bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Crystallization of Dark Chocolate as Affected by Temperature and Lipid Additives
Authors: LOISEL C. , LECQ G. , KELLER G. , OLLIVON M.
Published: July 2006

The dynamic crystallization was studied in a lab‐scale Scraped Surface Heat Exchanger by following variations with time of torque applied during different isotherms between 24.9°C and 31.0°C. Crystallization was in two steps for T 26.2°C but it was in one step at T<26.2°C. The first step corresponded to crystallization of about 1% solid fat and was related to that of saturated triacylglycerols (SSS) which segregated from other cocoa butter triacylglycerols (TAGs) because of their low solubility in TAGs. The second step, an abrupt increase of apparent viscosity, leading to complete crystallization was attributed mainly to the monounsaturated TAGs in the β form. Different amounts of tristearin increased the apparent viscosity and reduced the latent time preceding the first step, but did not influence the main crystallization. Stearic acid and distearin additions also influenced chocolate crystallization.
Recrystallization in Ice Cream as Affected by Stabilizers
Authors: SUTTON ROBIN L. , WILCOX JEAN
Published: July 2006

Addition of locust bean gum (LBG) or guar gum to ice cream mixes gave products with smaller ice crystals after heatshock than control samples without either stabilizer. LBG was more effective at inhibiting recrystallization than guar. Increasing stabilizer concentration resulted in greater inhibition. With LBG we found some evidence for an optimum concentration above which no further inhibition occurred. We found no evidence for phase volume effects.
Functional and Nutritional Properties of Extruded Whole Pinto Bean Meal (Phaseolus Vulgaris L.)
Authors: BALANDRÁN‐QUINTANA R.R. , BARBOSA‐CÁNOVAS G.V. , ZAZUETA‐MORALES J.J. , ANZALDÚA‐MORALES A. , QUINTERO‐RAMOS A.
Published: July 2006

Pinto bean meals with 18, 20, and 22% moisture were extruded at 140,160 and 180°C, using screw speeds of 150,200 and 250 rpm in a single‐screw laboratory extruded. Expansion index, bulk density, water absorption and solubility indices, in vitro protein digestibility, and trypsin inhibitor activity in extrudate were measured. Temperature and feed moisture influenced (p<0.05) expansion index, bulk density, water absorption index and in vitro protein digestibility. Water solubility index was affected by temperature only. Trypsin inhibitors were inactivated completely for all conditions. Screw speed had no effect on any dependent variable. Best product was produced with 22% feed moisture at 160°C.
Ripe Olives Storage Liquids Reuse During The Oxidation Process
Authors: BRENES M. , GARCÍA P. , ROMERO C. , GARRIDO A.
Published: July 2006

Storage of ripe olives in liquids with high acetic acid content under anaerobic conditions led to glucose accumulation, low ethanol, and high chemical oxygen demand (COD). In contrast, low acid concentrations and anaerobic conditions produced a high level of ethanol and slightly lower COD while aerobic conditions produced low glucose, ethanol and COD. Surface color of ripe olives improved when storage liquids were used in the second washing of the darkening step. Firmness also increased with increasing proportion of storage liquids reuse, although olives from highly acidic media were softer than those stored in low acid media.
Liquid Smoke Effects on Escherichia Coli O157:H7, and its Antioxidant Properties in Beef Products
Authors: ESTRADA‐MUÑOZ R. , BOYLE E.A.E. , MARSDEN J.L.
Published: July 2006

Experiments were performed to evaluate the antibacterial properties of liquid smoke (LS), against E. coli O157:H7, in model (agar) and meat systems. The effects of 8% LS on growth of E. coli O157:H7 attached to ground beef, and 1.5% LS on warmed‐over flavor (WOF) in precooked beef patties were also studied. E. coli O157:H7 growth was reduced (p<0.05) 2.3 log10 CFU/g in ground beef patties after 3d refrigerated storage. TBA numbers, aroma scores and pH values were lower (p<0.05) in LS treated beef patties. LS reduced undesirable flavor development and may help assure the safety of beef products.
Lignin Effect on Calcium Absorption in Rats
Authors: SHEN XIN , WEAVER CONNIE M. , MARTIN BERDINE R. , HEANEY ROBERT P.
Published: July 2006

The effect of lignin on calcium absorption was studied in a rat model. Lignin preparations were isolated directly from wheat bran and from kale by two treatments, enzymatic and acidic. Calcium absorption in the presence or absence of isolated wheat bran lignin, isolated kale lignin, commercially available pine lignin, and wheat bran was determined by femur uptake of 45Ca. The fractional calcium absorption of wheat bran was significantly lower than for the control. However, there were no differences in calcium absorption between the various lignin sources and the control without lignin. Thus, lignin is probably not inhibitory to calcium absorption in plant foods.
Color of Nonfat Fluid Milk as Affected by Fermentation
Authors: RANKIN SCOTT A. , BREWER JENNIFER L.
Published: July 2006

Nonfat milks inoculated and fermented with exopolysaccharide and non‐exopolysaccharide producing cultures were compared to nonfat, 2% milkfat and whole milk with instrumental and sensory color measurements. L‐(whiteness) and a‐ values (red/greeness) for fermented nonfat milks were higher than nonfat milk. No differences in L‐, a‐, or b‐ values (yellow/blueness) were found between milks fermented with exopolysaccharide as compared to non‐exopolysaccharide producing strains. A trained sensory panel scored edge and center whiteness of fermented milks whiterthan nonfat milk. Milks fermented with exopolysaccharide producing cultures were scored higher than non‐exopolysaccharide producing cultures with respect to edge and center whiteness. Fermentation and exopolysaccharide production may increase visual perception of whiteness in milk.
Bacterial Extracellular Ice Nucleator Effects on Freezing of Foods
Authors: LI JINGKUN , LEE TUNG‐CHING
Published: July 2006

Extracellular ice nucleators (ECINs) were incorporated into foods and subjected to subzero freezing. Time‐temperature profiles, ice‐formation patterns and textures were examined by thermocouple, microscopy and texture analyzer. Onset temperatures (initial freezing), enthalpies and freezing rates were measured by DSC. Addition of ECINs to liquid foods elevated ice nucleation temperatures and promoted freezing. Solid or semisolid products frozen with ECINs resulted in a fiber‐like texture. These effects were more apparent at –10°C or higher. Differential scanning calorimetry revealed onset temperatures were increased 11°C by addition of ECINs, but length of time to complete the phase transition was extended at constant cooling rates. Results indicated that ECINs can be used instead of whole bacterial cells for efficient freezing and textural modification.
Antioxidant Effects of Carnosine and Phytic Acid in a Model Beef System
Authors: LEE BEOM JUN , HENDRICKS DELOY G. , CORNFORTH DAREN P.
Published: July 2006

Antioxidant and color stability effects of carnosine and phytate were compared in a fresh beef model system and in cooked beef. Both compounds increased the rate of pH decline in pre‐rigor muscle. Phytate also increased the rate of post‐mortem glycogen catabolism. Both antioxidants inhibited metmyoglobin formation in raw samples during storage. Phytate was more effective than carnosine for inhibition of lipid peroxidation. Heme iron content was negatively related to lipid peroxidation in cooked beef (r=–0.92). Phytate was also more effective for inhibition of iron release from heme during cooking. Phytate is recommended over carnosine as an effective antioxidant in cooked meats.
Reversed Micellar Extraction of Hen Egg Lysozyme
Authors: CHOU SHU‐TING , CHIANG BEEN‐HUANG
Published: July 2006

Egg white was diluted to 10 times its original volume with 50 mM phosphate buffer (pH 9.2) containing 0.1 M potassium chloride. The aqueous solution was mixed with an equal volume of isooctane containing 50 mM bis‐(2‐ethylhexyl) sodium sulfosuccinate at 10°C for 50 min. After extraction, the organic phase containing lysozyme was separated from the aqueous phase and mixed with an equal volume of 50 mM phosphate buffer (pH 11.8) containing 1M potassium chloride. Backward extraction was then performed at 30°C for 45 min. The procedures recovered 90% lysozyme from the eggwhite. The specific activity of the extract was near 73,000 units/mg.
Heat‐induced Egg White Gels as Affected by pH
Authors: HANDA AKIHIRO , TAKAHASHI KEIKO , KURODA NAMIO , FRONING GLENN W.
Published: July 2006

The functional properties of heat‐induced egg white gels were investigated at five pH values. Textural characteristics were determined using the Instron Universal Machine. Hardness, elasticity, cohesiveness, chewiness, and fracturability were maximum at pH 11. Hunter L values were maximum at pH 5 and 7. Microstructure studied with electron microscopy was distinctly different at the five pH values. Alkaline gels showed a fine ordered network that might have contributed to excellent textural characteristics. Water‐holding capacity (WHC) was high at alkaline pH, but decreased with addition of 2‐mercaptoethanol, suggesting that disulfide bonds were important in egg white gels. Sodium dodecyl sulfate (SDS) improved WHC at pH 7 and 9. No significant correlation was observed between textural profiles and WHC.
Functional Properties and Bitterness of Sodium Caseinate Hydrolysates Prepared with a Bacillus Proteinase
Authors: SLATTERY H. , FITZGERALD R.J.
Published: July 2006

The functional and physicochemical characteristics, and bitterness were evaluated on sodium caseinate hydrolysates generated with a commercial Bacillus proteinase complex. At low degrees of hydrolysis (0.5 and 1.0% DH) the hydrolysates compared to the unhydrolyzed substrate had increased emulsion activity at pH 2 and 4. However, higher DH resulted in lower emulsion activities. At pH 8 and 10, the low DH hydrolysates displayed increased foam expansion and decreased foam drainage compared to the starting substrate. The Bacillus proteinase hydrolysates at higher DH had similar bitterness values to tryptic hydrolysates at equivalent DH. However, the Bacillus hydrolysate at 0.5% DH was less bitter (p<0.05) than the tryptic hydrolysate at the same DH.
Monitoring Proteolysis During Cheddar Cheese Ripening Using Two‐Dimensional Gel Electrophoresis
Authors: CHIN H.W. , ROSENBERG M.
Published: July 2006

A 2‐D gel electrophoretic method, consisting of isoelectric focusing and alkaline urea‐PAGE was used to monitor proteolysis during ripening (180d, 5°C and 8°C) of full‐ and reduced‐fat Cheddar cheese. The method enabled quantifying changes in levels of peptides in cheese with good spot‐resolution. Results can complement those from other analyses, especially those for determining low MW peptides. Notable effects were found for cheese composition and ripening temperature on gel pattern and on relative levels of selected proteolysis products. In both cheese varieties, most peptides reached a maximum during the first 3 ripening months and gradually disappeared as ripening advanced.
Isolation of Tomato Seed Meal Proteins with Salt Solutions
Authors: LIADAKIS GEORGE N. , TZIA CONSTANTINA , OREOPOULOU VASSILIKI , THOMOPOULOS CHRISTOS D.
Published: July 2006

Salt solutions were used in isolating tomato seed meal proteins. Na2SO3 and NaCl solutions at different concentrations, and pH were included in a central composite design to find optimum conditions of protein isolation. The highest total protein yield was achieved with water extraction (no salt present). Salt extraction at pH 7.5 produced isolates with protein content of 93.4% (NaCl 5% w/v) and 77.1% (Na2SO3 0.5% w/v). Observed values were in good agreement with predicted values. Isolates extracted with different salt solutions ranged from less soluble but very resistant to heat and Ca2+, to very surface active with functional properties comparable to commercial soy isolates.
Calcium Chloride Added to Irrigation Water of Mushrooms (Agaricus Bisporus) Reduces Postharvest Browning
Authors: KUKURA J.L. , BEELMAN R.B. , PEIFFER M. , WALSH R.
Published: July 2006

The influence of 0.3% CaCl2 added to irrigation water on mushroom tyrosinase activity and postharvest browning was examined. Calcium concentration of mushrooms was significantly increased with the addition CaCl2 to irrigation water but had no effect on inherent tyrosinase activity but reduced postharvest browning. The CaCl2 had even more pronounced improvement in shelf life as indicated by reduced browning following a standard bruising treatment. Transmission electron micrographs indicate that increased levels of calcium in mushrooms irrigated with CaCl2may have decreased browning by increasing vacuolar membrane integrity; thereby reducing the opportunity for tyrosinase to react with its substrates.
Dough Properties and Crumb Strength of White Pan Bread as Affected by Microbial Transglutaminase
Authors: GERRARD J.A. , FAYLE S.E. , WILSON A.J. , NEWBERRY M.P. , ROSS M. , KAVALE S.
Published: July 2006

Microbial transglutaminase forms nondisulfide covalent crosslinks in proteins and is being used in foods. This enzyme may produce beneficial effects during breadmaking that are comparable to traditional oxidizing improvers, hypothesized to act via formation of disulfide crosslinks. Transglutaminase greatly improved the crumb strength of baked loaves and provides a potential solution to a common consumer complaint. Transglutaminase also reduced the required work input and substantially improved the water absorption of the dough. Each of these effects would lower processing costs for commercial baking
Thermal Properties of Restructured Beef Products at Different Isothermal Temperatures
Authors: TSAI SHWU‐JENE , UNKLESBAY NAN , UNKLESBAY KENNETH , CLARKE ANDREW
Published: July 2006

Thermal properties and components of restructured beef products formulated with five binders (0.5–5.0%) were determined after heating to 35, 45, 55, or 65°C. Binders were: isolated soy protein, sodium caseinate, waxy modified corn starch, carrageenan, and oat flour. Water losses were greater when no binders were used until 65°C was attained. Density was influenced by both temperature and binder; specific heat was influenced by temperature; and thermal conductivity and thermal diffusivity were influenced by binder. All thermal properties correlated with water and/or protein contents of restructured beef products.
Survival of Yersinia enterocolitica During Fermentation and Storage of Yogurt
Authors: BODNARUK PETER W. , WILLIAMS ROBERT C. , GOLDEN DAVID A.
Published: July 2006

The fate of Yersinia enterocolitica was investigated during the manufacture and storage of yogurt produced using commercial starter cultures YC470 (rapid acid‐producer), YC180 (slow acid‐producer), both containing Streptococcus thermophilus and Lactobacillus bulgaricus, and a “home‐use” culture that contained these bacteria as well as Lactobacillus acidophilus. Preparations were fermented at 44°C and stored at 4°C. During the first few hours of fermentation, Y. enterocolitica populations increased in all preparations. Y. enterocolitica populations were reduced to undetectable levels after 72 and 96h in YC470 and YC180 yogurt, respectively, but survived up to 144h in “home‐use” yogurt. The home‐use starter produced lactic acid in greater amounts and more rapidly (p<0.05) than YC470 or YC180 starters, but enabled longer survival. Y. enterocolitica survival was least (p<0.05) in yogurt produced using the YC470 starter culture.
Lipolytic Starter Culture Effects on Production of Free Fatty Acids in Fermented Sausages
Authors: KENNEALLY P.M. , SCHWARZ G. , FRANSEN N.G. , ARENDT E.K.
Published: July 2006

Fermented sausages, inoculated with lipolytic and non lipolytic starter cultures and a control containing glucono‐δ‐lactone (GDL) and an antibiotic mixture were prepared. The sausages were analyzed on the basis of color, pH, water activity, weight loss, moisture and fat contents. Microbiological analyses were performed to measure total viable counts, lactobacilli and, staphylococci and micrococci. The increase in total and individual free fatty acids, and lipid oxidation was monitored. Results showed no difference (p>0.05) in the level of free fatty acids between treatments, indicating that lipolysis was most likely due to endogenous meat enzymes.
Chemical Changes and Visual Appearance of Albacore Tuna as Related to Frozen Storage
Authors: Ben‐gigirey Begoña , De Sousa Juan M. Vieites Baptista , Villa Tomas G. , Barros‐velazquez Jorge
Published: July 2006

Fresh albacore tuna (Thunnus alalunga) were frozen and stored at –18°C and –25°C for 1 yr. Chemical and visual analyses were carried out at 1, 3, 6, 9 and 12 mo storage. Storage time correlated (P<0.05) with the low loss of moisture at –18°C, slight reduction of TVBN at –25°C and low increases of DMA, TMA, and TBARS at both temperatures. TMAO concentration (p=0.07), drip loss on cooking (p=0.52), peroxide value (p=0.059), FFA concentration (p=0.33) and pH (p=0.20)did not change significantly with period of storage but −25°C resulted in a lower production of DMA and FFA than −18°C. Results from chemical analyses correlated well with basic visual appearance.
Physical and Molecular Properties of Wheat Gluten Films Cast from Heated Film‐Forming Solutions
Authors: Roy S. , Weller C. L. , Gennadios A. , Zeece M. G. , Testin R. F.
Published: July 2006

The effect of heating film‐forming solutions on physical and molecular properties of cast wheat gluten (WG) films was determined. Glycerol‐plasticized films were cast from alkaline (pH 10), heat‐treated (55,75, or 95°C for 10 min) solutions of WG in aqueous ethanol. Protein solubility (PS) of films in water decreased (P<0.05) with increasing temperature. Gel permeation chromatograms showed reduced extractability of protein fractions other than ω‐gliadins in WG films. This reduced extractability was due to disulfide (S‐S) bond formation. SDS‐PAGE patterns of native WG and WG film samples suggested increased cross‐linking through covalent S‐S bonds in films from solutions heated at 75 or 95°C. Water resistance in potential packaging applications of WG edible films could be modified by adjusting heat‐treating temperature.
Ionomeric Films of Alginic Acid
Authors: Pavlath A. E. , Gossett C. , Camirand W. , Robertson G. H.
Published: July 2006

Transparent, flexible films could be made by casting aqueous solutions of alginic acid, but they dissolved in water. When films were made from a solution of alginic acid and multivalent ions, they were still water soluble. However, when alginic acid films were immersed in a solution of salts with multivalent ions, they dissolved in water much more slowly, if at all. Treatment with calcium and zinc resulted in films insoluble in water and their tensile strength increased by an order of magnitude. Iron and magnesium ions had little effect on properties of the films. Copper and aluminum showed intermediate effect, but treatment with cupric ion resulted in a fast crosslinking of the surface without affecting the inside of the film. This resulted in the formation of a tube when opposing surfaces were pulled apart.
Tensile, Solubility, and Electrophoretic Properties of Egg White Films as Affected by Surface Sulfhydryl Groups
Authors: Handa A. , Gennadios A. , Froning G. W. , Kuroda N. , Hanna M. A.
Published: July 2006

Films plasticized with polyethylene glycol were cast from alkaline (pH 10.5, 11.0, or 11.5), aqueous egg white (EW) solutions with or without heating (40°C for 30 min). Prior to casting, concentration of surface sulfhydryl (SH) groups was determined and they increased (P < 0.05) (3.81–19.45 μM/g protein) with both pH and heating, presumably due to protein denaturation and cleavage of disulfide (S‐S) bonds. Concentration of surface SH groups correlated (P < 0.05) with film tensile strength (r = 0.70), elongation at break (r = 0.86), and film total soluble matter (r =−0.94). Most likely, surface SH groups formed S‐S bonds through air oxidation and/or sulfhydryl/disulfide interchange, thus contributing to EW film formation. SDS‐PAGE patterns in presence or absence of 2‐mercaptoethanol confirmed occurrence of S‐S bonding in dried EW films.
Color in Concentrated Milk Proteins with High Sucrose as Affected by Glucose Replacement
Authors: Pauletti M.S. , Matta E.J. , Castelao E. , Rozycki D S.
Published: July 2006

A model system of sucrose, whole dry milk powder, and distilled water was used to evaluate color development during heating. Sucrose replacement by glucose and moisture were the selected variables in a second‐order central composite design. The main color response was the Kubelka‐Munk index K/S calculated from reflectance colorimetric measurement using the Self‐Backing Reflectance Transformation (SBRT) procedure. Browning reached a zone of maximum K/S when sucrose replacement increased. Additional replacement in the maximum zone did not increase browning, but produced an opposite effect decreasing browning, depending on moisture content. Chromophore group formation was higher between 40 and 75% of sucrose replacement by glucose and at 20‐30% moisture content.
Monitoring Molecular Diffusion of Sucrose in Xanthan Solutions using Ultrasonic Velocity Measurements
Authors: Basaran T. K. , Coupland J. N. , McClements D. J.
Published: July 2006

Measurements of the velocity of ultrasound through a sample as a function of diffusion distance were used to study molecular diffusion of sugars through biopolymer solutions. A1 wt% xanthan solution was prepared which consisted of a lower layer containing no sucrose, and an upper layer containing sucrose (10, 20, 30, or 40 wt%). The velocity of ultrasound through the biopolymer solutions was measured as a function of sample height and time, and then converted into sucrose concentration‐distance profiles using an empirical calibration curve. The translational diffusion coefficient of the sucrose in the upper and lower layers was determined by fitting the experimental data to a Fickian diffusion model. The measured diffusion coefficients were in reasonable agreement with published values for sucrose in aqueous solutions in the absence of xanthan, which suggests the biopolymer had little influence on molecular diffusion.
Physical Characteristics of a Composite Film of Soy Protein Isolate and Propyleneglycol Alginate
Authors: Rhim J. W. , Wu Y. , Weller C. L. , Schnepf M.
Published: July 2006

Different levels (5, 10, 15, 17.5 or 20% w/w of solid) of propyleneglycol alginate (PGA) were incorporated into soy protein isolate (SPI) films to form biodegradable composite films with modified physical properties. Color of the SPI films was affected (P<0.05) by the incorporation of PGA. Tensile strength increased (P<0.05) with addition of PGA up to 17.5%, while the percentage elongation at break decreased with incorporation of PGA of higher levels. Water vapor permeability and water solubility also decreased by adding PGA up to 10%, but further addition of PGA increased values for these properties. Results suggest that the site of reaction with PGA on the protein chain may become saturated with PGA at the 10% level.
Peanut Protein Film as Affected by Drying Temperature and pH of Film Forming Solution
Authors: Jangchud A. , Chinnan M. S.
Published: July 2006

Films were made from peanut protein concentrate solution of pH 6.0, 7.5 or 9.0, and dried at 70, 80 or 90°C. Both total solubility and protein solubility of film decreased with increasing temperature but increased with increasing pH. Film color was darker and more yellow when pH increased. Tensile strength (TS) and elongation (E) increased but water vapor permeability (WVP) and oxygen permeability (OP) decreased as temperature increased. At pH 9 and 90°C, film had the lowest WVP and OP, and the highest TS.
Consumer‐rated Quality Characteristics as Related to Purchase Intent of Fresh Pork
Authors: Brewer M. S. , McKeith F. K.
Published: July 2006

Consumers (n=556) rated pink color, wet/dry appearance, overall acceptability and purchase intent of normal, pale, soft and exudative (PSE), and dark, firm and dry (DFD) pork loin slices in PVC packages in five retail supermarkets. DFD samples appeared driest and PSE samples appeared wettest. Samples in the higher ranked two purchase intent categories appeared more wet than those in the lower three categories. The pinker PSE samples and all DFD samples were in the higher ranked purchase intent categories. Purchase intent generally paralleled overall acceptability; however, prediction equations indicated that wet/dry appearance, color and overall acceptability all contributed to purchase intent decision depending on muscle condition.
Simulation and Verification of Two‐Dimensional Ohmic Heating in Static System
Authors: Fu W.‐R. , Hsieh C.‐C.
Published: July 2006

Temperature distribution in a two‐dimensional electrical heated system was determined both by computer simulation and experimental measurement. A commercial software program package was used for simulation. The experiment was conducted in a system where the vertical dimension was minimal to minimize natural convection during ohmic heating. In a rectangular static system containing a rectangular particle, computer simulation showed a trend verified by similar experimental results. Heat loss to the environment and physical property values used in simulation were major factors affecting differences between experimental and simulation results. There was no evidence for the presence of any coldest spot other than at the center of particles.
Effects of Onion Quercetin on Oxidative Stability of Cook‐chill Chicken in Vacuum‐sealed Containers
Authors: Karastogiannidou C.
Published: July 2006

The effects of onion quercetin were evaluated in relation to the storage stability of cooked dark chicken meat in retarding post‐cooking oxidative changes. Autooxidation was followed using the 2‐thiobarbituric acid (TBA) test. Dried onion flesh at 1.6% (w/w), typical for common cooking, reduced (P < 0.001) the TBA value in cooked chicken during refrigerated storage, when mixed before processing. The NaCl did not act as a prooxidant. The antioxidant effect (by TBA) of onion mixed with chicken meat prior to processing was equivalent to that of its measured quercetin content, quantified by high‐performance liquid chromatography.
Stability and Antioxidant Activity of Beta Carotene in Conventional and High Oleic Canola Oil
Authors: Goulson M.J. , Warthesen J.J.
Published: July 2006

Conventional canola oil (CO) and high oleic canola oil (HOCO) were stored under autoxidative and photooxidative conditions, β‐carotene was added at 0 to 120 ppm. The oils were diluted in mobile phase and injected onto an HPLC column to track β‐carotene changes over time. Peroxide values were followed to assess the oxidative stability of the oils. β‐carotene was more stable in HOCO than in CO under autoxidative conditions, but no difference between oils was observed under photooxidative conditions. The HOCO was more stable against autoxidation, and CO was more stable against photo‐oxidation. Antioxidant activity was shown by β‐carotene in both oils, which contained natural tocopherols, during both autoxidative and photooxidative conditions.
Instrumental Crispness and Crunchiness of Roasted Hazelnuts and Correlations with Sensory Assessment
Authors: Saklar S. , Ungan S. , Katnas S.
Published: July 2006

Crispness and crunchiness of 15 samples of roasted hazelnuts were investigated. Force deformation curves from compression cell testing were analyzed and mechanical response variables were determined for roasted hazelnuts. Regression equations based on roasting air temperature, air velocity, and roasting time explained (R2_0.9 –0.98, p < 0.001) the mechanical response variables. Samples were also evaluated by a quantitative descriptive panel. Among the mechanical response variables, the first fracture point (F1) observed on the force deformation curve and the slope (S2) for the line between the first and second fracture points strongly correlated (inverse) with sensory crispness (R =–0.96) and crunchiness (R _–0.92), respectively.
Ultrasonic Velocity in Cheddar Cheese as Affected by Temperature
Authors: Mulet A. , Benedito J. , Bon J. , Rossello C.
Published: July 2006

The ultrasonic velocity in Cheddar cheese is temperature dependent. This relationship can be used to make corrections when determining ultrasonic texture or to determine mean temperatures in cooling/heating processes. At 0 < T < 35 °C ultrasonic velocity was 1590 to 1696 m/s, at 0 and 35 °C, respectively. Differential Scanning Calorimetry thermograms linked the temperature dependence of ultrasonic velocity to fat melting. Three parts are distinguished in the curve as a consequence of the fat melting and the appearance of free oil. The most reliable temperature interval to carry out ultrasonic measurements in Cheddar cheese is identified as 0 to 17 °C.
Principal Factor Analysis of Extruded Sorghum and Peanut Bar Changes During Accelerated Shelf‐life Studies
Authors: Anderson J.C. , Jones B.D.
Published: July 2006

A prototype meal bar of extruded sorghum‐peanut wafer with filling and enrobing was subjected to accelerated shelf‐life testing at 60°C for 4 wks Samples were withdrawn each week for analyses including slurry pH, Kramer shear texture measures, CIE L*a*b* color, water activity, peroxide values, malonaldehyde content, available lysine, and proximate composition. Principal factor analysis with varimax rotation was used to assess associations of related factors. Six factors accounted for 77.5% of variance. Significant changes occurred with respect to the control over 4 wk storage, particularly in a sharp reduction of pH, and increased pigmentation. Other measures were minimally changed.
Polyvinyl Acetate as a High‐gloss Edible Coating
Authors: Hagenmaier R.D. , Grohmann K.
Published: July 2006

Edible coating formulations were made with food‐grade polyvinyl acetate (PVA) dissolved in alcohol‐water mixtures. PVA coatings had high gloss and relatively high permeance to O2 and water vapor, and they formed glossy surfaces on chocolate candy, citrus fruit, and apples. Addition of propylene glycol helped to retain coating gloss when the alcohol content of the solvent was reduced to less than 70%. Fresh apples or citrus fruit with PVA coatings had higher internal O2 than fruit with shellac and resin coatings and, consequently, less tendency to ferment and produce alcohol during storage. Fruit with PVA coatings did not whiten or ‘blush’ after contact with water.
Photochemical Treatment to Improve Storability of Fresh Strawberries
Authors: Baka M. , Mercier J. , Corcuff R. , Castaigne F. , Arul J.
Published: July 2006

We investigated the effect of pre‐storage exposure to shortwave ultra‐violet (UV‐C) light on the decay and quality of fresh strawberries. Fresh strawberries (cv. Kent, 25% to 50% red) were exposed to UV‐C at doses of 0.25 and 1.0 kJ/m2 and stored at 4 °C or 13 °C. UV treatment controlled the decay caused by Botrytis cinerea at both temperatures and extended the shelf‐life of the fruits by 4 to 5 d. UV‐treated fruits had a lower respiration rate, higher titratable acidity and anthocyanin content, and were firmer than the untreated fruits. The percentage of free sugars increased faster in UV‐treated fruits at the beginning of the storage period. A lower electrical conductivity in fruits treated with 0.25 kJ/m2 suggests a slower rate of senescence compared to the control. A higher electrical conductivity observed with 1.0 kJ/m2suggests damage to the fruits. Overall, UV treatment at 0.25 kJ/m2 appears to slow down the ripening and senescence of strawberry fruits stored at 4 °C.
Pecan Kernel Breakage and Oil Extracted by Supercritical CO2 as Affected by Moisture Content
Authors: Li M. , Bellmer D. D. , Brusewitz G. H.
Published: July 2006

During supercritical CO2 extraction of oil from pecans, kernel breakage frequently occurs when the depressurization time is short. The purpose of this study was to investigate the effects of initial moisture content of pecan kernels and moisture equilibration time on pecan breakage and oil recovery when extracting with supercritical CO2. Initial pecan moisture content, adjusted to 3.5% to 11.0%, had a significant effect on breakage when using a short depressurization time. With higher pecan moisture, less kernel breakage occurred. Increasing moisture equilibration time from 1 to 48 h reduced kernel breakage and produced an average of 30% more oil during extraction. Moisture content did not significantly affect the amount of oil extracted.
Quantification of Connective Tissue (Hydroxyproline) in Ground Beef by Autofluorescence Spectroscopy
Authors: Wold J. P. , Lundby F. , Egelandsdal B.
Published: July 2006

Autofluorescence spectra (excitation wavelengths 300, 332, 365, 380 and 400 nm) were obtained by an optical system to determine collagenous connective tissue (hydroxyproline) and fat content in ground beef. Chemically determined contents ranged from 0.72–7.12% connective tissue and 1.5–17.7% fat. Partial least squares regression (66 samples) resulted in the lowest root mean square error of 0.37% connective tissue (R=0.97) and 1.89% fat (R=0.84) for excitation wavelengths 380 and 332 nm, respectively. The wavelength 332 nm may be feasible for simultaneous determination of fat and connective tissue. Autofluorescence spectroscopy might be well suited for rapid on‐line determination of collagen in ground beef.
Volatilities of Short‐Chain Fatty Acids in a Fermented Milk Model System as Affected by Stabilizers
Authors: Chen L. , Boyle‐Roden E. , Rankin S.A.
Published: July 2006

A fermented milk model system was employed to investigate the volatilities of butyric, caprylic, and caproic acids as affected by low, intermediate, and high levels of carrageenan, guar and xanthan gums. Carrageenan exhibited no effect on fatty acid volatility. Intermediate levels of guargum increased the volatility of caprylic acid. Low and high levels of guar gum had no effect on free fatty acid volatility. At low and high levels, xanthan gum had no effect on volatilities of fatty acids. The intermediate level of xanthan gum increased volatilities of caproic and caprylic acids. The effects of viscosity were potentiated with increased fatty acid chain length.
Postharvest CO2 and Ethylene Production and Quality Maintenance of Fresh‐Cut Kiwifruit Slices
Authors: Agar I. T. , Massantini R. , Hess‐Pierce B. , Kader A. A.
Published: July 2006

The quality attributes and gas production of fresh‐cut kiwifruit slices (Actinidia deliciosa cv. Hayward) were studied to identify the optimum ranges of storage temperature, relative humidity, and atmospheric composition. Also the effects of wounding, C2H4 addition or removal, and chemical treatments (calcium, ascorbic acid, citric acid) on deterioration rate were investigated. Flesh softening was the major quality loss of stored fresh‐cut kiwifruit slices. Fresh‐cut kiwifruit slices had a shelf‐life of 9–12 days if treated with 1% CaCl2 or 2% Ca lactate, and stored atO‐2°C and >90% relative humidity in an C2H4‐free atmosphere of 2 to 4 kPa O2 and/or 5to10kPaCO2.
Contribution of Free and Glycosidically Bound Volatile Compounds to the Aroma of Muscadine Grape Juice
Authors: Baek H.H. , Cadwallader K.R.
Published: July 2006

Free and glycosidically bound volatile compounds were isolated and identified from muscadine grape juice. Most abundant in free and bound form was the muscadine character‐impact aroma compound 2,5‐dimethyl‐4‐hydroxy‐3(2H)‐furanone (Furaneol). Other aroma compounds, such as o‐aminoacetophenone and 2‐phenylethanol were found in free and bound forms. A high level of 2‐phenylethanol was intheglycosideformand many bound monoterpenes were identified. p‐Vinylguaiacol, a potential off‐flavor in muscadine juice was found at a low level in bound form. Enzymatic hydrolysis of glycoside precursors could lead to release of volatile compounds with both potentially positive and deleterious effects on the overall aroma.
Color and Pigment Stability of Red Radish and Red‐Fleshed Potato Anthocyanins in Juice Model Systems
Authors: Rodriguez‐Saona L. E. , Giusti M. M. , Wrolstad R. E.
Published: July 2006

Color and pigment stability of model juices (pH 3.5) were evaluated during 65 wk of storage at 2°C and 25°C in the dark. Two acylated pelargonidin‐based anthocyanins, red‐fleshed potatoes (Solanum tuberosum) and red radishes (Raphanus sativus), and 2 extraction methods, C‐18 resin and juice processing, were used and compared to FD&C Red #40. Color (CIELch) and pigment degradation depended on storage temperature, anthocyanin structure and extraction method, with chemically extracted radish anthocyanins showing the best overall stability. At room temperature (25°C), higher stability was obtained with C‐18 purified radish anthocyanins (22 wk half‐life) and lowest with potatojuice concentrate (10 wk half‐life). Refrigeration increased the half‐life of pigments to over a year.
Hydroxyl Scavenging Activity of Glucose, Fructose, and Ribose‐Lysine Model Maillard Products
Authors: Wijewickreme A. N. , Krejpcio Z. , Kitts D. D.
Published: July 2006

Nondialyzable model Maillard reaction products (MRPs) were synthesized by reacting L‐lysine with D‐glucose, D‐fructose, and D‐ribose under different conditions of reaction time, temperature, pH, and water activity (aw). Five experiments common to all three models yielding greater than 0.5g of MRPs were assessed for antioxidant activity. All MRPs exhibited detectable, but variable, non site‐specific hydroxyl radical (·OH) scavenging activity (30–90%) in the deoxyribose assay. MRPs derived from a ribose‐lysine study showed the highest ·OH scavenging activity (80–90%) in both deoxyribose and DNA nicking assays. All MRPs at higher concentrations (0.2 mg/mL) decreased lipid peroxidation in linoleic acid emulsions. Relative effectiveness of different MRPs to scavenge free radicals can vary with reaction conditions and substrates.
Boning and Storage Temperature Effects on the Attributes of Soft Jerky and Frozen Cooked Free‐flow Mince
Authors: Farouk M. M. , Swan J. E.
Published: July 2006

Hot or cold boning and frozen or chilled storage of beef for 1 mo had no effect on sensory panel acceptability of soft beef jerky (easier to chew than traditional jerky) processed using a two step drying method and a frozen cooked free‐flow mince (ground beef) made from the beef. For jerky, panel scores for texture and overall acceptability decreased with increased peak force and softness scores increased with increased final yield. Sensory panelists disliked the greyish‐brown color of the cooked free‐flow mince. The most acceptable free‐flow mince was produced by cooking Alogs@ to 73°C, then mincing at –6°C. The degree of freeflowness and the amount of fines tended to increase with decreasing mincing temperature.
Screw Configuration Effects on Macroscopic Characteristics of Extradates Produced by Twin‐screw Extrusion of Rice Flour
Authors: Choudhury G. S. , Gautam A.
Published: July 2006

The effects of 29 screw configurations on rice flour extrudates were investigated. The moisture content, screw speed and feed flow rate during all extrusion experiments were 15%, 400 rpm, and 12kg/h, respectively. Temperature profile in the 8 barrel sections from feed to die end were set at 0, 30, 30, 30, 70, 100, 150, and 150°C. Incorporation of kneading block (KB) and reverse screw element (RSE) in screw profiles significantly influenced apparent density, product expansion (radial, axial and overall), and breaking strength. Apparent density and overall expansion were functions of die temperature. KB was the best element for maximizing radial expansion. Product hardness (breaking strength) decreased with increasing radial expansion.
Firmness and Cell Wall Characteristics of Pasteurized Jalapeño Pepper Rings as Affected by Calcium Chloride and Rotary Processing
Authors: Gu Y.S. , Howard L. R. , Wagner A. B.
Published: July 2006

Rotary processing resulted in more uniform heat penetration and texture retention throughout the container than resulted after nonagitated processing. Localized softening in nonagitated peppers was due to prolonged heating at the top of the container, which hydrolyzed large molecular weight pectic substances (chelator and nonextractable) to more soluble forms. Calcium improved the texture by maintaining greater levels of insoluble pectic substances (chelator, dilute alkali and nonextractable) and reducing pectin solubilization. The combination of rotary processing and calcium chloride treatment resulted in a product with fresh‐like, uniform texture throughout the container.
Ascorbic Acid Retention in Shredded Iceberg Lettuce as Affected by Minimal Processing
Authors: Barry‐Ryan C. , O'Beirne D.
Published: July 2006

The effects of slicing method, packaging atmosphere and storage temperature were determined on total ascorbic acid (TAA) content of modified atmosphere packaged shredded lettuce. TAA was extracted from the lettuce samples and levels were monitored using either titration with 2,6‐dichlorophenolindophenol solution or an assay kit. Slicing affected (p<0.05) ascorbic acid retention in the order manual tearing > manual slicing > machine slicing. Flushing with 100% nitrogen increased retention (∼5%, p<0.05) over packages with product modified atmospheres. Storage at 3°C increased retention (∼20%, p<0.05) compared with storage at 8°C. Scores for product appearance generally followed losses of TAA in the lettuce (p<0.05).
Chlorophyll Fluorescence as an Indicator of Physiological Changes in Cold‐Stored Broccoli After Transfer to Room Temperature
Authors: De Ell J. R. , Toivonen P.M.A.
Published: July 2006

Our objective was to determine if chlorophyll fluorescence could be used as an indicator of physiological changes in cold‐stored broccoli after transfer to room temperature. Mass loss, respiration, and ammonia content increased when the broccoli were held at 18°C for 72h, whereas the chlorophyll fluorescence measurements (Fv/Fm, T½ and Fmd) decreased. Broccoli color began to change after 24h, as hue decreased rapidly and chroma increased. Fv/Fm decreased markedly only after the first 24h when the color changes began, whereas T½ and Fmd decreased continuously as the broccoli aged. Both T½ and Fmd correlated negatively with mass loss and respiration.
Pressure‐Temperature Degradation of Green Color in Broccoli Juice
Authors: Weemaes C. , Ooms V. , Indrawati  , Ludikhuyze L. , Van den Broeck I. , Van Loey A. , Hendrickx M.
Published: July 2006

Broccoli juice greenness was marginally affected by pressure at low temperatures (30‐40°C). At 800 MPa and slightly higher temperatures (50‐60°C), first‐order degradation of green color was observed. The greenness loss was suggested to be due to chlorophyll‐pheophytin conversion with no further pheophytin degradation. Pheophytin degraded further when higher temperatures (≥70°C) were combined with elevated (or atmospheric) pressures (0.1–850 MPa). At these conditions greenness loss could be modeled by two consecutive first‐order degradation steps. Temperature dependency of the rate constants for both degradation steps could be described by the Arrhenius equation with activation energies increasing with pressure. However, their pressure dependency could not satisfactorily be described by the Eyring equation.
Modeling Milk Clotting Activity in the Continuous Production of Microbial Rennet from Mucor miehei
Authors: Seker S. , Beyenal H. , Tanyolaç A.
Published: July 2006

Production of microbial rennet, a milk clotting enzyme, from a commercial strain of Mucor miehei (NRRL 3420) was investigated in a continuously fed fermenter system for prolonged periods. The spherical film‐wise growth of the culture has been accomplished and the effects of medium pH, mixing and dilution rates, and feed of D‐glucose concentration on milk clotting activity was investigated. In model simulation studies, maximum milk clotting activity was generated from a multiple linear function. This was expressed in terms of fermentation medium pH, D‐glucose, dissolved oxygen concentrations and dilution rate at the time of maximum milk clotting activity.
Physicochemical Properties of Dry Red Kidney Bean Proteins and Natural Microflora as Affected by Gamma Irradiation
Authors: Dogbevi M. K. , Vachon C. , Lacroix M.
Published: July 2006

Gammaγ‐irradiation affected (p≤0.05) the physicochemical properties of dry red kidney beans (Phaseolus vulgaris.) Protein deamidation, solubility and hydrophobicity increased and the number of sulfhydryl groups was reduced after irradiation. Irradiation also affected the outgrowth of natural mold contaminants. A dose of 1.5 kGy reduced the number of molds by 2 log cycles immediately after the treatment. However, incomplete inhibition was observed with the highest irradiation dose (3 kGy). Species of Aspergillus and Penicillium. were completely inhibited at 1.5 and 3 kGy respectively.
Rapid Detection of Pseudomonas in Seafoods Using Protease Indicator
Authors: Jabbar H. , Joishy K. N.
Published: July 2006

The effects of Pseudomonas and the proteases it synthesizes in seafoods rendering them unfit for consumption are not fully recognized. A sandwich enzyme‐linked immunosorbent assay (ELISA) was developed wherein protease produced by Pseudomonas isolated from shrimp was used as antigen, and anti‐protease IgG conjugated with alkaline phosphatase was the second antibody. Purified protease and seafood samples, naturally contaminated or artificially inoculated with Pseudomonas, were positive by ELISA. The conventional culture method took 3 days to complete, but ELISA detected Pseudomonas with in 24h. The rapidity, simplicity and efficacy of this test make it useful for implementation of HACCP systems.
Primers for Amplifying an Alanine Racemase Gene Fragment to Detect E. coli Strains in Foods
Authors: Yokoigawa K. , Inoue K. , Okubo Y. , Kawai H.
Published: July 2006

Specific oligonucleotide primers for detecting Escherichia coli in various foods were designed based upon the conserved sequences of the E. coli air gene from positions 322 to 345 and from 664 to 687. Bacteria and food samples were treated at 100°C for 10 min in 1% Tween 20 containing 5% NaCl and 1 mM EDTA, then used as templates for polymerase chain reaction (PCR). The oligonucleotide primers were specific to E. coli, except for Shigella species, when tested with 67 strains of E. coli, including such serotypes as O157:H7 and O111, and 32 strains of non‐E. coli species. The oligonucleotide primers could prove useful for detecting E. coli in beef, chicken, pork, tomato, soybean, potato, cow's milk, and egg.
Antiplasticization by Water in Reduced‐Moisture Food Systems
Authors: Seow C.C. , Cheah P.B. , Chang Y.P.
Published: July 2006

Antiplasticization of synthetic glassy polymers by low‐molecular weight diluents at low concentrations is a well‐known phenomenon which leads to increased rigidity rather than flexibility of the polymer‐diluent blends. Based on the food polymer science approach, we hypothesized that increases (rather than decreases) in modulus and brittleness, commonly observed when certain solid food systems are humidified from the dry state, are synonymous with antiplasticization by water. Sugars and polyols, important components of foods, behave in much the same manner as water in acting as either antiplasticizers or plasticizers of food polymer systems. Several mechanisms may be involved in antiplasticization by low‐molecular mass diluents. Simultaneous changes in various physical properties, resulting from antiplasticization or plasticization by water and other diluents, may profoundly influence the quality and acceptability of food products.