bluuebunny/crossref_metadata_2025 huggingface dataset:
PROCESSING EFFECT ON PROXIMATE COMPOSITION AND MINERAL CONTENT OF MEATS OF BLUE MUSSELS (Mytilus edulis)
Authors: SLABYJ EOH DAN M. , CARPENTER PAUL N.
Published: August 2006

Blue mussels (Mytilus edulis) have been frozen or canned. The raw and processed meats (fresh, frozen and canned) were analyzed for proximate composition and mineral content (23 elements) using spectrograph, atomic absorption spectrophotometer, specific ion electrodes or calorimetric procedure. Initial steaming of blue mussels resulted in significant increase in dry weight of meats, but a decrease in carbohydrates and ash content. Further processing (freezing or canning) tended to increase ash but reduced dry weight and carbohydrate content. Only I, K and Na concentration was significantly reduced upon initial steaming. Further processing (freezing and canning) resulted in significant loss in Mg and K while Mn and Na content showed an increase in concentration. Increase in Na content showed an increase in concentration. Increase in Na content is attributed to high concentration of this element in the brine solution used, while Mn appeared to be concentrated by the blue mussel tissue against a negative gradient when in brine. Essential trace elements were not preferentially leached.
EFFECT OF Pseudomonas fragi ON THE COLOR OF BEEF
Authors: BALA K. , MARSHALL R.T. , STRINGER W.C. , NAUMANN H.D.
Published: August 2006

Growth of Pseudomonas fragi had a significant (P > 0.05) effect on the color of beef stored at 1°± 1°C. Beef color was measured with a Hunter Color/Difference Meter and percentages of myoglobin (Mb), oxymyoglobin (O2 Mb), and metmyoglobin (MMb) on meat surfaces were determined using a Beckman DU Spectrophotometer with a reflectance attachment. As surface growth of P. fragi increased from log 2.2 to 7.2/cm2 during 20 days storage at 1°± l°C, the pH increased from 5.5 to 6.6, free fatty acid values (FFA) increased from 0.62 to 2.60 and percent O2 Mb decreased from 100% to 0%. Data indicated that proteolytic and lipolytic degradation products of P. fragi may be important in decreasing the color stability of beef stored at 1°± 1°C.
DEVELOPMENT OF Yersinia enterocolitica ON RAW AND COOKED BEEF AND PORK AT DIFFERENT TEMPERATURES
Authors: HANNA M.O. , STEWART J. C. , ZINK D. L. , CARPENTER Z. L. , VANDERZANT C.
Published: August 2006

Yersinia enterocolitica counts of inoculated beef and pork as determined from confirmed isolates picked from trypticase soy agar plates were similar to the counts of confirmed enamel‐black colonies on bismuth sulfite agar plates. With three strains of Y. enterocolitica increases in count occurred on raw beef held over a 10‐day period at 0–1°C. When inoculated raw or cooked beef and pork were stored at 7°C (0–10 days) or at 25°C (0–24 hr) large increases in Y. enterocolitica count occurred. At 25°C the increases in Y. enterocolitica counts were somewhat greater on cooked than on raw products. These differences in count may have been caused by (a) differences in the physicochemical characteristics of the meat (raw vs cooked) and/or (b) differences in the level and type of microbial flora that developed on these products. In addition to Y. enterocolitica, Staphylococcus and Micrococcus spp. often were dominant on cooked products, Pseudomonas and Microbacterium spp. on raw meats.
ASTRINGENCY IN AN INTERMEDIATE MOISTURE BANANA PRODUCT
Authors: RAMIREZ‐MARTINEZ J. R. , LEVI A. , PADUA H. , BAKAL A.
Published: August 2006

In the development of an intermediate moisture banana product, it was found that ripe banana halves dehydrated to a moisture content of about 30%, following blanching and/or sulfiting, are remarkably astringent. In order to understand the cause of this phenomenon, total phenolics, leucoanthocyanins and vanillin‐reacting compounds were determined and found to be more extractable in astringent semidried bananas. Light microscopy observations showed that both blanching and sulfiting contribute to the leakage of tannin‐like compounds from the latex cells. Overall results conform with a mechanism by which appearance of astringency in semidried banana is due to diffusion of the astringency‐causing agents from the latex cells to the surrounding tissue.
LIGHT AND SCANNING ELECTRON MICROSCOPE STUDIES ON DRY BEANS: EXTRACELLULAR GELATINIZATION OF LIMA BEAN STARCH IN WATER AND A MIXED SALT SOLUTION
Authors: ROCKLAND LOUIS B. , JONES FRANCIS T. , HAHN D. M.
Published: August 2006

Gelatinization temperatures of freely dispersed Lima bean starch were determined in pure water and a dilute aqueous salt solution. The composition of the salt solution was based on the hydration medium employed to process quick‐cooking beans. Morphological changes in the starch granules during the gelatinization process were examined microscopically. In either an excess of pure water or salt solution the dispersed granules expanded and exhibited a characteristic sequence of explicit configurations. Various stages of gelatinization were characterized in light or scanning electron photomicrographs as: (1) swollen; (2) dimpled or indented; (3) doughnut or erthrocyte‐like; (4) rubber‐raft shaped; (5) pancake; and (6) dispersed or diaphanous. The dispersed granules retained a veil‐ or film‐like residue which has been defined as a “membrelle.” Gelatinization was initiated at a specific temperature and progressed to completion over a limited temperature. With increasing temperatures, the proportion of granules affected increased until all the granules were dispersed. The gelatinization temperature range was 71–79°C in water and was 79–85°C in the salt solution.
EXTRACTION OF GOSSYPOL AND OLIGOSACCHARIDES FROM OILSEED MEALS
Authors: CANELLA M. , SODINI G.
Published: August 2006

Removal of gossypol from cottonseed meal and fermentable sugars from soybean meal by butanol‐HCl solution was tested. Acidic butanol treatment yields low gossypol cottonseed protein concentrates and low oligosaccharides soy protein concentrates, respectively. This procedure does not appreciably alter proteins, as it is shown by the comparison of electrophoretic patterns of albumins and globulins extracted from meal and corresponding protein concentrates.
QUANTITATIVE DETERMINATION OF SORBIC ACID AND SODIUM BENZOATE IN CITRUS JUICE
Authors: BENNETT M. C. , PETRUS D. R.
Published: August 2006

A procedure has been developed using anion exchange high pressure liquid chromatography (HPLC) which is capable of determining microgram quantities of two common food preservatives, sodium benzoate and sorbic acid, in citrus juices. The compounds are eluted from the column with a simple buffer system and detected with a variable wavelength spectrophotometer. Simultaneous determination is possible. Centrifugation and filtration are the only sample preparations required and HPLC analysis time is less than 10 min. Results, confirmed by ultraviolet absorption and phosphorimetric analyses, are accurate and reproducible. Analysis of fortified juice samples in the common ranges yields values within 5% of the prepared concentration.
STIMULATION OF Bacillus cerus GROWTH BY PROTEIN IN COOKED RICE COMBINATIONS
Authors: MORITA TOSHIKO N. , WOODBURN MARGY J.
Published: August 2006

The addition to cooked rice of beef, chicken or egg proteins or Casamino acids (with B‐complex vitamins) resulted in stimulation of growth of B. cereus strain 158/73 at 23 and 43°C. A critical level of 105 cells per g of food was reached by 7–20 hr at 23°C and 3–9 hr at 43°C. The same trend was observed with two other strains. Cooking the rice in water naturally high in minerals or the addition of B‐complex distilled water. Addition of starch or glucose to Brain Heart Infusion broth had little effect on growth of three strains of B. cereus under still or shaken conditions.
MAXIMUM‐LIKELIHOOD ESTIMATION OF 120 FOR INOCULATED PACKS
Authors: ROSS EDWARD W.
Published: August 2006

This paper describes a statistical procedure for estimating the 12D dose in the radiation‐sterilization of canned food, using data from an inoculated pack experiment. The method assumes a two‐parameter distribution, of which the shifted‐exponential is taken as a prototype, and uses the maximum‐likelihood principle to estimate the parameters and hence 12D. The procedure is embodied in a computer program which estimates 12D and provides confidence limits on both 12D and the kill at zero dose. The method is described and illustrated by three examples and appears to obtain more information from the data than other methods do.
A MULTIENZYME TECHNIQUE FOR ESTIMATING PROTEIN DIGESTIBILITY
Authors: HSU H. W. , VAVAK D. L. , SATTERLEE L. D. , MILLER G. A.
Published: August 2006

An in vitro method using a multienzyme system for the estimation of protein digestibility has been developed. The multienzyme system consists of trypsin, chymotrypsin and peptidase. It was found that the pH of a protein suspension immediately after 10 min digestion with the multienzyme solution was highly correlated with the in vivo apparent digestibility of rats. Regression analyses of 23 samples tested showed that the correlation coefficient between pH at 10 min and in vivo apparent digestibility was 0.90 with a standard error of estimate of 2.23. The regression equation was Y = 210.464 ‐ 18.103, where “X” was the pH of protein suspension immediately after the 10 min digestion with the multienzyme solution. The most significant advantage of this in vitro method for predicting apparent protein digestibility was that it can be completed within 1 hr and with a high degree sensitivity. The method can detect the effects of trypsin inhibitor, chlorogenic acid, and heat treatment on protein digestibility. Strong buffer salts may affect the measurement of protein digestibility, but the buffering effects found in general food proteins and products tested did not create any problem with the procedure.
DEGRADATION OF ASCORBIC ACID IN A DEHYDRATED FOOD SYSTEM
Authors: KIRK J. , DENNISON D. , KOKOCZKA P. , HELDMAN D.
Published: August 2006

The stability of reduced and total ascorbic acid in a dehydrated model food system was determined as a function of water activity, moisture content, oxygen and storage temperature. Sorption isotherm data obtained at 10, 20, 30 and 37°C for the model system were used to calculate the BET monomolecular moisture content at these respective temperatures. The model system containing 11.25 mg of ascorbic acid per 100g (25% RDA) was equilibrated at water activities below, at and above the water activity corresponding to the calculated monomolecular moisture content for the adsorption isotherms The samples were then sealed in tin cans and stored under isothermal conditions to prevent any shift in water activity during storage. Reduced, dehydro‐ and total ascorbic acid levels were measured using an automated o‐phenyl‐enediamine fluorometric assay procedure and their rates of degradation determined for each storage temperature and water activity. Under all storage conditions total and reduced ascorbic acid losses could be described by first‐order kinetic functions. Rate of ascorbic acid destruction was dependent upon water activity, moisture content and storage temperature when stored in containers with no headspace. The rate of ascorbic acid destruction was shown to dramatically increase with the presence of oxygen.
EXTERNAL COLOR AS MATURITY INDEX OF MANGO
Authors: MALEVSKI Y. , BRITO L. GÓME.Z , PELEG M. , SILBERG M.
Published: August 2006

Haden mangoes at the green maturity stage were classified according to their maximum yellow and red external color intensity using a Hunterlab Color Difference Meter, and were allowed to ripen at 23 × 2°C. The mangoes were checked daily and when completely ripe, the internal color intensity and the content of T.S.S. were determined. lntensification of surface coloration was related to the initial color intensity of the mangoes. Fruits with a more intensive initial red or yellow coloration had ripened more rapidly than mangoes with less intensive coloration. All fruits with initial coloration of bL < 22 or aL < 0 had ripened within 12 days whereas 33% of the mangoes with values of bL > 16 and 22% of the mangoes with aL > 0 did not ripen within that time period. Fully ripened mangoes which had initially a more intensive coloration had developed a more desirable internal coloration and a higher content of T.S.S. It was concluded that both, the maximum red and maximum yellow color intensities at harvest, could serve as a good index of mango maturity. The maximum red coloration was found to be a more sensitive maturity index than the maximum yellow coloration.
FACTORS AFFECTING THE STORAGE STABILITY OF SHREDDED LETTUCE
Authors: BOLIN H. R. , STAFFORD A. E. , KING A. D. , HUXSOLL C. C.
Published: August 2006

Numerous factors affect the storage stability of shredded Iceberg lettuce, with temperature being most important. Pouches of shredded lettuce stored at 2°C retained a marketable quality 2.5 times longer than those held at 10°C. Also, if the product was sealed in a gas impermeable container it lasted longer. In addition, a sharp blade exercising a slicing action was superior to either a sharp blade chopping or a dull blade slicing or chopping. Smaller shred size reduced storage life, as did the presence of any free moisture or cellular fluids on the lettuce surface. The higher the microbial load the shorter the storage life. Of the chemical dips tested none increased storage life significantly. Physical damaging of the shredded lettuce was detrimental to its storage stability.
EFFECT OF FAT LEVEL AND RADAPPERTIZATION DOSE LEVEL ON THE QUALITY OF PORK ROLLS
Authors: SHULTS GARY W. , COHEN JOSEPH S. , MASON VERA C. , WIERBICKI EUGEN
Published: August 2006

The effects of radiation processing on pork rolls with 0.75% salt and 0.3% sodium tripolyphosphate added were studied. Pork rolls were prepared with three fat levels (10, 15 and 20%) and irradiation processed at doses of 30, 45 and 60 kJ/kg, ‐30°× 10°C irradiation temperature. Differences in the sensory quality, consumer preference and shear press values were determined. No significant differences were determined among the ratings for the sensory characteristics or preference, although irradiation at 60 kJ/kg tended to lower product quality and preference ratings. Shear press values decreased with increasing fat levels. No decrease in shear press values was found among samples irradiated at 30, 45 and 60 kJ/kg.
EFFECT OF FORMULATION VARIABLES ON SENSORY QUALITY OF SPICED LUNCHEON LOAVES
Authors: CARPENTER J. A. , REAGAN J.O. , BROWN D. D. , HALL F. W.
Published: August 2006

The effects of three levels of fat (25, 30 and 35%), nonfat dry milk (NFDM) (0, 5 and 10%) and added water (yields of 115, 130 and 125% of the original meat block) on the sensory qualities of spiced luncheon loaves were evaluated. A 20‐member trained taste panel evaluated each loaf for color, flavor, firmness and general acceptability characteristics and a Universal Instron Testing Instrument was employed for objective texture measurements. Fat level and added water (yield) had highly significant (P > 0.01) effects on color while fat level influenced the flavor characteristics of the product. All variables tested significantly (P > 0.01) affected firmness, while fat content influenced (P > 0.01) the general acceptability of the loaves. For all responses measured, a significant (P > 0.05) interaction between levels of fat and NFDM existed. Taste panel members indicated a preference for loaves containing 30% fat and 5.0% NFDM. Color scores and firmness decreased as the amount of added water increased. Product shrinkage increased as added water (yield) was increased but decreased as the amount of NFDM was added to the formula.
ON THE EVALUATION OF B.E.T. CONSTANTS FROM THE B.E.T. ISOTHERM EQUATION
Authors: IGLESIAS HÉCTOR A. , BOQUET REINALDO , CHIRIFE JORGE
Published: August 2006

It is shown that the conventional (or unweighed) least squares method must not be used to evaluate the B.E.T. constants, Xm and C, when using a rearranged linear B.E.T. plot recently suggested in the literature. This is illustrated using literature data on water sorption in several foods. In this case a semi‐weighted (or weighted) least squares analysis becomes necessary. It is also shown that the unweighted least squares analysis should not be applied even to the familiar linear B.E.T. plot. In this particular case, however, and because of a fortuitous coincidence, this procedure leads to not significant differences — at least in food research — in the numerical values.
EFFECT OF SOY PROTEIN FLAKES AND ADDED WATER ON MICROBIAL GROWTH (TOTAL COUNTS, COLIFORMS, PROTEOLYTICS, STAPHYLOCOCCI) AND RANCIDITY IN FRESH GROUND BEEF
Authors: THOMPSON S. G. , OCKERMAN H. W. , CAHILL V. R. , PLIMPTON R. F.
Published: August 2006

Ground beef and soy‐beef mixtures were stored at 3°C, and microbiological enumerations and thiobarbituric acid (TBA) measurements conducted to investigate the effect of soy protein concentrate on ground beef shelf life. Soy‐beef formulations have lower oxidation rates than the ground beef mixtures as indicated by lower thiobarbituric acid (TBA) values. At the end of 6 storage days, the soy‐beef formulations had higher numbers of staphylococci, coliforms, proteolytics, and total organisms, but this was usually not statistically significant. The ground beef and tap water mixtures consistently gave the lowest counts of all enumerations.
EVALUATION OF A CALCIUM ALGINATE FILM FOR USE ON BEEF CUTS
Authors: WILLIAMS S. K. , OBLINGER J. L. , WEST R. L.
Published: August 2006

Effects of a calcium alginate coating on retail beef pieces and steaks were studied. Microbiological analyses were performed on beef pieces following treatments with: (1) a calcium alginate coating; (2) a 200 ppm HOCl solution; (3) a combination of 1 and 2; (4) a coliform inoculation and/or (5) no treatment (control). Each sample was wrapped in a polyvinyl chloride (PVC) film and stored at 5°C for up to 7 days. The rate of microbial growth for total and coliform counts on the meat was not significantly different with coated and uncoated meat samples. The HOCl treated meat had significantly lower total microbial counts and coliform populations when compared to either the calcium alginate or the HOCl‐calcium alginate treated meat. Acceptance of the calcium alginate film involved retail display and organoleptic evaluations of 40 2.54 cm thick beef steaks. Steaks that received the calcium alginate coating were significantly lower in shrinkage loss, drip and degree of off‐odor detected through 96 hr storage when compared to the uncoated steaks. The coating significantly prolonged muscle color through 96 hr storage. No significant differences were observed between treatments for appearance, surface discoloration, flavor, juiciness, tenderness, overall acceptability or cooking loss.
AVAILABILITY AND MICROBIAL STABILITY OF RETAIL BEEF‐SOY BLENDS
Authors: BELL W.N. , SHELEF L.A.
Published: August 2006

The availability and microbial quality of retail beef‐soy blends in the Detroit area were investigated. Samples were stored at 4°C and microbial populations, pH, hydration and organoleptic qualities were studied from purchase day to spoilage. Retail hamburger meat, dry and re‐hydrated texturized soy protein, and blends (10‐70%) were also studied. The rate of microbial growth in the soy‐beef blends (25% soy) was faster than in beef, and spoilage was detected after 5‐6 days at 4°C. The spoilage microflora was similar to that of fresh beef, consisting predominantly of gram negative psychrophiles. Spoilage was accompanied by an increase in pH, slime formation and off‐odors. It is concluded that at levels acceptable to the consumer (approx 25% soy) beef‐soy blends spoil in a manner similar to that of ground beef and should be stored and treated as such.
MEAT MASSAGING: THE EFFECTS OF SALT, PHOSPHATE AND MASSAGING ON THE PRESENCE OF SPECIFIC SKELETAL MUSCLE PROTEINS IN THE EXUDATE OF A SECTIONED AND FORMED HAM
Authors: SIEGEL D. G. , THENO D. M. , SCHMIDT G. R.
Published: August 2006

Samples of the tacky exudate formed on meat surfaces as a result of salt, phosphate and massaging were removed at intervals during 24 hr of massaging, and analyzed by SDS polyacrylamide gel electrophoresis to determine the relative percentage of various myofibrillar proteins present. The results showed that phosphate exerts the greatest effect on the relative percentages of actin, myosin and tropomyosin, and its action occurs primarily on meat surfaces before the massaging process is initiated. The massaging process involves great degrees of tissue destruction at the cellular level which aids in the extraction, solubilization, concentration and distribution of the major myofibrillar proteins on surfaces and in interiors of muscle chunks, which is beneficial in the improvement of binding.
EFFECT OF ICED STORAGE ON FREE FATTY ACID PRODUCTION AND LIPID OXIDATION IN MULLET MUSCLE
Authors: DENG J. C.
Published: August 2006

The influence of two periods of iced storage followed by up to 12 months frozen storage on development of free fatty acid and oxidative rancidity was studied. Mullet held in the round for 1 day and 7 days iced storage were processed into various forms of mullet flesh: mullet in the round, boneless skin‐on and skin‐off fillets with and without anti‐oxidant treatment and were then stored at ‐18°C. Generally, higher free fatty acid levels and less lipid oxidation (TBA and peroxide value) were observed in frozen mullet fillets (with and without skin) with a longer period of iced storage, except for the frozen skin‐on fillets which showed no significant difference in oxidation between the two periods of iced storage. However‐ frozen, antioxidant‐treated (immersed, in 0.25% TBHQ + 2% ascorbic acid) fillets with the longer period of iced storage had less free fatty acid production than the fillets with the shorter period of iced storage. Oxidative rancidity followed the same trend as free fatty acid development in the skin‐off fillets, but was not significantly affected by the duration of iced storage in the skin‐on fillets. In mullet frozen in the round after the two different periods of iced storage, the trend of free fatty acid production was similar to the development of oxidative rancidity. Both free fatty acid and oxidative rancidity were higher in the frozen sample with 7 days iced storage than the samples with 1 day iced storage.
STORAGE STABILITY OF INTERMEDIATE MOISTURE FOOD PROCESS CHEESE FOOD PRODUCTS
Authors: KREISMAN L. N. , LABUZA T. P.
Published: August 2006

A series of intermediate moisture food processed cheese foods were made utilizing water, nonfat milk solids and propylene glycol to change the water activity to 0.81, 0.86, 0.90, 0.91 and 0.94. The stability of these cheeses was tested over a 6‐month period at room temperature. The cheeses were challenged with three molds (Aspergillus niger, Aspergillus glaucus and Penicillium roqueforti), and two pathogenic bacteria (Staphylococcus aureus and Salmonella anatum). Changes in color, texture, meltability and organoleptic acceptability were followed. The high aw cheeses (0.90‐0.94) supported the growth of the three molds, while only the 0.94 aw cheese food supported the growth of Staphylococcus aureus. The lower aw cheeses (0.81 and 0.86) were stable microbiologically. However, the lowest aw cheese was initially not acceptable in terms of the other parameters, while the 0.86 aw cheese became unacceptable after 6‐8 wk. The IMF cheese food at a aw 0.90 was the most acceptable, with a shelf life of about 5 months.
SOYMILK: A COMPARISON OF PROCESSING METHODS ON YIELDS AND COMPOSITION
Authors: JOHNSON K. W. , SNYDER H. E.
Published: August 2006

Soymilk was produced by (A) heating of intact soybeans after soaking but before disruption, (B) heating of soaked soybeans to 80°C during disruption, and (C) disruption of soaked soybeans with no prior heating. The results show that process A has low yields of solids and low recoveries of protein in comparison with processes B and C. Heating of soybeans preceding disruption seems to keep protein bodies intact when soybean cells are disrupted. Homogenization will redisperse protein bodies that have been fixed by heat, and homogenization at high pressure (8,000 psi) and high temperature (75°C) is more effective than lower pressures and temperatures. Data are presented on rates of water or buffer uptake by steeping soybeans, on times and temperatures needed to eliminate the green‐beany flavor and on the solids analysis by spectrophotometry.
MEASUREMENT OF THE THERMO‐PHYSICAL PROPERTIES OF COMMON COOKIE DOUGH
Authors: KULACKI F. A. , KENNEDY S. C.
Published: August 2006

Despite the volume of research done on food properties, the literature reports little related to the baking industry, particularly confectionary dough. This paper reports results of an experimental study of thermal conductivity, specific heat, density and thermal diffusivity of two different types of cookie dough. Thermal conductivity of both doughs were moderately dependent on temperature. Thermal diffusivities of each type dough were evaluated using experimental values of thermal conductivity, specific heat and density. Total experimental uncertainty in the thermal diffusivity was estimated as 0.134 for the AACC formula and 0.15 for the hard‐sweet formula dough.
MEAT MASSAGING: EFFECTS OF SALT AND PHOSPHATE ON THE ULTRASTRUCTURE OF CURED PORCINE MUSCLE
Authors: THENO D. M. , SIEGEL D. G. , SCHMIDT G. R.
Published: August 2006

Samples of rectus femoris were collected from cured ham muscles which had been massaged for 0, 1, 2, 4, 8 or 24 hr with 0, 1, 2, or 3% of added salt in the presence or absence of 0.5% phosphate for examination with a scanning election microscope (SEM). After several hours of massaging, fiber disruption became evident. Further massaging resulted in longitudinal disruption of the fibers. Myofibrils were observed to separate and shred from the surface of the fibers. After 24 hr of massage, all treatments showed massive fiber disruption and loss of normal structural integrity. The effects of massaging were more pronounced in the presence of salts and phosphates at all time intervals.
EFFECTS OF PRERIGOR CONDITIONING TREATMENTS ON LAMB MUSCLE SHORTENING, pH AND ATP
Authors: BOWLING R. A. , SMITH G. C. , DUTSON T. R. , CARPENTER Z. L.
Published: August 2006

Effects of prerigor conditioning treatments on processing time, quality characteristics and muscle properties were determined using three muscles from each of 84 lamb carcasses. Carcasses (n = 72) were subjected, beginning 1 hr post‐exsanguination, to one of six conditioning treatments and compared to normally chilled lambs (n = 12). Treatments differed in conditioning period, conditioning chamber environment (temperature, relative humidity, air velocity) and in use of electrical stimulation. All carcasses were maintained at 0°C after the 2‐8 hr conditioning period until fabrication at 72 hr postmortem. Panel ratings (SPR), shear force (SF), water‐holding capacity (WHC) and sarcomere length (SL) were determined for longissimus dorsi (LD), biceps femoris (BF) and semimembranosus (SM) muscles. Lambs in treatments +49 and +32 had the slowest rate of temperature decline, high rates of pH and ATP decline, low WHC, the most pronounced sarcomere shortening and the toughest LD and BF. Carcasses in the +16 treatment reached temperatures critical to cold shortening (9‐11°C) 8‐9 hr later than carcasses in the ‐16 treatment, had longer sarcomeres, had more tender BF (SF) and SM (SPR and SF) muscles but had much lower WHC. Among carcasses conditioned at ‐32°C, those which were electrically stimulated (ES) had lower carcass temperatures at 3 and 4 hr postmortem, had faster rates of pH (LD and BF) and ATP (LD) decline and lower WHC but did not differ in tenderness from those which were not ES. Production of tender lamb, with minimal energy expenditure and no increase in cooler shrinkage, was best accomplished by chilling lambs for 8 hr at +16°C (65% relative humidity and 9m/min air velocity).
POLYPHENOL OXIDASE OF d'ANJOU PEARS (Pyrus communis L.)
Authors: HALIM D. H. , MONTGOMERY M. W.
Published: August 2006

Stability, substrate and inhibitor specificity and electrophoretic properties of a crude polyphenol oxidase (PPO) preparation extracted from d'Anjou pears (Pyrus communis L.) were investigated. The pH optimum of PPO occurs at 7.0. Heat inactivation of PPO followed first order kinetics and approximately 50% of PPO activity was inactivated after heating for 11.7, 6.25, 2.24 and 1.1 min at temperatures of 70°, 75°, 80° and 85°C, respectively. Crude PPO extract was active towards o‐dihydroxyphenols, but inactive towards monophenols. Disc electrophoresis revealed eight active isozymes toward catechol, 4‐methyl catechol, chlorogenic acid, caffeic acid, dopamine, d‐catechin and DL‐dopa. Similar electrophoretic patterns were observed with all substrates. No differences in the electrophoretic patterns were observed between fresh PPO preparations and preparations which had been frozen or dialzyed. Pear PPO was relatively sensitive to most inhibitors tested with the exception of sodium chloride. Of the inhibitors studied L‐cysteine and diethyldithiocarbamate were the most effective against pear PPO.
OXYGEN EFFECT ON THE DEGRADATION OF ASCORBIC ACID IN A DEHYDRATED FOOD SYSTEM
Authors: DENNISON D.B. , KIRK J.R.
Published: August 2006

The stability of reduced and total ascorbic acid in a low moisture dehydrated model food system was determined as a function of water activity, moisture content, oxygen and temperature. Ascorbic acid degradation rates were satisfactorily described by first‐order kinetics and were dependent on water activity and temperature. Rate constants obtained for the model system stored with a large excess of oxygen (303 cans) were compared with those reported previously for the case of limited gaseous oxygen (TDT cans). At all conditions of temperature and water activity the degradation of ascorbic acid was greater for the condition of excess oxygen (303 cans). This effect is interpreted as reflecting the consumption of oxygen dissolved in the moisture of the product and the continuous dissolution of excess molecular oxygen present in the 303 cans. The significance of this oxygen effect is further manifested by the change in activation energies for RAA and TAA destruction at 0.1 aw from 7.0 kcal/mole limited oxygen to 10.7 kcal/ mole in excess oxygen conditions. These data suggest that dissolved and gaseous oxygen are primary factors in the storage stability of ascorbic acid in dehydrated food systems.
INHIBITION OF LYSINOALANINE FORMATION IN FOOD PROTEINS
Authors: FINLEY J. W. , SNOW J. T. , JOHNSTON P. H. , FRIEDMAN M.
Published: August 2006

Lysinoalanine (LAL), an amino acid derivative which exhibits nephrotoxic properties when fed to rats, is currently of considerable interest to the food industry. LAL has been shown to be present in a number of alkaline and/or heat treated food products. Rate studies were carried out to measure the formation of LAL in the presence and absence of mercaptoamino acids such as cysteine and glutathione. Addition of the mercapto amino acids to casein and soy protein during alkaline processing nearly eliminated the formation of LAL.
KINETIC PARAMETERS FOR THERMAL INACTIVATION OF PANTOTHENIC ACID
Authors: HAMM D. J. , LUND D. B.
Published: August 2006

Decimal reduction values (D values) and activation energies for destruction of pantothenic acid (PA) in KH phthalate buffer, pH 4, 5 and 6, in meat puree and in pea puree at temperatures between 118‐143°C were determined using the thermal death time tube method and the Arrhenius equation, Samples were assayed according to AOAC (1975) microbiological method for pantothenic acid. Activation energies ranged from 20,000‐38,000 Cal/mole. As pH increased from 4 to 7, activation energies also increased. The D1 2 1 values ranged from 4‐32 hr for buffered systems and from 38‐40 hr for food systems. These large D values for foods would indicate that PA is not very heat labile and is more stable in these food systems compared to buffered systems.
EFFECT OF PLANT FIBER ON LIPASE, TRYPSIN AND CHYMOTRYPSIN ACTIVITY
Authors: SCHNEEMAN BARBARA OLDS
Published: August 2006

Wheat bran, whole alfalfa, rice bran, safflower meal, cellulose acetate, xylan, Solka‐Floc and pectin were tested for their ability to affect lipase, trypsin and chymotrypsin activity in vitro. Almost all of the fibers tested, excluding pectin, caused a significant loss of lipase activity. Incubation with Solka‐Floc and xylan resulted in some loss of chymotrypsin activity. Alfalfa and safflower meal exerted the most potent effect on trypsin activity and Solka‐Floc had a slight effect. With all the fibers tested, a part of the enzyme solution was absorbed into the fiber matrix thereby decreasing the availability of total filterable enzyme activity in vitro.
SENSORY CHARACTERISTICS AND MICROBIOLOGICAL EVALUATION OF STORED MECHANICALLY TENDERIZED BEEF SEMIMEMBRANOSUS MUSCLE
Authors: BOYD K. J. , OCKERMAN H. W. , PLIMPTON R. F.
Published: August 2006

One pass through a mechanical tenderizer improves the tenderness of Good grade beef semimembranosus roast. When comparing roast that had been tenderized four times with untenderized roast, cooking drip was increased (P < 0.01), cooking evaporation was decreased (P < 0.01) and cooking rate was faster (P < 0.01). Both aerobic and anaerobic microbial numbers were higher (P < 0.01 and P < 0.05, respectively) for samples tenderized four times than untenderized controls or those tenderized one or two times. Taste panel acceptability at 4 wk was decreased (P < 0.05) compared to acceptability at the initial period or following 2 wk of storage.
POSTMORTEM AGING OF BOVINE MUSCLE: A COMPARISON OF TWO PREPARATION TECHNIQUES FOR ELECTRON MICROSCOPY
Authors: VARRIANO‐MARSTON E. , DAVIS EUGENIA A. , HUTCHINSON T. E. , GORDON JOAN
Published: August 2006

Two preparatory techniques for electron microscopy were employed to investigate ultrastructural changes in bovine muscle during postmortem aging. The ultrastructural changes in aged muscle prepared by ultrarapid frozen thin sectioning procedures were less extensive than those observed in fixed, dehydrated, and embedded muscle, and this suggested that the preparation procedure may affect observed structural characteristics. The major changes observed in unfixed, frozen hydrated muscle were evident as alterations in electron scattering in the striations of the myofibrils indicating that ion redistribution occurred during postmortem aging. Structural alterations observed in aged tissue prepared by standard techniques included disruptions in the Z line, breaks at the Z‐I junction and fading or disappearance of the M line.
TYRAMINE IN FERMENTED SAUSAGES: FACTORS AFFECTING FORMATION OF TYRAMINE AND TYROSINE DECARBOXYLASE
Authors: EITENMILLER R. R. , KOEHLER P. E. , REAGAN J. O.
Published: August 2006

Factors influencing tyramine formation and the presence of tyrosine decarboxylase activity in natural microflora and starter (Pediococcus cerevisiae) fermented sausages were determined. Maximal levels of tyrosine decarboxylase were found during the period of rapid acid development in the natural microflora fermentations. Higher levels of decarboxylase were present in the natural fermented sausages compared to the starter fermented sausages. Tyrosine decarboxylase activity increased during the drying treatment in the natural microflora sausages but remained low in the starter fermented sausages. Greater tyramine contents were found in the natural microflora sausages which had free L‐tyrosine added prior to fermentation. Tyramine contents of the natural microflora and starter fermented sausages without added L‐tyrosine generally reached similar tyramine levels. In the starter fermented sausages, tyramine and tyrosine decarboxylase development comparable to the amounts found in natural microflora fermented sausages occurred only in a sausage which contained added L‐tyrosine that was inoculated with a tyrosine decarboxylase positive Streptococcus faecalis. The study indicated that the natural meat microflora developed during the aging of salted meat can develop tyrosine decarboxylase activity necessary for rapid conversion of tyrosine to tyramine. The use of a starter culture such as P. cerevisiae appears to decrease the possibility of development of a microflora during fermentation that would possess both tyrosine decarboxylase activity and proteolytic activity necessary to produce fermented sausages with potentially hazardous tyramine concentration.
TEMPORARY ANOXIA AS A MEANS OF PREVENTING SUGAR ACCUMULATION DURING STORAGE AT 4°C
Authors: AMIR JACOB , KAHN VARDA , UNTERMAN MIRIAM
Published: August 2006

Temporary anoxia (about 20 days) was found to be an effective means to prevent sugar accumulation in potato tubers during storage at 4°C. The sugar level of such tubers re‐exposed to normal atmosphere remained low during additional storage at 4°C for 3 months. During this time, the high level of lactic acid which had accumulated in tubers during temporary anoxia was greatly reduced.
CAROTENE OXIDIZING FACTORS IN RED PEPPER FRUITS (Capsicum annuum L.): OLEORESIN‐CELLULOSE SOLID MODEL
Authors: KANNER JOSEPH , MENDEL HAVA , BUDOWSKI PIERRE
Published: August 2006

An oleoresin‐cellulose model was used for studying the interacting processes which influence carotene bleaching in powdered paprika. Special attention was given to the effects of water activity and the addition of aqueous pepper extracts, copper and ascorbic acid. The stability of carotenoids in the model system increased slightly with increasing water activity, but the effect of moisture become considerable when the system also included ascorbic acid and copper sulfate. When aw in powdered paprika exceeded 0.32, carotenoid bleaching proceeded in three stages. After an initial bleaching, there was a prolonged period of stability, after which oxidation resumed. The intermediate period of stability was absent in the dry product. Results obtained with the oleoresin‐cellulose model showed that the three‐stage carotenoid bleaching at high aw values was characteristic of the combined action of copper and ascorbic acid. It is concluded that these two materials, by becoming soluble at high water activities, play an important part in the stabilization of carotenoids in powdered paprika. Under conditions of high water activity, the prooxidant effect of a water‐soluble protein is overcome by the marked antioxidant action of the ascorbic acid‐copper system. However, in the dry product the decisive factor in carotenoid bleaching is the proteinous fraction which was previously shown to have peroxidase activity.
PURIFICATION AND CHARACTERIZATION OF ENDO‐POLYGALACTURONASE FROM Rhizopus arrhizus
Authors: LIU YUAN K. , LUH BOR S.
Published: August 2006

An endo‐polygalacturonase (RAPG) from Rhizopus arrhizus grown on rotted apricot has been purified and characterized. Through dialysis, ammonium sulfate fractionation, and successive chromatography on DEAE‐cellulose, Sephadex G‐100 and Sephadex G‐75 columns, a 274‐fold purification was achieved. RAPG was stable at pH 3.8–6.5. Its optimum activity was at pH 5.0. The activation energy (Ea) was 11.9 Kcal/mole. The Q1 0 value was 2.01 between 20° and 30°C. RAPG has a Vmax at 1.430 μmoles reducing product/min, and Km at 0.054% pectic acid (DP = 70). Both sodium and potassium ions stimulated RAPG activity in the 0.05–0.10M range. Tannic acid was an effective inhibitor, while chlorogenic, caffeic, p‐coumaric and gallic acids were not. The molecular weight of RAPG was 30,270 by SDS‐gel electro‐phoresis. Both viscosity drop and thin layer chromatography of the end products study proved that RAPG performed a random mechanism in the depolymerization process. RAPG also showed a synergistic effect when tomato pectinesterase was added to the reaction mixture with pectin as the substrate.
FREEZE‐ETCH ULTRASTRUCTURE OF WAXY MAIZE AND ACID HYDROLYZED WAXY MAIZE STARCH GRANULES
Authors: CHABOT JEAN F. , ALLEN JOHN E. , HOOD LAMARTINE F.
Published: August 2006

Freeze‐etching was used to study the ultrastructure of waxy maize starch and acid‐treated (0.5M HCl, 25°C, 24 hr) waxy maize starch. The outer surfaces of the untreated granules were smooth with a faint fibrillar pattern. Granule cross‐fractures had a fine particulate appearance with some radially‐oriented ridges. Internal cracks were evident. Starch granules soaked in acid developed surface pits. Areas of hydrolysis had a distinctive structure and occurred in restricted zones. The shape of the acid‐treated starch granules remained unchanged. However, inner regions showed extensive ultrastructural changes and water infiltration. Freeze‐etching revealed bands of alternating high and low water content which formed lamellae in a few granules.
DETECTION OF STAPHYLOCOCCAL ENTEROTOXIN B BY AFFINITY RADIOIMMUNOASSAY
Authors: NIYOMVIT N. , STEVENSON K. E. , McFEETERS R. F.
Published: August 2006

The objective of this investigation was to develop a rapid, sensitive method for the detection and quantitation of staphylococcal enterotoxin B (SEB). Antibody to SEB was covalently attached to Sepharose 4B by use of cyanogen bromide activation. The antibody gel was diluted with Sephadex G‐25, and 1–2 ml packed volume of the diluted gel was placed in a small column. Assays were carried out by sequentially pumping sample, 1 2 5I‐labeled SEB, 0.05M Na‐phosphate buffer (pH 7.5) containing 0.15M NaCl, and 0.13M NH4OH (pH 10.5) containing 0.15M NaCl through the column. The amount of 1 2 5I‐labeled SEB removed from the column with the pH 10.5 solution was inversely related to the amount of SEB in the sample. After washing with the pH 7.5 buffer, the column was ready to reuse. Columns were used for over 100 determinations. The minimum SEB concentrations which could be detected were 1.2 ng/ml in buffer, 2.2 ng/ml in nonfat dry milk and 6.3 rig/g in hamburger. This affinity radioimmunoassay (RIA) was also suitable for measuring thermal inactivation of SEB. Results of this investigation show that this affinity RIA technique can be utilized for rapid detection of SEB.
γ‐GLUTAMYL DIPEPTIDE CONTENT IN SOYBEAN PROTEIN PRODUCTS AND OTHER COMMODITIES
Authors: WANG L. C. , CAVINS J. F. , WOLF W. J.
Published: August 2006

The amount of γ‐glutamyl dipeptides (γ‐glutamyl tyrosine and γ‐glutamyl phenylalamine) present in soybeans and other commodities was measured by a method consisting of alcohol extraction, preliminary purification and determination with an automated amino acid analyzer. Defatted soybean flakes of four varieties and one commercial sample contained 1.17–1.60 mg of the dipeptides per g. Most of the dipeptides in soybean concentrates and isolates were lost through processing. Corn, wheat, cottonseed meal, pork, beef, chicken and lamb appeared to contain only traces, but peanut flour has a content of 0.20 mg per g. The method adequately measures 50 μg of the dipeptides and recovers more than 95% of γ‐glutamyl phenylalanine standard added to samples of soybean flour and meat‐soybean flour mixtures.
METHOD FOR THE MEASUREMENT OF PHENOLS ASSOCIATED WITH THE SMOKY/HAMMY FLAVOR DEFECT OF COCOA BEANS AND CHOCOLATE LIQUOR
Authors: LEHRIAN D. W. , KEENEY P. G. , LOPEZ A. S.
Published: August 2006

A procedure for extraction of flavor components from cocoa beans and chocolate liquor with acetonitrile is described. After removal of interfering substances, phenolic compounds in the extract are reacted with N,2,6‐trichloro‐p‐benzoquinoneimine to form colored indophenols. A high correlation (0.89) was found between the concentration of phenols and the results of taste panel evaluation for the smoky/hammy defect caused by smoke contamination. The procedure is applicable to quality control evaluation of cocoa beans and chocolate liquor received from producing countries.
EVALUATION OF KINETIC MODEL FOR REACTIONS IN MOISTURE‐SENSITIVE PRODUCTS USING DYNAMIC STORAGE CONDITIONS
Authors: MIZRAHI SHIMON , KAREL MARCUS
Published: August 2006

A method using continuously changing moisture content and temperature was developed for evaluating the kinetics of deterioration in moisture‐sensitive products. The method can be applied to cases where the order of the reaction is known and the rate is dependent on water content and temperature. The kinetic parameters are calculated from the extent of deterioration, which is monitored in a product under continuously changing conditions. The accuracy of the method depends on the sensitivity of the analytical techniques used as well as on the proper selection of experimental conditions. The expected accuracy is adequate, but inferior to the traditional constant‐moisture/constant‐temperature kinetic tests.
EFFECT OF METHIONINE AND N—ACETYLMETHIONINE FORTIFICATION ON THE FLAVOR OF SOY BREAD AND SOY MILK
Authors: HIPPE R. L. , WARTHESEN J. J.
Published: August 2006

The effect of methionine fortification on the flavor of soy‐containing foods was investigated. A sensory panel was used to establish the detection threshold levels of methionine, recrystallized methionine and N—acetylmethionine in both the crust and the interior crumb of a fortified soy bread. Methionine was detectable at 0.10% addition in the bread crust and 0.20% in the interior crumb. Recrystallization of the methionine was not effective in reducing the flavors due to methionine addition. The N‐acetylmethionine detection threshold levels were 3–7 times higher than methionine, and neutralization of the N‐acetylmethionine allowed even higher levels of incorporation. Soy milk was used to evaluate the influence of methionine level and heat treatment on flavor development. Increasing the heating temperature or fortification level decreased the time required to produce detectable flavor differences. Gas chromatography and mass spectrometry were used to identify methional in a heated fortified soy milk.
BACTERIAL GROWTH IN WHOLE EGG AND EGG SUBSTITUTES INCLUDING INOCULATION WITH
Authors: PAUL MARIANNE E. , POTTER NORMAN N.
Published: August 2006

Bacterial growth patterns in liquid egg and two commercially produced egg substitutes were similar. Total aerobic, anaerobic, proteolytic and lipolytic populations of the products’ normal flora along with pH, titratable acidity and free fatty acid levels were determined at 2°C and 12°C over periods up to 28 days at the lower temperature. Bacterial populations increased substantially in all products except fresh and pasteurized egg at 2°C. Decreases in pH and increases in titratable acidity and free fatty acid levels generally paralleled bacterial growth. S. aureus and C. perfringens inoculated into the egg products in small numbers were outgrown by the natural flora present. S. aureus populations increased slightly over a period of about 4 days at 12°C and then tended to decline. C. perfringens declined rapidly or did not grow in any of the products at 12°, 20° and 37°C although total anaerobic counts increased considerably.
EFFECTS OF POST–COOKING SAMPLE TEMPERATURE ON SENSORY AND SHEAR ANALYSIS OF BEEF STEAKS
Authors: CAPORASO F. , CORTAVARRIA A. L. , MANDIGO R. W.
Published: August 2006

The effect of post‐cooking beef sample temperatures of 22°C (room temperature) and 50°C on sensory and shear analyses was determined. Oven roasted beef bottom round steak sample cores (1.88 cm) were halved, with one‐half being maintained at room temperature and the other at 50°C. A calibrated double boiler‐hot plate system was used to accurately control sample temperature. Six trained sensory panelists rated all samples on 7‐point rating scales for flavor, initial juiciness, sustained juiciness, initial tenderness and overall tenderness. Warner‐Bratzler shear determinations were also obtained. Samples held at 50°C had significantly higher flavor (P < 0.01), initial tenderness (P < 0.01) and overall tenderness (P < 0.02) values. Initial juiciness was significantly lower (P < 0.01) for the 50°C samples, while no significant differences in sustained juiciness were detected. Shear values were significantly lower (P < 0.01) for samples held at 50°C. Differences in sensory ratings due to post‐cooking sample temperature variation are greatest for initially perceived characteristics such as flavor, initial juiciness and initial tenderness.