bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved Method for Determining Food Protein Degree of Hydrolysis
Authors: Nielsen P.M. , Petersen D. , Dambmann C.
Published: July 2006

ABSTRACT When producing hydrolyzed proteins, it is important to determine the degree of hydrolysis (DH). The trinitro‐benzene‐sulfonic acid (TNBS) method is well established with regard to enzymatic hydrolysis. However, this method is laborious, cannot be used to follow a hydrolysis reaction continuously, and includes hazardous and unstable chemicals. This paper describes a method based on the reaction of primary amino groups with o‐phthaldialdehyde (OPA). The conclusion is that the OPA method of analyzing the DH of protein hydrolyses is more accurate, is easier and faster to carry out, has a broader application range, and is environmentally safer than the TNBS method.
Evaluation of Rice Starch‐Hydrocolloid Compatibility at Low‐Moisture Content by Glass Transitions
Authors: Li T.‐Y. , Chien J.T.
Published: July 2006

ABSTRACT The freeze‐dried and moisture‐equilibrated mixtures of TCN1 rice starch (RS), hydrocolloids, and their mixtures exhibited Tgs and sub‐Tgs when analyzed by differential scanning calorimetry (DSC). Among mixtures, the compatible mixture, RS and high‐methoxyl pectin, exhibited only a single Tg between the Tgs of the 2 components; whereas the incompatible mixture, RS and low‐methoxy pectin, showed 2 Tgs of the individual components. RS was partially compatible with guar gum and L‐ and K‐carrageenan. The compatibility of mixtures was further verified by dynamic mechanical analyses and showed results similar to DSC. Thus, Tg can be used as a probe to examine component compatibility of 2 hydrocolloids in a low‐moisture system.
Inactivation of Listeria monocytogenes in Recirculated Brine for Chilling Thermally Processed Bacon Using an Electrochemical Treatment System
Authors: Ye J. , Yang H. , Kim H.‐K. , Li Y.
Published: July 2006

ABSTRACT An electrochemical treatment system consisting of a pulsed electrical power supply and an electrical treatment chamber was designed and evaluated for inactivation Listeria monocytogenes in recirculated brine for chilling processed bacons. The brine was tested under different currents and temperatures. An average D‐value of 1.61 min in the storage tank could be achieved at 7 mA/cm3 current with the fresh brine (t = 0 h). For the spent brine (t = 20 h), the D‐value was 2.5 min in the treatment chamber at 35 mA/cm3. The average D‐values in the treatment chamber were approximately 2.5 min at all three temperatures (4, 0, ‐8 8C) at 35 mA/cm3.
Pediococcus pentosaceus L and S Utilization in Fermentation and Storage of Mackerel Sausage
Authors: Yin L.‐J. , Jiang S.‐T.
Published: July 2006

ABSTRACT During 72 h fermentation at 37 °C, rapid increase in lactic acid bacteria count (LAB), dramatic decline in pH and suppression in the growth of contaminating Pseudomonas, Staphylococcus, and Enterobacteriaceae of mackerel minces with Pediococcus pentosaceus strains L and S were observed (p < 0.05). When the mackerel mince was processed into Chinese style sausage with 4% sucrose, no significant changes in pH, growth of LAB, Aerobic Plate Count, and Pseudomonas of the fermented mackerel sausage with Pediococcus pentosaceus strains L and S were obtained (p > 0.05) during 3 wk storage at 4 °C, however, the growth of Enterobacteriaceae and Staphylococcus were effectively suppressed. The residual nitrite in sample decreased during processing and fermentation, and was minimally detected after 72 h fermentation. Suppression of VBN and psychrophilic microflora, and lowering residual nitrite suggest the potential of using these 2 strains in the fermented fish products.
Prediction of Rice Starch Quality Parameters by Near‐Infrared Reflectance Spectroscopy
Authors: Bao J.S. , Cai Y.Z. , Corke H.
Published: July 2006

ABSTRACT: A rapid predictive method based on near‐infrared spectroscopy (NIR), was developed to measure rice starch quality parameters. A calibration set of 100 samples and validation set of 62 samples of rice flour of Chinese genotypes was used. Results of partial least squares modeling indicated that NIR was reasonably accurate in predicting apparent amylose content (AAC) (standard error of prediction [SEP] = 1.39 percentage units, coefficient of determination [R2] = 0.91); pasting parameters of setback (SB) (SEP = 13.6 RVU, R2= 0.92), and breakdown (BD) (SEP = 10.2 RVU, R2= 0.88); and gelatinization peak temperature (Tp) (SEP = 1.33 °C, R2= 0.89). Gel consistency (GC), cool paste viscosity (CPV), gelatinization onset temperature (To), and textural properties of chewiness, hardness and gumminess, were modeled less well with R2 between 0.75 and 0.86. NIR analysis is sufficiently accurate for routine screening of large numbers of samples in early generation selection in rice breeding programs.
Texture and other Physicochemical Properties of Whole Rice Bread
Authors: Kadan R.S. , Robinson M.G. , Thibodeaux D.P. , Pepperman A.B.
Published: July 2006

ABSTRACT: Samples of experimental rice breads baked in a home bread machine were evaluated by physicochemical methods and compared with a local commercial whole‐wheat bread. The results showed that rice breads had less specific volume, harder texture, and were more prone to retrogradation during storage than whole wheat bread. All stored breads showed a peak at about 52 °C by differential scanning calorimetry (DSC) analysis, which is characteristic of retrograded starch. However, the δH for rice bread was about 3 times the value of whole‐wheat bread, suggesting its strong tendency to retrograde. X‐ray diffraction (XRD) evaluation also indicated the appearance of a strong 20 peak between 16.7 °C to 17.0 °C in rice bread than in whole‐wheat bread, which is consistent with starch retrogradation.
Drying and Crystallization of Sucrose Solutions in Thin Films at Elevated Temperatures
Authors: Howell T. , Hartel R.
Published: July 2006

ABSTRACT: Thin sucrose films were dried over 30‐min periods during which sucrose crystal growth rates were monitored by videomicroscopy. Drying parameters and sucrose solution properties were varied to determine their effect on initial sucrose crystal growth rates. Growth rates increased by a factor of 4.5 as temperature increased from 40 to 70 °C. Varying initial sucrose concentration (70 to 80%) and drying air velocity (2 to 5 m/s) produced no change in crystal growth rates. Increases in film thickness from 150 to 450 μm and the presence of moisture in the drying air reduced growth rates by 33% at 70 °C, but had no effect at 50 °C. The addition of invert sugar (up to 5%) reduced growth rates by a factor of 2 to 3.
Effects of High‐pressure Processing on Carotenoid Extractability, Antioxidant Activity, Glucose Diffusion, and Water Binding of Tomato Puree (Lycopersicon esculentum Mill.)
Authors: Garcia A. Fernandez , Butz P. , Tauscher B.
Published: July 2006

ABSTRACT: High‐pressure‐treated tomato puree was investigated for changes in carotenoid extractability, antioxidant activity, glucose diffusion, and water binding. No effect of pressurization was observed in the total concentrations of the main water‐insoluble antioxidants, lycopene and β‐carotene, extracted with tetrahydrofuran, but lower recovery of carotenoids with petroleum ether suggested structural changes in the tomato pulp tissue, due to processing. Total antioxidant capacity of the water‐soluble fraction was unchanged immediately after pressure treatment, but was better preserved during 21 d at 4 °C, compared with untreated samples. High‐pressure treatment resulted also in enhanced water binding. Glucose diffusion through dialysis tubing was lower after high‐pressure treatment, leading to a higher glucose retardation index.
Purification and Characterization of an α‐L‐Rhamnosidase from Aspergillus terreus of Interest in Winemaking
Authors: Gallego M.V. , Piñaga F. , Ramón D. , Vallés S.
Published: July 2006

ABSTRACT: An enzyme with α‐L‐rhamnosidase activity was purified to homogeneity from a culture filtrate of Aspergillus terreus after growth in a medium containing L‐rhamnose as the sole carbon source. The biosynthesis of this enzyme was repressed by glucose. The enzyme had a molecular mass of 96 kDa on sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and an isoelectric point of 4.6 as determined by analytical isoelectric focusing. The pH and temperature optima for the enzyme were found to be 4.0 and 44 °C, respectively. Using p‐nitrophenyl‐α‐L‐rhamnopyranoside as a substrate, the enzyme exhibited Michaelis‐Menten kinetics with KM and Vmax values of 0.17 mM and 84 U/mg, respectively. The enzyme was inhibited competitively by L‐rhamnose (K1 2.5 mM). Divalent cations such as Ca2+ Mg2+ Zn2+ and Co2+ stimulated the a‐L‐rhamnosidase activity, whereas this was inhibited by Hg2+ and Cd2+. Ethanol (12% v/v) and glucose (21% w/v) decreased enzyme activity by approximately 20%, while this was not affected by SO2.
Heat‐Induced Changes of Myosin and Sarcoplasmic Proteins in Beef During Simmering
Authors: Tajima M. , Ito T. , Arakawa N. , Parrish F.C.
Published: July 2006

ABSTRACT: Changes of proteins in beef cubes, soup stock, and scum (a complex of coagulated proteins, fat, and minerals floating on soup stock) during simmering in sub‐boiling water at 95 °C for 3 h were investigated by SDS‐PAGE and Western blotting. Of the soluble proteins in soup stock heated for 1 h, 3 components having molecular weights between 47 and 36 kDa reacted with myosin antibody. Those bands disappeared from soup stock after heating for 3 h, however, they were observed in the scum. Bands of 70 and 58 kDa, which reacted with myosin antibody and were observed after 1 h of heating at 95 °C, were also observed after 30 min of heating under pressure.
Identification and Characterization of Molecular Species of Collagen in Fish Skin
Authors: Yata M. , Yoshida C. , Fujisawa S. , Mizuta S. , Yoshinaka R.
Published: July 2006

ABSTRACT: Pepsin‐solubilized collagen (PSC) prepared from the skin of 3 fish species—common horse mackerel, yellow sea bream, and tiger puffer—were separated into 2 fractions, major and minor, by ammonium sulfate precipitation. These collagen fractions were further purified by phosphocellulose column chromatography. From the results of SDS‐PAGE, peptide mapping, and amino‐acid analysis, the purified major and minor collagens were identified to be type I and V collagens, respectively. These results suggest that type V collagen might be widely present in fish skin as a minor collagen.
Influence of Gonadal Stage of Hake (Merluccius Hubbsi Marini) on Biochemical Properties of Myofibrils Stored at 2 to 4 °C
Authors: Pagano M.R. , Paredi M.E. , Crupkin M.
Published: July 2006

ABSTRACT: The influence of the gonadal stage of hake on the biochemical properties of myofibrils stored at 2 to 4 °C was studied. At 0 time and during storage, both Mg2+‐Ca2+‐ATPase activity and Ca2+ sensitivity of myofibrils from post‐spawned hake were significantly higher (p < 0.01) than those of pre‐spawned fish. The profiles of SDS‐PAGE gels of unstored and stored myofibrils from pre‐spawned hake showed a partially denatured myosin heavy chain. The actin‐myosin ratio in myofibrils from pre‐spawned hake was significantly lower (p < 0.01) than the ratio in post‐spawned hake. Irrespective of the gonadal condition of fish, no changes in the myosin‐actin ratio of stored myofibrils were observed.
Linking Solid Phase Extraction and Enzyme‐Linked Immunosorbent Assay to Measure Chlorpyrifos in Fish Tissue
Authors: Wan P. , Santerre C.R. , Deardorff D.C.
Published: July 2006

ABSTRACT: A method for measuring chlorpyrifos in fish tissue coupling solid phase extraction (SPE) and enzyme‐linked immunosorbent assay (ELISA) is described. Fish tissue was added to a silica gel column and extracted with hexane. The eluant was passed through an SPE column (C‐18) and analyzed using ELISA. The method, which was comparable to an FDA GC/ECD method, gave recoveries from 83.4% to 87.5% for fortified fish samples, a lower limit of detection of 0.01 ppm, a linear range from 0.01 to 0.5 ppm, and correlation coefficients from 0.86 to 0.96. Nineteen contaminated fish samples analyzed using both ELISA and GC/ECD methods gave comparable chlorpyrifos concentrations with a correlation coefficient of 0.78.
Rheological Properties of Gellan Gels Containing Filler Particles
Authors: Jampen S. , Britt I.J. , Yada S. , Tung M.A.
Published: July 2006

ABSTRACT: Influences of rigid (glass) and deformable (gellan) particles dispersed in gellan gels were studied to better understand the effect of structure on the rheological properties of model composite foods. Composites with inclusions at 0%, 10%, 20%, and 30% volume fractions (VF) were tested under small deformation oscillatory shear. In gels containing rigid particles, the dynamic shear storage modulus (G′) decreased initially, exhibited a minimum around 20% VF, then increased at 30% VF behavior that was attributed to physical interactions among particles. In gels containing deformable particles, the linear decrease in G′ with increasing VF may be due to particle compliance under stress or to particle separation from the matrix, thereby causing gel weakening.
Textural Characterization and Kinetics of Potato Strips During Frying
Authors: Pedreschi F. , Aguilera J.M. , Pyle L.
Published: July 2006

ABSTRACT: A single puncture test (SPT) system was designed to determine textural changes in potato strips in situduring frying at 160, 175, and 190 °C. Puncture force changed drastically with time and depth in the strip during frying. Force‐distance curves were expressed as representative textural parameters as CF (core force), RF (rupture force), and S (springiness). Normalized parameters CF* and S* for core force and springiness were used in modeling textural changes in the core during initial tissue softening and later crust development process, respectively. High frying temperatures accelerated the process, and the finished fried potato strip was a composite structure made of a hard crust and a soft core.
Production and Stability of (E, Z)‐2, 6‐Nonadienal, the Major Flavor Volatile of Cucumbers
Authors: Buescher R.H. , Buescher R.W.
Published: July 2006

ABSTRACT: Factors affecting the production and stability of (E, Z) ‐2, 6‐nonadienal (NDE) from pickling cucumbers were examined. Production capability was rapidly destroyed in tissues exposed to freezing, fermentation or processing conditions. Lower concentrations were produced by exocarp tissues than mesocarp or endocarp tissues, which probably accounted for an almost linear relationship between fruit size and NDE production. NDE production was reduced by acidification, enhanced by linolenic acid, and unaffected by other unsaturated fatty acids NaCl or CaCl2. E‐2‐nonenal production was suppressed when NDE production was increased by linolenic acid. NDE was unstable in filtrates of homogenized tissues. Its stability was substantially improved by acidifying to pH 2 and unaffected by CaNa2EDTA. Extraction and concentration by vacuum distillation further enhanced stability. Loss of NDE in distillates averaged 0.3%/d during storage at 5 °C.
A Rapid Spectroscopic Technique for Determining Honey Adulteration with Corn Syrup
Authors: Sivakesava S. , Irudayaraj J.
Published: July 2006

ABSTRACT: A combination of Fourier transform infrared spectroscopy with multivariate procedures was used for determining the level of sugar addition to honey. Spectra of honey adulterated with different levels of glucose, fructose, sucrose, and corn syrup were recorded in the mid‐infrared range using the attenuated total reflectance accessory. The standard error of prediction (SEP) in validation set was between 1.99% and 2.22% using partial least square (PLS) on first derivative transformed data. Results showed that the combined model for 3 different varieties of honey gave lower correlation. It is demonstrated that Fourier transform infrared spectroscopy has good potential for detecting corn‐syrup adulteration in honey in less than 5 min.
Separation and Characterization of a Porcine‐specific Thermostable Muscle Protein from Cooked Pork
Authors: Chen F.‐C. , Hsieh Y‐H.P.
Published: July 2006

ABSTRACT: This study was undertaken to separate and characterize the porcine‐specific thermostable muscle protein (psTSMP) recognized by monoclonal antibody, MAb 5H9, which was previously raised against crude porcine thermostable muscle proteins for detection of pork in cooked meats. The 24 kD antigenic components isolated from cooked pork by immunoaffinity chromatography consisted of a basic protein (pI = 9.4) and a group of isoelectric variants (pI ranging from 5.4 to 7.2). The basic protein was further isolated by methyl hydrophobic interaction and sulfonate ion‐exchange chromatography. Immunoblot suggested the presence of this antigenic psTSMP in the tropo‐nin fraction. Based on its molecular weight, pI, thermostability, and immunoreactivity, the psTSMP was tentatively identified as troponin I.
Characterization and Stability of Pigments Extracted from Terminalia Catappa Leaves
Authors: López‐Hernández E. , Ponce‐Alquicira E. , Cruz‐Sosa F. , Guerrero‐Legarreta I.
Published: July 2006

ABSTRACT: Terminalia catappa is a tree growing in Southeast Mexico; its leaf color ranges from red to yellow and it is a potential source of natural pigments. Petroleum ether:acetone and hexane:acetone were used for pigment extraction. The maximum extraction was 24 mg/100 g of leaves with 70:30 petroleum ether:acetone. Seven pigments were identified in the extracts (violaxanthin, violeoxanthin, lutein epoxide, lutein, two lutein isomers and β‐cryptoxanthin). A lower pigment concentration was obtained in saponified than in unsaponified extracts. Antioxidant‐free extracts underwent deterioration when stored under light. Conversely, pigments remained stable after 10 days at 40 °C, provided they were preserved with 0.1% BHT and stored in the dark.
The Effect of Digestive Enzymes on the Adhesion of Probiotic Bacteria In Vitro
Authors: Ouwehand A.C. , Tölkkö S. , Salminen S.
Published: July 2006

ABSTRACT: Specific probiotics have several clinically proven health effects. Adhesion to the intestinal mucosa is considered important for many of these effects. In the current study, the effect of digestive enzymes and bile on the adhesion to intestinal mucus of 5 selected probiotics was studied. All of the digestive enzymes affected the adhesion of at least some of the tested strains. Bile was observed to reduce the adhesion of all strains tested. When the strains were sequentially exposed to 3 enzyme preparations and bile, the level of adhesion was reduced for all strains. The results suggest that the selection criterion “adhesion” for probiotics should be further refined.
Stability of Tocopherols and Retinyl Palmitate in Snack Extrudates
Authors: Suknark K. , Lee J. , Eitenmiller R.R. , Phillips R.D.
Published: July 2006

ABSTRACT: Fish‐ and peanut‐containing half‐products were obtained by extruding and drying tocopherol‐ and retinyl palmitate‐fortified mixtures of tapioca starch and minced fish or partially defatted peanut flour (PDPF 60:40, wet basis). Half‐products were puffed by deep‐fat frying. Vitamins were determined simultaneously at each step of snack production using a direct solvent extraction method. Extrusion significantly reduced the content of tocopherols and retinyl palmitate in both products. Reduction of retinyl palmitate in fish and peanut extrudates during snack production was 48% and 27%, respectively. Final products contained more tocopherol than intermediates because of the high tocopherol content in the frying oil and its uptake.
Fat Uptake in French Fries as Affected by Different Potato Varieties and Processing
Authors: O'Connor C.J. , Fisk K.J. , Smith B.G. , Melton L.D.
Published: July 2006

ABSTRACT: The uptake of lipid into French fries was investigated using two varieties of potato (‘Russet Burbank’ and ‘Agria’) and the New Zealand sweet potato, Ipomoea batatas, (kumara). The variety of potato used had a significant effect on lipid uptake, with ‘Agria’ having the lowest lipid content. The different cellular structures may have affected the fat uptake in the French fries by influencing either the loss of moisture during finish‐frying or the damage done to the original anatomy during processing before pre‐frying. The French fries that had undergone frozen storage had a higher amount of lipid contained in their inner core than did those that had been either chilled or prepared freshly for frying.
Carotenoid Content and Physicochemical and Sensory Characteristics of Carrot Chips Deep‐Fried in Different Oils at Several Temperatures
Authors: Sulaeman A. , Keeler L. , Giraud D.W. , Taylor S.L. , Wehling R.L. , Driskell J.A.
Published: July 2006

ABSTRACT: The influence of deep‐frying using different oils and temperatures on carotenoid content and physicochemical and sensory characteristics of carrot chips was investigated. Sliced carrots were steam‐blanched, cooled, soaked in 0.2% sodium metabisulfite, and deep‐fried in canola, palm, or partially hydrogenated soybean oil (PHSO) at 165, 175, or 185 °C. Frying temperature, but not oil, significantly (P < 0.05) affected the α‐carotene, β‐carotene, and total carotenoid contents. Oil type significantly (P < 0.05) influenced all color values. Increasing temperature lowered the redness value, which correlated with decreased carotenoid content, color darkening, and decreased hardness value. Trained panelists detected no differences among oil types in crispness, sweetness, odor, and acceptability. The best carrot‐chip product was that fried in PHSO at 165 °C.
Preparation of Chickpea Curd by Heat‐Induced Gelation
Authors: Cai R. , Baik B.‐K.
Published: July 2006

ABSTRACT: The effect of compressing time, pH, and protein concentration on the texture of chickpea curds prepared by heat‐induced gelation was assessed. The possible gelation mechanism was studied by differential scanning calorimetry (DSC), surface hydrophobicity, and viscometric analysis. Texture analysis showed that chickpea curd could be produced by steam cooking the protein fraction. DSC results indicated a decrease in the denaturation enthalpies (AH) for both legumin and vacilin as pH decreased from 6.5 to 6.0. Analysis of the surface hydrophobicity as a function of pH showed a sharp transition at pH 6.0. The viscosity of the protein fraction sharply increased at pH 5.2 producing an extremely hard curd. A mechanism for curd formation is proposed.
Reliability of Time Temperature Indicators Under Temperature Abuse
Authors: Shimoni E. , Anderson E.M. , Labuza T.P.
Published: July 2006

ABSTRACT: The present study systematically examined the reliability of 7 Monitor Mark time temperature indicators (TTI's) in isothermal and non‐isothermal scenarios simulating temperature abuse. The‘reaction order’(m) of the response function varies from 0.16 to ‐3.94. The response of the TTI's under isothermal storage agreed with both the Arrhenius and shelf life plot models, and the calculated activation energies range from 23.3 to 31.3 kcal/mol. Using mand k values from the isothermal experiments, all the TTI's reported the shelf life under temperature‐abuse storage within a safe margin. Five indicators showed a positive “history effect”. Given the positive history effect in the studied TTI's and their activation energy range, it is suggested that they may be useful when microbial growth is the major deteriorative mode of the food.
Effects of Combined Treatment of High Hydrostatic Pressure and Mild Heat on the Quality of Carrot Juice
Authors: Kim Y.‐S. , Park S.‐J. , Cho Y.‐H. , Park J.
Published: July 2006

ABSTRACT: This study was performed to investigate the effects of the combined treatment of high pressure and heat on the quality of carrot juice, and to optimize the process condition. About 95% of food quality‐related enzymes were lost at 400 MPa and 70 °C, for 10 min, while α‐ and β‐carotene were relatively stable at the combined process. The optimum process condition was estimated at 395 to 445 MPa, 70 °C, for 8 to 11 min. These results indicate that the combined treatment of high pressure and mild heat could be used as an effective process for production of high‐quality carrot juice.
Cholesterol and Lipid Oxidation Products in Cooked Meat as Affected by Raw‐Meat Packaging and Irradiation and by Cooked‐Meat Packaging and Storage Time
Authors: Du M. , Nam K.C. , Ahn D.U.
Published: July 2006

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

The potential of Fourier transform infrared photoacoustic spectroscopy (FTIR‐PAS) to characterize some common foods was studied. Lard, peanut butter, mayonnaise, and whipped topping were heated to 60 and 90 °C separately, and the spectra were obtained periodically for a period of up to 32 and 16 d, respectively. Key bands in the mid‐infrared spectral region were examined to monitor changes presumably due to lipid oxidation. Spectral data were analyzed, using principal component analysis (PCA) correlation, and linear discriminate analysis (LDA) techniques with Mahalanobis distances to estimate the extent of deterioration attributable to oxidation. The PAS was found to be simple, rapid, and nondestructive. It required limited sample preparation, and proved highly desirable for analyzing low‐moisture samples.
Milk Protein Analysis Using a Micro Fabricated Sieve: A Promising Possibility
Authors: Rao C.S.
Published: July 2006

ABSTRACT: In cheese making, proteins present in the micellar phase, i.e., α, β, κ, γ casein and their variants, determine the yield and properties of the final product (Walsh and others 1995). The current milk prices are based on solid components, that is, fat, total protein and other solids. However, the cheese yields are extremely sensitive to variations in protein sub‐components. Thus, total protein content, although a simple measure of yield, is not the most accurate one. In the future, the food industry might require simple tools to analyze protein components in a given sample of milk. Two features of such a tool, portability and accuracy, would be invaluable. In this article, a protocol for design of a micro‐scale sieve for the separation of proteins is conceived.
Loss of Fuminosin B1 in Extruded and Baked Corn‐Based Foods with Sugars
Authors: Castelo M.M. , Jackson L.S. , Hanna M.A. , Reynolds B.H. , Bullerman L.B.
Published: July 2006

The objective of this work was to determine the effect of added sugars on fumonisin B1 (FB1) levels in baked corn muffins and extruded corn grits. Muffins containing added glucose had significantly lower FB1 levels than muffins with sucrose, fructose, or no added sugar. Extrusion cooking of the grits resulted in significant (p< 0.05) reductions of FB1 in all treatments relative to unextruded controls, but use of glucose resulted in greater reductions of FB1 (45.3 to 71%) than did the use of fructose (29.5 to 53%) or sucrose (19.2 to 39%). When extrusion conditions were optimized, 92.1% loss of FB1 was found when grits were extruded with glucose. Adding glucose to thermally processed food can result in a substantial reduction in FB1 levels.
Prediction of Infinite Dilution Volatilities of Aroma Compounds in Water
Authors: Voutsas E.C. , Andreou C.I. , Theodorou D.G. , Tassios D.P.
Published: July 2006

ABSTRACT: The prediction of infinite dilution volatilities (Henry's law constants) of aroma compounds is examined. At 25 °C, the Bond Contribution model is recommended. At other temperatures where the Bond Contribution model cannot be used, the Kow‐UNIFAC group contribution model, coupled with either experimental or predicted by the Antoine‐Grain model vapor pressure values, provides estimates only of the volatilities with errors in the range of 20% to 40%. Finally, the effect of a cosolvent (ethanol) on the infinite dilution volatilities of some aroma compounds is examined.
Depletion Flocculation of Beverage Emulsions by Gum Arabic and Modified Starch
Authors: Chanamai R. , McClements D.J.
Published: July 2006

ABSTRACT: The creaming velocity, apparent viscosity, and ultrasonic attenuation spectra (1 to 50 MHz) of 5 wt% n hexadecane oil‐in‐water emulsions containing different droplet radii (r = 0.15 ‐ 0.7 μm), biopolymer types (gum arabic or modified starch), and biopolymer concentrations (0 to 2.5 wt%) were measured. Depletion flocculation was observed in the emulsions when the nonabsorbed biopolymer concentration exceeded a critical concentration (CFC). The CFC increased with decreasing droplet radius for both biopolymers because the magnitude of the depletion attraction increases with droplet size. The CFC was lower for gum arabic than modified starch because it has a higher effective volume in solution. Depletion flocculation led to an increase in creaming instability and apparent viscosity of the emulsions. Flocculation could be nondestructively monitored by measuring the decrease in ultrasonic attenuation of the emulsions. These results show that depletion flocculation by gum arabic and modified starch can have an adverse effect on the stability of beverage emulsions.
Prevention of Transient Discoloration of Beef
Authors: Tewari G. , Jayas D. S. , Jeremiah L. E. , Holley R. A.
Published: July 2006

Oxygen absorbent technology in conjunction with controlled atmosphere packaging(CAP) was used to prevent transient discoloration in master‐packaged beef steaks. Two types of commercial O2 scavengers were used in the study. The master packs were stored at 1± 0.5 °C. The steaks from master packs were presented in a display‐case for visual evaluation. Reflectance spectra from each steak‐surface were obtained to estimate metmyoglobin content. Steaks packaged without O2 scavengers showed more discoloration, and had significantly higher proportions of metmyoglobin when compared to steaks with O2 scavengers, after most storage intervals (p < 0.05). Prevention of metmyoglobin formation was influenced by the number but not the type of O2 scavenger employed (p > 0.05). Keywords: oxygen scavengers, centralized meat operations, transient discoloration
Sucrose Degradation Under Model Processing Conditions
Authors: Andrews L.S. , Godshall M.A. , Moore S.
Published: July 2006

ABSTRACT: During raw and refined sugars processing, chemical changes occur that affect yield and end product color. Model sucrose solutions of 65 and 15 brix were treated with invert sugar levels of 0 to 4%, adjusted to pH 6 to 9, then processed 85 7deg;C for 0 to 6 h. Sucrose loss was correlated with changes in invert sugar concentration under acid conditions. Invert sugars concentrations were correlated with color development under alkaline conditions. At both 65 and 15 brix sucrose, and pH below 7.5, samples showed a 25% increase in invert sugars from acid hydrolysis. Sucrose loss was 1.6% with 3% invert sugar present. At pH 8.5 and higher, color increased in direct correlation with invert sugar concentrations.
Impact of Juice Processing on Blueberry Anthocyanins and Polyphenolics: Comparison of Two Pretreatments
Authors: Lee J. , Durst R.W. , Wrolstad R.E.
Published: July 2006

ABSTRACT: Frozen blueberries (Vaccinium corymbosum L. cv. Rubel) were pilot‐plant‐processed into juice and concentrate: 2 treatments (heat and SO2) and a control. Pressed juice yield ranged from 74 to 83% (w/w), but only 13 to 23% of the anthocyanins and 36 to 39% of the polyphenolics were recovered in the pasteurized juice. A substantial amount of anthocyanins and polyphenolics (> 42% and > 15%, respectively of the starting material) were present in the presscakes. Measurements of total and individual flavonoids showed a great loss after the initial processing steps (thawing, crushing, and depectinization). Overall anthocyanin levels were higher in treated samples after each processing step, but polyphenolic levels remained similar to those in the control.
Identification of Ostrich Meat by Restriction Fragment Length Polymorphism (RFLP) Analysis of cytochrome b Gene
Authors: Abdulmawjood A. , Bülte M.
Published: July 2006

ABSTRACT: To enforce labeling regulations in the authentication of ostrich meat, it might be of importance to evaluate a method to identify the ostrich meat. A restriction site of the polymerase chain reaction (PCR) product has been used for the specific identification of ostrich meat. In the present study the part of the gene encoding cytochrome b was amplified and sequenced. The digestion of the PCR products using specific estriction enzymes Hae III, Hinf I, Rsa I, and Tru 91 were used to yield specific restriction profiles that allowed a direct identification of ostrich meat in raw and heat‐treated samples from meat of other food animal species.
Effects of Postharvest Putrescine Treatment on Extending Shelf Life and Reducing Mechanical Damage in Apricot
Authors: Martínez‐Romero D. , Serrano M. , Carbonell A. , Burgos L. , Riquelme F. , Valero D.
Published: July 2006

ABSTRACT: Apricots (Prunus armeniaca L. cv Mauricio) harvested at commercial ripening stage were treated with putrescine (1 mM), then mechanically damaged with a 25 N force and stored at 10 °C for 6 d. Putrescine treatment increased fruit firmness and reduced the bruising zones caused by the mechanical damage. Putrescine‐treated fruits (both damaged and nondamaged) showed different physiological behavior than controls. Color change, weight loss, ethylene emission, and respiration rate were reduced in putrescine‐treated fruits. The most remarkable effect of the mechanical damage was the significant increase in spermidine concentrations found after the compression in control apricots, which could be considered as a physiological marker of mechanical damage.
Changes in Volatile Components of Stored Tangerines and Other Specialty Citrus Fruits with Different Coatings
Authors: Hagenmaier R.D. , Shaw P.E.
Published: July 2006

ABSTRACT: Shellac and wax‐based citrus coatings were applied to Fallglo, Robinson, Sunburst, Dancy and Murcott tangerines, Nova and Orlando tangelos, and Temple oranges. Flavor volatiles were measured before and after storage. Concentrations of ethyl acetate, ethyl butyrate, isopentanol and 2‐methyl‐3‐buten‐2‐ol increased markedly for fruit with shellac‐based coatings, and were highly correlated with ethanol content, but at different ratios for the different varieties. The concentration increases were relatively less for fruit coated with the wax‐based coatings, and suggest that high‐gloss shellac and resin‐based coatings are not appropriate for tangerines.
Co‐crystallization of Sucrose at High Concentration in the Presence of Glucose and Fructose
Authors: Bhandari B.R. , Hartel R.W.
Published: July 2006

ABSTRACT: Co‐crystallization of sucrose from a highly concentrated sucrose syrup (≤ 7% moisture, w/w) at 131 °C with 0, 5, 10, 15, and 20% of fructose, glucose, or a mixture of fructose and glucose was investigated. The crystallization of sucrose was delayed in presence of these lower molecular weight sugars. The DSC melting endotherm of co‐crystallized samples exhibited a decrease in crystalline sucrose in the sample as a function of increased level of glucose and fructose. The mechanical strength of co‐crystallized granules was found to be related to the moisture content and the amount of glucose or fructose content in the sample. The samples containing 10, 15, and 20% glucose in co‐crystallized product demonstrated crystallization of glucose in its monohydrate form during 1 mo of storage.
Catalase Activity for Rapid Assessment of High Level Total Mesophilic Microbial Load in Milk
Authors: Kang D.H. , Dougherty R.H. , Clark S. , Costello M.
Published: July 2006

ABSTRACT: Total mesophilic microbial load (APC) is an important index for milk quality. It takes 48 h to enumerate APC with conventional plating methods. This report presents a rapid catalase activity test for monitoring APC in milk. Most aerobic microorganisms have strong catalase activities. Catalase activity in milk was monitored with a Pasteur pipette method in 5 min. The correlation between high APC numbers (> 4.0 log CFU/ml) and catalase activities was strongly correlated with r2=0.89. Classifying the APC into eight contamination groups was found to be a sound means of utilizing the resultant catalase activities to predict APC.
Effect of Yeast Extracts Containing Propionic Acid on Bread Dough Fermentation and Bread Properties
Authors: Gardner N. , Champagne C.P. , Gélinas P.
Published: July 2006

ABSTRACT: Three commercial yeast extracts (Oxoid, Champlain, Lallemand) fermented with immobilized cells of Propionibacterium freudenreichii were added in broths and bread formulations, and their effect on growth and gas production by bakers yeast was determined. Appearance and preservation of the breads were examined. There was significantly more gas produced by the yeast when fermented yeast extracts were added to the dough. In broths, the initial growth rate was slower with media containing fermented yeast extract when compared to their unfermented equivalents. Loaves formulated with propionic acid of the fermented yeast extract contained less ethanol. Paired t‐tests showed that breads formulated with fermented yeast extract were protected for a longer period against mold than those that contained non‐fermented yeast extract.
Intestinal Absorption of Lycopene from Different Types of Oleoresin Capsules
Authors: Böhm V.
Published: July 2006

ABSTRACT: After a 2‐wk depletion period, 24 volunteers, divided into 3 groups, ingested 5 mg/d lycopene for 4‐wk from 5 capsules containing tomato oleoresin or synthetic lycopene. Plasma samples were analyzed on carotenoids using C18 HPLC with diode array detection. Basal lycopene levels (0.19 to 0.31 μmol/L) in plasma of the 3 groups were in a comparable range (p > 0.05) and significantly decreased after the 2‐wk diet low in lycopene to 21 to 52 % of the basal values. Four out of 5 investigated capsules significantly (p < 0.05) enhanced the plasma lycopene levels relative to the depleted state after 1 wk of supplementation to 0.20 to 0.27 μmol/L. Increasing the surface of lycopene crystals by reducing the particle size was the most effective processing step to enhance intestinal absorption of lycopene. However, presence of tomato oil in oleoresin and partly removal of selective fatty acids affected the intestinal absorption of lycopene, too.
Overall Acceptability and Sensory Profiles of Peanut Spreads Fortified with Protein, Vitamins, and Minerals
Authors: Yeh J.Y. , Resurreccion A.V.A. , Phillips R.D. , Hung Y.C.
Published: July 2006

ABSTRACT: Three amino acid‐balanced, vitamin‐, and mineral‐fortified peanut spreads were investigated for consumer acceptability and sensory profile. An all‐peanut spread had the highest consumers' ratings on all of the “likings”, whereas peanut/soy spread with 40.5% fat (PSSA) had the lowest ratings on the overall liking, spreadability, flavor, and texture (< 6, “like slightly”). Overall, consumers accepted all‐peanut, peanut/non‐fat dry milk spread (PSM) and peanut/soybean spread with 44.5% fat (PSSB), but not PSSA. Significant differences (α= 0.05) existed in the descriptive attributes including brown color; surface oiliness; spreadability; roasted peanutty, roasted soybean, milk, woody/hulls, and sweet flavors; stickiness; hardness, graininess; adhesiveness; cohesiveness; cohesiveness of mass; mouthcoating; mouthdryness; and adhesiveness to teeth. PSSA and all‐peanut control were significantly different on most of the textural attributes. PSM exhibited no significant difference (α= 0.05) from all‐peanut control.
Influence of Dietary Supplementation with α‐Tocopheryl Acetate and Canthaxanthin on Cholesterol Oxidation in ω3 and ω6 Fatty Acid‐enriched Spray‐dried Eggs
Authors: Galobart J. , Guardiola F. , Barroeta A.C. , Löapez‐Ferrer S. , Baucells M.D.
Published: July 2006

ABSTRACT: The effect of feeding laying hens linseed oil or sunflower oil, with and without α‐tocopheryl acetate and/or canthaxanthin, was evaluated on cholesterol oxidation in spray‐dried whole egg at various storage periods. Storage of spray‐dried eggs at room temperature in the dark resulted in an increase in cholesterol oxidation products from 18.1 μg/g, after spray drying, to 39.3 μg/g, at 12 mo of storage. No differences were found with either dietary oil or canthaxanthin supplementation. However, α‐tocopheryl acetate supplementation resulted in a lower formation of cholesterol oxidation products during storage. No synergistic effect between α‐tocopherol and canthaxanthin was detected.
Characteristics of DNA Comet, Photostimulated Luminescence, Thermoluminescence and Hydrocarbon in Perilla Seeds Exposed to Electron Beam
Authors: Chung H.‐W. , Delincée H. , Han S.‐B. , Hong J.‐H. , Kim H.‐Y. , Kwon J.‐H.
Published: July 2006

ABSTRACT: Detection characteristics of perilla seeds exposed to electron beam doses of 0 to 2 kGy were investigated. DNA comet assay, photostimulated luminescence (PSL) and thermoluminescence (TL) measurements, and hydrocarbon determinations by GC‐MS were carried out. The irradiated samples showed comets with longer tails (152 ± 6 mm) than did nonirradiated samples (35 ± 11 mm). PSL values (photon counts) for the irradiated samples were more than 7865; whereas those of nonirradiated samples were less than 294. TL ratios (Glow 1/Glow 2) obtained from nonirradiated samples were less than 0.01 and above 0.48 from irradiated ones. The prominent radiation‐induced hydrocarbons were 16:2, 16:3, 17:1, and 17:2, of which 16:2 was the most abundant.
Gastrointestinal Absorption of Aluminum from Teas in Rats
Authors: Fujii W. , Kusumoto A. , Nakada T. , Suwa Y.
Published: July 2006

ABSTRACT: Gastrointestinal absorption of aluminum (Al) contained in black tea, green tea, and oolong tea compared with that of Al citrate was investigated using Wistar rats. The serum Al level in the rats administered orally with Al citrate increased by 7.9 times that of the basal level. In contrast, the administration of teas, at the equivalent dose of Al, increased only slightly the serum Al level (30 to 58%). Among 3 types of tea infusions, the serum Al level in the green tea group was relatively high compared to those in the black tea and oolong tea groups, although the difference was not significant. These results showed that the absorption rates of Al from ingestion of tea infusions were much lower than that of free form Al. It was also suggested that there were no marked differences in Al absorption rates from black tea, green tea, or oolong tea in the gastrointestinal tract.
Chitosan–yeast Interaction in Cooked Food: Influence of the Maillard Reaction
Authors: Rodríguez M.S. , Centurión M.E. , Agulló E.
Published: July 2006

ABSTRACT: The influence of Maillard reaction was studied on the recovery of free chitosan in cooked food prepared with this biopolymer and yeast. Formulations with different ingredients were prepared and heated. The percentage recovery of free chitosan was calculated. The formulations contained chitosan, yeast, and reducing sugars. In order to confirm the interaction between amino groups of chitosan and carbonyl groups of reducing sugars, theoretical model systems were prepared and x‐ray diffraction studies were made on these samples. When chitosan was used as an ingredient in cooked food fermented with yeast and sucrose, it lost some of its functional properties because of the Maillard reaction.
Antioxidant Properties of Cereal Products
Authors: Yu L. , Perret J. , Davy B. , Wilson J. , Melby C.L.
Published: July 2006

Four commercial cereal products were examined and compared for their free radical scavenging properties, chelating capacity, and total phenolic contents. The Quaker Oat Bran™ ready‐to‐eat cold cereal showed the greatest activity to quench DPPH radicals, while the Quaker oatmeal had the highest capacity against ABTS+. Significant Fe2+ chelating activity was also detected in these cereal products with EDTA equivalents of 0.08 to 0.48 mg/g cereals. The total phenolic contents were 203 to 524 mg per gram of cereal products. These results indicate that readily available cereal products contain significant levels of antioxidants and may be an important source of dietary antioxidants.
A Rapid and Small‐Scale Method for Estimating Antioxidative Potency of Peanut Sprouts
Authors: Hsu W.‐C. , Cho P.‐J. , Wu M.‐J. , Chiou R.Y.‐Y.
Published: July 2006

A method for estimating antioxidative potency (AOP) was achieved by incubating emulsified linoleic acid in a 1 mL iron/ascorbate system at 37 °C for 30 min followed by absorbance measurement at 234 nm to determine the conjugated diene hydroperoxide (CDHP) content. By that method, 100% AOP was obtained when 10 ppm butylated hydroxytoluene or 50 ppm α‐tocopherol was introduced. When freeze‐dried peanut sprouts were cooked with ground pork‐fat patties and the separated oils were stored at 60 °C for CDHP determination, the highest AOP was observed in the 144 h germinated sprout roots. After extracting the sprout roots with methanol and AOP evaluation by the iron/ascorbate and pork‐oil storage methods, both showed similar AOP trends as affected by extract concentration.
Effect of Cabbage Phospholipase D Treatment on the Oxidative Stability of Beef Homogenate and Egg Yolk Phosphatidylcholine Liposomes
Authors: Dacaranhe C.D. , Terao J.
Published: July 2006

The possibility that enzymatic hydrolysis of phospholipids increases the oxidative stability of muscle food was examined using cabbage phospholipase D (PLD). As judged by the amounts of thiobarbituric acid‐reactive substances and carbonyl content, treatment of meat homogenate with 500 ppm (840 units) PLD increased its oxidative stability during storage at 4°C for 7 d, as compared to the nontreated ones. The thin‐layer chromatographic analysis confirmed the formation of phosphatidic acid (PA) in the 500 ppm (840 units) cabbage PLD‐treated samples. In a nonheme and heme iron‐induced lipid oxidation of egg yolk phosphatidylcholine liposomes, cabbage PLD treatment also improved their oxidative stability. Cabbage PLD treatment is, therefore, likely to improve the oxidative stability of meat homogenate via PA generation.
Genetic Identification of Lophius budegassa and L. piscatorius by PCR‐RFLP Analysis of a Mitochondrial tRNAGlu/Cytochrome bSegment
Authors: Sanjuan A. , Raposo‐Guillán J. , Comesañta A.S.
Published: July 2006

Identification of Lophius budegassa(black‐bellied angler) and L. piscatorius(angler) (Lophiiformes) was carried out on the amplification of a 486 bp tRNAGlu/cytochrome b segment using the polymerase chain reaction (PCR). Direct DNA sequencing of 6 PCR products was carried out. Six restriction endonucleases (AluI, CfoI, HaeIII, HinfI, Mae, and ScrFI) with different species‐specific restriction fragment length polymorphism (RFLP) were selected. Digestions of PCR products from 30 individuals showed no intraspecific polymorphism. Double digestions (CfoI and HinfI, and HaeIII and ScrFI) were simpler and more rapid than single digestions. This technique is suitable for distinguishing tails of both Lophius species.