bluuebunny/crossref_metadata_2025 huggingface dataset:
Restructured Reindeer Steak Quality as Affected by Antioxidants and Frozen Storage
Authors: SWANSON R.B. , PENFIELD M.P. , DORKO C.L. , BARON R.F.
Published: August 2006

Restructured steaks were fabricated from forequarter muscles from field‐slaughtered Alaskan reindeer. Steaks were formulated with an antioxidant (1:1 mixture of BHA and TBHQ with a propylene glycol carrier) at 0.00, 0.01 and 0.02% of the fat and 0.5% salt. Steaks were flash‐frozen, vacuum‐packaged and stored at −18°C. Instrumental and sensory testing was conducted after storage (2, 6, 10, 14, 18, 22 wk). Minimal effects occurred on moistness, greasiness, softness and chewiness. Gamy flavor intensity decreased and off‐flavor intensity fluctuated with storage and antioxidant. Effects of antioxidants on color were not notable. Use of the antioxidant system is not justified by any oxidative or color effects. Frozen storage was not detrimental to restructured steak quality.
Tyrosinase, Laccase, and Peroxidase in Mushrooms (Agaricus, Crimini, Oyster, and Shiitake)
Authors: FLURKEY WILLIAM H. , KUGLIN JILL , DAWLEY RUTHELLEN
Published: August 2006

Enzyme assays and electrophoresis were used to monitor the activity of tyrosinase, laccase, and peroxidase in Agaricus bisporus (common cultivated button mushrooms and Crimini mushrooms), Oyster, and Shiitake mushrooms. The three enzymes could be differentiated using specific substrates and inhibitors. Tyrosinase seemed to be the major phenol oxidase in the Agaricus strains, while Oyster and Shiitake mushrooms had much lower levels. Peroxidase activity was low or undetectable in all types examined. Control of enzymatic browning in different mushroom types may depend upon the distribution of different oxidases within any given type.
Kiwifruit Juice Clarification using a Fungal Proteolytic Enzyme
Authors: DAWES H. , STRUEBI P. , KEENE J.
Published: August 2006

A commercial fungal proteolytic enzyme from Aspergillus niger was used in kiwifruit juice as a replacement for conventional fining agents to produce a stable clarified juice. Reductions in detectable protein levels of 73% and 82% were achieved using 500 mg/kg of enzyme and incubating at 60°C for 20 and 60 min respectively. Concentrates prepared from proteolytic enzyme‐treated juice had reduced browning and haze formation compared to a control, without affecting ascorbic acid level. When stored at 20°C, proteolytic enzyme treated concentrates (60 min) remained clear up to 90 days and had minimal haze (A650 nm= 0.047) and browning (A420 nm= 0.93) after 6 mo storage. The molecular size of the protein as well as protein concentration are important factors in haze formation.
Pigments of Monascus
Authors: BLANC P.J. , LORET M.O. , SANTERRE A.L. , PAREILLEUX A. , PROME D. , PROME J.C. , LAUSSAC J.P. , GOMA G.
Published: August 2006

A chemically defined medium with glutamic acid as nitrogen source was devised for the culture of two species of Monascus (M. ruber and M. purpureus), resulting in optimum production of their pigments and their chemical structures (both free and complexed) were compared. Structural data on two major complex pigments in aqueous solution were obtained by IR, UV, NMR and MS. They were free pigments linked to glutamic acid by amino groups, where nitrogen replaced the pyronoid oxygen.
Barrel‐Valve Assembly Affects Twin‐Screw Extrusion Cooking of Corn Meal
Authors: LIANG M. , HSIEH F. , HUFF H.E , HU L.
Published: August 2006

The effects of a barrel‐valve assembly on extrusion system dynamics and product properties with various screw speeds and specific feeding loads (SFL) were studied using an APV Baker twin‐screw extruder. Turning the barrel‐valve from the open to closed position resulted in a convex response of die pressure due to the axial offset of paired orifice plugs, with concomitant changes in system responses and extrudate properties. Variations in SFL by changing feed rate or screw speed caused more pronounced effects on product properties compared with barrel‐valve control.
Microwave Bumping: Quantifying Explosions in Foods During Microwave Heating
Authors: FU Y.C. , TONG C.H. , LUND D.B.
Published: August 2006

An apparatus was developed to quantify the degree of bumping due to the explosion of food particulates during microwave heating. The apparatus consisted of a sound recording device, a digital storage oscilloscope, and an electric filter. Degree of bumping for a product was defined by integration of the magnitude of an explosion over time of bumping. The sound spectrum of explosion was analyzed by Fast Fourier Transform (FFT) analysis. Frequency of bumping was usually in the range 1.6 kHz to 8 kHz. The character of microwave bumping varied according to localized microwave superheating effects, product formulations, and prior heat treatment of the food.
Water Activity, Glass Transition and Microbial Stability in Concentrated/Semimoist Food Systems
Authors: CHIRIFE JORGE , MARÍA DEL BUERA PILAR
Published: August 2006

This review examines recent published suggestions that “water dynamics” may be applied instead of water activity (aw) determination to predict microbial stability of concentrated and intermediate moisture food systems. Factors such as the relative effectiveness of additives for antimicrobial stabilization through aw‐lowering (i.e. glucose vs fructose, glycerol vs propylene glycol) and the importance of glass transition temperature as an indicator of microbial stability were examined, based on available experimental data. Determination of the glass‐rubber transition characteristics and/or the use of the “water‐dynamics” map does not enable prediction of the microbial stability of foods (i.e. inhibition of growth) with confidence. These were no more effective alternatives than the concept of water activity as a basis for predicting microbial growth in foods.
Temperature Affects Microstructure of Renneted Milk Gel
Authors: LAGOUEYTE N. , LABLEE J. , LAGAUDE A. , DE LA FUENTE B. TARODO
Published: August 2006

Scanning electron microscopy (SEM) and permeability measurements were used to evaluate the effect of coagulation temperature on renneted reconstituted milk gel characteristics (gelation and coagulation), especially with regard to gel microstructure and permability. SEM of milk gel showed casein micelle strands and clusters linked to form a very porous framework with gaps delimited by discontinuous walls. Casein micelles fused together more tightly and strands and clusters became denser and thicker as coagulation temperature increased, resulting in a more open structure with increased permeability.
Arnott Test Correlates with Dynamic Rheological Properties for Determining Cheddar Cheese Meltability
Authors: USTUNOL Z. , KAWACHI K. , STEFFE J.
Published: August 2006

Cheddar cheese with six different fat levels (34.3, 31.5, 26.8, 20.5, 12.6 and <1%) were manufactured and allowed to ripen 4 mo at 7°C. Melting characteristics of the cheeses were studied by the Arnott test and dynamic rheological testing. Meltability of Cheddar cheese was significantly influenced by its fat content as determined by the Arnott test. A significant correlation (r =–0.80) occurred between the minimum complex modulus G′ and meltability of Cheddar cheese. Minimum complex modulus G′ may be a useful predictor of cheese meltability.
Fynbo Cheese NaCl and KCl Changes during Ripening
Authors: ZORRILLA SUSANA E. , RUBIOLO AMELIA C.
Published: August 2006

In a model study we assumed that the cheese is a homogeneous solid with nonuniform initial concentration distributions, cheese surfaces are rendered impermeable after brining, and the generalized Fick's law form is valid for expressing the diffusive fluxes of solutes. NaCl and KCl concentrations at selected positions during distribution in Fynbo cheese kept at 12°C, after salting 10 hr in a brine of 100 g NaCl/L and 100 g KCl/L at the same temperature, were determined experimentally and compared with predicted values with the model at different storage times up to 30 days. Homogeneous distribution of solutes was reached at 20 days ripening, as predicted by the model and verified experimentally.
Activation Mechanisms of Pro‐Phenoloxidase on Melanosis Development in Florida Spiny Lobster (Panulirus argus) Cuticle
Authors: ALI M.T. , GLEESON R.A. , WEI C.I. , MARSHALL M.R.
Published: August 2006

Phenoloxidase (PO), pro‐PO [1] and pro‐PO [2], isolated from cuticular extracts of early premolt spiny lobster, resolved into doublets of molecular weights 156, 151, and 96.0, 93 kD, respectively. Trypsin‐activated forms of pro‐PO [1] and pro‐PO [2] were 123 and 83.6 kD, respectively. Apparently melanosis of shell and hyperdermal tissue in lobsters was related to stage of molt. The pro‐PO forms were activated in vitro by extracts of molting fluid which is secreted into the cuticle just before molt, and the activated PO co‐migrated in SDS‐PAGE with the endogenously activated PO. The molting fluid was hypothesized to be the source of the natural activator(s) of pro‐PO.
Leavened Dough pH Determination by an Improved Method
Authors: MILLER R. A. , GRAF E. , HOSENEY R. C.
Published: August 2006

pH measured on a 10% slurry may overestimate values on canned biscuit doughs because of carbon dioxide evolution during slurry preparation. Therefore, a pH method using a surface pH electrode was developed and used to measure pH of biscuits in sealed cans and after opening. pH increased upon opening and continued to increase gradually for 5 min. The slurry method overestimated true dough pH and did not show pH change with time. pH of yeast‐leavened bread dough measured by the slurry method was also higher than that by the surface method. The surface pH electrode is a reliable, accurate method of pH determination in leavened doughs.
Candida and Pseudomonas Lipase‐Catalyzed Hydrolysis of Butteroil in the Absence of Organic Solvents
Authors: MARANGONI ALEJANDRO G.
Published: August 2006

Candida rugosa lipase (CRL) and Pseudomonas fluorescein lipase (PFL) were used to hydrolyze a low‐melting point butteroil fraction in the absence of orgaic solvents. CRL and PFL displayed pH activity optima of 6.7 and 7.8, and temperature‐activity optima of 40–50°C and 35°C, respectively. Maximum activity for PFL was observed at 5% (v/v) water content. CRL showed higher specificity towards butyric acid relative to PFL after 3 hours of hydrolysis at 40°C (22.3 mol% vs 7.8 mol%, respectively). Both enzymes displayed, however, high specificities towards palmitic and oleic acids. CRL's inherent specificity towards butyric acid makes it an ideal choice for a biological catalyst to generate useful dairy flavor profiles.
Crosslinking Kinetics of Thermally Preset Alginate Gels
Authors: CHAVEZ MÓNICA S. , LUNA JULIO A. , GARROTE RAUL L.
Published: August 2006

The Sharp‐Interface model was used to describe the crosslinking kinetics of thermally preset calcium alginate gel at constant temperature. The model assumes diffusion of calcium ions through a preformed gel of sodium alginate and a selected carrier, and an instantaneous reaction between the calcium and sodium alginate. The proposed model was experimentally verified using two different carriers at the following concentrations: agar 0.6(g/100 mL)‐0.8(g/100 mL), and gelatine 4(g/100 mL); sodium alginate concentrations were 1(g/100 mL) and 1.5(g/100 mL), while a 2(g/100 mL) calcium lactate solution was used as calcium ion source. The diffusion coefficient of calcium ion was determined using a cell diffusion model. The model can be used to predict processing effects on food gels.
β‐Lactoglobulin Separation from Whey Protein Isolate on a Large Scale
Authors: MATÉ JUAN I. , KROCHTA JOHN M.
Published: August 2006

A method for obtaining large quantities of β‐lactoglobulin (β‐Lg) from commercial whey protein isolate (WPI) was developed. β‐Lg was separated from the rest of the whey proteins in a solution of 15% (W:W) WPI in distilled water adjusted to pH 2 and 7% NaCl. β‐Lg was then separated from NaCl using diafiltration. The results indicate that more than 65% of the β‐Lg originally in the WPI solution was recovered. The purity of the β‐Lg was greater than 95%.
Deposited Whey Protein Layers influence Solute Rejection in Reverse Osmosis
Authors: SCHWAB C. , KESSLER H. G.
Published: August 2006

A membrane process is often accompanied by build‐up of deposited layers on the membrane surface. Such layers change the performance of the system (e.g. the flux and rejection of solutes). Whey proteins were deposited on a reverse osmosis membrane to increase solute rejection. A gel‐like deposited layer increased the rejection level of the system, while a porous deposited layer did not affect it. Further, in‐situ denaturation of whey proteins helped to form the effective gel‐like secondary membrane.
Packaging Influenced Total Chlorophyll, Soluble Protein, Fatty Acid Composition and Lipoxygenase Activity in Broccoli Florets
Authors: ZHUANG H. , BARTH M.M. , HILDEBRAND D.F.
Published: August 2006

Polyunsaturated fatty acid (PUFA) degradation by lipoxygenase (LOX) may contribute to postharvest deterioration of vegetables and fruits. In broccoli, modified atmosphere packaging (MAP), automatic misting (AM) and vent packaging (VP) may reduce postharvest deterioration. MAP storage resulted in increased chlorophyll and C‐18 polyunsaturated fatty acids (PUFA) in broccoli florets by 96 hr. Reduced chlorophyll, PUFA and soluble protein were observed in nonpackaged (NP) samples. Chlorophyll remained near initial levels in vent packaged (VP) products. AM resulted in increased relative PUFA and reduced losses of soluble protein. VP reduced PUFA and soluble protein. Optimal pH of broccoli floret LOX was 5.5‐6.0. Water‐soluble LOX activity in MAP and NP samples followed a trend similar to PUFA changes in both samples. No differences were found among treatments when enzyme activity was expressed on soluble protein basis.
Lactobacillus plantarum survival in aerobic., directly brined olives
Authors: DURAN M.C. , GARCIA P. , BRENES M. , GARRIDO A.
Published: August 2006

Storage at 20°improved Lactobacillus plantarum survival in directly brined olives. The best inoculation dates were on the first and fifth days after brining for Cacereña and Hojiblanca cultivars respectively. Lb. plantarum was present throughout the storage period only in Hojiblanca olives covered with initial free‐salt solution and inoculated on the fifth day. In the presence of that bacterium, titratable acidity (0.5‐1%) and pH (<4.0) reached proper values for olive preservation. Yeast populations, consisting of Pichia membranaefaciens and Pichia fermentans, in Hojiblanca, and Pichia minuta, Pichia fermentans, Pichia membranaefaciens, and Rodotorula spp, in Cacereña, were found in all treatments.
Shelf Life of Minimally Processed Honeydew, Kiwifruit, Papaya, Pineapple and Cantaloupe
Authors: O'CONNOR‐SHAW R. E. , ROBERTS R. , FORD A. L , NOTTINGHAM S. M.
Published: August 2006

This study was to determine the shelf life of minimally processed honeydew melon, kiwifruit, papaya, pineapple, and cantaloupe stored at 4°C. Sensory assessments were carried out at 3‐day intervals by highly trained panels until the end of shelf life. Microbiological counts were made immediately after dicing fruit and at the end of shelf life. Results indicated that both the length of shelf life and type of spoilage were related to fruit species. Minimally processed fruit had longer shelf life at 4°than at temperatures recommended for whole fruit when these were greater than 4°C. Spoilage of 4°C‐stored kiwifruit, papaya and pineapple pieces was not a consequence of microbial growth.
Sunflower Head Residue Pectin Extraction as Affected by Physical Conditions
Authors: CHANG K. C. , DHURANDHAR N. , YOU X. , MIYAMOTO A.
Published: August 2006

Effects of extraction pH, temperature, and time on yield and quality of pectin from sunflower heads (Interstate cultivar) were investigated. The low‐methoxyl pectin was extracted, using 0.75% sodium hexametaphosphate at pH 3, 4, and 5 and at 75, 85, and 95°for 20, 40, and 60 min, respectively. Yield, molecular mass, and firmness of jellies of the pectins were determined. Three‐way statistical analysis on yield, molecular mass and gel firmness showed strong interactions among pH, temperature and time. Highest yields were obtained at pH 5, 95°for 20 min and pH 4, 85°for 40 min. Pectin extracted for 40 min at pH 3 and 4 and at 85°and 75°C, respectively, had the highest molecular mass. Gel firmness of sunflower pectin prepared at pH 5.4 was higher than that of a commercial citrus pectin.
Oxidative Stability in Raw and Roasted Pecans: Chemical, Physical and Sensory Measurements
Authors: ERICKSON M. C. , SANTERRE C.R. , MALINGRE M. E.
Published: August 2006

To develop predictive relationships for sensory responses of crunchiness and rancid aroma and flavor, raw and roasted pecans were stored under two different relative humidities (55 and 65%) up to 8 mo. In response to relative humidity, rancid scores did not differ with either raw or roasted pecans. Rancid scores in raw and roasted pecans during storage most closely paralleled peroxide value and thiobarbituric acid reactive substances, respectively. Multiple regression models employing two or three oxidative and chemical measurements led to better prediction of sensory scores. In general, primary oxidative products of triacylglycerols factored into the models for raw pecans while secondary oxidative products of total lipids factored into the models for roasted pecans.
Perception of Taste and Viscosity of Oil‐in‐Water and Water‐in‐Oil Emulsions
Authors: MARTIN N. BARYLKO‐PIKIELNA A. , MELA D. J.
Published: August 2006

A trained panel performed sensory assessments of intensity of taste and viscosity of 50% oil‐in‐water and water‐in‐oil emulsions prepared with varied concentrations of sucrose, NaCl, or citric acid. No main effects of emulsion type occurred for taste intensity or slope of the tastant concentration – intensity relationships. NaCl and citric acid increased perceived viscosity of both emulsion types, and these effects were most pronounced in oil‐in‐water emulsions. The results are hypothesized as related to functions of saliva and breakdown of emulsion structure in the mouth.
Food Packaging Polymer Films as Aroma Vapor Barriers at Different Relative Humidities
Authors: JOHANSSON F. , LEUFVEN A.
Published: August 2006

The influence of humidity on the sorption, diffusion and permeation of alcohols and aldehydes in three common food packaging polymers (linear low density polyethylene, LLDPE; high density polyethylene, HDPE; and ethylene vinyl alcohol copolymer, EVOH) was investigated. Higher humidity decreased diffusion of alcohols, and increased diffusion of aldehydes. This might be explained by the combination of the plasticizing effect of water with the interaction between aroma and water vapors. Relative humidity (RH%) had a greater influence on barrier properties of polyethylene film with lower crystallinity (i.e. LLDPE) than on more crystalline film (i.e. HDPE). The effect of water was more pronounced on polar EVOH film.
Vacuum‐Packaged Precooked Pork from Hogs Fed Supplemental Vitamin E: Chemical, Shelf‐Life and Sensory Properties
Authors: CANNON J.E. , MORGAN J.B. , SCHMIDT G.R. , DELMORE R.J. , SOFOS J.N. , SMITH G.C. , WILLIAMS S.N.
Published: August 2006

Precooked longissimus chops and semimembranosus/adductor roasts from pigs (n = 30) given no supplemental vitamin E (CON) or supplemented with 100 mg vitamin E/kg diet (VITE) were evaluated for lipid oxidation, microbial growth, sensory characteristics, cooking/storage losses and reheating losses. Chops and roasts were vacuum packaged, precooked to 60°C and stored at 2°C for 0, 7, 14, 28, or 56 days. Lipid oxidation was lower in VITE chops and roasts than in CON chops and roasts. Off‐flavor intensity scores were more acceptable and storage/ cooking losses were lower for VITE roasts than for CON roasts. Supplementation of vitamin E in a swine diet provided added protection against lipid oxidation and precooking pork under vacuum provided a palatable product with a shelf‐life of 56 days.
Rheological Properties of Cheddar Cheese as Influenced by Fat Reduction and Ripening Time
Authors: USTUNOL Z. , KAWACHI K. , STEFFE J.
Published: August 2006

Fat reduction in Cheddar cheese resulted in an increase in viscoelasticity as evidenced by increases in G’and G”. Proteolysis during ripening led to softening of all cheeses and thus decreases in G’and G” for cheeses containing 34, 27, and 20% fat. Cheese with 13% fat showed a decrease in G’upon ripening, but no change in G”. This lack of change in viscous behavior may be important to the texture of reduced‐fat Cheddar cheese and overall acceptability. Dynamic rheological testing was helpful in understanding rheological behavior associated with fat reduction in cheese.
Blanch Temperature/Time Effects on Rheological Properties of Applesauce
Authors: USIAK A. M. GODFREY , BOURNE M. C. , RAO M. A.
Published: August 2006

Peeled and cored ‘Idared’ and ‘Rome’ apples were blanched in water for 20, 40, and 60 min at 35°. 47°. 59°. 71°. and 83°C minor to making into applesauce by a conventional process each month from Nov. through March. USDA Consist meter values decreased as blanch temperature increased from 35° to 59°C and increased again from 71° to 83°C. There was little variation in flow behavior index (“n” values). Yield stress increased as blanch temperature increased from 35° to 59°C and decreased from 71° to 83°C. The consistency index (K) and serum viscosity were almost unchanged by blanching temperature but both decreased with increasing storage time of fresh fruit. Blanching apples at 59° to 71°C before making into applesauce gave substantially thicker sauces than unbalanced apples.
Dehydrated Precooked Pinto Bean Quality as Affected by Cultivar and Coating Biopolymers
Authors: SU H.L. , CHANG K.C.
Published: August 2006

The relationship of cultivars and coating treatment to quality of precooked dehydrated pinto beans was investigated. The pinto cultivars, studied were Fiesta, Othello, and Topaz, and 12 types of biopolymers, including modified starches, dextrins, maltodextrins, and alginate, were used as coating agents. Beans were blanched, soaked, steam cooked, coated by dipping in biopolymer solutions at 70°C and dried in a convection oven. Eight biopolymers effectively reduced splitting of beans without detrimental effects on rehydration, firmness, or color. Cultivar had a strong effect on wholeness of bean products and Fiesta was best for dehydration. Residual trypsin inhibitor activity of precooked pinto beans was ∼5%.
Nonspecific Enzyme‐Linked lmmunosorbent Assay for Molds in Foods
Authors: YONG R.K. , COUSIN M.A.
Published: August 2006

A nonspecific enzyme‐linked immunosorbent assay (ELISA) was developed to detect molds in foods by producing an antibody to a mixture of six common molds, Aspergillus versicolor, Cladosporium herbarum, Fusarium poae, Geotrichum candidum, Mucor circinelloides, and Penicillium chrysogenum. This antibody recognized these mold genera plus 10 others but not yeasts. Mold antigens added into Cheddar and cottage cheeses, fruit juices, nonfat dry milk, raisins, and yogurt could be detected. Molds (102 spores/g) inoculated into cottage cheese and yogurt and allowed to grow at 7 or 22°C were detected at 103 CFU/g. A nonspecific ELISA could be developed to detect general mold contamination of foods.
Plaice Skin Collagen Extraction and Functional Properties
Authors: MONTERO P. , ALVAREZ C. , MARTÍ M. A. , BORDERÍAS A. J.
Published: August 2006

Solutions and mechanical treatments for decolorizing and washing of collagen from plaice (Pleuronectes plutessa) skin were studied. The best means was high‐speed homogenization with 0.4M NaCl. Four ways of stabilizing this collagen were tried, involving freezing and freeze‐drying, and partial solubilization with 0.05M acetic acid prior to freezing or freeze drying or without partial solubilization. Only freeze‐drying caused reduction in solubility and emulsifying capacity. Viscosity was greatest when samples were pre‐solubilized. Emulsifying capacity was not changed when samples were frozen and decreased when they were either freeze‐dried or presolubilized. Optimum water‐holding capacity occurred in samples which had been previously solubilized.
Formulation and Copping Temperature Effects on Beef Frankfurters
Authors: HENSLEY J.L. , HAND L.W.
Published: August 2006

Frankfurters were manufactured using four fat and added water (AW) formulations (10% fat/30% AW; 15%/25%; 20%/20%; 30%/10%) and processed at chopping temperatures 9, 12, or 15°C. The batters were stuffed into cellulose casings, thermally processed, chilled and vacuum‐packaged. Frankfurters were analyzed for proximate composition, textural properties and purge. No differences occurred among treatments for processing yield (89.8%± 1.83). Frankfurters chopped to 12°C had the highest (P < 0.05) Kramer peak force values. As expected, purge increased in all treatments as storage time increased (P < 0.05). As AW increased, hardness and cohesiveness decreased and purge increased. Water level and fat reduction were the most critical factors affecting quality.
Partitioning of Printing Ink Solvents on Chocolate
Authors: AN DUEK‐JUN , HALEK G.W.
Published: August 2006

Partitioning (Kp) of printing ink solvents was studied in three types of chocolate with different fat content and degrees of crystallinity. At 25°C, chocolate liquor (48% fat and medium crystallinity) showed a higher Kp than chips (25% fat and higher crystallinity), but cream (29% fat and lowest crystallinity) showed the highest Kp. Order appeared to depend on degree of crystallinity. At 35°C and 45°C as samples became increasingly molten, effect of crystallinity diminished and order of increasing Kp depended on fat content. Kp order of solvents was the same in all chocolates and temperatures: toluene > isopropanol > methyl ethyl ketone > ethyl acetate > hexane in accord with Hildebrand solubility parameter differences.
Frozen Carrots Texture and Pectic Compotients as Affected by Low‐Temperature‐Blanching and Quick Freezing
Authors: FUCHIGAMI MICHIKO , MIYAZAKI KOICHI , HYAKUMOTO NORIKO
Published: August 2006

Carrots preheated for 2 hr at 60°C and then cooked became firmer than raw or cooked carrots. After preheating, the amount of high methoxyl pectin decreased, and low methoxyl pectin increased. Firmness of carrots decreased through freezing then thawing, but preheated carrots retained firmer texture than those blanched in boiling water. Quick‐freezing resulted in better texture than slow‐freezing. Loss in texture was accompanied by release of pectin. Slow‐freezing accelerated release of pectin as compared to quick‐freezing. Preheated carrots were slower in release of pectin. The degree of esterification of pectin substances in raw carrots decreased during preheating, freezing and thawing. Cell damage in quick frozen carrots was slight. Optimum preheating occurred with 30 min at 60°C or 5 min at 70°C. Preheating and then quick freezing were effective in improving texture of frozen carrots.
Chemical Pretreatment and Microfiltration for Making Delipidized Whey Protein Concentrate
Authors: KARLESKIND D. , LAYE I. , MEI F‐I , MORR C.V.
Published: August 2006

Chemical pretreatment, microfiltration (MF) and ultrafiltration (UF) were applied to produce delipidized whey protein concentrates (WPC). Processes including both chemical pretreatment and MF resulted in WPC with <0.5% lipids. Low‐pH UF and isoelectric point (PI) precipitation were more effective for lipid removal than chemical pretreatment by thermocalcic aggregation. Protein permeation ratios in MF processes were improved by UF preconcentration of whey. Protein permeation and flux were different between the two MF membranes used. Isoelectric point precipitation increased β‐Lg contents, but not α‐La, in the resulting WPC (B). Minor proteins exhibited lower concentrations in WPC B and MF WPC products.
Antioxidative Activity of Maillard Reaction Products in Cooked Ground Beef, Sensory and TBA Values
Authors: SMITH J. SCOTT , ALFAWAZ MOHAMMED
Published: August 2006

Maillard reaction products (MRPs) obtained by autoclaving egg albumin acid hydrolysate and glucose for 1 hr were added to ground beef which was cooked and stored at 4°C for 8 days. The antioxidative activity of MRPs was investigated by a trained sensory panel and the TBA test. The panel evaluated samples for loss of desirable cooked beef notes and generation of off‐flavors, such as cardboard and painty. With added 1% MRPs, painty aroma and flavor scores were low and did not (p > 0.05) change over time. The coefficients of determination were high (r2= 0.92 to 0.77, p < 0.0001) between aroma and flavor scores for any two similar attributes. The TBA values decreased by 17% with the addition of 0.5% MRP and by 39% with 1% MRP over time.
Lactate Dehydrogenase Monoclonal Antibody Immunoassay for Detection of Turkey Meat in Beef and Pork
Authors: WANG CHENG‐HSIN , SMITH DENISE M.
Published: August 2006

Relative epitope binding positions on turkey muscle LDH of four monoclonal antibodies (MAbs) was determined by comparing the absorbance by sandwich ELISA from different combinations of capture and biotinlabeled detector MAbs. Epitopes for MAbs E6B and B3C were close to each other. Binding of MAb B3C and G4D did not inhibit binding of D5E to LDH, thus a sandwich ELISA using D5E as capture MAb, and biotin‐labeled B3C as detector MAb was developed. The LDH MAb sandwich ELISA detected 1% adulteration of turkey breast or thigh muscle in raw beef and pork.
Pressure‐Induced Dimerization of Metmyoglobin
Authors: DEFAYE A.B. , LEDWARD D.A.
Published: August 2006

Pressure treatment at 7.5 kbar of solutions of metmyoglobin led, as shown by electrophoresis and chromatographic analysis, to the formation of spectrally similar monomeric and dimeric forms. The dimer was formed in the pH range 6–10, though maximum formation was around the isoelectric point (pH 6.9). At acid pH no dimer or higher oligomers formed. In sodium chloride (0.5 to 2M), at neutral pH lower concentrations of dimer formed than in its absence. The dimer was stabilized by SDS‐labile linkages and had a slightly lower thermal denaturation temperature than the monomer. If similar changes occur with other proteins, then food quality may be modified by pressure treatments.
Surimi‐Based Imitation Crab Characteristics Affected by Heating Method and End Point Temperature
Authors: BERTAK JULIA ALBERTINE , KARAHADIAN CAROL
Published: August 2006

Sensory panel scores and Instron compression tests indicated baked and microwaved imitation crab legs were softer (P < 0.05) than unheated controls. Sensory scores further indicated that baked samples were softer (P < 0.05) and less chewy than microwaved samples. End point temperature to which samples were heated (71°C and 93°C) had no effect on results. No differences in moisture content were found among samples, but heated samples were lower (P < 0.05) in expressible moisture than unheated controls. Heating may have caused free water to rebind with starches in the product, thus decreasing expressible moisture, which contributed to decreases in firmness and chewiness.
Microbial Transglutaminase and ε‐(γ‐Glutamyl)lysine Crosslink Effects on Elastic Properties of Kamaboko Gels
Authors: SEGURO KATSUYA , KUMAZAWA YOSHIYUKI , OHTSUKA TOMOKO , TOIGUCHI SEIICHIRO , MOTOKI MASAO
Published: August 2006

Kamaboko gels from Alaska pollock surimi (SA™ and 2nd™ grades) were prepared by setting at 10 or 45°C with Microbial transglutaminase (MTGase) and its effect on gel properties was investigated. At 10 and 45°C, gels from 2nd™ grade surimi paste showed increases in breaking strength, without decline in deformation. Gel from SA™ graded surimi paste showed an increase in breaking strength with no changes in deformation in 45°C setting, up to 0.03% MTGase. Crosslinking of myosin heavy chains through ε‐(γ‐glutamyl)lysine bonds was observed and a possible correlation was shown between ε‐(γ‐glutamyl)lysine content and gel strength (breaking strength X strain). ε‐(γ‐Glutamyl)lysine content up to 3 μmol/100g or MTGase 0.03% or higher improved gel properties.
Fresh Mushroom Quality as Affected by Modified Atmosphere Packaging
Authors: ROY S. , ANANTHESWARAN R.C. , BEELMAN R.B.
Published: August 2006

The effect of O2 concentration, at 2–6% CO2 on shelf‐life of fresh mushrooms in modified atmosphere packages (MAP) was studied. For conventional mushrooms optimum in‐package O2 was 6% to reduce cap development. Mushrooms irrigated with 0.3% calcium chloride during cropping had a higher rate of maturation and optimum O2 was 2% during storage. At this low O2 concentration, however, storage may be potentially hazardous and is not recommended. Surface moisture of mushrooms significantly increased during storage and may have obscured any beneficial effect of MAP on mushroom color. Precise control of relative humidity in the package is recommended.
Antioxidant Activity and Total Phenolics in Different Genotypes of Potato (Solanum tuberosum, L.)
Authors: AL‐SAIKHAN M.S. , HOWARD L.R. , MILLER J.C.
Published: August 2006

Antioxidant activity of potato compared with that of broccoli, onion, carrot and bell peppers was higher than all except broccoli. Patatin appeared to be the major water‐soluble compound that showed antioxidant activity. The activity varied among potato cultivars, but was not related to flesh color or total phenolics. Antioxidant activity was evenly distributed within tuber parts and/or sections, except for skin tissue which had the greatest antioxidant activity and total phenolic content. Total phenolics varied among cultivars, with some containing twofold higher concentrations than other cultivars. Phenolic content differences were genotype dependent and not related to flesh color.
Some Antinutritional Factors in Moringa peregrina (Al‐Yassar or Al‐Ban) and Soybean Products
Authors: AL‐KAHTANI HASSAN A.
Published: August 2006

Moringa peregrina and soybean defatted flours, protein concentrates, and isolates were assayed for trypsin (TIA) and α‐amylase (AIA) inhibitor activities, phytic acid, tannin and chlorogenic acid contents, and in vitro protein digestibility (IVPD). TIA in M. peregrina defatted flour (MDF) was lower (P < 0.05) but more heat resistant than in soybean. AIA in MDF was lower than in soybean and inhibited pancreatic amylase more than bacterial amylase. Some M.peregrina products were higher in phytic acid but lower in chlorogenic acid than soybean. Tannin was low in all samples. IVPD was slightly lower for M.peregrina than for soybean.
Direct ELlSAs for Sulfathiazole in Milk and Honey with Special Emphasis on Enzyme Conjugate Preparation
Authors: THOMSON CARRIE A. , SPORNS PETER
Published: August 2006

Direct competitive enzyme‐linked immunosorbent assays (ELISAs) were developed for sulfathiazole (ST) analysis. Polyclonal antibody rabbit serum adsorption to polystyrene microtiter plates was enhanced using a 1 μg/mL Protein A precoating solution. Detection limits (20% reduction in maximum enzyme signal) for ST in milk and honey were 12.0 and 34.7 ppb (ng/L), respectively. ST‐horseradish peroxidase (HRP) conjugates prepared by linking the N4‐amino group of ST to periodate‐treated HRP were more efficient than those prepared using a more conventional two‐step glutaraldehyde method. This represents a new method of preparing sulfonamide conjugates for use in ELlSAs.
Predicting Milk Shelf‐life Based on Artificial Neural Networks and Headspace Gas Chromatographic Data
Authors: VALLEJO‐CORDOBA B. , ARTEAGA G.E. , NAKAI S.
Published: August 2006

The usefulness of artificial neural networks (ANN) for milk shelf‐life prediction by multivariate interpretation of gas chromatographic profiles and flavor‐related shelf‐life was evaluated and compared to principal components regression (PCR). The training set consisted of dynamic headspace gas chromatographic data collected during storage of pasteurized milk (input information for the neural network used to make a decision) and its corresponding shelflife (prediction or response). ANN had better predictability than PCR. A standard error of the estimate of 2 days in shelf‐life resulting from regression analysis of experimental vs predicted values indicated a high predictability of ANN.
Sensory Evaluation of Reduced Fat Cheeses
Authors: DRAKE M.A. , HERFETT W. , BOYLSTON T.D. , SWANSON B.G.
Published: August 2006

The objectives of this research were to compare the effects of seven make‐procedures on the sensory quality of reduced fat Monterey Jacktype cheeses. Modifications (decreased cook temperature, decreased ripe time, decreased starter, homogenization, added milk‐solids‐not‐fat, added flavor cultures, and washed curd) were incorporated into standard make‐procedures for 33% reduced fat (RF) Monterey Jack‐type cheeses. Two controls, a standard full fat cheese, and a standard RF cheese, were also prepared. Cheeses were aged 3 and 7 mo prior to sensory evaluation. The full fat control cheese and the washed curd RF cheese received the highest flavor scores from trained dairy judges (n = 9) and the highest flavor and acceptance scores from a consumer panel (n = 125). Washed curd was an effective modification for optimum sensory quality of RF cheeses.
Viscoelastic Properties of Butter
Authors: SHUKLA A. , RIZVI S.S.H.
Published: August 2006

Viscoelastic properties were studied on butters prepared from fractionated high‐melting triglyceride (HMT) and anhydrous milk fat (AMF). The elastic moduli (G′), the viscous moduli (G″) and the complex viscosities (η*) were determined as functions of angular frequency (ω). With increasing frequency, η* and G″ decreased while G′ increased. Higher G′, G″ and η* values were obtained for HMT butter, indicative of its firmer characteristics. Shift factors, determined using method of reduced variables, followed the Arrhenius model, from which the energies of activation were calculated. Power law intercepts, determined by relating G* to ω, exhibited a semi‐logarithmic inverse relationship with temperature. Slight increase in power law intercepts was observed on storage due to thixotropic rearrangements of fat crystals.
Antioxidant Inhibition of Cholesterol Oxidation in a Spray‐Dried Food System during Accelerated Storage
Authors: HUBER K.C. , PIKE O.A. , HUBER C.S.
Published: August 2006

Spray‐dried egg yolk was used to evaluate antioxidant inhibition of cholesterol oxidation during accelerated (CU+2 and heat) storage. Liquid yolk was treated with equimolar amounts of BHA (0.01%, w/w of lipid), ascorbyl palmitate (0.023%), or a tocopherol blend (0.023%). Yolk batches were spray‐dried, stored at 60 ± 2°C for up to 28 days, and analyzed for cholesterol oxidation products (COPS) using gas chroma‐tography. COP levels generally increased during storage with 7‐ketocholesterol predominant. Significant antioxidant effects were manifest in decreased levels of 7‐ketocholesterol, 7α‐ and 7β‐hydroxycholesterol; while cholestane‐triol and cholesterol‐5,6‐epoxide levels were not affected. All antioxidants showed significant inhibitive effects relative to the control, and tocopherols were more effective than ascorbyl palmitate.
Thermal Gelation of Pork, Beef, Fish, Chicken and Turkey Muscles as Affected by Heating Rate and pH
Authors: LAN Y.H. , NOVAKOFSKI J. , McCUSKER R.H. , BREWER M.S. , CARR T.R. , McKEITH F.K.
Published: August 2006

Effects of heating rate (3°C or 0.7°C/min) and pH (5.5, 6.0, 6.5, or 7.0) on thermal gelation properties of different muscle systems were evaluated (10% protein, 2% NaCl) using pork, beef, fish, and chicken and turkey (breast and thigh) muscles. Results indicated that, at pH 6.5 and 7.0, force required to rupture the gel (Pf), force required to move plunger through the gel (Fp), and viscosity index (Ni), using a slow heating rate, were higher than with rapid heating. All muscles (except breast muscles with the slow heating rate) yielded higher (P<0.05) gel strength (Fp, Pf) at pH 6.0 than at the other pHs.
Consumer Acceptability of Beef Steak Tenderness in the Home and Restaurant
Authors: MILLER M.F. , HOOVER L.C. , COOK K.D. , GUERRA A.L. , HUFFMAN K.L. , TINNEY KS. , RAMSEY C.B. , BRITTIN H.C. , HUFFMAN L.M.
Published: August 2006

Acceptability of beef steak tenderness in home and restaurant environments was evaluated by 62 consumers. Steaks (loin, ribeye, or bottom and top round) were consumed by each panelist in their home and in a fine dining restaurant. Each consumer rated steaks for tenderness and overall acceptability in the home (over a 2‐mo period) and one steak per week (over a 7‐wk period) in the restaurant. Acceptability for steaks consumed at home and in the restaurant ranked between 3 (moderately tough) and 4 (slightly tough) on an 8‐point scale. The Warner‐Bratzler Shear force transition level for beef tenderness acceptability in the home was between 4.6 and 5.0 kg and in the restaurant between 4.3 and 5.2 kg. The unacceptable level of beef steak tenderness was ≤4.3 kg. Results suggested that consumers were more critical of beef tenderness in the home than in restaurants. Consumer responses may have been influenced by receiving free meals in the home or restaurant, as well as by the dining environment.
Dietary α‐Linolenic Acid and Mixed Tocopherols, and Packaging Influences on Lipid Stability in Broiler Chicken Breast and Leg Muscle
Authors: AHN D.U. , WOLFE F.H. , SIM J.S.
Published: August 2006

Addition of α‐linolenic acid alone or plus mixed tocopherols, to the diet of broiler chickens had significant effects on composition of muscle fatty acids. Degree of unsaturation in both neutral lipids and phospholipids was increased. Both the tocopherols in the tissues and the storage stability of the meat were affected by the degree of polyunsaturation in fatty acids and dietary tocopherols. The amount of tocopherols in leg meat was higher than that of breast meat, and the antioxidant effect of dietary tocopherols was significant in cooked leg meat with hot‐ and cold‐vacuum packaging. Dietary tocopherols were not effective in the control of lipid oxidation in loosely packaged cooked meat. Lipid oxidation in α‐linolenic acid‐enriched cooked broiler meat could be controlled by hot‐vacuum packaging, but the antioxidant effect of hot packaging plus dietary tocopherol was greater than hot packaging or tocopherol alone.
Peroxidase and Lipoxygenase Influence on Stability of Polyunsaturated Fatty Acids in Sweet Corn (Zea mays L.) during Frozen Storage
Authors: RODRIGUEZ‐SAONA L.E. , BARRETT D.M. , SELIVONCHICK D.P.
Published: August 2006

The effect of blanching treatments and packaging materials on lipoxygenase (LOX) and peroxidase (POD) activity and fatty acid stability of two cultivars of sweet corn (Jubilee and GH‐2684) were evaluated during 9 mo storage at −20°C. Complete inactivation of LOX and POD was obtained with 9 and 15 min of steam blanching, respectively. Relative fatty acid content revealed no change in fatty acid composition during storage. Control of degradation of polyunsaturated fatty acids (PUFA) did not depend on oxygen permeability of different packaging materials. Blanching had little effect on PUFA degradation after 9 mo storage.
β‐Glucan Enrichment of Barley Fractions by Air Classification and Sieving
Authors: KNUCKLES BENNY E. , CHIU MEI‐CHEN M.
Published: August 2006

Barley (Steptoe, Crystal and/or Waxbar) was dry milled and fractionated by small scale air classifiers and batch or continuous feed sifters to produce β‐glucan‐rich fractions. Sieving of barley (all cultivars) yielded lines fractions containing 88–90% starch and a final coarse enriched fraction containing 40–45% total dietary fiber including 16–19%β‐glucans and up to 82 μg/g total tocols. The enriched fraction was 20–25% (by wt) of the dehulled barley. The highest β‐glucan content by air classification was 9% due to ineffective separation of fines (particles <45 μm). Dry fractionation of barley produced a value added enriched product enhanced in factors (ie. tocols, dietary fiber, β‐glucans) which slow oxidation, lower cholesterol, moderate glycemic response and which provide unique functional properties in food systems.
Quality of Electron Beam Irradiated Strawberries
Authors: YU L. , REITMEIER C.A. , GLEASON M.L. , NONNECKE G.R. , OLSON D.G. , GLADON R.J.
Published: August 2006

Fresh ‘Tristar’ strawberries were treated by electron beam irradiation to determine the effects on postharvest quality attributes and shelf life. The intensity of red color rated by sensory panelists decreased as irradiation dosage increased from 0 to 2 kGy. Hunter ‘L’ values were higher for fruit treated with 2 kGy than for 0 and 0.5 kGy. Instron firmness values were lower for all irradiated fruit than for control fiuit. Panelists rated irradiated fruit less firm than nonirradiated fruit stored 1, 2 and 4 days. An increase in off‐flavor was noted among all treatments stored 6 and 8 days. Irradiation suppressed fungi on stored berries. Irradiation doses of 1 and 2 kGy extended shelf life 2 and 4 days, respectively. Electron beam irradiation technology has excellent potential for extension of shelf life of fresh strawberry fruits.
Stability of Metabolically Conjugated Precursors of Meat and Milk Flavor Compounds in Various Solvents
Authors: HAN L.‐H. , LINDSAY R.C.
Published: August 2006

The stability of selected metabolic conjugates (phenylglucuronide, phenylphosphate, and naphthylsulfate) was determined in model systems composed of water and various ratios (3:1, 1:1, 1:3) of selected solvents (hexane, chloroform, ethyl acetate, diethyl ether, or methanol) held at either 22°C or 40°C for 30 min under various pH conditions (pH 1.5, 3.2, or 6.5). Notable hydrolysis occurred only for the more polar solvents held in contact with acidic aqueous phases. Conditions were identified for minimizing hydrolysis of conjugates during extraction of fat and free alkylphenols from milk and meat products with diethyl ether. They were pH near neutral, short exposure time, near ambient temperature, presence of excess water, and saturation of aqueous phase with sodium chloride.
Screening of Proteolytic Enzymes to Enhance Foaming of Whey Protein Isolates
Authors: ALTHOUSE P.J. , DINAKAR P. , KILARA A.
Published: August 2006

Whey protein isolate (WPI) was modified to enhance foaming characteristics by controlled hydrolysis using proteolytic enzymes. Alcalase, acid fungal protease, chymotrypsin, pepsin and trypsin were used to hydrolyze 5% rehydrated WPI. Decree of hydrolvsis was estimated by freezing point depression and terminated at 2.5 to 3% by heating or pH adjustment. Controls were treated under similar conditions but without enzymes. Hydrolysates were separated into permeate and retentate by ultrafiltration and concentrated by reverse osmosis before freeze drying. Foam capacity, stability and surface tension of hydrolysates were measured. Permeate from Alcalase exhibited the best foaming characteristics, comparable to egg white.
Heat Stability of Oil‐in‐Water Emulsions Containing Milk Proteins: Effect of Ionic Strength and pH
Authors: HUNT JOSEPHINE A. , DALGLEISH DOUGLAS G.
Published: August 2006

ABSTRAC

Emulsions (20 wt% soybean oil; 2 wt% protein) made with caseinate at pH 7 and with whey protein isolate (WPI) at pH 7 and 3 were stable to heating at 90 and 121°C. WPI emulsions destabilized at pH values between 3.5 and 4.0. In the presence of KCI (12.5–200 mM), large particles were formed in WPI emulsions at pH 3 and the emulsions were viscous. At pH 7, moderate concentrations of KCI decreased the heat stability and gels were formed. KCI had less effect on WPI emulsions made at pH 3. Combining the emulsions with caseinate allowed some control of the heat‐induced gelation.
Plasmin Inactivation with Pulsed Electric Fields
Authors: VEGA‐MERCADO HUMBERTO , POWERS JOSEPH R. , BARBOSA‐CÁNOVAS GUSTAVO V. , SWANSON BARRY G.
Published: August 2006

Plasmin (fibrinolysin E.C.3.4.21.7), an indigenous enzyme in bovine milk, added to simulated milk ultrafiltrate (SMUF) at 100 μg/mL (pH 6.11 and ionic strength 0.056 M) was treated at 10°C and 15°C with pulsed electric fields (HVPEF) of 15, 30 and 45 kV/cm and number of pulses 10, 20, 30, 40 and 50. The plasmin activity measured using a commercial assay, was reduced 90% after 50 pulses at both 30 and 45 kV/cm and at a processing temperature of 15°C. Similar inactivation was obtained when plasmin (100 μg/mL) in SMUF was heated at 40°C for 15 min. Inactivation of the enzyme depended on the number of pulses applied during treatment, intensity of the applied field, and processing temperature.