bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of Aflatoxin Biosynthesis: Induction of Aflatoxin Production by Various Carbohydrates
Authors: ABDOLLAHI A. , BUCHANAN R. L. 
Published: August 2006

ABSTRACTThe ability of various compounds to induce aflatoxin biosynthesis by Aspergillus parasiticus was investigated by initially culturing the organism in a peptone basal medium that does not support aflatoxin production, and then transferring the organism to a replacement medium containing the test compound. Ribose, xylose, glucose, fructose, sorbose, mannose, galactose, maltose, sucrose, raffinose, and glycerol induced aflatoxin production. This induction of aflatoxin production was blocked when cycloheximide was incorporated into the replacement medium. Aflatoxin biosynthesis was not induced by lactose, lactic acid, sodium pyruvate, oleic acid, citric acid, sodium acetate, α‐methyl‐D‐glucoside, 3‐0‐methyl‐D‐glucoside, cAMP, or cGMP. The results suggest that the synthesis of one or more of the enzymes responsible for aflatoxin formation is regulated by the availability of specific readily‐metabolizable carbon sources.
Ascorbic Acid Retention in Retort Pouched Green Beans
Authors: CHEN T. ‐S. , GEORGE W. L. 
Published: August 2006

ABSTRACTThe L‐ascorbic acid (AA) retention in and sensory quality of green beans processed under home‐canning conditions in retort pouches and metal cans were compared. Green beans processed in cans retained slightly more AA than that processed in the pouches, possibly due to overprocessing of the pouched product. Metal cans offered better AA retention in the green beans than the retort pouches during 11 wk of storage at 21°C, due mainly to a higher rate of AA degradation occurring in the pouched product during the first week of storage. Sensory evaluation showed that the retort pouched beans were significantly better (p < 0.05) than the canned green beans in flavor, texture, and overall acceptance, but not in color.
Nutritive Quality of Fermented Sorghum
Authors: AU PAUL M. , FIELDS MARION L. 
Published: August 2006

ABSTRACTThe relative nutritive value (% RNV) of sorghum fermented at 25°C and at 35°C increased significantly (P < 0.05) over the % RNV of the control. During the consecutive 7‐day fermentation at 25°C, time had no effect on the % RNV. The highest % RNV (56.45%) was achieved at the end of 1 day. Fermentation at 35°C was influenced by the time, with the highest % RNV (61.11%) obtained at the end of 7 days. Available lysine and methionine increased substantially (P < 0.01) over the control when sorghum was fermented at 25°C or 35°C for 4 days. Sorghum fermented at 25°C and at 35°C had methionine contents of 25.68 and 26.79 mg/g N, respectively, whereas the control contained only 11.25 mg/g N. Lysine levels were 33.2 and 34.5 mg/g N in sorghum fermented at 25°C and at 35°C, respectively, whereas the control contained 9.1 mg/g N. None of the available B‐vitamins studied was altered significantly in the fermented samples.
Campylobacter fetus ssp. jejuni: Recovery Methodology and Isolation from Lamb Carcasses
Authors: STERN NORMAN J. 
Published: August 2006

ABSTRACT Campylobacter fetus ssp. jejuni has increasingly been implicated as the causative agent in human cases of gastroenteritis. The first account of C. jejuni isolation from red meats—lamb carcasses—is reported. Recovery of Campylobacter from meat surfaces was tested as follows: selective agar plates consisted of tryptic soy agar, 5% lysed defibrinated horse blood, 10 mg/L vancomycin, 2500 units/L polymyxin B, 5 mg/L trimethoprim lactate, and 15 mg/L cephalothin (Keflin; VPTK: plates). These VPTK plates were incubated at 35°C for 72 hr in a gas atmosphere of 5% O2, 10% CO2, and 85% N2. With these selective elements, recovery from meat surfaces inoculated with a calculated 32 Campylobacter cells per cm2 was accomplished in 5 of 5 replicate tests. At levels of 3.2 and 0.3 cells of Campylobacter per cm2, recoveries were accomplished in 2 of 5 replicate tests at each inoculum level.
Effects of Certain Electrical Stimulation Parameters on Quality and Palatability of Beef
Authors: McKEITH F. K. , SMITH G. C. , SAVELL J. W. , DUTSON T. R. , CARPENTER Z. L. , HAMMONS D. R. 
Published: August 2006

ABSTRACTGrain‐finished steers and heifers (n=390) were slaughtered in a commercial plant and assigned to one of five groups: (a) electrical stimulation (ES) immediately after exsanguination, (b) ES immediately before evisceration, (c) ES immediately after evisceration, (d) ES immediately after splitting, and (e) untreated (not ES). ES consisted of either 150 or 550 volts for either 1 or 2 mm. Electrically stimulated carcasses had more youthful, brighter colored lean and less “heat‐ring” than untreated (not ES) carcasses. Steaks from electrically stimulated carcasses had (P<0.05) lower shear force values, were more tender, had less panel‐detectable connective tissue and higher overall palatability ratings than did steaks from untreated (not ES) carcasses. Steaks from carcasses receiving 550‐volt ES usually had more youthful, brighter colored lean and lower shear force values, were more tender, had less panel‐detectable connective tissue and higher overall palatability ratings than steaks from carcasses that received 150‐volt electrical stimulation. Quality and palatability traits of carcasses electrically stimulated for 1 mm were not different from those of carcasses receiving 2 mm of electrical stimulation. Electrical stimulation at different stages in the slaughter‐dressing sequence did not evoke differential responses in quality or palatability factors.
Influence of Postmortem Changes in Bovine Muscle on the Water‐Holding Capacity of Beef. Postmortem Storage of Muscle at Various Temperatures Between 0 and 30°C
Authors: Honikel K. O. , Hamid A. , Fischer C. , Hamm R. 
Published: August 2006

ABSTRACTBovine neck muscles were incubated between 0° and 30°C soon after slaughter. At different times postmortem biochemical and physical parameters and cooking loss in homogenates with or without salt were measured. The rate of pH fall in muscle depends on the incubation temperature. At 0.5°C the pH drops fast at first, leveling off afterwards but between 7° and 14°C there is an initial lag period of 2‐3 hr. At 30°C no lag phase occurs. The increased rate of postmortem metabolism at 0.5°C is accompanied by cold shortening which occurs before onset of rigor and is followed by little rigor shortening. Above 16°C rigor shortening increases with rising temperature without prerigor contraction. Neither shortening nor development of rigor have an immediate influence of WHC of muscle and unsalted muscle homogenates; the small decrease of WHC postmortem is due to pH fall only and independent of temperature. Salted homogenates prepared from muscles at different time postmortem show above pH 6.0 a similar relationship between pH and WHC. At the onset of rigor mortis (pH 5.9), however, the WHC of the salted homogenate decreases strongly. The practical consequences of these results with regard to processing of beef are discussed.
Isolation of Potentially Virulent Yersinia enterocolitica from Variety Meats
Authors: STERN NORMAN J. 
Published: August 2006

ABSTRACTSixty‐three samples of variety meats were examined for the presence of Yersinia enterocolitica. Surface swab samples in a modified selenite enrichment broth were incubated at 23°C for 2 and 3 days and then streaked onto MacConkey agar with Tween 80 or refrigerated bismuth sulfite agar, with and without a potassium hydroxide preplating treatment. The organism was isolated from 2 of 23 porcine throat swabs but was not isolated from 40 bovine tongue, kidney, heart, or liver swabs. The isolates from the throat swabs were classified into Nilehn and Wauters biotypes 3 or 4. One porcine isolate was of serotype 0:19, while another isolate from the second Y. enterocolitica‐bearing porcine throat swab was nontypeable. The nontypeable isolates autoagglutlnated in tissue culture when grown overnight at 35°C, suggesting that these isolates are potentially virulent. The results of this study support the contention of European researchers that swine may be a significant source of Y. enterocolitica involved in human infections.
Effect of Nisin on the Outgrowth of Clostridium botulinum Spores
Authors: SCOTT VIRGINIA N. , TAYLOR STEVE L. 
Published: August 2006

ABSTRACTNisin, an antibiotic produced by certain strains of Streptococcus lactis, is effective in preventing the outgrowth of Clostridium botulinum spores. Type A C. botulinum spores were the most resistant to the inhibitory action of nisin requiring 1000‐2000 I.U. of nisin/ml for a 50% inhibition of outgrowth on TPYG agar plates. Type E spores were more sensitive requiring only 50‐100 I.U./ml for 50% inhibition of outgrowth on TPYG agar plates. Type B spores displayed an intermediate level of sensitivity requiring 500‐1000 I.U. of nisin/ml for 50% inhibition of outgrowth on TPYG agar plates. Similar levels of nisin were necessary to prevent spore outgrowth in TPYG broth and BHI broth over a 7‐day incubation period. With prolonged incubation periods of up to 65 days in TPYG broth, spore outgrowth was observed sporadically at higher nisin levels with the type A and B spores which may indicate some decomposition of nisin with storage. Nisin levels of 5000 I.U./ml for the type A spores and 2000 I.U./ml for the type B spores and the Minnesota E spores were insufficient to prevent spore outgrowth by C. botulinurn in cooked meat medium. For the Beluga E spores, a nisin level of 2000 I.U./ml was necessary to prevent spore outgrowth in cooked meat medium. The need for higher levels of nisin in cooked medium to prevent spore outgrowth may be due to the binding of the nisin by meat particles.
Regulation of Aflatoxin Biosynthesis: Characterization of Glucose as an Apparent Inducer of Aflatoxin Production
Authors: ABDOLLAHI A. , BUCHANAN R.L. 
Published: August 2006

ABSTRACTAflatoxins were not produced when A. parasiticus was cultured on medium containing peptone plus mineral salts. Transferring the microorganism to a glucose‐containing medium resulted in aflatoxin production. Initiation of aflatoxin synthesis could be blocked by treatment with cycloheximide or actinomycin D. It appears that glucose or a product of its metabolism, acting at the transcriptional level induces one or more of the enzymes responsible for aflatoxin synthesis.
Determination of Alpha‐Keto Acids in Banana Pulp by High Performance Liquid Chromatography
Authors: KOZUKUE NOBUYUKI 
Published: August 2006

ABSTRACTA liquid chromatographic procedure has been developed for the separation and quantification of α‐keto acids. The DNPH‐derivatives are separated on a column of LiChrosorb Si‐60 (5 μm), eluted with petroleum ether/ethyl formate/propionic acid (65/35/5, v/v/v), and the column effluent is monitored by UV spectrophotometory at 350 nm. A total analysis of DNPH‐keto acids was completed in less than 10 min. The amount of pyruvic, α‐ketoglutaric, and oxaloacetic acid in ripe banana pulp was 347, 225, and 13 μg/100g fresh weight, respectively. This technique has been used effectively to analyze α‐keto acids in biological samples.
Casein Inhibition of Clostridium perfringens Growth and Exoprotease Production
Authors: CURRAN JOANNE M. , SOLBERG MYRON , BLASCHEK HANS P. , ROSEN DAVID 
Published: August 2006

ABSTRACTGrowth of C. perfringens strain 3624 on a defined medium containing ANRC Reference Casein as the nitrogen source was investigated. Gas production, monitored manometrically as an index of growth, indicated a depressed growth response of the organism in the casein‐containing medium. Increased growth response resulting from pepsin treatment of the casein was largely due to the enzyme serving as a nitrogen source. Chelation of iron by casein was not responsible for the growth inhibition. Casein suspended in complete medium was not inhibitory to the organism. Growth studies indicated that native casein was not available as a nitrogen source to the organism. Acid hydrolyzed casein and commercial casein hydrolysate served as suitable nitrogen sources for growth of the organism, however exoprotease production was repressed in both media as well as in medium containing native casein as the sole nitrogen source. C. perfringens strain 3624 produced exoprotease in the completely defined medium containing synthetic amino acids, indicating the possible presence of an amino acid or a metabolite, not produced in the casein‐containing medium which functioned to derepress the enzyme synthesizing mechanism.
Textural Characteristics of Beef: Effects of the Heating System
Authors: BRADY PAMELA L. , PENFIELD MARJORIE P. 
Published: August 2006

ABSTRACTTextural characteristics of beef semitendinosus roasts heated in 93 and 149°C ovens to 60 and 70°C were compared with those of small samples of semitendinosus heated as cylindrical cores in glass tubes in a water bath. The small samples were heated to the same endpoint temperatures as the roasts were at rates comparable to heating at the two oven temperatures. Cooking losses varied with heating method and in some cases with endpoint temperature and rate of heating. Heating method did not affect the textural parameters of penetration hardness, cohesiveness, and chewiness and shear cohesiveness and firmness. Hydroxyproline solubilization was greater in water bath samples than in intact samples heated at the slower rate. The extent of heat‐related changes and their effects on final meat quality partially is determined by the heating system.
Sensory Scores and Shear Force Values for Beef Roasts Cooked Either Before or After Chilling
Authors: BERRY B. W. , RAY E. E. , STIFFLER D. M. 
Published: August 2006

ABSTRACTSensory and physical characteristics were determined on beef semimembranosus and semitendinosus muscles removed and cooked either 1.5 hr post‐exsanguination or after 7 days of chilling by either steam, hot water vat or convectional electric cookery. The effects of cookery method on sensory and physical characteristics were not statistically significant (P > 0.01). Hot‐boned roasts from both muscles served as cubes had higher shear force values, higher amounts of connective tissue (sensory panel), and lower tenderness and higher juiciness scores than cold‐boned cooked roasts. However, no differences in sensory characteristics were found between hot‐and cold‐boned cooked semitendinosus roats evaluated in a thinly sliced form. These results suggest that acceptable tenderness in beef roasts cooked hot‐boned may be achieved when the product is used in a thinly‐sliced or similar form.
Fish Protein Concentrate (FPC) from Bombay Duck Isolated by Radiation‐Heat Combination Procedure: Functional and Nutritional Properties
Authors: WARRIER S. B. , NINJOOR V. 
Published: August 2006

ABSTRACTA process involving gamma‐irradiation (200 Krad) and heat treatment (60°C, 10 min), for the preparation of fish protein concentrate (FPC) from a tropical fish Bombay duck (Harpodon nehereus) is described. The procedure enabled the precipitation of 75% of proteins from Bombay duck muscle which accounted for 80% of myofibrillar proteins. The solubility of FPC was 3% in water and 15% in 5% NaCl. However, the preparation could be solubilized by treatments with alkali (0.2N NaOH) or proteolytic enzymes. Among the enzymes tested for FPC solubilization, pronase was Pound to be the most effective both with respect to the extent and the rate of hydrolysis. The FPC displayed good functional properties in terms of emulsifying capacity and wettability. The PER was better than that obtained for casein when fed to rats at 11% protein level.
Mushroom Response to Postharvest Hyperbaric Storage
Authors: ROBITAILLE HENRY A. , BADENHOP ARTHUR F. 
Published: August 2006

ABSTRACTVessels suitable for storing mushrooms [Agaricus bisporus (Lange) Singe] at absolute pressures to 35 atm were constructed from 43 liter (1A) gas cylinders and plumbed for conducting static or continuous‐flow experiments. Neither pressurization nor gradual depressurization over 6 hr injured mushrooms. Pressure did not affect respiration, but significantly reduced moisture loss during storage. Mushrooms depleted O2 to very low levels and showed high tolerance to CO2. Pressure was used to safely increase CO partial pressure (p) 35‐fold. At 0.035p, CO reduced mushroom browning but not respiration. A completely autonomous storage system with CO2 removal and automatic O2, replenishment was developed.
Application of an Improved Experimental Washer for Leafy Greens for Canning
Authors: HOLLEY E.M. , SISTRUNK W.A. 
Published: August 2006

ABSTRACTA study was conducted to compare the quality of the effluent and canned spinach, turnip greens, and mustard when washed by experimental and industrial washing systems. Three 4‐hr runs were conducted on spinach and one each on turnips and mustard greens. The effluent from the industrial washing system was significantly higher in total suspended solids, total solids, suspended solids, chemical oxygen demand, and nitrates than that from the experimental washer. Washing system has very little effect on quality of canned spinach. The major differences in quality were caused by cultivar and age of raw product. Total plate counts were not affected by washing system.
Role of Flavonoids in the Production of Color in Biscuits Prepared with Wheat and Cottonseed Flours
Authors: BLOUIN F. A. , ZARINS Z. M. , CHERRY J. P. 
Published: August 2006

ABSTRACTBiscuits prepared with 80% wheat and 20% liquid‐cyclone‐processed and hexane‐defatted glandless cottonseed flours were yellow‐brown. To isolate and identify pigments responsible for color, the cottonseed flours were extracted with aqueous isopropyl alcohol. These extracts were fractionated into nonflavonoid and flavonoid components by Sephadex column chromatography. Biscuits containing the extracted cottonseed flours (free of flavonoids) were brown, those prepared with the nonflavonoid fractions were tan, and those to which the flavonoid mixtures were added were yellow. Chromatographic and ultraviolet ‐visible spectral methods showed that there are seven major flavonoids in both flours, tentatively identified as isoquercitrin, rutin, quercetin 3‐0‐neohesperidoside, quercetin 3‐0‐neohesperidoside, kaempferol 3‐0‐neohesperidoside, quercetin 3‐0‐gluco‐glucoside, and kaem pherol 3‐0‐glucoglucoside.
Comparison of Spectrophotometric and HPLC Methods to Quantify Betacyanins
Authors: SCHWARTZ S. J. , HILDENBRAND B. E. , VON ELBE J. H. 
Published: August 2006

ABSTRACTQuantitative data for betacyanins determined by a spectrophotometric method and a high performance liquid chromatography (HPLC) method were compared. Pigment solutions at pH 4.0, 5.0 and 6.0 were heat treated under a nitrogen atmosphere and analyzed for pigment losses at appropriate intervals. Fresh, blanched and canned beets were measured for pigment content by the two methods. Quantitative determinations of pigment in all purified or undegraded samples compared well when analyzed by either method. Discrepancies between results of the two procedures occurred and increased up to 15% with extended heat treatment of the pigment. The differences were: attributed to formation of degradation products or interfering substances. Of the two, the HPLC method is preferred when interfering substances are present.
Comparison of Sodium and Sodium/Potassium Salt Mixtures in Processed Vegetables
Authors: WYATT C. JANE 
Published: August 2006

ABSTRACTGreen beans and torn were heat processed with different concentrations of a salt mixture as a sodium chloride (NaCl) substitute. The sodium (Na) and potassium (K) concentrations of the finished product were deter mined as well as the flavor desirability by an untrained panel. Certain levels of the salt mixture were judged not significantly different in desirability from the reference which contained 1.5% NaCl. The use of an equal mixture of NaCl and KCl was effective in improving the Na/K ratio.
Quantitative Determination of Ascorbic Acid in Potatoes and Potato Products by High Performance Liquid Chromatography
Authors: AUGUSTIN JORG , BECK CLAUDIA , MAROUSEK GAIL I. 
Published: August 2006

ABSTRACTA simple, rapid and accurate method for the quantitative determination of ascorbic acid in potatoes and potato products has been developed. The system is based on the reverse‐phase, ion‐pairing concept of high‐performance liquid chromatography. Sample preparation is minimal and involves a one‐step extraction followed by filtration and/or centrifugation. Recoveries were near the 100% level. As low as 0.02 mcg ascorbic acid could be determined.
Antimicrobial Activity of Butylated Hydroxyanisole, Tertiary Butylhydroquinone, and Potassium Sorbate in Combination
Authors: DAVIDSON P. M. , BREKKE C. J. , BRANEN A. L. 
Published: August 2006

ABSTRACTButylated hydroxyanisole (BHA), tertiary butylhydroquinone (TBHQ), and potassium sorbate, alone and in combination, were tested for antimicrobial activity against Staphylococcus aureus and Salmonella typhimurium in trypticase soy broth. Concentrations of the antimcrobials which resulted in 0‐50% growth lnhibition of the test organisms after 72 hr at 32°C were used in combination. Sorbate‐BHA and sorbate‐TBHQ combinations caused a 12 hr delay in growth initiation of S. aureus. No delay in growth initiation was found with BHA‐sorbate combinations against S. typhimurium, but all combinations had synergistic antimicrobial activity against the: microorganism. TBHQ showed little or no effect on growth of S. typhimurium.
Predicting Water Activity from 0.30 to 0.95 of a Multicomponent Food Formulation
Authors: LANG K. W. , STEINBERG M. P. 
Published: August 2006

ABSTRACTThe objective was to develop an equation to calculate the aw of a mixture of known composition at a given moisture content. A simple equation was derived by combining the Smith isotherm with the Lang‐Steinberg mass balance: log (1–aw) = [MW–Σ(aiwi)]/Σ(biwi) where M is moisture content of the mixture, W is total dry weight of the mixture, ai and bi are Smith isotherm parameters for the individual ingredient, and wi is the dry weight of the ingredient. For comparison of experimental and calculated aw values, an experimental value was used to calculate M from the mixture isotherm and this M was used to calculate aw, from the model. Four binary and one ternary mixtures of two macromolecules, two solutes and one complex ingredient were included. Twenty‐one comparisons between calculated and experimental aw, over aw 0.30–0.95 resulted in a maximum error of only 1.86% and a mean error of ‐0.25%, showing excellent agreement. Only one constraint was found; when the mixture contains i solute (sugar or salt) and the aw, is below the aw of saturation for that solute, that solute is deleted from the summations in the Model.
Rapid Purfication of β ‐Galactosidase (Aspergillus Niger) from a Commercial Preparation
Authors: GREENBERG N. A. , MAHONEY R. R. 
Published: August 2006

ABSTRACTβ‐Galactosidase (A. niger) was purified from a commercial source in order to study the protein nature of the enzyme and some of its kinetic properties. The enzyme was rapidly purified by acetone precipitation, gel filtratior, and affinity chromatography. The specific activity of the purified enzyme was twice as high as that found in previous studies. The Km and Vmax for o‐nitrophenyl β‐D‐galactopyranoside were 2.02 mM and 345 μmoles/min/mg protein respectively at pH 4.5 and 37°C. The procedure described yields a highly active enzyme which may be suitable for immobilization and hydrolysis of lactose. The molecular weight of the enzyme was 117,000 and the isolectric point was 4.9. The enzyme appears to be a glycoprotein and may contain multiple molecular forms.