bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey of Rabbit Skeletal Muscle Peptidases Active at Neutral pH Regions
Authors: OKITANI AKIHIRO , OTSUKA YUZURU , KATAKAI RYOICHI , KONDO YASUHIRO , KATO HIROMICHI
Published: August 2006

A survey of oligopeptide hydrolases active at neutral pH regions responsible for increased free ammo acids on aging of high ultimate pH muscles were performed examining chromatographic behavior and substrate specificity of rabbit skeletal muscle extract. The DEAE‐cellulose chromatography of muscle extract revealed five major activity peaks respectively ascribable to a dipeptidase, an aminotripeptidase, an ammopeptidase, leucine aminopeptidase and the 160,000 dalton‐aminopeptidase purified previously by us. Since the 160,000 dahon‐ammopeptidase showed a broader substrate specificity than the two other aminopeptidases, it is most likely that this enzyme shares the largest part in the tetrapeptide hydrolysis in rabbit skeletal muscle at neutral pH regions.
High Performance Liquid Chromatographic Determination of Organic Acids in Dairy Products
Authors: MARSILI R. T. , OSTAPENKO H. , SIMMONS R. E. , GREEN D. E.
Published: August 2006

A simple isocratic HPLC technique was developed for the quantitative analysis of organic acids in dairy products. An Ammex HPX‐ 87 column at 65°C, 0.0090N H2SO4 mobile phase and UV detection at 220 and 275 nm were utilized. Orotic, citric, pyruvic, lactic, uric, formic, acetic, propionic, butyric, and hippuric acids were quantitated for whole milk, skim powder, cultured buttermilk, sour cream, cottage cheese, yogurt, sharp Cheddar cheese, and blue cheese. Over 90% recoveries of acids added to whole milk were observed for ail acids except butyrid; the average recovery for butyric was 86%.
Effect of Temperatures on Fish Alkaline Protease, Protein Interaction and Texture Quality
Authors: DENG J. C.
Published: August 2006

The effect of the activity of fish alkaline protease and protein denaturation on texture changes in mullet muscle during heating were studied. The proteolytic enzyme and the urea denatured hemoglobin substrate were incubated at different pH values and various temperatures. The enzyme activity was optimal at pH 8 and at 65°C. The extent of protein‐protein interactions in mullet actomyosin solutions increased with increasing temperature. The rate of protein‐protein interactions increased sharply as temperature increased from 35°C to 45°C at pH 6. When mullet muscle was heated at various temperatures ranging from 55°‐85°C, the shear force value increased (toughening) during the initial stage of heating and then decreased (softening). The toughening of fish flesh is probably due to muscle protein interactions, and the later tenderizing of fish flesh may be explained by alkaline protease activity (hydrolysis) masking the protein denaturation effect. When fish flesh was cooked at 100°C, no tenderizing effect was observed. This was probably due to loss of enzyme activity and only protein denaturation had significant effect on texture quality.
Vibrio cholerae in Marine Foods and Environmental Waters: A Literature Review
Authors: DePAOLA ANGELO
Published: August 2006

Seafoods have been implicated in a number of cholera outbreaks in the United States and abroad. The incidence of Vibrio cholerue in the environment may be attributed to its extended survival in seawater or to short‐ or long‐term carriers. Strains of V. cholerue which do not agglutinate in 0 group 1 antiserum (NAG) have been associated with a number of gastroenteritis, septicemia, and meningoencephalitis cases in recent years, and genetic studies illustrate a close relationship between the deoxyribonucleic acid (DNA) of NAG and V. cholerae. The ability of NAGS to elicit responses in toxigenicity testing systems similar to those caused by V. cholerae has also been demonstrated. The incidence of NAGS and V. cholerue in U.S. coastal waters and seafoods, their survival, and the conditions that promote genetic changes and increase NAG virulence must be fully evaluated to determine the public health significance of these organisms. These studies are needed to reevaluate the effectiveness of the National Shellfish Sanitation Program (NSSP) growing area standards and criteria so that consumers may be protected against shellfish‐associated vibrio diseases.
Functional Properties of the Great Northern Bean (Phaseolus vulgaris L.) Proteins: Emulsion, Foaming, Viscosity, and Gelation Properties
Authors: SATHE S. K. , SALUNKHE D. K.
Published: August 2006

Functional properties of the Great Northern bean (Phaseolus vulgaris L.) flour, albumins, globulins, protein concentrates, and protein isolates were investigated. Protein concentrates had the highest water and oil absorption capacity (5.93 and 4.12 g/g, respectively) among all the samples studied. Protein concentrates registered the highest emulsion capacity (72.6g oil emulsified/g) while albumins had the highest emulsion stability (less than 5 ml separation of phase in 780 hr at room temperature of 21°C). Foaming ability of the Great Northern bean proteins was fair. Foamability of the proteins was concentration dependent.
Characterization of Red Bean (Phaseolus radiatus var. Aurea) Starch and Its Noodle Quality
Authors: LII CHENG‐YI , CHANG SHUH‐MING
Published: August 2006

Red bean (Phaseolus radiatus var. aurea) starch was isolated by a wet‐milling process and steeping in 0.1% sodium hydroxide which gave the best starch purity. Physical properties of the starch including granule sizes, gelatinization temperature range, iodine affinity, X‐ray diffractogram, swelling and solubility pattern, Brabender amylogram, gel strength and degree of syneresis, were examined. Starch noodles were prepared from red bean starch and compared with those from mung bean. Noodle quality was exmained by solid loss during cooking, tensile strength and organoleptic tests. The results indicated that red bean starch noodles gave fairly good quality, although not as good as mung bean starch noodles.
Recovery of Salmonellae from Foods using a Combined Enrichment Technique
Authors: SVEUM W.H. , KRAFT A.A.
Published: August 2006

The separate steps of preenrichment in lactose broth and selective enrichment in tetrathionate (TET) or selenite‐cystine (SC) broths were combined into single procedures for the detection of both injured and uninjured salmonellae in foods. Following 4 hr of incubation, iodine or selenite were added to combined lactose‐tetrathionate (CTET) or selenite basal broths, forming selective environments. CTET broth was as efficient as conventional TET and SC broths but the combined selenite media were not. Salmonellae were detected in foods in 30 hr using direct fluorescent antibody and combined enrichment techniques. The combined procedure resulted in savings of assay time, labor and materials.
Effect of Proteolytic Bacteria in the Natural Fermentation of Corn to Increase its Nutritive Value
Authors: TONGNUAL PENKWAN , NANSON NANCY J. , FIELDS MARION L.
Published: August 2006

There was no significant difference in % relative nutritive value, lysine or tryptophan levels between natural lactic fermentations of Costa Rican corn meal fermented with tap water of pH 7.2 and 5.3 However, the fermented values were all significantly (P<0.05) higher than nonfermented values. Most of the increase in % relative nutritive value occurred in the first 48 hr. Free essential amino acids increased and the amino acid balance changed during typical fermentations. Proteolytic bacteria decreased after 3 days of the fermentation and declined to a few cells per ml by the 4th day. Proteolysis decreased by the second day of natural lactic fermentation.
Physicochemical Changes in Potato Granules During Storage
Authors: OORAIKUL B. , MOLEDINA K.H.
Published: August 2006

Physicochemical properties of freeze‐thaw (F‐T) and add‐back (A‐B) potato granules, such as swelling power (SP), water‐holding capacity (WHC), degree of starch retrogradation, moisture change, and rate of rehydration were monitored over about 100 wk of storage. SP of both types of granules decreased to minima after 40 wk then increased on further storage, while WHC showed an opposite trend, reaching maxima after 52 wk. Degree of starch retrogradation in the granules increased to maxima after 40 wk then declined. Moisture content of the granules also increased slightly during the first 33 wk then decreased on further storage. These changes caused the reduction in the rehydration rate of the granules from 8.3 × 10−2 see−1 to 5.5 × 10−2 set−1 (F‐T) and 5.2 × 10−2 sec−1 (A‐B) after 36 wk of storage, after which the rate again increased. Addition of Ca++ to the granules during precooking and cooling steps of the process appeared to cause similar changes.
Properties of Free Radicals in Protein and Amino Acid Pyrolysates
Authors: UCHIYAMA SADAO , UCHIYAMA MITSURU
Published: August 2006

The ESR intensities (g=2.0042 ∼ 2.0053) of free radicals in L‐lysine and casein pyrolysates increased with increase of the heating time. In L‐lysine pyrolysate (200°C, 20 min), the fraction insoluble in organic solvents and water accounted for 48.1% of the ESR intensity of the whole pyrolysate; the component responsible appeared to be a product of condensation polymerization, but the elemental analysis data indicated a smaller value for nitrogen than that expected for polylysine. The pyrolysis of casein brought about denatured products insoluble in water. The free radicals formed were stable for a week in distilled water and were unaffected by digestion with pepsin or pancreatin (37°C for 3 hr).
Relationship between In Vitro Digestibility of Casein and its Content of Lysinoalanine and D‐Amino Acids
Authors: FRIEDMAN MENDEL , ZAHNLEY JAMES C. , MASTERS PATRICIA M.
Published: August 2006

Alkali and heat induce changes in proteins. These include racemization of L‐ to D‐amino acids and crosslinking via lysinoalanine. Since high‐quality proteins are presumably well‐digested, possible effects of D‐amino acid and lysinoalanine contents on food casein digestibility was examined. The following variables, which were expected to influence all three parameters, were evaluated: (a) pH (8‐14); (b) temperature (25‐75°C); and (c) time of treatment (10 min to 24 hr). An approximately inverse relationship was observed between D‐ammo acid and lysinoalanine content and the extent of proteolysis. Such changes may lower the quality and safety of foods.
Characterization of a Heat‐Resistant Strain of Bacillus coagulans Isolated from Cream Style Canned Corn
Authors: FEIG S. , STERSKY A. K.
Published: August 2006

A highly heat resistant strain of Bacillus coagulans was isolated from canned cream style corn. Spores of this organism grown at 45deg;C on Mn++ supplemented nutrient agar had the following heat resistance characteristics: in phosphate buffer, D100= 86.00, D105= 27.5, D110= 6.1 min and z = 8.6C; in cream style corn extract, D110= 9 min. For spores grown at 50 and 55°C, the D110 values in buffer were 2.5 and 1.8 min, respectively. The B. coagulans isolate matched the description in Bergey's Manual of Determinative Bacteriology, except for its higher heat resistance. Two additional Bacillus strains were intermediate between B. coagulans and B. stearothermophilus.
Comparison of Growth Response by Chemostat Cultured and Batch Cultured Clostridium perfringens Cells in Various Food Substrates
Authors: GOLDNER STEVEN B. , SOLBERG MYRON
Published: August 2006

A constant source of exponential phase cells of Clostridium perfringens ATCC 3624 could reduce the time required to carry out the protein quality evaluation test of Solberg et al. (1979) to 4 hr. Clostridium perfringens ATCC 3624 was grown in an anaerobic chemostat using the chemically defined medium, R&S, with glucose as the growth limiting nutrient. The dilution rate was set at 0.06 hr−1, the pH at 7.2, and the temperature at 43°C. In the transition from a batch culture to a continuous culture an initial oscillatory cell density response was observed. In the steady state, which was continued for as long as 50 days, the cells were typical Gram positive rods, occurring singly or in chains as long as 15 rods, which were occasionally without septa. The fermentative and biochemical responses of the cells did not change. No sporulation occurred when the cells were growing in the chemostat, but spores were observed in the glucose free culture effluent after incubation at 37°C for 24 hr. When cells produced in the chemostat, were cultured in complex media they demonstrated a growth response similar to cells which had been grown in a batch culture. In defined medium the generation time for the chemostat cultured cells was decreased approximately 17%. The chemostat cultured cells can be used as inoculum for the C. perfringens protein quality assay.
Evaluation of the Effects of Liquid Bridges on the Bulk Properties of Model Powders
Authors: SCOVILLE E. , PELEG M.
Published: August 2006

Measured amounts of water were admixed with uniform size glass beads (107‐475 micron) to form model powders with controlled interparticle liquid films. The viscosity of the films was modified by dissolving carrageenan and its surface tension by a detergent. These model powders were tested for loose bulk density, compressibility, irrecoverable work in compaction, cohesion and residual modulus after relaxation. The effect of the films on these bulk characteristics was considerable in the fine model powders but diminished with the increase of particle size. In comparison to particle size, the film viscosity (l‐2000 cp) and surface tension (72 and 35 dyne cm−1) had little or insignificant effect on the bulk properties. The results are explained in terms of the internal structure of the bed and their possible implications in real powders are evaluated.
Papaya Polygalacturonase and its Role in Thermally Injured Ripening Fruit
Authors: CHAN HARVEY T. , TAM STEVEN Y.T. , SEO STANLEY T.
Published: August 2006

The polygalacturonase (E.C. 3.2.1.15) (PGase) activity in papayas increased with fruit ripeness. PGase activity was highest in the placenta with the activity decreasing outwardly from the placenta to the exocarp. Extended hot water treatments (46°C for 65 and 90 min) caused delayed softening of the fruit tissue which was correlated to a decrease in PGase activity. The decrease in PGase activity after the heat treatments was more severe in the riper fruits (quarter and half ripe) than the less ripe fruits (colorbreak stage).
Development, Evaluation and Industrial Production of a Powdered Soy‐Oats Infant Formula Using a Low‐Cost Extruder
Authors: DEL VALLE F. R. , VILLANUEVA H. , REYES‐GOVEA J. , ESCOBEDO M. , BOURGES H. , PONCE J. , MUNOZ M. J.
Published: August 2006

A low cost powdered infant formula made from soybeans, oats and sucrose, fortified with methionine, vitamins and minerals, has been developed. A dry process for making the formula, which employs a low‐cost Brady extruder, has also been developed. The resulting product is of good microbiological quality and disperses readily in water to give a milk‐like suspension of satisfactory stability to settling. The essential amino acid pattern of the formula, its PER and NPU values, nitrogen balance data with infants, proximal chemical analysis, calorie distribution and low level of trypsin inhibitor indicate it to be adequate for feeding infants 3 months or older. Clinical trials with infants also showed that the formula was well accepted and tolerated, and produced adequate weight gain. Retail prices of the product, packed in cans and polyethylene bags, are appreciably lower than those of comparable cow's milk and other soya‐based infant formulas available in the market. The product is currently being manufactured and sold in several parts of Mexico.
Nutritional and Sensory Properties of Canned and Stored Moin‐Moin
Authors: ADENIJI AYODEJI O. , POTTER NORMAN N.
Published: August 2006

Canned moin‐moin was studied for nutritional and sensory properties after processing and following storage at 22.2°C and 29.4°C for periods up to 6 months. Comparisons were made with freshly prepared, traditional steamed moin‐moin. The canned product remained a very good source of thiamin after thermal processing and storage losses. Chemical assays of lysine, available lysine, methionine, and tryptophan showed no losses of these amino acids from processing or storage, but PER values indicated that thermal processing significantly decreased protein quality of products in rat feeding studies. PER values of canned product then remained stable in storage. After 6 months at both storage temperatures, a Nigerian taste panel ranked overall acceptability of the canned product at 6.5 on a 9 point nedonic scale, compared to 7.5 for the freshly prepared traditiona moin‐moin.
Some Rheological Characteistics of Soy Extrudates in Tension
Authors: FINKOWSKI J. W. , PELEG M.
Published: August 2006

Experimental soy flour extrudates, prepared under different processing conditions were tested in tension by an Instron Universal Testing Machine. All the extrudates exhibited a nonlinear stress‐strain relationship that is indicative of progressive development of structural failure. Complementary relaxation curves at three prefailure deformation levels were linearized and used for calculation of asymptotic relaxed moduli (also called equilibrium moduli). The relationship between the module and the strain or the initial stress indicated that both the break elongation and the ultimate strength could independently be estimated from the relaxation data. A mathematical and computer procedure for such predictions is described and its applicability demonstrated with experimental results.
Effect of Tumbling and Tumbling Temperature on Total Aerobic Plate Counts (Incubated at 25°C) and Quality of Boneless, Cured Hams
Authors: KNIPE CURTIS LYNN , PLIMPTON R. F. , OCKERMAN H. W.
Published: August 2006

The effects of intermittent tumbling (up to 18 hr) and processing temperature (25°C or 3°C) on internal temperature and exudate total aerobic plate counts incubated at 25°C (ATPC) in boneless, cured hams were determined. The design used 80 hams in five replicates involving four treatment groups (tumbled at 25°C tumbled at 0°C, control held at 25°C and control held at 0°C). The significant (P < 0.01) tumbling effect on the rise in internal ham temperature occurred after 3 hr, but only accounted for a difference of 1.26°C‐1.32°C, independent of processing temperature. While tumbling significantly improved the cooked yield by 3.45%, processing at 25°C rather than at 0°C resulted in a significant (P<0.05) yield reduction of 2.15% after 9 hr of processing. The exudate ATPC was significantly (P<0.01) reduced after 18 hr of tumbling.
Effect of Heat Processing in Cans and Retort Pouches on Sensory Properties of Fowl Meat
Authors: LYON B. G. , KLOSE A. A.
Published: August 2006

Fowl meat processed in cans and flexible retortable pouches was evaluated for heat effects on sensory properties. A trained panel evaluated texture and off‐flavor of canned boned chicken, uncooked fowl meat retorted in flexible pouches, cooked meat retorted in flexible pouches, and simmered fowl meat (control). Results indicated that the retort pouch process may offer a method for improving the texture of processed fowl meat from spent hens by adequately cooking to tenderize the meat but not overcooking it to the extent that meat chunks are reduced to fibrous, shredded, or stringy components. Off‐flavor development was related to pre‐cooking before retorting.
Rheology of Enzyme Modified Cheese
Authors: JAO Y. C. , CHEN A. H. , CHAUDHARI R. V. , GOLDSTEIN W. E.
Published: August 2006

The rheological properties of commercial enzyme modified cheese products (Dariteen®, Miles Laboratories, Inc.) are investigated with a micro‐rheolog type of viscometer with cone‐and‐plate geometry. These products exhibit thixotropic shear‐thinning behavior, where viscosity changes with the duration and the rate of the applied shear. A viscosity model invoking gradually increasing and decreasing shear rate is investigated. The model involves expression of viscosity as a function of shear rate in the range 1.92‐384 sec−1 for the case of Increasing shear rate and 384‐1.92 sec−1 for the case of decreasing shear rate. In these investigations, temperature and moisture content range from 24‐72°C and 42.3‐59.3%, respectively. Hysteresis curves representative of the phenomena are also illustrated.
A Study of Solvent Extraction of Lipids from Whole Peanut Kernels Using All‐Purpose Automatic Solvent Extractor
Authors: BHUCHAR V. M. , AGRAWAL A. K. , SHARMA S. K.
Published: August 2006

Extraction of lipids from whole peanut kernels can be accomplished much faster in an automatic solvent extractor with a lower solvent: seed ratio than by immersion or in a Soxhlet extractor. A possible explanation of the function of moisture in the extraction of lipids from the whole peanut kernels has been put forward. This mode of extraction is expected to produce economically fat‐lean kernels, while oil is obtained as a co‐product.
Sweet Potato Quality After Baking
Authors: LOSH JUNE M. , PHILLIPS JEAN A. , AXELSON JULEIN M. , SCHULMAN ROBERT S.
Published: August 2006

Painter and Jewel sweet potatoes baked at oven temperatures of 150, 180, 200, and 230°C were judged for sensory qualities and were evaluated for resistance to pressure (softness) and content of sugars. Roots baked at 200 and 230°C were scored significantly higher for sweetness, mouthfeel, moistness, overall flavor, and over all quality; contained a greater percentage of reducing sugars; and were measured as softer than roots baked at 150 and 180°C. Painter roots were scored significantly higher for sweetness, mouthfeel, moistness, overall flavor, and overall quality than the Jewel variety. Positive correlations were observed between the concentration of reducing sugars, the resistance to pressure, and the sensory evaluation; and negative correlations were noted between the moisture content and the subjective measurements.
Effect of Electrical Stimulation and Postmortem Boning Time on Sensory and Cookery Properties of Ground Beef
Authors: CROSS H. R. , TENNET IVONNE
Published: August 2006

Ground beef was prepared from electrically stimulated and nonstimulated sides of 24 U.S. Utility grade carcasses that were boned 1, 3 or 24 hr postmortem. Postmortem electrical stimulation had no negative effects or, the physical, sensory or cooking properties of ground beef patties. Time of boning had significant effects on percent height change during cooking, total cooking loss, tenderness, and juiciness. As cooning time increased, the effects on the traits were negative.
Measuring Skeletal Muscle Fiber Width or Diameter: Variance Within and Among Methods
Authors: KHAN HANIF A. , HARRISON DOROTHY L. , DAYTON ARTHUR D.
Published: August 2006

A bovine longissimu; dorsi muscle was divided into anterior and posterior pieces, half of each piece was roasted at 140°C to 70°C. “Widths” or “diameters” of fibers from each position (anterior, posterior) and treatment (raw, cooked) were measured by three methods: A, width of separated fibers on a longitudinal plane; B, width of fibers in ongitudinal sections; and C, fiber diameter calculated from the area of fibers in cross sections. Bartlett's test for homogeneity of variance indicated greater (P<0.05) variance among observations by method A than by methods B or C; position‐treatment variances were larger (P<0.05) for method A than for B or C.
Thin‐Layer Chromatographic Separation of Beet Pigments
Authors: BILYK ALEXANDER
Published: August 2006

A new simple method for the thin‐layer chromatographic (TLC) separation of betalaines has been developed and is described in this paper, The individual components were separated by preparative TLC on cellulose‐coated plates and analyzed by a multiple development TLC technique with solvent mixtures consisting of ethanol, isoppropanol, water, and acetic acid. Separated components of various hues were clearly visible after development without application of an indicator. Spectral analyses of fractions also were conducted. By this TLC procedure, analytical data were obtained more rapidly and conveniently than could be obtained by other methods such as electrophoresis.
Effect of Japanese Green Tea oh Nitrosamine Formation in Vitro
Authors: NAKAMURA MASAMICHI , KAWABATA TOSHIHARU
Published: August 2006

The effect of Japanese green tea extract and various phenolic components of green tea on nitrosamine formation in vitro were investigated. We found that green tea extract seems to enhance the nitrosation of four secondary amines under acidic conditions; however, there exists an optimum concentration for the catalytic effect on nitrosamine forma ion. Among various polyphenols in Japanese green tea, only catechins catalyze nitrosamine formation, while pyrocatechol, pyrogallol, and gallic acid inhibit the reaction. No significant effect on the nitrosation reaction could be observed in the presence of either flavonols or flavones.
Factors Influencing the Activity of a Heat‐Resistant Lipase of Pseudomonas
Authors: ADAMS D. M. , BRAWLEY T. G.
Published: August 2006

The heat resistant lipase of Pseudomonas spp. MC50 hydrolyzed coconut oil, corn oil, butter oil and olive oil. Lipase activity was maximum at 1% corn oil. The effects of pH and temperature on lipase activity varied with the substrate. The pH optima were in the range pH 8–9; the temperature optima were in the range 35–40°C. Of several emulsifiers tested, four supported significant lipase actiivity, and three supported no lipase activity and may have inhibited the lipase. Emulsifier concentration influenced lipase activity. All stabilizers tested supported lipase activity; above 0.36% stabilizer concentration had no effect.
Thermal Inactivation of Clostridium botulinum Toxin Types F and G in Buffer and in Beef and Mushroom Patties
Authors: BRADSHAW J. G. , PEELER J. T. , TWEDT R. M.
Published: August 2006

The time‐temperature relationships for the inactivation of crude toxins prepared from Clostridium botulinum type F strain Wall 8 and type G strain G89 were determined in three different heating menstrua. Toxins dilated to 7,700–32,000 mouse LD50 units/0.5 ml in beef and mushroom patties (pH 6.05), in 0.1M phosphate buffer (pH 6.05), and in 00.1M acetate buffer (pH 5.0) were heated at temperatures from 65.6–76.7°C. In the beef patties, inactivation times ranged from an average of 108.1–1.6 min for type F toxin, and from an average of 158.8–1.8 min for type G toxin. Less time was required in phosphate buffer.
Partial Purification and Characterization of a Neutral Protease from Bovine Skeletal Muscle
Authors: KANG C. K. , DONNELLY T. H. , JODLOWSKI R. F. , WARNER W. D.
Published: August 2006

A method has been developed for the partial purification of a calcium activated neutral protease from bovine muscle, since application of methods previously used for rabbit or porcine muscle gave little or no yield. The new method involves extraction with phosphate‐buffered KCl, saling out with (NH4)2SO4, affinity chromatography on mercurial agarose followed by gel filtration. The bovine protease required calcium ion and reducing agent for activity with a pH optimum at 7.5 and hydrolyzed myofibrillar proteins.
Reproducibility of Microbiological Counts on Frozen Cod: A Collaborative Study
Authors: SLABYJ BOHDAN M. , MARTIN ROY E. , RAMSDELL GORDON E.
Published: August 2006

Reproducibility of aerobic plate count (APC), coliform and fecal coliform counts in frozen cod was examined by 14 laboratories (3 government, 4 university and 7 industry) using primarily FDA recommended procedures. In order to assure homogeneity of samples, the fish was comminuted and thoroughly mixed. The 35°C and the “room temperature” (26°C) APC on Sample A (a good quality product) were 1.3 × 105/g and 2.6 × 105/g, respectively, and for Sample B (a questionable quality product) the counts were 2.9 × 105/g and 6.4 × 105/g, respectively. Standard deviations among counts (log10 values) were 0.26 and 0.32 for the 35°C counts and 0.24 and 0.40 for the 26°C counts of Sample A and B, respectively. The std. dev. were reduced to 0.19, 0.22, 0.17 and 0.25, respectively, when counts that did not show significant overlap (based on Dur can's New Multiple Range Test) were excluded from the calculations. Coliform counts on Sample A (not inoculated) ranged from <30 to 4.6 × 105/100g. Coliform and fecal coliform counts for Sample B (inoculated at estimated level of 1 × 104/100g) were 5.8 × 103/100g and 5.5 × 103/100g, with a std. dev. of 0.43 and (.37, respectively. The std. dev. for the coliform counts was reduced to 0.30 when counts from one laboratory were excluded, based on Duncan's New Multiple Range Test.
Chlorogenic Acid and Other Phenolic Compounds in Fourteen Sweet Potato Cultivars
Authors: THOMPSON D. P.
Published: August 2006

Fourteen cultivars of sweet potatoes were analyzed qualitatively for their phenolic content at harvest and after storage. The phenolic content of the sweet potato cultivars, Centennial, Jasper, Jewel, LO‐323, L3‐243, L3‐151, L4‐62, L4‐112, L4‐131, NC‐702, NC‐718, NC‐719, NC‐345, and V2‐237, was assayed. The qualitative examination of the sweet potato phenolics resulted in the separation and identification of four isomers of caffeolyquinic acid. A fifth compound, which exhibited phenolic acid characteristics, was separated but could not be identified.
Storage Stability of α‐Tocopherol in a Dehydrated Model Food System Containing Methyl Linoleate
Authors: WIDICUS W. A. , KIRK J. R.
Published: August 2006

The storage stability of α‐tocopherol in a dehydrated model food system containing methyl linoleate was evaluated. The degradation rate of α‐tocopherol was best described by zero order kinetics with rates significantly greater than 0 (p≤0.002), correlation coefficients (|R|)≤0.88 and standard deviations from 4–13% of the reported rate constants. The zero order rate constants were dependent on the initial α‐tocopherol concentrationn, indicating that the concentration of α‐tocopherol and unknown reactant(s) does affect the storage stability of α‐tocopherol. The storage parameters of water activity, storage container oxygen content, and storage temperature affected the rate of α‐tocopherol loss indicating that these parameters must be controlled to maximize α‐tocopherol storage stability.
Changes in Water Structure in Postmortem Muscle, as Determined by NMR T1 Values
Authors: CURRIE R. W. , JORDAN R. , WOLFE F. H.
Published: August 2006

Longitudinal relaxation times (T1) have been used to assess changes in muscle water as rig or developed in both rat and beef muscle. A significant correlation between the initial rise in T1 and the slope calculated from T1 values measured post rigor was observed. Changes in T1 and thus water structure seem to be very sensitive to pre‐rigor events such as pH fall.
Effect of Radiation and Conventional Processing on the Thiamin Content of Pork
Authors: THOMAS M. H. , ATWOOD B. M. , WIERBICKI E. , TAUB I. A.
Published: August 2006

A study was undertaken to compare the effect of ionizing radiation and thermal processing on the thiamin content of pork. Ground pork was either thermally processed in cans or, after enzyme‐inactivation, irradiated in pouches with electrons or gamma rays. Thiamin in treated and untreated samples was measured by the thiochrome method. The results show that thiamin retention in pork decreases as the irradiation dose increases, but that retention increases as the temperature of irradiation decreases. Moreover, irradiation with gamma rays (low dose‐rate) leads to lower retention than irradiation with electrons (high dose‐rate). Results also show that conventional thermal processing causes loss of thiamin comparable to or greater than irradiation at effective processing conditions for sterilization.
Changes in Physical Properties of Meat Batters During Heating
Authors: SCHWEID J. M. , TOLEDO R. T.
Published: August 2006

Techniques for measuring changes in physical properties of meat batters during heating that would be suitable for studying kinetics of gelation were studied. Change in absolute modulus as measured by a dynamic tester was too variable to be useful in studying gelation kinetics. However, differences in consistency show up as significant differences if the absolute moduli of the raw batters. Increase in volume during heating was strictly a temperature effect and the rate of expansion at the same heating medium temperature was the same for a bitter that was gelling compared to a gelled batter in the same mold. Pressure change on heating of a batter at constant volume showed a pattern consistent with expected behavior of proteins on heating. Plots of pressure against temperature were a series of linear sections with the transition points occurring at 33–36°C and at 57–67°C. These temperature ranges are known to start insolubilization of muscle proteins and start solubilizaation of collagen respectively. Plots of unaccomplished pressure change against time on semi logarithmic coordinates was used to calculate a time constant for each stage of the process thereby giving a measure of the rate of gelation.
Brining Procedures to Produce Uniform Salt Content in Fish
Authors: KOSAK PHILIP H. , TOLEDO ROMEO T.
Published: August 2006

Inhibition of outgrowth and toxin production by Clostridium botulinum type E in smoked fish homogenates has been demonstrated at 3% water phase salt. Having the required salt content on a product that would not be too salty requires a uniform salt distribution throughout the fish. A two‐stage brining procedure was developed that resulted in minimal differences in water phase salt contents between the thin and thick sections of a fish. The first stage involved soaking in 10% NaCl for 15 hr, using a fish to brine ratio of approximately 1 lb to IL. A second stage soak in 2% NaCl for 24–48 hr depending on the size of the fish leached out excessive salt in the thin sections of the fish while leaving the salt iinside the thick sections. Analysis of samples from four different areas on the smoked fish brined using the two stage procedure revealed a uniform salt content.
Natural Lactic Acid Fermentation of Corn Meal
Authors: FIELDS M. L. , HAMAD AHMED M. , SMITH DUANE K.
Published: August 2006

A natural lactic acid fermentation occurs when water is mixed with corn meal and incubated at 37°C. Lactobacillus fermentum, Lactobacillus cellobiosus and Pediococcus acidilactici were isolated; viable coliforms, yeast and molds disappeared from the fermentation by the second day. Lactics dominated during the 4 days of study of the fermentation. Eh decreased during the first 24‐hr period which corresponded to the time coliforms were present in the fermenting corn meal. The percent yield of dry solids was related to the amount of water present. With less water, higher levels of acid were present inhibiting the flora which prevented less breakdown of the substrate and hence higher yields were obtained.
Fermentation of Corn for Nigerian Agidi
Authors: UMOH VERONICA , FIELDS MARION
Published: August 2006

Agidi, a Nigerian food made from corn, was prepared by the traditional Nigerian method and by a modified procedure in which fermented corn was used. The fermented agidi (with or without pH adjustment of the corn) was significantly higher (P < 0.05) in tryptophan and lysine than the nonfermented agidi. Sensory analyses indicated that flavor for the fermented (either pH adjusted or not) had a score greater than average (scale of 1 to 5, with 5 being the highest on the desired scale). However, since total sensory score (total points for color, firmness, acidity and flavor) was less than the traditional agidi, blending of the two is indicated for best acceptance and nutrition.
A Proximity Equilibration Cell for Rapid Determination of Sorption Isotherms
Authors: LANG K. W. , McCUNE T. D. , STEINBERG M. P.
Published: August 2006

Sorption isotherm data are obtained by instrumental determination of water activity at a known moisture content or determination of moisture content after equilibration against a saturated salt solution. The latter method is simpler and the salt solutions are primary standards. However, the equilibration takes a long time, one to ten weeks, depending upon food composition. Thus, the objective of this work was to devise a method that retains the saturated salt solution but accelerates the rate of equilibration. In an equilibration environment between a food product and a saturated salt slurry, the driving force is the difference in vapor pressure; therefore the faster the vapor space reaches equilibrium with the saturated salt slurry, the quicker the maximum driving force for water absorption will be applied to the sample. It was felt that a reduction in the size of the usual large desiccater to a single sample size would provide the necessary area to volume ratio. The vessel chosen was a small plastic chamber (65 mm/53 mm). In this chamber, the surface area to vapor volume ratio was 0.3101 as compared to 0.0335 for the standard desiccator. The sample was contained in a standard aluminum weighing tray modified by removing a 44 mm diameter circular section from the bottom. This was replaced with a 47 mm diameter circle of Whatman No. 1 quantitative filter paper to support the sample and at the same time allow transmission of moisture. This would allow water molecules to travel in a straight line and thus the shortest distance between the saturated salt slurry and the sample. This small vessel with a single sample supported on a filter paper will be referred to as a Proximity Equilibration Cell (PEC). Using this technique, it was found that a 2/mm deep sample of corn starch required only 6 days for complete equilibration, as compared to 21 days for the conventional desiccator. Thus, the PEC satisfied the objective by reducing time by 70%. In making comparisons with the same salts in conventional and the PEC, it was noted that the end point was higher in the latter. Evidently, absorption in case of the conventional desiccator was so slow at the end that no weight gain could be detected in 24 hr but equilibrium had not yet been attained. In contrast, the PEC equilibrated so rapidly that it allowed a closer evaluation of true equilibrium.
Nutritive Value of an Extrusion‐Texturized Peanut Protein
Authors: ALID G. , YANEZ E. , AGUILERA J. M. , MONCKEBERG F. , CHICHESTER C. O.
Published: August 2006

Defatted peanut flour was texturized in a Wenger X‐25 extruder at 25.1% moisture content and 140°C product temperature. Texturization did not have any significant effect on the amino acid pattern nor on the PER of defatted flour. For example, the PER of the flour was 1.57 as compared to 1.54 for the textured product. Supplementation of both products with 0.3% DL‐threonine, 0.2% L‐lysine and 0.2% DI ‐methionine resulted in a 39 and 41% increase in PER, respectively (PER = 2.18).
Solubilization of California Small White Bean (Phaseolus vulgaris L.) Proteins
Authors: SATHE S. K. , SALUNKHE D. K.
Published: August 2006

California Small White beans contained 25.90% crude protein on dry weight basis. Albumins accounted for 11.30% of the total crude proteins. Alkali (1N NaOH) extractable proteins had an isoelectric pH of about 4.0. About 88% of the total crude proteins were recovered employing acid/alkali extraction. Polyacrylamide gel electrophoretic analyses indicated that the acid soluble proteins were comprised of at least five components whereas the alkali soluble proteins consisted of at least two components.
An Automated Fluorimetric Method for the Determination of Histamine in Canned Fish Products
Authors: LUTEN J. B.
Published: August 2006

An automated extraction and fluorimetric detection procedure for the determination of histamine in fish products is described. Proteins are removed pr or to the automated procedure. Histamine, added at different concentration levels to a homogenized fish sample, is recovered quatitatively. The results from a study of histamine in samples of commercially canned mackerel, tuna, herring and sardines showed that ∼79% of the investigated samples had histamine levels lower than 1 mg% while ∼8% had a histamine content higher than 10 mg%.
Using Einzymatic Proteolysis to Reduce Copper‐Protein Catalysis of Lipid Oxidation
Authors: YEE J.J. , SHIPE W.F.
Published: August 2006

Copper‐catalyzed oxidation of methyl linoleate was studied in a model emulsion systsm containing either proteins or their hydroly‐sates. Experiments were conducted with egg albumin, sodium caseinate, and soy proteins. Both the TEA test and diene conjugation measurements revealed that the prooxidant effects of proteins can be reduced by protoolysis. The evidence indicates that the prooxidant activity of complexes of copper and intact proteins is greater than that of copper and proteolytic products. This reduction of prooxidant activity is another example of how proteolysis can improve the functional properties of proteins.
Some Functional Properties under Heating of the Globin Prepared by Carboxymethyl Cellulose Procedure
Authors: HAYAKAWA S. , OGAWA T. , SATO Y.
Published: August 2006

Conditions for gel formation of heated globin and inhibition of thermocoagulation of ovalbumin and bovine serum albumin by globin were investigated. Globin was highly soluble even when heated at 100°C at pH below 5. Globin also considerably inhibited thermocoagulation of ovalbumin and serum albumin near their isoelectric point. A great increase of viscosity was observed when 1% globin solution was heated at above 80°C in the narrow pH range between pH 5.2 and 5.4. Heated globin formed a transparent gel at concentration above 3% under well controlled heat conditions.
Identification of Volatile Flavor Compounds of Fresh, Frozen Beef Stew and a Comparison of These with Those of Canned Beef Stew
Authors: PETERSON ROBERT J. , CHANG STEPHEN S.
Published: August 2006

The volatile flavor compounds of fresh, frozen beef stew were isolated, fractionated and identified by standard methodology. A total of 132 compounds was either positively or tentatively identified. A comparison of the volatile compounds and their relative amounts in the fresh, frozen stew with those previously identified in canned stew demonstrated both qualitative and quantitative differences between the volatiles of the two stews. This difference was due mostly to the greater number and amounts of the oxygen‐containing compounds such as alcohols, 2‐alkenals, esters, lactones, and ionones found in the fresh, frozen stew as compared with the greater number and amounts of hydrocarbons and nitrogen and/or sulfur‐containing heterocycles found in the canned stew.
Moisture Equilibrium in Apples at Several Temperatures: Experimental Data and Theoretical Considerations
Authors: ROMAN GRACIELA N. , URBICAIN MARTIN J. , ROTSTEIN ENRIQUE
Published: August 2006

Moisture equilibrium data for desorption of water from apples was determined at 20°, 30°, 40°, 50° and 60°C. The rehydration 40°C isotherm was also found. The experimental procedure was a gravimetric dynamic method. Sorptive capacity decreases as temperature increases. Rehydration of the dried material results in hysteresis. The data are interpreted in thermodynamic terms. Specific surface and monolayer concentrations are also found. Pore size distribution studies show that the most frequent pore radius at 20°C and 40°C are, respectively, 26 Å and 22 Å. Hysteresis data are compared with what would be expected from the cellulose wall, indicating that solubility and other effects increase sharply the sorptive capacity of the fruit. A comparison of desorption and adsorption characteristics shows that dehydration results in serious damage of the fruit structure.
Growth and Compositional Changes During the Various Developmental Stages of Some Saudi Arabian Date Cultivars
Authors: SAWAYA W. N. , KHATCHADOURIAN H. A. , KHALIL J. K. , SAFI W. M. , AL‐SHALHAT A.
Published: August 2006

Compositional changes during fruit maturation were studied in two important date cultivars grown in Saudi Arabia. Physical analyses showed that the fruit weight, length, diameter and weight of seed were highest at the mature color stage. Chemical analyses including moisture, total nitrogen, fat, fiber, ash, tannins, vitamin C, β‐carotene, and 10 nutritionally essential minerals showed that all were highest at the early stages of development and decreased during maturation. Reducing sugars were dominant in both cultivars and showed progressive increase during ripening with fructose and glucose as the only detected constituents. Sucrose content reached its maximum in both cultivars at the mature color stage then dropped sharply at the ripe stage. The total sugar content in both cultivars tended to increase all throughout maturation.
Investigation of the Physical and Chemical Properties of Banana Starches
Authors: LII CHENG‐YI , CHANG SHUH‐MING , YOUNG YA‐LAN
Published: August 2006

Banana (Musa sp.) starch was isolated after steeping in 0.05N sodium hydroxide. The starch had a granule size of 20–60μ, a gelatinization temperature range of 74–83°C, and a B‐type X‐ray diffraction pattern. The Brabender viscoamylogram and the swelling pattern indicated a fairly restricted‐swelling starch. The starch had low iodine affinity (ca 3.30%) and contained diesterified phosphate. During ripening, the amount of starch converted into reducing sugars and sucrose increased with degree of ripeness. Small granules were converted more rapidly than large granules. Other physical and chemical properties remained similar throughout ripening.
Partial Purification and Characterization of an Acid Phosphatase from Papaya
Authors: CARRENO RAPHAEL , CHAN HARVEY T.
Published: August 2006

A phosphatase in papaya was extracted, partially purified, and characterized. With p‐nitrophenyl phosphate as substrate, the enzyme had a pH optimum of 6.0, which categorized it as an acid phosphatase, a temperature optimum of 37°C, and a Km of 1.0 mM. Heat inactivation of papaya acid phosphatase was biphasic, and the kinetics of both phases were first order reactions. D values at 60°, 65°, 70°C for the heat resistant phase were 21.0, 11.7, and 4.0 min, respectively. For the heat labile and heat resistant isozymes of papaya acid phosphatase, the activation energies, Ea, for thermal inactivation were 60.0 Kcal/mole and 37.8 Kcal/mole, respectively. The apparent molecular weight of the enzyme as determined by gel filtration was 120,000 daltons.
Application of Leaching Model to Describe Potato Nutrient Losses in Hot Water Blanching
Authors: KOZEMPEL M. F. , SULLIVAN J. F. , MONICA E. S. DELLA , EGOVILLE M. J. , TALLEY E. A. , JONES W. J. , CRAIG J. C.
Published: August 2006

Nutritive losses of hot water blanched potatoes were studied. The potatoes lost significant amounts of some amino acids‐glutamic acid, aspartic acid, valine, phenylalanine, arginine, methionine and tryptophan. They also lost a significant amount of gamma‐amino butyric acid. The concentration of the water soluble vitamins, ascorbic acid, riboflavin, thiamin, and niacin was significantly reduced. A leaching model, with diffusion as the rate controlling step, successfully predicted losses of these vitamins as a function of process parameters.
Functional Properties of Modified Black Gram (Phaseolus mungo L.) Starch
Authors: DESHPANDE S. S. , SATHE S. K. , RANGNEKAR P. D. , SALUNKHE D. K.
Published: August 2006

Black gram (Phaseolus mungo L.) starch was modified by heat and moisture treatments, acetylation, oxidation, cross‐linking, and adding free fatty acids (palmitic, stearic, and linoleic). Heat and low moisture treatment, acetylation, oxidation, and cross‐linking lowered the starch gelatinization temperature by 1–6°C, while adding fatty acids and the high moisture‐heat treatment raised it by 1–4°C. All modifications caused an increase in least gelation concentration of starch. High moisture‐heat treatment increased both water and oil absorption of starch. At 95°C, heat‐moisture treated, acetylated, and oxidized starches were more soluble, while fatty acid treated and cross‐linked starches were less soluble compared to raw starch. The modified starches had greater swelling capacity and solubility at pH 2.0 and 10.0. Heat‐moisture treated and chemically modified starches had lower swelling capacity (at 95°C) than that of isolated starch, whereas addition of fatty acids increased it.