concentration of wall material, emulsion solids content, and butter fat concentration related to emulsion solids. All powders showed no stickiness. MEY was always >85% and wall material composition had little influence. MEE was strongly affected by butter concentration. MEE increased as emulsion solids increased, reaching 95% at 22% of emulsion solids. Best results, MEY = 97.22% and MEE = 91.72% were obtained spray‐drying an emulsion of 30 % total solids (3.6% maltodextrin and 40% butter).
Moisture Sorption Characteristics of Composite Foods Filled with Chocolate
Authors: Kim S. S. , Kim S. Y. , Kim D. W. , Shin S. G. , Chang K. S.
Published: July 2006

We compared the moisture sorption isotherms (MSI's) and their temperature dependence of composite foods with those of crust and filling. The MSI were determined on cracker, cookie, chocolate, and two types of composite foods such as CFI (cracker/chocolate/cracker) and CF2 (cookie/chocolate/cookie) at 20,30, and 40°C and 11–85% relative humidity, and fitted into the Guggenheim‐Anderson‐de Boer (GAB) equation. Chocolate had the lowest monolayer (mo) value, equilibrium moisture content (EMC), and sorption energy levels, followed by cookie and cracker. The CFI had higher EMC values and sorption energy than CF2. The GAB mo values and C1 values decreased with temperature, while C2 values increased with temperature.
Protein Structure and Network Orientation in Edible Films Prepared by Spinning Process
Authors: Rampon V. , Robert P. , Nicolas N. , Dufour E.
Published: July 2006

Biodegradable film was prepared by spinning soy protein isolate in a coagulating buffer. Tensile properties and molecular structure of the film were investigated. FTIR results showed that no secondary structure differences appeared between protein film and isolate. The protein aggregation observed in the isolate was increased by the immersion and dispersion of the isolate in the isoelectrical pH buffer. Fluorescence spectroscopy did not demonstrate tertiary structural differences between isolate and film. Stretching the film in two orthogonal directions did not result in significant differences of tensile properties (p≤0.05), indicating no network orientation. Therefore, the film structure could be the result of a random aggregation of proteins displaying a globular shape.
Heat and Mass Transfer Coefficients in Drying of Starch Based Food Systems
Authors: Irudayaraj J. , Wu Y.
Published: July 2006

Experiments were conducted to measure the temperature and moisture content of starch and starch‐fructose samples during drying. A two‐dimensional finite element model was developed. An exhaustive parameter estimation technique was applied in conjunction with the model and drying data to estimate the moisture filtration coefficient kp and the surface heat and mass transfer coefficients, hq and hm. Minimization of the deviation between experimental and simulation data resulted in a kp value of 0.51*10−7 kg.m/N.h and 0.52*10−7 kg.m/N.h for the starch and starch‐fructose samples. Corresponding values of hq were 15.8 W/m2K and 21.2 W/m2K and that of hm were 1.12*10−6 m/s and 0.94*10−6 m/s respectively.
Degradation Kinetics of (−)‐Epigallocatechin Gallate as a Function of pH and Dissolved Oxygen in a Liquid Model System
Authors: Zimeri J. , Tong C.H.
Published: July 2006

The degradation kinetics of (−)‐epigallocatechin gallate (EGCG) as a function of pH (4 to 7) and dissolved oxygen concentration (0 to 7.59 mg/L) in citrate buffer solutions were determined. EGCG degradation followed a pseudofirst order kinetic model, regardless of the conditions when the fractional conversion technique was applied for data reductions. The rate constant increased log‐linearly with respect to both pH and dissolved oxygen concentration. The temperature dependence of the rate constant was adequately modeled by the Arrhenius equation with an average activation energy of 18.7 ± 1 kcal/mol. A mathematical model that relates the rate constant to temperature, pH, and dissolved oxygen concentration was developed and validated. These results can help predict losses of EGCG during processing and/or storage.
Functional Properties of Milk‐Egg Mixtures
Authors: Matringe E. , Tan Luu R. Phan , Lorient D.
Published: July 2006

We used an experimental design (Scheffe simplex‐centroid design) to examine ingredient interactions in food protein mixtures and their effects on functional properties. A defined and limited number of milk, albumen, and egg yolk blends were made and evaluated for heat gelation properties and for emulsifying and foaming capacity and stability. The method accounted for nonlinear interactions between the ingredients. Synergistic effects were revealed on heat gelation and emulsifying properties but antagonistic effects for foaming properties were noted.
Selective Increase in Conjugated Linoleic Acid in Milk Fat by Crystallization
Authors: Kim Y.‐J. , Liu R.H.
Published: July 2006

The objective of this work was to obtain concentrated natural conjugated linoleic acid (CLA) from milk fat by urea complexation. Milk fat was hydrolyzed to provide free fatty acids, followed by crystallization with different ratios of urea. The profiles of fatty acids achieved by urea complexation showed different fatty acid compositions. Long‐chain unsaturated fatty acids, including CLA, were concentrated after crystallization. The highest amount of CLA was achieved by the first crystallization with a 2:1 urea/fatty acid ratio. CLA was elevated 2.5‐fold. The C18:1/C18:0 fatty acid ratio was increased from 2 to 51, and stearic acid (C18:0) was decreased 17‐fold.
Formation of α‐terpineol in Citrus Juices, Model and Buffer Solutions
Authors: Haleva‐Toledo E. , Naim M. , Zehavi U. , Rouseff R.L.
Published: July 2006

The formation of α‐terpineol from its putative precursors in citrus juice (d‐limonene and linalool) was investigated in juice, buffers and model solutions. α‐Terpineol content was higher in commercial lemon juice than in orange or grapefruit juices. Its content exceeded its taste threshold of 2.5 mg/L in orange juice stored for 1 month at 35 °C. During storage of homogenized model solutions fortified with d‐limonene or linalool, α‐terpineol was simultaneously formed and degraded, especially at 45 °C and its formation was strongly dependent on pH. Linalool was a more reactive substrate than limonene for α‐terpineol formation; the protonation in linalool was faster than in limonene. However, since there was more limonene than linalool in citrus juices, a‐terpineol appeared to have been formed to about the same extent from both precursors.
HMF Formation during Heat‐treatment of Milk‐type Products as Related to Milkfat Content
Authors: Morales F.J. , Jiménez‐Pérez S.
Published: July 2006

Homogenized lactose/caseinate model systems and milk with different fat content were heated at 110 to 150 °C for up to 30 min. Free and total hydroxymethylfurfural (HMF) were measured by reverse‐phase high‐performance liquid chromatography. Multifactor analysis of variance was applied to determine whether milkfat content contributed to free and total HMF formation. There was a negative effect of milkfat on the formation of total HMF in both systems. However, free HMF formation was promoted by higher milkfat content in milk, but not in the lactose‐caseinate model. Milkfat affected also the free and total HMF formation in commercial pasteurized milk, ultra heat‐treated milk, and bottle‐sterilized milk.
Physical and Molecular Properties of Egg‐white Lipid Films
Authors: Handa A. , Gennadios A. , Hanna M.A. , Weller C.L. , Kuroda N.
Published: July 2006

Polyethylene glycol‐plasticized films were cast from alkaline (pH 11.25), heated (45 °C for 20 min), aqueous egg white (EW) solutions, with or without (10% or 20% w/w of EW) milkfat (two fractions), oleic acid, or egg yolk lysophospho‐lipid (LPL). The lipids did not reduce (P > 0.05) film water vapor permeability. Oleic acid increased (P < 0.05) tensile strength and elongation, and surface sulfhydryl group (SH) concentrations in EW solutions. Oleic acid probably increased negative charges on EW proteins, unfolding protein chains, and exposing SH groups. LPL also slightly increased (P < 0.05) surface SH concentrations in non‐heated mixtures. Electrophoretic patterns suggested oleic acid interactions with ovalbumin, ovotransferrin, and lysozyme. No lysinoalanine was in film‐forming mixtures based on lysine measurements.
Effects of Eubacterium coprostanoligenes and Lactobacillus on pH, Lipid Content, and Cholesterol of Fermented Pork and Mutton Sausage‐Type Mixes
Authors: Madden U.A. , Osweiler G.D. , Knipe L. , Beran G.W. , Beitz D.C.
Published: July 2006

Pork and mutton sausage‐type mixes produced using Eubacterium coprostanoligenes with or without Lactobacillus as starter culture showed changes in pH, cholesterol and lipid content. Viability of E. coprostanoligenes was assessed by culturing samples from each treatment and analyzing for coprostanol, a cholesterol metabolite. The pH and/or cholesterol decreased (P < 0.05) in the sausage‐type mixes inoculated with E. coprostanoligenes or Lactobacillus or their combinations. Variability in lipid content was observed among and within treatments. Very low (6.2 μg/g dry matter) concentrations of coprostanol were produced in sausage‐mixes and cultures except when inoculated with 2.0 g of E. coprostanoligenes (from 8.2 to 130.6 μg/g dry matter).
Salt‐free Miso Fermentation Using Ethanol, Sugars, and Polyols
Authors: Chiou R.Y.‐Y.
Published: July 2006

Steam‐cooked soybeans mixed with rice koji (2:1, w/w) were ground into a fine paste, combined with NaCl or sucrose, and supplemented with ethanol for miso fermentation at 28 °C for 8 wk. In products containing the same concentrations of NaCl and sucrose, proteolytic activities decreased with an increase in ethanol concentration. At the same level of ethanol (7.5% or 15%), protein hydrolysis was highest in products containing 12.5% sucrose and 0% NaCl and lowest in products containing 0% sucrose and 12.5% NaCl. NaCl enhanced and sucrose reduced the effects of ethanol on inhibition of koji proteases. A salt‐free fermentation was achieved using 15% ethanol and 12.5% sucrose. When sucrose (12.5%) was substituted by glucose, fructose, sorbitol, or glycerol and supplemented with 15% ethanol, prevention of protease inactivation by ethanol was similar to that with sucrose.
Use of Artificial Neural Network to Predict Temperature, Moisture, and Fat in Slab‐Shaped Foods with Edible Coatings During Deep‐Fat Frying
Authors: Mittal G.S. , Zhang J.
Published: July 2006

ABSTRACT: An artificial neural network (ANN) was developed to predict heat and mass transfer during deep‐fat frying of infinite slab‐shaped foods coated with edible films. Frying time, slab half‐thickness, film thickness, food initial temperature, oil temperature, moisture diffusivity of food and film, fat diffusivity through food and film, thermal diffusivity of food, heat transfer coefficient, initial moisture content of food, and initial fat content of food (mfo) were inputs. Temperature at the center (T1), average temperature (Tave), fat content (mfave), and moisture content (mave) of food were outputs. Four ANNs with 50 nodes each in 2 hidden layers with learning rate = 0.7 and momentum = 0.7 provided most accurate outputs, that is maximum absolute errors for T1 and Tave were < 1.2 °C, < 0.004 db for mave, and < 0.003 db for mfave. The predictions of mf varied linearly with mf.
Quality Evaluation of Edible Film‐Coated Chicken Strips and Frying Oils
Authors: Holownia K.I. , Chinnan M.S. , Erickson M.C. , Mallikarjunan P.
Published: July 2006

ABSTRACT: Methyl cellulose (MC) and hydroxypropylmethylcellulose (HPMC) edible film materials were applied to marinated whole chicken strips either prior to breading, after breading, or were incorporated in the breading. Subsequently, the influence of an edible film's location relative to the crust on fried food product quality and the quality of the frying oil were determined. Films applied to chicken strips prior to the breading had fried crusts with higher fat and lower moisture levels. Decreased degradation of frying oils was recorded when product coated with HPMC (food grade E4M) films had been fried compared to non‐coated product. It is postulated that these edible films hindered the migration of moisture and acetic acid into the frying oil and this activity was responsible for reduced free fatty acid generation in those oils used to fry the coated products.
Physicochemical Properties of Frozen Red Hake (Urophycis chuss) Mince as Affected by Cryoprotective Ingredients
Authors: Lian P.Z. , Lee C.M. , Hufnagel L.
Published: July 2006

ABSTRACT: Effects of alginate, iota‐carrageenan, soy protein concentrate (SPC), sodium tripolyphosphate (STPP), and sorbitol on physicochemical and sensory properties of red hake mince stored at −20 °C for 17 wk were investigated. The addition of 0.4% alginate, 4% sorbitol, and 0.3% STPP kept the mince from hardening and improved its dispersibility during mixing. This is believed to be a result of reduced protein denaturation as evidenced by higher levels of water, salt, SDS‐soluble proteins, and higher free sulfhydryl contents than the untreated control mince, which hardened with compact texture and exhibited considerable syneresis. Alginate appears to be responsible for preventing muscle fiber interaction through electrostatic repulsion and chelating Ca2+, thus improving dispersibility. Sorbitol and STPP with or without SPC and iota‐carrageenan did not improve the dispersibility.
Molecular Composition of Onion Pectic Acid
Authors: MATSUURA Y. , MATSUBARA K. , FUCHIGAMI M.
Published: July 2006

ABSTRACT: Pectin was extracted, then pectic acid was purified without autolysis. It contained 93.7% uronic acid and 6.3% neutral sugar. Using exopolygalacturonase, exopolygalacturonate lyase and endopolygalacturonase, the molecular composition of onion pectic acid was determined; the proportion of galacturonic acid residue from the nonreducing end to rhamnogalacturonan (RG) was 9.7%, while that of the reducing end to RG was 46.7%. From RG to RG, the proportion of galacturonic acid residue was 41.0%, and the RG region was 2.6%.
Partial Purification and Characterization of Chinook Salmon (Oncorhynchus tshawytscha) Calpains and an Evaluation of Their Role in Postmortem Proteolysis
Authors: Geesink G.H. , Morton J.D. , Kent M.P. , Bickerstaffe R.
Published: July 2006

The involvement of calpains in the proteolysis of salmon muscle during refrigerated storage was investigated. Salmon m‐calpain and μ‐calpain were purified and partially purified, respectively. Salmon μ‐calpain had similar calcium requirements and specific activity against casein as ovine m‐calpain. Salmon μ‐calpain had similar calcium requirements as ovine μ‐calpain but a lower specific activity against casein than ovine μ‐calpain. Autolysis patterns of both calpains differed from those of ovine calpains, and their activities were less than those of mammalian muscles. Calpastatin activity was relatively high and comparable to that of bovine muscles. Little proteolysis and fiber fragmentation resulted during refrigerated storage. However, proteolysis could be reproduced by incubation of myofibrils with m‐calpain.
Apple Cultivar and Maturity Affect Haze‐Active Protein and Haze‐Active Polyphenol Concentrations in Juice
Authors: Siebert K.J. , Lynn P.Y.
Published: July 2006

Juices were prepared from single apple cultivars in 3 crop years. The levels of haze‐active (HA) protein and HA polyphenol were much more similar in 1997 and 1998 than in 1996. Fuji had by far the highest HA protein while Spartan, Jonagold, and Monroe were intermediate. HA polyphenol levels were less consistent, but Empire, Liberty, and Monroe were low, and Jonamac, Jonagold, Golden Delicious, Cortland, and Ida Red were intermediate. The highest HA polyphenol was found in Rome. During fruit maturation, HA protein tended to increase while HA polyphenol declined. This led to a distinct tendency toward a lower HA polyphenol/HA protein ratio with time.
Quality Improvement of Mackerel Surimi with NADPH‐Sulfite Reductase from Escherichia coli
Authors: Wu J. , Li C.‐Y. , Ho M.‐L. , Jiang S.‐T.
Published: July 2006

The application of NADPH‐sulfite reductase, produced from Escherichia coli, on mackerel surimi was investigated. The activity of this reductase was very stable. There was about 70%, 80%, and 90% activity left even after 8–wk storage at 25 °C and 12–wk storage at 4 or ‐30 °C, respectively. Increase in mackerel‐surimi gel properties containing reductase was consistent with the amounts of reactive sulfhydryl groups detected. SDS‐PAGE indicated that NADPH‐sulfite reductase could reconstitute myosin heavy‐chain and increase soluble actomyosin. From the data obtained, E. coli NADPH‐sulfite reductase effectively improved the gel properties of mackerel surimi.
Functionality Changes in Oxidatively/Antioxidatively Washed Beef‐Heart Surimi During Frozen Storage
Authors: Parkington J.K. , Xiong Y.L. , Blanchard S.P. , Xiong S.
Published: July 2006

Beef‐heart surimi prepared using 4 washing solutions (sodium phosphate buffer alone, buffer+NaCl, buffer+propyl gallate, and buffer+sodium tripolyphosphate) and mixed with cryoprotectants was stored at 29°C and analyzed periodically up to 12 mo. All samples showed increases in gelling capacity during storage, corresponding to oxidative changes in proteins (carbonyls, hydrophobicity). Emulsifying activity of surimi, however, did not change during storage. No major differences were found between washing conditions, but propyl gallate‐washed surimi tended to have the least oxidation and least increase in gel elasticity. Overall, frozen storage not only preserved the shelf life but also enhanced gelation of beef‐heart surimi washed with these solutions.
Headspace Evaluation of Methanethiol and Dimethyl Trisulfide in Aqueous Solutions of Soy‐protein Isolates
Authors: Boatright W.L. , Lei Q.
Published: July 2006

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Thermostability of Hen Egg Yolk Granules: Contribution of Native Structure of Granules
Authors: Anton M. , Denmat M. Le , Gandemer G.
Published: July 2006

ABSTRACT: To understand why protein granules resist heat treatment, we measured denaturation, viscosity, and solubility of heated native and disrupted granules and estimated the effect on their emulsifying ability. Granule disruption by sodium chloride caused protein solubility to drop dramatically and viscosity to rise sharply above 72° C. Solubility of native granules was unaffected by heat, and viscosity increased slightly. Electrophoresis revealed that, whatever the granules structure, low‐density lipoproteins (LDL) and α‐high‐density lipoproteins (α‐HDL) were denatured, whereas phosvitin and β‐HDL were resistant to heat. Disrupted granules provided weaker emulsifying ability than native granules. The structure of native granules cannot prevent protein denaturation but can avoid aggregation of LDL and α‐HDL from different granules.
Detection of Residues of Genetically Modified Soybeans in Breaded Fried Turkey Cutlets
Authors: Stram Y. , Vilk A. , Klinger I.
Published: July 2006

The 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

Electron‐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

Changes 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

High 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.
Effect of Cloud Particle Characteristics on the Viscosity of Cloudy Apple Juice
Authors: Genovese D.B. , Lozano J.E.
Published: July 2006

ABSTRACT: Particle size, shape, and volume fraction as well as soluble pectin content and electro‐viscous effects on cloudy apple juice viscosity were investigated. Particle characteristics were micrographically determined by electron microscopy. More than 2300 particles were digitalized and statistically analyzed. Cloudy apple juice resulted in a suspension of irregular shape particles ranging from 0.25 to 5 μm in size. A 10 °Brix juice had a particle volume fraction of φ0= 3.93 ∞ 10‐3. Relative viscosity values were fitted to the generalized Sudduth equation. Intrinsic viscosity resulted 5.8 times greater than the theoretical value predicted by Einstein (α= 2.5). This was attributed to the first electro‐viscous effect. Results also indicate that the effect of particle non‐sphericity on cloudy apple juice viscosity can be neglected. Soluble pectin was found to increase juice viscosity significantly. Combined effects result in a strong linear increase of relative viscosity.
Improvement of the Sensory Properties of Dry Fermented Sausages by the Superficial Inoculation and/or the Addition of Intracellular Extracts of Mucor racemosus
Authors: Bruna J.M. , Fernández M. , Hierro E.M. , Ordóntez J.A. , de la Hoz L.
Published: July 2006

ABSTRACT: The effect of inoculation of the “salchichón” (dry fermented sausage) surface with an atoxigenic, proteolytic, and lipolytic strain of Mucor racemosus and/or the addition of a intracellular extract of the same mold on the ripening process was studied. Four batches of salchichón were manufactured: control, superficially inoculated, added with intracellular extract, and a combination of both treatments. Superficial mold modified the amino and free fatty acid contents, volatile compounds, and sensory properties. Intracellular extract degraded free amino acids, producing a rise in ammonia and volatile compounds. Both treatments combined improved significantly the sensory properties, which were given scores higher than control sausages at the end of ripening.
Germination, Growth, and Toxin Production of Nonproteolytic Clostridium botulinum as Affected by Multiple Barriers
Authors: Elliott P.H. , Schaffner D.W.
Published: July 2006

ABSTRACT The effect of combinations of pH (6.5, 5.75), NaCl (0.25,1.75%), and incubation temperatures (7,13 °C) on spore germination, outgrowth, and time to toxicity of nonproteolytic Clostridium botulinum was examined in a broth system. Spores of four toxin type E and nonproteolytic type B were inoculated (104/ml) into Tryptone Peptone Glucose Yeast Extract (TPGY) broth. Cultures were monitored for three weeks, or until toxin was detected. A modified FSIS‐amplified ELISA (comparable in sensitivity to the mouse bioassay) was used to screen cultures for neurotoxin. Combinations of the most inhibitory level for each barrier reduced the degree and rate of germination, the lag and growth rate of vegetative cells, and the time to toxicity.
Bihon‐Type Noodles from Heat‐Moisture‐Treated Sweet Potato Starch
Authors: Collado L.S. , Mabesa L.B. , Oates C.G. , Corke H.
Published: July 2006

ABSTRACT Sweet potato starch (SPS) has limited uses in the Philippines, but modification of its properties may make it more suitable for use in traditional products that normally use other types of starch. Heat‐moisture treatment was applied to native SPS (HMTSPS), which was used as a substrate and composite with maize starch (MS) to produce bihon‐type starch noodles. Preliminary quality scoring showed that acceptability scores of raw starch noodles, plain boiled, and sautéed noodles made from 100% HMTSPS and 50% HMTSPS:50% MS were not significantly different from the commercial bihon. However, consumer testing is recommended to further validate acceptability of the sweet potato for bihon.
Carotenoid Retention In Canned Pickled Jalapeño Peppers and Carrots As Affected by Sodium Chloride, Acetic Acid, and Pasteurization
Authors: Guerra‐vargas M. , Jaramillo‐flores M. E. , Dorantes‐alvarez L. , Hernández‐sánchez. H.
Published: July 2006

ABSTRACT The combined effect of salt, acetic acid, and pasteurization temperature on the retention of carotenoids in canned pickled carrots and green jalapeño peppers was studied by a central composite design. The results were analyzed by response surface methodology. The carotenoid standards were obtained by open column chromatography and the quantitation was done by HPLC. Only the main carotenoids were quantified: α‐ and β‐carotene in carrots and α‐, β‐carotene, lutein, and violaxanthin in peppers. After analyzing the experimental results and the restrictions of the Mexican Regulations, 2% NaCl and 2% acetic acid concentrations were recommended. The optimal pasteurization conditions were 70 °C/12.45 min for carrots and 83 °C/5.2 min for peppers.