bluuebunny/crossref_metadata_2025 huggingface dataset:
Rheological Properties Including Tensile Fracture Stress of Semolina Extrudates Influenced by Moisture Content
Authors: LIU H. , QI J. , HAYAKAWA K.
Published: July 2006

Semolina extrudates were reshaped, immediately after extrusion to form 0.5 mm thick × 2 mm wide × 130 mm long strips. Moisture content (W) was adjusted to 5 to 39% (dry basis) equilibrating in desiccators containing saturated salt solutions. The following tensile rheological properties of the prepared samples were determined at room temperature (21‐24°C) using a Rheometrics solid analyzer: Young modulus (E), yield stress (σy), fracture stress (σc) and fracture stain (ɛc). Each of E, σy and σc was fitted by a semilogorithmically linear function of W with a negative slope. The property ɛc fitted two semilogarithmically linear functions: for W < 24.2% a line with a positive slope and for W > 24.2% a line with near zero slope. Such data for moisture ranges used in conventional pasta drying can help to optimize conditions for pasta production without stress cracking.
Enzymatic Production of Ribonucleotides from Autolysates of Kluyveromyces marxianus Grown on Whey
Authors: BELEM M.A.F. , GIBBS B.F. , LEE B.H.
Published: July 2006

After 20h fermentation of medium containing 5% (w/v) dehydrated whey, at 30°C, pH 4.5, yeast cells were harvested, diluted in 0.1M KH2PO4, and autolyzed at different pHs (6.5–7.5) and temperatures (45–55°C). Phosphodiesterase (0.2–1.0% w/v, 65°C, pH 6.5, 6h) and adenyl deaminase (0.5‐1.0% w/v, 60°C, pH 5.5, 4h) were added to the autolysates. After heat treatment (100°C, 15 min), samples were analyzed by RP‐HPLC and LC/MS. Production of 5′‐ribonucleotides was maximized at 50°C, pH 6.5. Yields of 5′‐AMP (800 μg/g of biomass) and 5′‐GMP (2000 μg/g) increased considerably after addition of 1.0% phosphodiesterase. 5′‐IMP increased only after addition of 1.0% adenyl deaminase.
Supercritical Fluid Extraction Compared with Solvent Method for Incurred Sulfamethazine in Chicken Eggs
Authors: PENSABENE J.W. , FIDDLER W. , DONOGHUE D.J.
Published: July 2006

To obtain eggs containing “normally incurred” sulfamethazine (SMZ), 10 hens were fed a single dose of 75 mg/kg SMZ by capsule. The amount of SMZ in some of the eggs (n = 21) was determined by two extraction methods, supercritical fluid extraction (SFE) and solvent extraction. The mean SMZ values ranged from 0.10 to 0.78 ppm, with an overall mean of 0.32 ppm and no difference (p>0.05) was found between the methods. However, SFE provided a distinct advantage over other methods since the amount of sample manipulation and solvent use and disposal was minimal. Determination of SMZ in the normally incurred eggs over an 8‐day period by SFE showed that levels reached a maximum after the first day, then declined slowly. However, SMZ exceeding 0.10 ppm still occurred 5 days after dosing.
Properties of Single‐ and Double‐Encapsulated Butteroil Powders
Authors: ONWULATA C.I. , KONSTANCE R.P. , HOLSINGER V.H.
Published: July 2006

Spray‐dried powders with 50% butteroil encapsulated in sucrose were double‐encapsulated by dispersion in a molten matrix of vegetable waxes (high‐pressure‐treated by a patented process) followed by pressure treating at 414 KPa and sieving. A 20–40% increase in particle size resulted from double encapsulation and powders were less flowable (P < 0.01). Scanning Electron Microscopy of double‐encapsulated powders showed one or more sucrose‐encapsulated particles embedded in a matrix of solid vegetable wax. Double coating reduced moisture uptake by 20%, possibly ameliorating the need for special packaging during storage. The flow and mechanical behavior of the encapsulated powders were different (P < 0.05) from the other powders studied.
Lipid Classes, Fatty Acids, Flavor and Storage Stability of Washed Sheep Meat
Authors: RHEE K.S. , CHO S.H. , KIM J.O. , KIM M.N.
Published: July 2006

Lamb was used for all experiments, except flavor evaluations for which mutton was used. Washing ground lamb 4 times with high‐pH (8.2) tap water, at a meat‐to‐water ratio of 1:4 and with a 15 min extraction/washing cycle, sharply lowered total fat content (primarily by removing neutral lipids), lipid oxidation potential, and the volatile branched‐chain fatty acids which reportedly contribute to undesirable species‐related flavor of sheep meat. A trained sensory panel determined that washed‐cooked mutton had “very weak” species‐related flavor (<2 on a 9‐point scale).
Mechanism of inactivation of heat‐tolerant spores of Bacillus stearothermophilus IFO 12550 by Rapid Decompression
Authors: HAYAKAWA ISAO , FURUKAWA SOICHI , MIDZUNAGA AKIHIRO , HORIUCHI HIROSHI , NAKASHIMA TAICHI , FUJIO YSUAKU , YANO YUKIO , ISHIKURA TSUYOSHI , SASAKI KADZUO
Published: July 2006

The effect of three rapid decompression methods to clear the mechanism of inactivation of heat tolerant spores of Bacillus stearothermophilus IFO 12550 was investigated. Pressurization of the spores at 200 MPa and 75°C for 60 min caused a kill of 104 CFU/mL by the link‐motion system but the nonrotational rod valve and E.G. seal methods gave a kill of about 103 CFU/mL. Sterilization was due to the physical breakdown of spore coat, and was induced by its physical permeability of water at high pressure and temperature. Rapid decompression by the link‐motion system at 200 MPa decreased the D‐value of the spores from 3000 min (100°C, one atmosphere) to 6 min, 11 min, and 17 min at 95, 85, and 75°C, respectively.
Rapid Method for Quantification of Cholesterol in Turkey Meat and Products
Authors: KING A.J. , PANIANGVAIT P. , JONES A.D. , GERMAN J.B.
Published: July 2006

A direct saponification method was developed to determine cholesterol quantitatively in turkey meat and its processed products at a detection limit of 10 ppm. Five solvents and two derivatizing agents were evaluated. The method involved direct saponification with ethanolic KOH, homogeneous‐phase toluene extraction of unsaponifiables, derivatization of cholesterol to a trimethylsilyl ether and quantitation by gas chromatography with flame ionization detection using 5α‐cholestane as internal standard. Compounds were confirmed by gas chromatography‐mass spectrometry.
Potassium Sorbate Diffusivity in American Processed and Mozzarella Cheeses
Authors: HAN JUNG HOON , FLOROS JOHN D.
Published: July 2006

The diffusivity of potassium sorbate in cheeses was determined by using diffusion models and computer programming for examining the residual surface concentration and the penetration of surface‐applied potassium sorbate into cheese. To determine diffusivity, the concentration of potassium sorbate in sliced cheese was measured by penetration time and distance from surface. The diffusivity was calculated by nonlinear regression with experimental data based on Fick's law. The diffusivity of potassium sorbate through American processed cheese was 1.31∞10‐6 cm2/sec and for Mozzarella cheese 6.74∞10‐7 cm2/sec. This indicated that Mozzarella cheese would maintain surface concentration of potassium sorbate above the critical fungistatic level two times longer than American processed cheese.
Enhanced Mass Transfer During Osmotic Dehydration of High Pressure Treated Pineapple
Authors: RASTOGI N.K. , NIRANJAN K.
Published: July 2006

High pressure pretreatment (100–700 MPa) was applied to enhance mass transfer rates during osmotic dehydration of pineapples and accelerate the process. Experimentally determined diffusivity values, based on a Fickian model, increased fourfold for water and twofold for sugar. Diffusivity values were correlated with pretreatment pressure by an equation of the form D=A exp(–B/P), which suggests that diffusivity would level after an initial increase in pressure. The increase was attributed to breaking‐up of cells walls which facilitated the transport of water. Evidence for the extent of cell wall break‐up with applied pressure was based on differential interference contrast microscopic examination of tissue. Preliminary experiments on rehydration characteristics showed high pressure pretreated samples did not absorb as much water as controls.
Optimization of Low Temperature Blanching of Frozen Jalapeño Pepper (Capsicum annuum) using Response Surface Methodology
Authors: QUINTERO‐RAMOS A. , BOURNE M.C. , BARNARD J. , ANZALDÚA‐MORALES A.
Published: July 2006

The effects of low‐temperature long‐time blanching of diced jalapeño pepper prior to freezing on extrusion force, color and pH of the product were evaluated and optimized by response surface methodology. The blanch temperature was the most important factor, while hold time had no significant effect on product quality. Maximum extrusion force and color parameter a*(green‐red) correlated with temperature. The pH and the color parameters L*(brightness) and b*(blue‐yellow) showed no significant variation with the experimental variables. The recommended blanch temperature of 55°C produced a firmness value of 779N and a color value of –10.55 of parameter a* in frozen jalapeño peppers.
On‐line Measurement of Residence Time Distribution in a Food Extruder
Authors: CHOUDHURY GOUR S. , GAUTAM AKHILESH
Published: July 2006

A technique was based on electrical conductivity of material in a die, and used a series circuit consisting of a 5 mm dia die, a 10 ohm resistor, and a 15V dc power supply. Material conductivity was altered with addition of an electrolyte tracer at the feed inlet. Change in current flow was measured as a proportional voltage response across the resistor. Using a twin‐screw extruder, with L/D 32:1, the RTD of rice flour at 15% moisture was determined using sodium nitrate as tracer. Under steady state, the voltage across the resistor was measured. The on‐line results correlated well with the established erythrosine dye method. The effects of screw configuration, feed flow rate, and screw speed were precisely determined by the on‐line method.
Lactobacillus acidophilus Group Lactic Acid Bacteria Applied to Meat Fermentation
Authors: ARIHARA K. , OTA H. , ITOH M. , KONDO Y. , SAMESHIMA T. , YAMANAKA H. , AKIMOTO M. , KANAI S. , MIKI T.
Published: July 2006

Lactobacillus acidophilus group bacteria (L. acidophilus, L crispatus, L. amylovorus, L. gallinarum, L. gasseri, L. johnsonii), probiotic lactic acid bacteria, were applied to meat fermentation. Of six strains, L. gasseri (predominant lacto‐bacilli in human intestinal tracts) JCM1131T exhibited greatest fermentation performance in meats. This strain resisted gastric acid and bile, and would thus have no detrimental effects in the intestinal tract. Inoculation of the strain depressed the propagation of S. aureus cells and their enterotoxin production during meat fermentation. Results suggest probiotic lactic acid bacteria could be effectively utilized for meat fermentation to produce healthy meat products.
Black Currant Nectar: Effect of Processing and Storage on Anthocyanin and Ascorbic Acid Content
Authors: Iversen C. K.
Published: July 2006

The degradation of anthocyanins and ascorbic acid in black currant nectar was studied during processing and storage. A continuous production process was used where the nectar was bottled within 4.0h; 20% of both components were lost in the main stream process. The choice of enzyme mainly affected the recovery of ascorbic acid. Pasteurization resulted in a loss of 2‐6 % of the ascorbic acid content. About 50% of the original content of monomeric anthocyanins remained after 6 months storage at 20°C. The stabilities of delphinidins and cyanidins during storage were very similar. Deaeration of the nectar before bottling had no effect on anthocyanin content.
Polyphenoloxidase Activity and Color of Blanched and High Hydrostatic Pressure Treated Banana Puree
Authors: Palou E. , López‐Malo A. , Barbosa‐Cánovas G. V. , Welti‐Chanes J. , Swanson B. G.
Published: July 2006

The effects of blanching and high hydrostatic pressure (HHP) treatments on natural flora evolution, polyphenoloxidase (PPO) activity and color of banana puree adjusted to pH 3.4 and water activity (aw) of 0.97 were evaluated during 15 days storage at 25°C. Standard plate as well as yeast and mold counts of HHP treated purees were <10 CFU/g throughout storage. Blanching time was found to affect (P<0.05) puree color. HHP treatments retained the initial color of the banana purees. Longer browning induction times and slower browning rates were observed when a longer blanching time was combined with a 689 MPa pressure treatment. A residual PPO activity < 5% was observed in the puree when a 7 min blanch was followed by HHP treatment at 689 MPa for 10 min.
Diffusion of Aqueous Sugar Solutions as Affected by Locust Bean Gum Studied by NMR
Authors: Martin D. R. , Ablett S. , Darke A. , Sutton R. L. , Sahagian M.
Published: July 2006

Time domain proton NMR was used to study translational diffusion and molecular mobility of sugar and water molecules in simple aqueous solutions to determine how the addition of hydrocolloid stabilizers affect their mobility. Results showed that addition of Locust Bean Gum (LBG) did not affect the diffusion or mobility of either the sugar or water molecules over distances up to 10μm in unfrozen solutions. The diffusion properties of the sugar and water molecules were not affected by either biopolymer cryogelation or the presence of ice. We hypothesized that retardation of the ice crystal growth rates in aqueous sugar solutions caused by the presence of LBG was not a bulk property of the solution. The most likely cause is a modification of the local interfacial region between the ice crystal surface and the surrounding unfrozen solution.
Storage Stability of Ground Pork Containing Meat from an Advanced Meat Recovery System
Authors: Calhoun C.M. , Gaebler D.M. , Mandigo R.W.
Published: July 2006

Pork trim‐finely textured (PTFT), generated by advanced meat recovery which mechanically removes meat from bones under pressure, has properties that may cause shelf‐life instability. Lipid oxidation, microbial growth and pH of retail displayed fresh ground pork patties were not affected (P>0.05) by addition of up to 15% PTFT. Ground pork with 15% PTFT and 3.3% sodium lactate (NaL) stored in chubs at–2.2°C for 14 days was ground and modified atmosphere packaged (MAP) or overwrapped (OW) and retail displayed for 4 days. Lipid oxidation increased (P<0.05) due to PTFT incorporation but was reduced by NaL. MAP and/or NaL reduced microbial counts and lipid oxidation. MAP maintained redness (a*) and prevented metmyoglobin formation.
Sensory Characteristics of Cottage Cheese Whey and Grapefruit Juice Blends and Changes During Processing
Authors: Branger E.B. , Sims C.A. , Schmidt R.H. , O'Keefe S.F. , Cornell J.A.
Published: July 2006

Studies were conducted to determine the sensory characteristics of pasteurized blends of cottage cheese whey and grapefruit juice (0%, 25%, 50%, 75% and 100% whey), and the effects of processing alternatives and storage at 3°C. A trained sensory panel rated six attributes (grapefruit, sweetness, sourness, astringency, cheesiness, saltiness). Cheesiness and saltiness increased, while sourness, astringency, sweetness, and grapefruit flavor decreased as the percentage of whey increased. Protein removal did not affect the sensory characteristics, but vacuum stripping reduced cheesiness and increased grapefruit flavor and sweetness. Lactose hydrolysis increased sweetness and decreased cheesiness in blends with more than 50% whey. The flavor of most blends was stable for 14 wk at 3°C.
Secondary Flow and Residence Time Distribution in Food Processing Holding Tubes with Bends
Authors: Sandeep K.P. , Zuritz C.A.
Published: July 2006

Residence times of nearly neutrally buoyant polystyrene particles flowing with an aqueous solution of carboxymethylcellulose were measured in each of 4 straight sections of holding tubes that were connected by 180° bends. Equations were developed to predict mean, minimum, and standard deviations of residence times in individual tubes and in the entire assembly as a function of viscosity, particle size, particle concentration, and flow rate. The residence time distribution in the 4th tube was always narrower than that in the 1st tube, and the ratio of the mean to minimum residence time was always between 1.07 and 1.20. These results can help in the design of appropriate holding tubes for food processing.
Color Improvement and Metallo‐chlorophyll Complexes in Continuous Flow Aseptically Processed Peas
Authors: Canjura F.L. , Watkins R.H. , Schwartz S.J.
Published: July 2006

Fresh and frozen green peas were blanched in zinc solution (50 to 500 mg/L) and thermally processed in a particle cell reactor, which simulates a continuous flow aseptic processing system. The thermal process temperatures ranged from 121 to 145 °C at holding times from 0 to 20 min. The degradation of chlorophyll and the resulting formation of Zn‐pheophytin a and Zn‐pyropheophytin a were monitored. Quantitative analysis of the metallo‐chlorophyll complexes was performed by high‐performance liquid chromatography. Complex formation increased during heat processing and was dependent on the zinc concentration absorbed within the peas during blanching. At 130 to 145 °C, the formation of Zn‐pyropheophytin a increased and processing between 121 to 125 °C promoted the formation of Zn‐pheophytin a. Improvements in color relative to control samples suggested that the process might be applicable to two‐phase continuous aseptic processing of vegetables.
Thermally Induced Changes in Protein Extractability of Postrigor Turkey Breast Meat Measured by Two Methods
Authors: Rathgeber B.M. , Boles J.A. , Xavier I.J. , McCurdy A.R. , Shand P.J.
Published: July 2006

Extractability of sarcoplasmic and myofibrillar proteins was reduced in postrigor turkey breast meat held at 40 °C for as short as 30 min. These reductions in protein extractability were successfully detected, using either a filtration‐based methodology or one based on centrifugation. However, the coefficient of variation for the filtration method was as much as 4 times greater than for centrifugation. Additionally, the filtration method overestimated sarcoplasmic protein extractability due to the inability to exclude myofibrillar proteins. Centrifugation results indicated the extractability of proteins in 0.55 M KCl was reduced to 52% of controls for samples held at 40 °C for 120 min. Additionally, holding postrigor turkey breast muscle at 40 °C resulted in increased myosin degradation.
Accelerated Mass Transfer During Osmotic Dehydration of High Intensity Electrical Field Pulse Pretreated Carrots
Authors: Rastogi N.K. , Eshtiaghi M.N. , Knorr D.
Published: July 2006

High intensity electrical field pulse (0.22 to 1.60 kV/cm) pretreatment was tested to accelerate the osmotic dehydration of carrot. Applied energy in the range of 0.04 to 2.25 kJ/kg, increased cell disintegration index in the range of 0.09 to 0.84 with < 1 °C rise in the product temperature. The effective diffusion coefficients of water and solute, determined using a Fickian diffusion model, increased exponentially with electric field strength according to D = A exp(‐B/E). The rise in effective diffusion coefficient may be attributed to an increase in cell wall permeability, facilitating transport of water and solute. Such increase was evidenced by cell disintegration index and softening of product.
Detection of Internal Hollows in Cooked Rice Using a Light Transmittance Method
Authors: Suzuki M. , Horigane A.K. , Toyoshima H. , Yan X. , Okadome H. , Nagata T.
Published: July 2006

We previously reported that nuclear magnetic resonance (NMR) micro imaging detected the hollows in cooked rice but required a specialist to operate equipment. Convenient detection of hollows is useful in the characterization of cooked rice. X‐ray imaging and light transmittance photography were studied as alternatives to NMR micro imaging. X‐ray imaging detected about 50% of all hollows. Light transmittance photography detected almost all hollows in cooked rice (Oryza sativa cv. Koshihikari) effectively and rapidly, relatively quantifying hollow sizes and numbers.
Water Vapor Permeability, Solubility, and Tensile Properties of Heat‐denatured versus Native Whey Protein Films
Authors: Pérez‐Gago M.B. , Nadaud P. , Krochta J.M.
Published: July 2006

Whereas native whey protein films were totally water soluble, heat denatured films were insoluble. Heat‐denatured whey protein films had higher tensile properties than native whey protein films. However, native and heat‐denatured films had similar water vapor permeability (WVP). The pH of the film‐forming solution did not have any notable effect on film solubility, mechanical properties, or WVP. Results suggest that covalent cross‐linking due to heat denaturation of the whey protein is accountable for film water insolubility and higher tensile properties but does not affect WVP of the films.
Transaminase Affects Accumulation of Free Amino Acids in Electrically Stimulated Beef
Authors: Sekikawa M. , Seno K. , Shimada K. , Fukushima M. , Mikami M.
Published: July 2006

Electrical stimulation (ES) of a beef carcass increases the content of free amino acids, which affects meat flavor. Levels of glutamic acid (Glu)‐aminopeptidase activity were similar in both control and ES meat but decreased during storage to about 65% at 14 days. When 2‐ketoglutaric acid (a substrate of transaminase) was added to the sarcoplasm, the level of Glu increased. Transaminase activity was unaffected by storage and was about 20% greater in ES than in the control. Transaminase activity in beef was confirmed when radioactive 2‐ketoglutaric acid was added to the sarcoplasm. Results suggest that transaminase contributes to accumulation of some amino acids such as Glu in beef during conditioning.
Selected Vitamin Contents and Retentions in Bison Patties as Related to Cooking Method
Authors: YUAN X. , MARCHELLO M. J. , DRISKELL J. A.
Published: July 2006

Contents and retentions of selected vitamins in broiled and grilled bison patties from four producers were determined. Mean vitamin contents of uncooked bison patties were (per 100 g wet weight): 0.038 mg thiamin, 0.220 mg vitamin B‐6, 1.457μg vitamin B‐12, and 0.286 mg vitamin E; no differences were observed among producers. Differences were found (P<0.05) among producers for vitamins B‐6, B‐12, and E (broiled only), but not for thiamin contents of cooked bison patties. The mean retention values in cooked patties were: 68.9% thiamin; 67.5% vitamin B‐6; 67.0% vitamin B‐12; and 76.1% vitamin E. Bison patties are rich sources of vitamin B‐12 and good sources of vitamin B‐6.
Empirical and Dynamic Rheological Data Correlation to Characterize Melt Characteristics of Imitation Cheese
Authors: Mounsey J.S. , O'Riordan E.D.
Published: July 2006

Imitation cheese was manufactured with various levels of pre‐gelatinized maize starch. Melt characteristics were assessed by an empirical melt test, based on the Olson and Price method. Using dynamic rheology, the storage modulus (G′), the loss modulus (G”) and the loss angle (tan δ) were measured as a function of temperature (22‐100°C). Melt‐ability decreased with increasing levels of starch. Maximum tan δ values and the temperature at which they occurred decreased with increasing starch levels. A high correlation (r2=+0.96) was found between the maximum tan δ values and melt‐ability as assessed by the empirical method. Tan δ may be a useful indicator of imitation cheese melt‐ability.
Gelation of Barley ß‐Glucan Concentrate
Authors: Burkus Z. , Temelli F.
Published: July 2006

The gel behavior of barley β‐glucan (BBG) gum extracted in our laboratory was compared to low‐ and high‐viscosity commercial BBG gum and cornstarch using compression between parallel plates. Effects of β‐glucan concentration and hydration temperature on gel behavior were examined. BBG gum gelled at ≥5% concentration and gel strength increased (p≤0.05), but not proportionally, with concentration. Hydration temperature did not influence gel strength. Commercial β‐glucan had higher (p≤0.05) gel strength than our BBG gum at 5% concentration. Cornstarch produced ∼78% softer gel than BBG gum at 6% concentration. BBG may have potential as a gelling agent.
Proteolysis and Functional Properties of Mozzarella Cheese as Affected by Refrigerated Storage
Authors: Chaves W.H. Viotto , Grosso C.R.F.
Published: July 2006

Each of three cheese batches was randomly divided into two parts, one was subjected to slow freezing for 15 days and the other maintained under refrigeration. Thereafter the cheeses were tempered under refrigeration for 1 mo and evaluated weekly. In general, cheeses presented low melting capacity as a result of low levels of proteolysis. This low intensity of proteolysis was probably a function of the destruction of the lactic starter and partial inactivation of the coagulant during stretching of the cheese. Free oil content increased during storage for both treatments, but more in the tempered samples.
Volatiles Production and Lipid Oxidation in Irradiated Cooked Sausage as Related to Packaging and Storage
Authors: Ahn D. U. , Olson D. G. , Jo C. , Love J. , Jin S. K.
Published: July 2006

Irradiation dose affected production of volatiles in vacuum‐and aerobic‐packaged cooked pork sausage, but its effect on TBARS was minor. Storage increased production of volatiles and changed their composition only in aerobic‐packaged sausage. Among volatile components, 1‐heptene and 1‐nonene were influenced most by irradiation dose, and aldehydes by packaging type. TBARS and volatiles of vacuum‐packaged irradiated cooked sausage did not correlate well. However, TBARS had very high correlation with amount of aldehydes, total volatiles, ketones and alcohols with long retention times in aerobic‐packaged pork sausage. Heptene and 1‐nonene could be indicators for irradiation; and propanal, pentanal, and hexanal for oxygen‐dependent changes of cooked meat.
Desmin Degradation in Postmortem Fish Muscle
Authors: Verrez‐Bagnis V. , Noel J. , Sautereau C. , Fleurence J.
Published: July 2006

The degradation of desmin was studied in postmortem white dorsal muscle from sea bass, brown trout, turbot and sardine, stored at 0–4°C. Based on desmin specific antibody tests, results showed that the extent and rate of desmin degradation in postmortem fish muscle varied considerably among species. There was no degradation of desmin during the first 4 days postmortem storage of sea bass and brown trout, whereas 10 to 20% of muscle desmin was degraded during the first 4 days of postmortem storage of turbot. Sardine muscle presented a very complex pattern of desmin degradation products and aggregated desmin fragments detected within the first 24h. Most polypeptides were larger than the nondenatured desmin. Desmin degradation would not be a suitable marker for evaluation of postmortem changes of stored fish.
Color and Texture of Acidified Ripe Olives in Pouches
Authors: García P. , Brenes M. , Romero C. , Garrido A.
Published: July 2006

The effects of pouch material (aluminum, plastic), packing pH (3.8,4.3), acidifying compound (lactic, gluconic), and storage temperature were tested on polyphenol content and color of holding brines, surface color, and firmness of ripe olives. Using pouches of plastic films, pH 4.3–4.0 holding solution, and lactic or gluconic acid products with color and texture similar to traditional canned ripe olives were produced. They could be properly stored at room temperature (25°C). As storage temperature rose, color improved but texture was seriously degraded at 50°C.
Production of Polysaccharide by Rahnella aquatilis with Whey Feedstock
Authors: Pintado M. E. , Pintado A. I. E. , Malcata F. X.
Published: July 2006

The rates were monitored on biomass increase, polysaccharide production and viscosity development of whey broth and a control synthetic broth during fermentation by Rahnella aquatilis and organic acids, lactose, peptides and free amino acids were measured. Growth curves were similar and characterized by maximum specific growth rates of 0.61 h−1 for whey and 0.63 h−1 for synthetic medium. The yields of polysaccharide were 0.59 g/glactose for the synthetic medium and 0.56 for whey. Small peptides (<4,000 Da) and most free amino acids in both fermentation media were consumed within 24h.
Factors Influencing Recovery of Heat‐injured Bacillus thuringiensis Spores. Statistical Approach
Authors: Faille Christine , Fontaine Françoise , Membré Jeanne‐Marie
Published: July 2006

The influence of several factors on recovery of heat‐treated Bacillus thuringiensis spores was examined including treatment conditions (time/temperature), dilution buffer (phosphate buffer, peptone water at 15 mg/L), recovery temperature and enumeration medium constituents (lysozyme, catalase, lactic acid hemicalcium salt, glucose, MgSO4, sodium chloride). A fractional factorial design was used to determine the incidence and interactions of these factors. Specific significant factors (treatment conditions, dilution buffer, recovery temperature, glucose and NaCl addition) were derived from this analysis and then tested in a general linear regression model which assessed their influences. The maximal count was obtained when spores diluted in peptone buffer were incubated at 25°C in nutrient agar containing NaCl and glucose.
Texture Changes Associated with Insolubilization of Sarcoplasmic Proteins During Salt‐vinegar Curing of Fish
Authors: Toyohara M. , Murata M. , Ando M. , Kubota S. , Sakaguchi M. , Toyohara H.
Published: July 2006

The effect of salt‐vinegar curing on mackerel meat was investigated. In salt curing, the firmness of the meat increased concomitantly with the decrease in water content and the increase in insolubilization of sarcoplasmic protein of phosphorylase. In subsequent vinegar curing, the firmness and cohesiveness of the meat increased concomitantly with the increase in insolubilization of the sarcoplasmic proteins of enolase, creatine kinase, aldolase, and glyceraldehydephosphate dehydrogenase. No apparent proteolytic breakdown was detected in the salt‐vinegar curing. The findings suggested that the precipitation of substantial amounts of sarcoplasmic proteins might contribute to the texture change caused by salt‐vinegar curing.
Starch Retrogradation and Texture of Cooked Milled Rice During Storage
Authors: Perdon A.A. , Siebenmorgen T.J. , Buescher R.W. , Gbur E.E.
Published: July 2006

The effect of storing cooked Bengal and Cypress milled rice at ‐13, 3, 20, and 36 °C on texture and degree of starch retrogradation was investigated. Cooked rice firmness increased, while stickiness decreased, during storage at ‐13 and 3 °C. Starch retrogradation, measured with a differential scanning calorimeter, was observed for both cultivars during storage at ‐13 and 3 °C, but not at 36 °C. At 20 °C, retrogradation occurred in Cypress, but not in Bengal. Starch retrogradation showed positive linear trends with firmness for both cultivars at all storage temperatures (R2= 0.80) and with stickiness for Bengal stored at ‐13 and 3 °C and for Cypress stored at 3 and 20 °C (R2 = 0.88).
Protein Denaturation and Structural Damage During High‐Pressure‐Shift Freezing of Porcine and Bovine Muscle
Authors: Fernández‐Martín F. , Otero L. , Solas M.T. , Sanz P.D.
Published: July 2006

ABSTRACT: Pork and beef muscles were subjected to 200 MPa and −20 °C with or without water freezing. Both tissues responded to the treatment with similar behavior. Protein denaturation was greater when freezing occurred. Pressure‐induced cold denaturation was complete for actin and very considerable for myosin and other muscle proteins. Connective proteins remained practically unaltered by pressurization and/or freezing. Structural changes in the muscle at sarcomere levels caused by pressurization were more severe when freezing occurred. Color, drip loss, and textural properties on the pressurized samples also revealed an additional deleterious influence of freezing. Pressurization alone and pressure‐shift freezing resulted unsuitable for muscle preservation.
Extrusion Cooking Process for Amaranth (Amaranthus caudatus L.)
Authors: Chávez‐Jáuregui R.N. , Silva M.E.M.P. , Arěas J.A.G.
Published: July 2006

ABSTRACT: Amaranth (Amaranthus caudatus L.) extrusion was optimized by response surface methodology (RSM). Response (dependent) variables were: expansion ratio, shearing strength, and sensory texture acceptability. Independent variables were processing temperature and feed moisture. All other process variables (screw speed, screw compression ratio, feed speed, and die diameter) were kept constant (200 rpm, 70 g.min−1, and 3 mm, respectively). The most expanded products also had the best texture and were obtained at 150 °C and 15% moisture. These conditions resulted in greater expansion, greater shearing force of extrudates, greater extrudate surface area per unit weight, and reduced shearing stress at maximum shearing force. This study showed that under conditions that induced the maximum expansion ratio, extrusion produced a highly acceptable snack product based on amaranth flour.
pH Affects the Thermal Inactivation Parameters of R‐Phycoerythrin from Porphyra yezoensis
Authors: Orta‐Ramirez A. , Merrill J.E. , Smith D.M.
Published: July 2006

ABSTRACT: R‐phycoerythrin (PE), a protein that fluoresces in the visible range, was purified from Porphyra yezoensis. PE had a molecular mass of 292 kDa and an isoelectric point of 4.1 to 4.2. Thermal inactivation parameters of PE, calculated on the basis of fluorescence loss, were determined under different pH conditions. PE was more thermostable between pH 5.0 and 8.0, and became more heat sensitive at pH 4.0 and 10.0. PE at pH 6.0 had the highest D value (12258.7 min) at 70 °C. The z values of PE increased from 4.58 °C at pH 5.0 to 9.15 °C at pH 9.0. PE could be used as a time‐temperature integrator by adjusting the inactivation kinetics of PE to match those of target microorganisms in a thermal process.
Stability of Washed Frozen Mince from Channel Catfish Frames
Authors: Hoke M.E. , Jahncke M.L. , Silva J.L. , Hearnsberger J.O. , Chamul R.S. , Suriyaphan O.
Published: July 2006

ABSTRACT: Sodium citrate, sodium erythorbate, sodium citrate plus sodium erythorbate, sodium citrate plus sodium erythorbate, and polyphosphate were used in washed and unwashed channel catfish mince. Washing reduced (P 0.05) lipids and increased (P 0.05) Hunter ‘L’value (lightness) of mince. Thiobarbituric reactive substances and free fatty‐acid changes during frozen storage were reduced in the washed mince. Addition of antioxidants did not significantly improve the overall quality and shelf‐life of the frozen mince. Washing did not have an effect on the fatty‐acid composition of neutral and phospholipids in the mince.
The Effect of Caramel Coloring on the Multiple Degradation Pathways of Aspartame
Authors: Wang R. , Schroeder S. A.
Published: July 2006

ABSTRACT: Multiple degradation pathways accounting for the breakdown of the dipeptide sweetener a‐L‐aspartyl‐L‐phenylalanine methyl ester (a‐APM) in 4 mM phosphate, pH 3.1 and a simulated cola beverage are described. At 20‐, 35‐, 45‐ and 55 °C caramel coloring concentrations greater than 700 ppm increased the rate of hydrolysis of the methyl ester forming a‐L‐aspartyl‐L‐phenylalanine. At 55 °C and pH 3.1 caramel coloring also enhanced the breakdown of a‐APM degradation products. The influence of caramel coloring on the rates of degradation varied considerably for a‐APM and each degradation product. A model is proposed based on the expected solution properties of caramel coloring which accounts for the enhanced degradation.
HPLC Determination of Amino Acids in Musts and Port Wine Using OPA/FMOC Derivatives
Authors: Herbert P. , Barros P. , Ratola N. , Alves A.
Published: July 2006

ABSTRACT: Musts and port wines pose specific problems for amino acid analysis because of high sugar content. An HPLC technique was applied to the simultaneous quantification of primary and secondary amino acids in these matrices as their OPA‐FMOC derivatives. This method enabled the fully automated analysis of 21 amino acids in 20 minutes. The average detection limit was 1.3 mmole/L, precision was 5%‐12% for wine samples and accuracy by the standard addition method was 108.3 % (recovery value). Ten port wine and 43 must samples were analyzed for free amino acid contents. Proline represented 73% of the total for wine samples.
Rapid PCR‐RFLP Method for the Identification of Marine Fish Fillets (Seabass, Seabream, Umbrine, and Dentex)
Authors: Cocolin L. , D'Agaro E. , Manzano M. , Lanari D. , Comi G.
Published: July 2006

A rapid and reliable PCR‐RFLP method was optimized to identify marine fish fillets. Seabass, seabream, umbrine, and dentex were considered in the study. After DNA extraction and PCR, the 359 bp amplification products, obtained from gene encoding the cytochrome b, were subjected to restriction enzyme analysis. All the enzymes tested were not able to distinguish all the 5 species at the same time, but the combination of the results obtained from the digestion HaeIII and NlaIII can be used to differentiate the fish fillets considered. The method described is sensitive, rapid, and reliable, and it could be used to expose fraudulent substitutions with less valuable fish.
Effect of Hydration Time and Salt Addition on Gelation Properties of Major Protein Additives
Authors: Choi Y.J. , Cho M.S. , Park J.W.
Published: July 2006

Gelation properties of 4 major protein additives were measured with and without salt during various hydration times. As hydration time increased, stress and strain of beef plasma and egg white gradually decreased regardless of salt. Unsalted whey proteins did not form a gel until the hydration time reached 48 h. Stress values of salted beef plasma with no hydration were significantly high. Soy protein isolate did not form a measurable gel at 9% concentration regardless of the presence of salt under rheological instruments, however its denaturation temperature was detected under DSC. Effect of salt on gel color was more pronounced with whey protein concentrate.
Effects of Pulsed Electric Fields on the Activities of Microorganisms and Pectin Methyl Esterase in Orange Juice
Authors: Yeom H.W. , Streaker C.B. , Zhang Q.H. , Min D.B.
Published: July 2006

Orange juice was treated with pulsed electric fields (PEF) in a pilot‐plant system to optimize PEF‐processing conditions for maximum microbial inactivation and to investigate the effects of PEF on pectin methyl esterase (PME) activity. Electric‐field strengths of 20,25,30, and 35 kV/cm and total treatment times of 39, 49, and 59 μs were used. Higher electric‐field strengths and longer total treatment times were more effective to inactivate microorganisms and PME (p < 0.05). PEF treatment of orange juice at 35 kV/cm for 59 μs caused 7–log reductions in total aerobic plate count and yeast and mold counts. About 90% of PME activity was inactivated by PEF treatment at 35 kV/cm for 59 μs. PEF‐treated orange juice at 35 kV/cm for 59 ms did not allow growth of microorganisms and recovery of PME at 4, 22, and 37 °C for 112 d.
Cultivar, Maturity, and Heat Treatment on Lycopene Content in Tomatoes
Authors: Thompson K.A. , Marshall M.R. , Sims C.A. , Wei C.I. , Sargent S.A. , Scott J.W.
Published: July 2006

Using high performance liquid chromatography, tomato cultivars which contain the Crimson gene (og) were usually found to have higher lycopene content (5086 to 5786 μg/100 g fresh weight) than those cultivars lacking the gene (2622 to 4318 μg/100 g fresh weight). A comparison of the color readings taken from tomatoes at the equatorial region with those of the homogenate prepared from the same region showed that the hue of tomato homogenate was a better indicator of lycopene content than tomato surface hue. The tomatoes' lycopene content was not affected by ethylene treatment or cooking for 4, 8, and 16 min at 100 °C.
Effects of Ingredients on the Functionality of Fat‐free Process Cheese Spreads
Authors: Swenson B.J. , Wendorff W.L. , Lindsay R.C.
Published: July 2006

Emulsifying salts and hydrocolloids, cook time, cook temperature, and pH were evaluated to characterize their effects on firmness, meltability, and spreadability of fat‐free process‐cheese spreads. Disodium phosphate and trisodium citrate produced properties closest to those of a full‐fat reference cheese, with trisodium citrate providing the most meltability. In all cases, incorporation of hydrocolloids resulted in increased firmness, decreased melt, with varying results on spreadability. Increases in cook time generally produced softer, more meltable cheeses, while increases in cook temperature decreased firmness and increased meltability and spreadability.
Fractionation of Chicken Fat Triacylglycerols: Synthesis of Structured Lipids with Immobilized Lipases
Authors: Lee K.‐T. , Foglia T.A.
Published: July 2006

Chicken fat was temperature‐fractionated either without or with solvent, and by supercritical carbon dioxide extraction to produce trlacylglycerol (TAG) fractions of varying monounsaturated fatty acid (MUFA) content. Solvent fractionation from acetone at low temperature (‐38 and ‐18°C) was the most effective process for enriching the MUFA‐containing TAG of chicken fat in the liquid fractions. Caprylic acid was incorporated into the MUFA‐enriched TAG fraction in lipase‐catalyzed acidolysis reactions to produce structured lipids (SLs). Immobilization of the lipase within sol‐gel phyllosilicate matrices allowed for the reusability of both lipases.
Rehydration Kinetics of High‐Pressure Pretreated and Osmotically Dehydrated Pineapple
Authors: Rastogi N.K. , Angersbach A. , Niranjan K. , Knorr D.
Published: July 2006

Rehydration kinetics of high‐pressure pretreated (100, 300, and 500 MPa for 10 min) and osmotically dehydrated pineapple (Ananas comsus) cubes (2 × 2 × 1 cm) were studied at different temperatures (5, 25, and 35°C), and compared with ordinary osmotically dehydrated samples. The effective diffusion coefficients for water and solute were determined, assuming the rehydration process to be governed by Fickian diffusion. Diffusion coefficients for water absorption into the tissue as well as for solute diffusion out of the tissue were found to be lower in the samples subjected to high‐pressure treatment. Further, the diffusion coefficients decreased with increase in treatment pressure. A possible explanation for the observed decrease in diffusion coefficients can be attributed to the permeabilization of cell membranes, the release of cellular components, and structural changes of the cell materials. The diffusion coefficients were correlated with rehydration temperature (T) and treatment pressure (P) by an Eq. of the form D = A exp[–(B.P + C/T)], where A, B, and C are constants.
Prevalence of Salmonellae on Beef Products at Butcheries and their Antibiotic Resistance Profiles
Authors: Gashe B.A. , Mpuchane S.
Published: July 2006

We determined the aerobic plate count at 5 and 25 °C, presence of total coliforms, fecal coliforms, andEscherichia coli, and prevalence ofSalmonellaspecies in 354 meat products collected from butcheries. The aerobic counts varied from 3.5 to 10.7 log10CFU/g. Most of the microorganisms were psychrotrophic. Coliforms were present in all samples except kidneys.Escherichia coliwas present at ≥2 log10CFU/g in ≥50% of the minced meat, liver, and stew.Salmonellaspecies were present in 9.9% of the samples. Minced meat and tripe contained more salmonellae than the other beef. Serogroup E or G (57.1%) was the most predominant serotype. Tetracycline resistance (33.3%) was higher than that of other antibiotics.
Lycopene Stability in Tomato Powders
Authors: Anguelova T. , Warthesen J.
Published: July 2006

The chemical stability of lycopene in 2 commercial tomato powders was evaluated during storage. Liquid chromatography and spectral analysis were used to determine lycopene loss and the formation of cis isomers and degradation products. Tomato powder products were stored at 6 and 45 °C or under fluorescent light for up to 6 wk. Several lycopene degradation products were tentatively identified in the initial and stored powders. After 6 wk at 45 °C, 60% of the lycopene was degraded. At lower storage temperatures the losses were about 30% after 6 wk. Mechanisms of loss appear to be both isomerization and oxidation.
Technical Approach to Simplify the Purification Method and Characterization of Microbial Transglutaminase Produced from Streptoverticillium ladakanum
Authors: Ho M.‐L. , Leu S.‐Z. , Hsieh J.‐F. , Jiang S.‐T.
Published: July 2006

In order to fast and economically purify MTGase from Streptoverticillium ladakanum, a stepwise elution method was developed and compared with linear gradient elution method. MTGase was purified to electrophoretical homogeneity by using CM Sepharose CL‐6B and Blue Sepharose Fast Flow chromatographies by linear gradient or stepwise methods. The recovery of MTGase by linear gradient and stepwise methods were 68.4% and 81.0%, respectively. The optimal temperature and pH were 40 °C and 5.5, respectively. It was stable at pH 5.0 to 7.0 and had a rate constant (KD) of 6.21 °o 10‐5 min‐1 for thermal inactivation at 45 °C. The purified MTGase was activated by K+ Na+, Ca2+, Mn2+, and Mg2+, not affected by Fe3+, EDTA, but inhibited by Cu2+, Zn2+, Hg2+, Ni2+, Co2+, Cd2+, PCMB, NEM, IAA, and PMSF. A simple stepwise method was developed for the purification of MTGase from S. ladakanum.
Textural, Water Holding, and Sensory Properties of Low‐fat Pork Bologna with Normal or Waxy Starch Hull‐less Barley
Authors: Shand P.J.
Published: July 2006

All ultra‐low‐fat (< 1%) pork bolognas had similar cook yield and composition. Addition of 4% hull‐less waxy barley flour or meal to formulations provided the greatest purge control; 4% normal starch barley, wheat flour and potato starch were intermediate; 0.25% kappa‐carrageenan or 1% soy protein concentrate had little effect on water holding and texture. Expressible moisture and purge were significantly correlated to moisture content and batter viscosity. Formulations with wheat flour and waxy barley meal were scored the firmest, while bologna with potato starch required the most force to compress. For most sensory properties, barley fractions performed similarly to wheat flour; however, waxy barley provided superior water holding during storage.
pH Induced Aggregation and Weak Gel Formation of Whey Protein Polymers
Authors: Mleko S. , Foegeding E.A.
Published: July 2006

Whey protein polymers were formed by heating (80 °C) a 4% (w/v) whey protein (WP) isolate dispersion at pH 8.0 for 15, 25, 35, 45, or 53 min. Dispersions were adjusted to pH 6.0, 6.5, 7.0, 7.5, or 8.0 after heating and the rheological properties were determined. Viscosity increased with increased heating time and decreased pH. At pH 7.0 and 7.5, high‐viscosity dispersions with pseudoplastic and thixotropic flow behavior were formed, while weak gels were formed at pH 6.0 and 6.5. The storage (elastic) and loss (viscous) moduli of pH‐induced gels increased when temperature was increased from 7 °C to 25 °C, suggesting that hydrophobic forces are responsible for gelation. Key Words: weak‐gels, whey proteins, polymers, gelation, functionality
Viscoelastic Changes of Rice Starch Suspensions During Gelatinization
Authors: Hsu S. , Lu S. , Huang C.
Published: July 2006

Dynamic rheometry was utilized to characterize viscoelastic changes during heat‐induced gelatinization of 2 domestic rice starch suspensions, 1 from waxy and the other from indica rice. Gelatinization included 4 stages: suspension into sol, sol transition to gel, network destruction, and network strengthening. Increase in storage modulus (G′) was observed as early as about 47°C. For indica rice, the maximum value (G′max) was higher, and the decrease afterwards was slower, owing to its higher amylose content. The effects of heating time and temperature were found additive. Sealing samples with oil affected the accuracy of measurement. Finally, the network of starch gels had a larger fractal dimension than that of soy protein isolates previously investigated, suggesting firmer food texture.