bluuebunny/crossref_metadata_2025 huggingface dataset:
Sugars and Free Amino Acids in Stored Russet Burbank Potatoes Treated with CIPC and Alternative Sprout Inhibitors
Authors: Yang J. , Powers J.R. , Boylston T.D. , Weller K.M.
Published: July 2006

Glucose, fructose, sucrose and free amino acids were measured in stored Russet Burbank potatoes treated with sprout inhibitors isopropyl‐N‐(3‐chlorophenyl) carbamate (CIPC), 1,4‐dimethylnaphthalene (DMN), cineole and salicylaldehyde. Storage effects on sugar and amino acid contents were dependent on the specific sprout inhibitor. Salicylaldehyde treatment (200 ppm) produced a rapid increase of reducing sugar content and a greater amount of free amino acids than other treatments. A smaller amount of tyrosine was found in DMN (40 ppm) treated tubers compared to all other treatments. After 16 wk at 7°C, all potatoes treated with inhibitors had 10.5–11.8 mg/g dry weight reducing sugar content which would be considered acceptable for French fry processing.
Composition and Physicochemical Properties of Chevon Patties Containing Oat Bran
Authors: Dawkins N.L. , Phelps O. , McMillin K.W. , Forrester I.T.
Published: July 2006

Chevon (goat) meat‐based patties were formulated with oat bran (15–50% w/w) and evaluated for nutrient content and physicochemical properties. Moisture, fat, and protein decreased with increased oat bran. Patties containing oat bran had higher concentrations of unsaturated fatty acids and lower cholesterol. Additions of oat bran also reduced sodium and zinc. Soluble and insoluble fiber content of patties increased, while cooking loss and shear force of patties decreased with increased oat bran. Nutritional value of patties was enhanced with minimal composition and texture changes at 15 or 20% oat bran addition.
Milk Alkaline Phosphatase Purification and Production of Polyclonal Antibodies
Authors: Vega‐Warner A. V. , Wang C.‐H. , Smith D. M. , Ustunol Z.
Published: July 2006

Purification was by electroelution from native polyacrylamide gels or by sequential use of three columns. Electroelution was faster and resulted in a higher yield (23.4 vs 1.6%) than column purification. The enzyme had a molecular mass of 187 kDa, and the isoelectric point ranged from 5.4 to 6.0. ALP purified by electroelution was used as the antigen to immunize rabbits for polyclonal antibody (PAb) production. Western blot analysis showed that PAbs cross‐reacted with bovine milk and placenta ALP, but did not cross‐react with ALP from calf or bovine intestinal mucosa, Escherichia coli or with other milk proteins.
Optimizing Cholesterol Removal in Cream Using β‐Cyclodextrin and Response Surface Methodology
Authors: Ahn J. , Kwak H.S.
Published: July 2006

Average cholesterol reduction increased as β‐cyclodextrin concentration increased, regardless of other factors. The process was optimized using RSM. When β‐cyclodextrin addition was 10%, the effect of stirring speed was more noticeable than that of stirring time. When stirring speed was at 1,600 rpm, 94.2% of cholesterol was reduced in 30 min. When stirring time was 20 min, the cholesterol was reduced 97.99% using 15%β‐cyclodextrin. When stirring speed was 1,200 rpm, the effect of β‐cyclodextrin addition was greater than that of stirring time. Although the percentage of cholesterol reduction varied with different factors and conditions, about 94% of cholesterol was removed from cream.
Oxytetracycline Residues in Cultured White Shrimp Tissue by HPLC and a Microbial Receptor Assay
Authors: Bermúdez‐Almada M.C. , Pérez‐Tello M.G. , Valenzuela‐Quintanar A.I. , Vázquez‐Moreno L.
Published: July 2006

The residue depletion of oxytetracycline (OTC) from muscle tissue of cultured shrimp (Penaeus vannamei) was evaluated. OTC was measured using high performance liquid chromatography (HPLC) and a microbial receptor assay. Samples were taken on days 7, 14 and 21 during the treatment and 23, 25 and 28 after the treatment. OTC was detectable in all groups after 7 days depletion time at concentrations of 0.28, 0.19 and 0.05 μg/g for diets containing 500, 250 and 100 mg/kg OTC, respectively. Results by the microbial receptor assay were in good agreement with those by HPLC.
Thermal Pasteurization Effects on Color of Red Grapefruit Juices
Authors: Lee H.S. , Coates G.A.
Published: July 2006

Changes in color due to thermal pasteurization of two cultivars of red grapefruit juice were studied. Juices were pasteurized at 91°C using a plate heat exchanger. Apparently, thermal pasteurization changed all three color parameters (CIE L*, a*, b*) in the juice, causing a slight color shift towards lighter and brighter. Thermal pasteurization especially affected CIE b* value and chroma in juice. The reflectance spectrum in the visible region (400 nm to 700 nm) clearly showed changes in spectral distribution of light reflected from juice after pasteurization. There were no changes (P>0.05) in major carotenoid pigments (β‐carotene and lycopene) in the juices after pasteurization.
Pasta‐Like Product from Pea Flour by Twin‐Screw Extrusion
Authors: Wang N. , Bhirud P.R. , Sosulski F.W. , Tyler R.T.
Published: July 2006

The effects of extrusion parameters on the characteristics of a pasta‐like product were investigated. Increasing moisture content of the dough decreased brightness, bulk density, cooking loss and stickiness, but increased cooking time and firmness. Raising the barrel temperature increased cooking time, firmness and stickiness, but brightness, bulk density and cooking loss decreased. Increasing the screw speed increased cooking time, cooking loss, firmness and stickiness, but decreased brightness and bulk density. The product exhibited superior integrity, flavor, and texture after cooking, and less change after overcooking, compared to pasta‐like products prepared from pea flour using a conventional pasta extruder.
Thermal Aggregation and Dynamic Rheological Properties of Pacific Whiting and Cod Myosins as Affected by Heating Rate
Authors: Yongsawatdigul J. , Park J. W.
Published: July 2006

Thermal aggregation of cod myosin and Pacific whiting myosin were compared at different heating rates. Turbidity of Pacific whiting started to increase at 30°C and decreased at >50°C, and fluorescence intensity of ANS‐myosin of both species was greater at slower heating rates at 20–80°C. Storage modulus (G′) of cod myosin gradually increased as temperature increased resulting in more elastic gel at slower heating rates. G′ of whiting myosin rapidly increased at 30°C, maximized at 45–48°C and decreased afterward. The onset temperature of a decreased G′ shifted from 45°C to 49°C as heating rate increased from 0.5 to 2°C/min. Whiting myosin heated at 2°C/min retained more myosin heavy chain.
Cloud Stabilization of Orange Juice by High Pressure Processing
Authors: Goodner J.K. , Braddock R.J. , Parish M.E. , Sims C.A.
Published: July 2006

High pressure processing (HPP) was investigated as a means to preserve cloud in freshly squeezed orange juice. Cloud loss is a major quality defect in orange juice, and methods of preserving cloud without the extreme temperatures used in commercial pasteurization are desirable. Pressures from 500 to 900 MPa were investigated at dwell times of 1 sec, 1 min and 10 min. Higher pressures and longer processing times were more effective at preserving cloud, while all treatments yielded a microbially stable product. A 90‐day shelf life under refrigeration conditions could be achieved using pressures of 700 MPa and higher combined with treatment times of 1 min.
Bifidobacterium longum Survival During Frozen and Refrigerated Storage as Related to pH during Growth
Authors: Reilly S.S. , Gilliland S.E.
Published: July 2006

Four strains of Bifidobacterium longum were grown at pH 5.5, 6.0, 6.5 and 7.0 and evaluated for survival and bile tolerance during frozen and subsequent refrigerated storage in milk. There were no reductions in cell numbers following initial freezing. There were effects for strain, pH and storage for three of the four strains of B. longum du ring storage at 5°C in milk. Bifidobacterium longum S9 was more stable than other strains in that no losses occurred, regardless of pH during growth. Results were variable for strains II, III, and ATCC 15707 grown at the various pH levels. Bifidobacterium longum S9 did not lose bile resistance during refrigerated storage as the other three strains did.
Reduction of Microbial Counts at a Commercial Beef Koshering Facility
Authors: Hajmeer M. N. , Marsden J. L. , Crozier‐Dodson B. A. , Basheer I. A. , Higgins J. J.
Published: July 2006

Effectiveness of a water soaking, salting, and water rinsing (koshering) process in reducing microbial counts was examined. Beef briskets (30) were sampled at four stages in the plant, viz. prewashing, postwashing, after 24 h chilling, and after koshering. Quantitative aerobic plate, coliforms, and Escherichia colicounts, and qualitative analysis for Salmonella were determined. PROC MIXED and GLM procedures were applied to determine statistical differences among least square means (LSM) at p.0.05. Microbial counts did not always decrease from prewashing to postwashing, after 24 h chilling, or after koshering but koshering reduced APC, coliforms, and E. coli from initial counts. Salmonella were also reduced.
Effectiveness of Sanitizing Agents in Inactivating Escherichia coli in Golden Delicious Apples
Authors: Sapers G.M. , Miller R.L. , Mattrazzo A.M.
Published: July 2006

Research was undertaken to develop improved methods of sanitizing apples contaminated with Escherichia coli. Unwaxed Golden Delicious apples, inoculated with non pathogenic E. coli, were washed with 200 ppm Cl2, commercial washing formulations, 5% H2O2, or combinations of H2O2 with commercial formulations at ca. 20°C or 50°C. Heated commercial formulations achieved a 2.5 log reduction in E. coli load, compared to a 2 log reduction for 200 ppm Cl2. However, heated combinations of H2O2 with acidic surfactants achieved a 3–4 log reduction. Residual H2O2 in treated apples dissipated within several hours. These results demonstrate the efficacy of H2O2 in decontaminating apples containing E. coli.
Modeling the Thermal Properties of a Cup Cake During Baking
Authors: Baik O. D. , Sablani S. S. , Marcotte M. , Castaigne F.
Published: July 2006

Thermal properties of a cup cake were estimated under conditions simulating industrial baking. Densities (p: 803‐236 kg/ m3), specific heats (Cp: 2516‐2658 J/kgK) and thermal conductivities (k: 0.1064‐0.2064 W/mK) were estimated using a pycnometric/geometric cutting method, a modulated differential scanning calorimeter and a line heat source probe. Cp and k were based on internal temperatures after specific baking times. Thermal diffusivities (a: 1.02×10−7‐1.698×10−7m/s2) were obtained by dividing the thermal conductivities by the product of specific heats and densities. Based on thermal property data, simple empirical models were developed for further prediction.
Tapioca‐Fish and Tapioca‐Peanut Snacks by Twin‐Screw Extrusion and Deep‐Fat Frying
Authors: Suknark K. , Phillip R. D. , Huang Y.‐W.
Published: July 2006

Two half‐products were prepared from tapioca starch/catfish fillet‐belly flap mince (60:40) and tapioca starch/partially defatted peanut flour (PDPF) (60:40) by twin‐screw extrusion. The process variables were temperature in the last two zones of the extruder (90,95,100°C) and screw speeds (100, 250, 400 rpm). Moisture content (40%, wet basis) and feed rate (27 g/min) were held constant. Simultaneously increasing temperature and screw speed resulted in increased expansion, and decreased bulk density and shear strength. Degree of starch gelatinization in half‐products ranged from 87 to 95%. Optimum conditions predicted by response surface methodology were: for fish half‐products 94–100°C and 220–400 rpm and for peanut half‐products, 95–100°C and 230–400 rpm.
Low‐fat Fried Foods with Edible Coatings: Modeling and Simulation
Authors: Williams R. , Mittal G.S.
Published: July 2006

We studied the use of edible films to reduce fat absorption in fried foods. A mathematical model was developed incorporating heat, moisture and fat transfer in the food and the film. Moisture diffusivities of the food and the film were 0.33×10−7 m2/s and 0.25×10−7m2/s, respectively. Fat diffusivities were 0.103×10−8m2/s for the food and 0.604×10−9m2/s for the film. Thermal diffusivities were 0.102×10−6m2/s for the food and 0.156×10−6m2/s for the film. Film diffusivities were determined for gellan gum films at a thickness of 2.0 mm during frying.
Pecan Texture as Affected by Freezing Rates, Storage Temperature, and Thawing Rates
Authors: Anzaldúa‐Morales A. , Brusewitz G.H. , Anderson J.A.
Published: July 2006

Pecan texture was measured by texture profile analysis (TPA) at 80% compression before and after being frozen at 6 controlled rates, to 3 minimum temperatures and thawed at 2 rates. Freezing and thawing rates had more influence than storage temperature on pecan texture. Certain TPA parameters (i.e., hardness, area 1, fracturability and slope of linear segment of force vs. deformation curve) were more affected than others by freezing and thawing rates. Freezing and thawing at high rates had the least effect on pecan texture.
Microbial and Sensory Quality of Fresh Camel Meat Treated with Organic Acid Salts and/or Bifidobacteria
Authors: Al‐Sheddy I. , Al‐Dagal M. , Bazaraa W. A.
Published: July 2006

Fresh camel meat samples were treated by dipping in solutions of sodium acetate (10% w/w), potassium sorbate (1.5% w/w), sodium lactate (5% v/v of 60% solution), or trisodium citrate (1.5%w/w) alone or combined with Bifidobacterium breve cell suspension (5%) and stored at 4°C. The pH, psychrotrophs, and sensory attributes were evaluated. Sodium acetate alone or combined with bifidobacteria maintained pH level, extended microbial shelf life (>12 days) and minimized surface discoloration. Bifidobacteria cell suspension when applied alone had negligible effects on microbial and sensory attributes. However, when combined with sodium acetate or potassium sorbate, bifidobacteria exhibited an additive effect on suppressing spoilage microorganisms.
Total Volatile Basic Nitrogen and other Physico‐chemical and Microbiological Characteristics as Related to Ripening of Salted Anchovies
Authors: Hernández‐Herrero M. M. , Roig‐Sagués A. X. , López‐Sabater; E. I. , Rodríguez‐Jerez J. J. , Mora‐Ventura M. T.
Published: July 2006

In canned anchovies the moisture content after salting decreased from 75.5% to 54%.The loss was accompanied by an increase in salt and ash contents. Free fatty acid (FFA) contents increased gradually throughout ripening. The FFA content variability was too wide to consider it as an index to monitor ripening. Although peroxide and TBA values provide an indication of onset of lipid oxidation, alternative methods are recommended based on tertiary compounds of lipid oxidation. Total volatile basic nitrogen (TVB‐N) increased linearly in fish muscle and brine during ripening. TVB‐N determination in the brine could be a feasible monitoring method for degree of ripening.
Modification of Proteins from Soymilk Residue (Okara) by Trypsin
Authors: Chan W.‐M. , Ma C.‐Y.
Published: July 2006

Okara protein isolates were hydrolyzed by trypsin to about 5% to 14%. Solubility was increased more than twofold by the modification, and water hydration capacity and emulsification activity index were also improved. The okara protein products had good essential amino acid profiles and the trypsin‐hydrolysates also had increased in vitro digestibility and available lysine content. The low solubility of okara protein makes it difficult to incorporate it into many food systems. Okara protein hydrolysates, with improved solubility and other functional properties, could be used as a low‐cost protein ingredient in processed foods.
Volatiles from Unpasteurized and Excessively Heated Orange Juice Analyzed with Solid Phase Microextraction and GC‐Olfactometry
Authors: Bazemore R. , Goodner K. , Rouseff R.
Published: July 2006

Commercial orange juice was divided into unpasteurized (no heat treatment) and excessively heated (240 s at 96 °C) samples. Juice headspace volatiles were collected using a carboxen‐polydimethylsiloxane (PDMS) fiber and thermally desorbed into a gas chromatograph. Aroma active components were evaluated by three trained panelists using the Osme system. Some aroma active peaks (18) were common to both heat treated and untreated juice headspace extracts. Other peaks (6) were observed only in unheated extracts or were unique (5) to heated juice headspace extracts. The carboxen fiber was more selective for terpenes than early eluting alcohols and aldehydes compared to pentane‐ether liquid‐liquid extraction.
Baking Performance, Rheology, and Chemical Composition of Wheat Dough and Gluten Affected by Xylanase and Oxidative Enzymes
Authors: Hilhorst R. , Dunnewind B. , Orsel R. , Stegeman P. , van Vliet T. , Gruppen H. , Schols H.A.
Published: July 2006

Baking trials were performed with six wheat doughs prepared with xylanase, peroxidase, or glucose oxidase (GOX), and their combinations. Judging dough properties, baking performance, bread volume, and crumb structure, the dough containing xylanase plus peroxidase performed best. Flow relaxation measurements with doughs indicated that peroxidases introduced new transient linkages, whereas glucose oxidase also introduced cross‐links permanent on long time scales. Rheological tests and chemical analysis revealed small differences between control and xylanase and/ or peroxidase containing gluten and more pronounced differences for GOX containing gluten. No evidence was found that xylanase specifically removed arabinoxylans from gluten or that peroxidase catalyzed the formation of covalent bonds between arabinoxylans and gluten proteins.
Kinetic Study of Antibrowning Agents and Pressure Inactivation of Avocado Polyphenoloxidase
Authors: Weemaes C. , Ludikhuyze L. , Van den Broeck I. , Hendrickx M.
Published: July 2006

Pressure inactivation at room temperature (25 °C) of avocado polyphenoloxidase (pH 5.0) in absence or presence of 10 mM ethylene diaminetetraacetic acid (EDTA), NaCl, or benzoic acid or 0.05 mM 4‐hexylresorcinol or glutathione could be described by a fractional conversion model. There appeared to be a resistant enzyme fraction (∼10% to 20%), necessitating about 825 MPa for inactivation in absence of antibrowning agents. EDTA addition resulted in sensitization of the pressure‐sensitive enzyme fraction, which was attributed to the acid effect. Benzoic acid or NaCl addition resulted in a marked stabilization, whereas addition of glutathione resulted only in a minor stabilization of the pressure‐sensitive enzyme fraction. 4‐Hexylresorcinol displayed a sensitizing effect below and a stabilizing effect above 700 MPa. The pressure dependency of the inactivation rate constant was altered (p < 0.05) by addition of 4‐hexylresorcinol or benzoic acid.
Ripening Profiles of Goat Cheese Produced from Milk Treated with High Pressure
Authors: Trujillo A.J. , Royo C. , Ferragut V. , Guamis B.
Published: July 2006

Goat cheeses were made from pasteurized (72 °C, 15 s) and high‐pressure (HP)‐treated milk (500 MPa, 15 min, 20 °C). At 45 days of ripening, cheeses made from both types of milk were similar in moisture, quality, electrophoretic profiles, water‐soluble nitrogen, and total free fatty acid contents. Cheeses made from HP‐treated milk had higher pH and salt, matured more quickly, as determined by formation of total free amino acids, and developed strong flavors. Reverse‐phase high‐performance liquid chromatography showed differences between the peptide profiles of the cheeses. Differences in small peptides and free amino acids indicated a higher extent of proteolysis in cheeses made from HP‐treated milk.
Amaranthus Betacyanin Pigments Applied in Model Food Systems
Authors: Cai Y. , Corke H.
Published: July 2006

Amaranthus betacyanin pigments and commercial colorants were evaluated to determine color characteristics and stability at different temperatures in jelly, ice cream, and a model beverage. The betacyanin exhibited brighter color characteristics than red radish anthocyanin, with similar color stability during 20‐wk storage (≤ 14 °C) or during the initial 4‐wk storage (≤ 25 °C), but was less stable than red radish anthocyanin at 37 °C. The betacyanin was not as stable as synthetic Food, Drug, and Cosmetics Red No. 3 under most storage conditions. Ascorbic acid had a protective effect on Amaranthus pigments. Excessive sucrose (≥ 16%) decreased stability of the pigments. The betacyanin tested may be a feasible natural colorant for jelly, higher pH beverages, and ice cream under selected conditions.
Decreasing Oil Uptake of Doughnuts During Deep‐fat Frying Using Curdlan
Authors: Funami T. , Funami M. , Tawada T. , Nakao Y.
Published: July 2006

The ability of the dry ingredient curdlan (0% to 1% w/w) to lower oil uptake and moisture loss in doughnuts during deep‐fat frying was compared with that of cellulose derivatives. An index expressing the ratio between oil uptake and moisture loss was developed. The addition of curdlan showed a linear effect on reducing each parameter (p < 0.001) within a range of 0% to 0.5%. This effect of curdlan probably is attributed to its thermal gelling property, and the heat‐induced gel during frying probably functioned as an oil and moisture barrier. Cellulose derivatives were less effective than curdlan in this respect.
Structure and Composition of Mushrooms as Affected by Hydrogen Peroxide Wash
Authors: Sapers G.M. , Miller R.L. , Choi S.‐W. , Cooke P.H.
Published: July 2006

An experimental H2O2/browning inhibitor wash treatment and its effect on mushroom structure and composition were studied. Experimentally washed mushrooms (Agaricus bisporus) were compared with conventionally washed mushrooms and untreated controls. Examination by scanning electron microscopy showed damage to hyphae producing a matted appearance at the pileus surface with both experimental and conventional washed samples. Mushrooms after the experimental wash had an elevated sodium content from the sodium erythorbate browning inhibitor but contained no H2O2 residue. In pileus tissue, soluble phenol levels were higher and the content of free amino acids was lower in mushrooms after the experimental wash. No other notable compositional differences or adverse effects of treatment on quality were found.
Isostrength Comparison of Large‐Strain (Fracture) Rheological Properties of Egg White and Whey Protein Gels
Authors: Li H. , Errington A.D. , Foegeding E.A.
Published: July 2006

The effects of protein concentration and heating conditions on the physical properties of whey protein isolate (WPI) (in 50 mM NaCl, pH 7) and egg white (pH 9) gels were examined. Egg white and WPI gels had similar values for shear stress at fracture (i.e., isostrength), while trends for shear strain at fracture were protein‐type specific. The rigidity ratio (R0.3), ratio of the rigidity at fracture (Gf) to the rigidity at 30% of fracture strain, measured departure from the stress‐strain relationship of an ideal Hookean solid. All gels fit master curves of Gf vs R0.3, which were described by a power law model of R0.3=A(Gf)‐°19, where “A” showed protein type‐specific characteristics.
Growth and Production of Enterotoxin A by Staphylococcus aureus on “Home‐style” French Fries
Authors: Doan C.H. , Davidson P.M.
Published: July 2006

Staphylococcus aureus strains were inoculated onto fresh‐cut oil‐blanched potato strips stored at 21 or 26.7 °C for up to 9 h to determine if the microorganism was capable of growth and staphylococcal enterotoxin (SE) production. Potato strips were assayed for SE using a commercial ELISA kit prior to and following finish frying. S. aureus increased by 2.5 to 2.8 log CFU/g over 9 h at 26.7 °C, and SE was detected after 5 h. SE remained serologically detectable following finish frying of the potato strips. It is recommended that oil‐blanched potato strips stored at 26.7 °C be finish fried and served, or discarded, within 3 to 4 h to prevent possible production of SE.
β‐Carotene and Ascorbic Acid Retention in Fresh and Processed Vegetables
Authors: Howard L.A. , Wong A.D. , Perry A.K. , Klein B.P.
Published: July 2006

Broccoli, carrots, and green beans (grown in 2 consecutive years) were randomly divided into 3 treatments: fresh‐refrigerated (F‐R), frozen (FZ) or canned (C) (carrots only). FZ or C vegetables were processed within 24 h and stored for up to 1 yr. F‐R vegetables were held at 4 °C for 3 wk (broccoli and green beans) or 6 mo (carrots). Trans b‐carotene (Tb‐C) and total ascorbic acid (AA) were determined at specified times, before and after microwave cooking. Vitamin content differed between years due to environmental conditions. Blanching resulted in AA loss, but retention remained stable after freezing broccoli and green beans. F‐R green beans lost >90% AA after 16 d storage. Linear decreases in AAwere found in most F‐R or FZ vegetables. Tb‐C decreased slightly during freezer storage. Reductions in Tb‐C occurred in canned carrots. Microwave cooking had minimal effects on AA or Tb‐C.
Relative Effects of Ingredients on Cake Staling Based on an Accelerated Shelf‐life Test
Authors: Gélinas P. , Roy G. , Guillet M.
Published: July 2006

An accelerated shelf‐life test was developed to estimate the texture of devil's food cake stored 21 d at 21 °C, by studying the effects of packaging film water permeability and storage temperature over time. Best results were obtained after 7 d at 34 °C with low water permeability films. The test was used to determine the effects of 28 ingredient combinations on the incidence of cake staling. Staling was greatly reduced by partly replacing shortening with butter and glucose with sucrose. To a lesser extent, replacement of natural cocoa with dutched cocoa and use of high concentrations of fats, sugars, egg whites, or sodium bicarbonate also slowed staling rate.
Headspace Volatiles and Physical Characteristics of Vacuum‐microwave, Air, and Freeze‐dried Oregano (Lippia berlandieri Schauer)
Authors: Yousif A.N. , Durance T.D. , Scaman C.H. , Girard B.
Published: July 2006

ABSTRACT: Mexican oregano (Lippia berlandieri Schauer) was dried using a freeze drier, conventional hot air drier, and a recently developed vacuum‐microwave drier. The effect of the drying method on the relative content of major flavor volatiles, rehydration rate, color, and structural integrity of the herb was evaluated. Dynamic headspace analysis of volatiles present in fresh or dried oregano revealed that β‐myrcene, α‐terpinene, γ‐terpinene, p‐cymene, and thymol were the major volatile compounds of the plant. The level of thymol in vacuum‐microwave‐dried oregano was found to be comparable to that of fresh or freeze‐dried samples (1.3 times the thymol concentration of air‐dried). Air‐dried samples of oregano were darker, were less green, and exhibited lower rehydration rates than those prepared by vacuum‐microwave or freeze‐drying. Structures of vacuum‐microwave and freeze‐dried oregano appeared to be quite similar as observed on electron micrographs.
The Use of Fractional Conversion Technique to Investigate the Effects of Testing Parameters on Texture Degradation Kinetics
Authors: Stoneham T.R. , Lund D.B. , Tong C.H.
Published: July 2006

ABSTRACT: To study the effects of testing parameters on texture degradation, texture loss of potatoes heated at 80 °C was measured using an Instron universal testing machine as well as a texture analyzer under 2 instrument crosshead speeds, 2 sample sizes, and either compression or shear modes of mechanical deformation. Using the fractional conversion as a texture index, the kinetics of texture degradation of potatoes fitted a single 1st order reaction model, and the rate constant (or D value) was shown to be independent of the test used to determine the texture index. The average D value was 30 ± 1.2 min at 80 °C.
High Hydrostatic Pressure Treatments for Beer Stabilization
Authors: Castellari M. , Arfelli G. , Riponi C. , Carpi G. , Amati A.
Published: July 2006

ABSTRACT: Crude cloudy beers from a small‐scale brewery were treated with high hydrostatic pressure (HHP‐600 MPa, 5 min) or heat pasteurized (60 °C, 10 min). The treatments did not affect pH, ethanol, extract, bitterness, or phenolics in comparison with untreated beers; HHP beers retained permanent haze, similar to untreated samples. Heat pasteurized beer resulted in a more rapid increase of the a* (red) and a slower decrease of the b* (yellow) color parameters than in HHP samples. The microbiological stability of HHP beers was comparable with heat‐treated beers, and the development of yeast and lactic acid bacteria was inhibited for 49 d of storage.
Solar Drying of Bananas: Mathematical Model, Laboratory Simulation, and Field Data Compared
Authors: Phoungchandang S. , Woods J.L.
Published: July 2006

ABSTRACT: A mathematical model for the solar drying of bananas was developed using a numerical solution procedure to generate a computer simulation. The solution incorporated terms for solar absorption, long‐wave emission, natural or forced convection, and evaporation. The model was in good agreement with laboratory results obtained under artificial lights and also field data from researchers in Thailand. The model showed drying to be insensitive to ambient relative humidity but sensitive to factors affecting banana temperature. Reducing exposure to wind was shown to increase banana temperature and so reduce drying time by typically 15%, while also lowering the final moisture content achievable. The results are potentially useful to producers.
Interaction of Vanillin with Soy and Dairy Proteins in Aqueous Model Systems: A Thermodynamic Study
Authors: Li Z. , Grün I.U. , Fernando L.N.
Published: July 2006

ABSTRACT: Interactions of vanillin with soy, casein, and whey proteins were studied in aqueous model systems using a thermodynamic approach. Vanillin‐protein binding was examined at 12 and 4 °C using 3 proteins and 6 vanillin concentrations. The results were analyzed using a Klotz plot. Number of binding sites (n) and dissociation constants (Kd) were derived from the plots. The thermodynamic parameters (ΔG°, ΔH°, and ΔS°) for the bindings were calculated. Under identical experimental conditions, whey protein was found to have higher affinity to vanillin than the other 2 proteins. Bindings of vanillin with casein and whey protein were enthalpy driven, while the interaction of vanillin with soy protein was highly entropy driven. The results inferred that conformational changes of soy protein might be important in binding of vanillin.
Production of Hydrogen Peroxide by Lactobacillus delbrueckii subsp. lactis as Influenced by Media Used for Propagation of Cells
Authors: Jaroni D. , Brashears M.M.
Published: July 2006

ABSTRACT: Cells of Lactobacillus delbrueckii subsp. lactis I were grown in several media to determine the most suitable medium for production of H2O2 during refrigerated storage. H2O2 was detected from cells that were resuspended in phosphate buffer containing variable amounts of glucose. Cells grown in MRS broth produced more H2O2 during refrigerated storage than those grown in LBS pr PTM. Cells grown in LBS produced more H2O2 then those grown in PTM. For both MRS and LBS, cells inoculated in phosphate buffer containing 0% glucose produced significantly more H2O2 than those containing 1% or 10% glucose. MRS medium appears to be the best medium for growing cells for the production of H2O2.
Induction of Resistance of Salmonella typhimurium to Environmental Stresses by Exposure to Short‐Chain Fatty Acids
Authors: Kwon Y.M. , Park S.Y. , Birkhold S.G. , Ricke S.C.
Published: July 2006

ABSTRACT: Short‐chain fatty acids (SCFA), which are widely used as food preservatives and are also present in the gastrointestinal (GI) tract of animals at high concentrations, may play a role in the persistence of Salmonella typhimurium in the environment. To test the hypothesis, S. typhimurium was adapted to SCFA for 1 h and the % survivors against various stress conditions was determined. For adaptation, the SCFA mixtures at the concentrations found in small (SI) and large intestine (LI) were used. The % survivors against extreme acid (pH 3.0), high osmolarity (2.5 M NaCl), and reactive oxygen (20 mM H2O2) was greatly increased by exposure to SCFA LI, but to a much less extent by SCFA SI. The results suggest that encountering SCFA by S. typhimurium in the large intestine of the host food animal or food materials treated with them may increase the persistence of S. typhimurium in food animal pre‐and postharvest production by enhancing overall stress resistance.
Microbial Flora Associated with Louisiana Processed Frozen and Fresh Nutria (Myocastor Coypus) Carcasses
Authors: Lyon W.J. , Milliet J.B.
Published: July 2006

ABSTRACT: Nutria (Myocastor coypus) are semiaquatic vegetarians that have caused extensive destruction to coastal wetlands of Louisiana. There have been efforts to harvest nutria and market their meat for human consumption. This study seeks to address the microbial safety of nutria meat. Four regions of processed nutria carcasses, including the hindquarters, neck, back, and abdomen, were evaluated for microbial contamination during processing. Bacterial isolates were isolated and identified from each region of the carcass using selective and nonselective media, phenotypic tests, and the VitekTM identification system. The majority of microorganisms identified were spoilage organisms. The pathogenic microorganisms isolated Escherichia coli, Stophylococcus aureus, and Burkholderia mallei. This study will be used to develop an HACCP plan for processing nutria.
In Vitro Antioxidant Activity of Black Tea and Mediterranean Herb Infusions Toward Iron Under Simulated Gastrointestinal Conditions
Authors: Matsingou T.C. , Kapsokefalou M. , Salifoglou A.
Published: July 2006

ABSTRACT: Dietary components, such as polyphenols, may be capable of scavenging reactive oxygen species implicated in biological damage. In order to understand their significance in disease prevention, the behavior of systems harboring antioxidants and prooxidants was investigated. Various Mediterranean herbs and black‐tea infusions were investigated in vitro, in the presence of iron, under simulated gastrointestinal conditions. All infusions exhibited variable antioxidant activity relative to the controls in the absence or presence of digestive enzymes and bile salts. Correlations of antioxidant activity with iron and polyphenols in dialysates were performed. The results of the in vitro assay demonstrate that it can offer more details on potential antioxidants relative to other model systems.
Sensory and Compositional Relationships Between Commercial Cheddar‐flavored Enzyme‐modified Cheeses and Natural Cheddar
Authors: Hulin‐Bertaud S. , Kilcawley K.N. , Wilkinson M.G. , Delahunty C.M.
Published: July 2006

ABSTRACT: The odor and flavor characteristics of 15 commercial Cheddar‐flavored enzyme‐modified cheeses (EMC) and 3 natural Cheddar cheeses were determined and compared using descriptive sensory analysis. These sensory characteristics of Cheddar EMC were significantly different from those defined for natural Cheddar cheeses. EMC provided a range of “vomit,”“bitter,”“astringent,”“chemical,” and “eggy/sulphur” flavors, whereas the natural Cheddar cheeses were characterized by “sweet,”“caramel,”“creamy,”“nutty,” and “buttery” flavors. Relationships between the composition of EMC and their sensory attributes showed significant correlation. The flavor attributes “pungent,”“vomit,”“astringent,” and “eggy/sulphur” were strongly related to a high fat content and low pH. These relationships were discussed and compared to those observed for natural Cheddar cheeses.
Reactions of Chlorogenic Acid with Lysozyme: Physicochemical Characterization and Proteolytic Digestion of the Derivatives
Authors: Rawel H.M. , Kroll J. , Riese B.
Published: July 2006

ABSTRACT: The lysozyme‐chlorogenic acid‐derivatives formed at different pH were characterized in terms of their physicochemical and digestion properties, whereby pH 10 led to the highest derivatization. The results showed reduction of lysine residues and a distinctive decrease of the tryptophan fluorescence with increasing lysozyme derivatization. The solubility decreased over a broad pH range with a parallel increase in hydrophobicity of the derivatives. The isoelectric points were shifted to lower pH values and high molecular fractions were formed. The influence of the protein derivatization on the in vitro digestibility was also demonstrated. The peptic digestion of the derivatized lysozyme was adversely affected, whereas the tryptic and chymotryptic hydrolysis seemed to be favored.
Modified Atmosphere Packaging of Pomegranate
Authors: Artés F. , Villaescusa R. , Tudela J.A.
Published: July 2006

ABSTRACT: Spanish ‘Mollar de Elche’ sweet pomegranates (Punica granatum L.) were stored at 2 or 5 °C for 12 wk in unperforated polypropylene (UPP) film of 25 μm thickness in modified atmosphere packaging (MAP). Perforated polypropylene (PPP) film of 20 μm thickness and conventional cold storage were applied as control treatments. Quality was evaluated after storage and after shelf life of 6 d at 15 °C and 75% RH. PPP at 5 °C was the best treatment for maintaining red skin‐color of the arils at the end of storage. All treatments suffered a decrease in total anthocyanins content at the end of shelf life. After shelf life, UPP fruits had higher values of absorbance at 510 and 446 nm. MAP strongly reduced water loss and chilling injuries without incidence of decay.
Inhibition of Thermal Degradation of Mackerel Surimi by Pig Plasma Protein and L‐kininogen
Authors: Lee J.‐J. , Tzeng S.‐S. , Wu J. , Jiang S.‐T.
Published: July 2006

ABSTRACT: Use of purified L‐kininogen to prevent actomyosin (AM) degradation by cathepsins, and pig plasma proteins to reduce mackerel modori were investigated. Myosin heavy chain (MHC) degradation in AM containing various cathepsins was significantly inhibited by purified L‐kininogen. The texture of mackerel gel increased to 2‐fold and 1.7‐fold in breaking force (g) and deformation (cm) separately after adding 1% pig plasma protein. SDSPAGE showed that degradation of MHC in mackerel surimi was significantly reduced after 1% pig plasma protein addition at several temperatures. It suggested that the pig plasma protein containing L‐kininogen could effectively reduce the modori phenomenon of mackerel surimi during processing.
Formulation Protocol and Dicationic Salts Affect Protein Functionality of Model System Beef Batters
Authors: Pigott R.S. , Kenney P.B. , Slider S. , Head M.K.
Published: July 2006

ABSTRACT: The objective of this study was to determine if addition, and order of addition, of CaCl2 and MgCl2 affected protein functionality of lean beef preblends. Four treatments were applied to non‐preblended (NPB) batters prior to thermal processing. Six treatments were applied to preblended (PB) batters 12 h prior to thermal processing. All treatments contained 2% NaCl. Dicationic salts decreased raw pH in NPB and PB batters, while cooked pH was unaffected. Magnesium chloride in NPB and CaCl2+ MgCl2 in PB batters resulted in the highest total soluble protein (TSP). Calcium chloride + MgCl2 in NPB batters resulted in firmer gels compared to the control. Magnesium chloride, in both NPB and PB, caused the greatest increase in soluble myosin, and preblending decreased myosin solubility.
Water Vapor Transmission Rates and Sorption Behavior of Chitosan Films
Authors: Wiles J.L. , Vergano P.J. , Barron F.H. , Bunn J.M. , Testin R.F.
Published: July 2006

ABSTRACT: This study measured the water vapor transmission rates (WVTR) and moisture sorption of chitosan films over a range of water vapor pressures at 25 °C. Films of a constant thickness were made using chitosan with 3 levels of deacetylation. Films were tested at test relative humidity (RH) difference between RH values of 84%, 75%, 69%, 53%, 43%, 33%, 23%, 11%, and 0 at 25 °C using ASTM F1249‐90 or ASTM E 96‐80. The equilibrium moisture content in the films ranged from 3.7% to 31.8% (dry basis) corresponding to 11% to 84% RH. WVTRs of films increased with increase in water vapor pressure. The mean WVTR ranged from 6.7 to 1146 (g/m2/d) over the range of water vapor pressure from 2.68 (11% RH) to 19.9 mmHg (84% RH). The percentage of deacetylation of chitosan films and the viscosity of the cast solution did not have an effect on the WVTR properties of chitosan films.
An Ultrasonic Method for Assessing the Residence Time Distribution of Particulate Foods During Ohmic Heating
Authors: Marcotte M. , Trigui M. , Tatibouët J. , Ramaswamy H.S.
Published: July 2006

ABSTRACT: The residence time distribution (RTD) was investigated using ultrasound during continuous ohmic heating of 1) starch solution and 2) carrot particles/starch solution mixtures. For liquid experiments, a copper pigment was used as a tracer. Ultrasonic sensors were placed at the end of the tube to measure changes in sound attenuation. The copper concentration was determined in samples taken at time intervals. For particulate foods, one kilogram of carrot/solution mixtures was introduced. Results of the ultrasonic method were compared to carrots weights in collected samples. Variations of sound attenuation illustrated well the RTD of solutions and carrot particles. Results of the ultrasonic method agreed with the pigment method for liquid and the gravimetric method for particulate foods.
Influence of Ozone, Hydrogen Peroxide, or Salt on Microbial Profile, TBARS and Color of Channel Catfish Fillets
Authors: Kim T.J. , Silva J.L. , Chamul R.S. , Chen T.C.
Published: July 2006

ABSTRACT: Channel catfish (Ictalurus punctatus) fillets were treated with hydrogen peroxide (HP), ozonated water (OZ), and ascorbic acid plus salt (AS) or salt solution (BR). All treatments except AS decreased (p 0.05) Aeromonas, while OZ did not decrease Staphylococcus and Acinetobacter. All treatments except 5 ppm OZ reduced (p 0.05) initial TCC and PPC. At 0.7% HP, BR, and 10 ppm OZ fillets showed odor spoilage after 8,10 and 10.5 d, respectively. Fillets treated with HP, OZ, and BR had higher (p 0.05) TBARs than control fillets. HP treated fillets had lower (p 0.05) Hunter ‘L’ values, while BR treated fillets had higher ‘a’ and lower (p 0.05) Hunter ‘L’, ‘b’, and SI values than controls.
Degradation of Vitamin A Palmitate in Corn Flakes During Storage
Authors: Kim Y.‐S. , Strand E. , Dickmann R. , Warthesen J.
Published: July 2006

ABSTRACT: The amounts of vitamin A palmitate lost and isomers formed in corn flakes fortified with a vitamin A palmitate were determined during storage at ambient (avg. 23 °C) and elevated (45 °C) temperatures. Two vitamin A palmitate isomers, 9‐cis and 13‐cis, were found. The initial vitamin A palmitate consisted of 5% of 13‐cis and less than 1% of 9‐cis with the remaining being all‐trans. In corn flakes fortified with either a complete vitamin mixture or vitamin A palmitate only, the distribution of these compounds was nearly constant throughout storage irrespective of sample type and storage conditions. The rate constant and reaction kinetics on the degradation of vitamin A palmitate were also obtained. After 6–8 wk storage, more than 90% of vitamin A palmitate was lost in all samples except corn flakes fortified with complete vitamin mixture and kept at ambient temperature. This study showed that the loss of vitamin A palmitate fortified in corn flakes was substantial even at ambient temperature. The presence of other vitamins including vitamin A, B1, B6, B12, C, and D reduced the loss of vitamin Abut the loss was still significant.
Rhubarb Juice as a Natural Antibrowning Agent
Authors: Son S.M. , Moon K.D. , Lee C.Y.
Published: July 2006

To search for natural antibrowning agents, rhubarb juice was tested on fresh‐cut apple slices and found to have a potent effect. Liberty apple slices were treated in various concentrations of rhubarb juice (5%–100%), and the rate of discoloration at room temperature was measured by a Hunter Colorimeter. Apple slices treated in the 5%– 10% solution showed browning activity with dL values of 2.3 – 2.5 at two hours. However, the concentrations of rhubarb juice above 20% inhibited apple browning effectively with no change in the L value for several hours. Analysis of oxalic acid in rhubarb juice showed that the 20% solution contained about 67 mg/100g.
Comparison of Electrochemical and Chemical Acidification of Skim Milk
Authors: Bazinet L. , Lamarche F. , Ippersiel D. , Gendron C. , Mahdavi B. , Amiot J.
Published: July 2006

The purpose of this study was to compare chemical and electrochemical acidification, in order to identify differences between the two acidification procedures. The results reveal differences in the acidification profiles obtained with the two methods. Whereas chemical acidification showed a salting‐in effect from addition of salts, bipolar‐membrane electroacidification (BMEA) removes salts through electrochemical demineralization, favoring protein precipitation. Hence, at pH 4.6, all the caseins were precipitated by BMEA, while some were not yet precipitated by chemical acidification. Nevertheless, the chemical composition and the casein fraction composition of the isolates were the same for both chemical and electrochemical acidification.
Polysaccharide Constituents of Coffee‐Bean Mucilage
Authors: Avallone S. , Guiraud J.‐P. , Guyot B. , Olguin E. , Brillouet J.‐M.
Published: July 2006

Alcohol‐insoluble residues (AIRs) were isolated from hand‐dissected and commercial mucilages of depulped coffee beans. Both AIRs had similar polysaccharide composition: pectic substances (about 30%), cellulose (about 8%), and neutral noncellulosic polysaccharides (about 18%). Crude pectins were extracted from AIRs (dry‐matter yield: about 23% to 35%) with dilute nitric acid (pH 1.5, 90 °C). Both pectins contained about 60% uronic acids with high degree of methyl esterification (about 62%) and moderate degree of acetylation (about 5%). Their molecular weights were low (about12 to 29 kDa). They did not gel in the presence of sucrose at acidic pH.
MRI Observation and Mathematical Model Simulation of Water Migration in Wheat Flour Dough During Boiling
Authors: Fukuoka M. , Mihori T. , Watanabe H.
Published: July 2006

Existing cooking rate equations fail to describe the change of moisture content profile in starchy foods during cooking. There is a need for a new model. In this paper, an experiment on water migration during boiling was performed using a slab of wheat flour dough. The moisture content profile was measured by an MRI method. The result was compared with predictions made using mathematical models. The existing mathematical model was found to predict a much more rapid change than that measured by experiment. The accuracy of the prediction was considerably improved when a new model was applied: a mathematical model based on a new concept that water migration is driven by water demand.
Stability and Activity of β‐Galactosidase in Sonicated Cultures of Lactobacillus delbrueckii ssp. bulgaricus 11842 as Affected by Temperature and Ionic Environments
Authors: Kreft M.E. , Jelen P.
Published: July 2006

Stability of β‐galactosidase and related lactose hydrolyzing activity in sonicated cultures of Lactobacillus bulgaricus 11842 was investigated in the presence of Na+ or K+ ions. After sonication in Na+ or K+ buffers at various pH levels, cultures were held at various temperatures, before adding test lactose solutions. Hydrolysis was monitored by cryoscopy. Cultures sonicated in K+ buffer had higher activity and stability than those in Na+ buffer; both were highest at pH 6 and 7. Stability was unaffected at pH 6 and 7 below 56 °C. Holding at 61 °C for 60 min caused 70% activity loss with K+ ions at pH 6 and 7, while with Na+, activity loss was almost complete.