bluuebunny/crossref_metadata_2025 huggingface dataset:
PENETRATION OF SUBSTANCES INTO MUSCLE
Authors: KILIC B. , CASSENS R.G.
Published: May 2007

The rate and depth of penetration of two dye markers, hematoxylin and eosin, into beef muscle were compared. The effects of temperature, aging, meat texture, and type of muscle were investigated. Samples (1 cm3) were placed into dye markers, and then were sectioned at selected time intervals and examined microscopically. Hematoxylin penetrated into the meat slower than eosin; depth of hematoxylin penetration decreased with decreasing temperature, firmer meat texture and aging. Penetration rate was faster at the beginning than at the end of the test period. Penetration rate and depth of oxygen into beef, lamb, and pork were investigated also. The samples (8 cm3) were placed in a modified atmosphere package containing 80% oxygen and 20% carbon dioxide. The samples were cut at selected time intervals up to 26 h after addition of oxygen and oxygen penetration rate and depth were measured. Oxygen penetration was deeper in beef than in pork and deeper in pork than in lamb. Oxygen penetration rate was faster initially and then slowed as time progressed.
EFFECTS OF CHITOSAN ON GELLING PROPERTIES OF LOW QUALITY SURIMI
Authors: KATAOKA J. , ISHIZAKI S. , TANAKA M.
Published: May 2007

In order to produce a strong and elastic gel from low quality walleye pollock surimi, use of chitosan was examined. The strength of gels was nearly doubled by the addition of 1.5% chitosan when salted surimi pastes were set below 25C. In contrast, chitin did not cause any changes in the physical texture of gels. When salted surimi pastes containing 1.5% chitosan were set at 20C, a large decrease in the proportion of myosin heavy chain was observed with a concomitant increase in components with molecular weights heavier than myosin heavy chain. Since the addition of EGTA, an inhibitor of transglutaminase, to surimi reduced gel strength and minimized myosin heavy chain polymerization, it is suggested that the enhancing effect ofchitosan on the gel formation of walleye pollock surimi could be due to the activity of the endogenous transglutaminase known to be present in this surimi.
COMPARATIVE STUDIES OF NONMEAT ADJUNCTS USED IN THE MANUFACTURE OF LOW‐FAT BEEF BURGERS
Authors: DESMOND E.M. , TROY D.J. , BUCKLEY D.J.
Published: May 2007

Seventeen commercially available functional ingredients were assessed in low‐fat beef burger formulations. There were differences (P<0.05) in cook yields between the different low‐fat meats. The burger containing alginate/calcium lactate had the highest cook yield at 71.30% with good textural qualities, but scored low in overall flavor. Most adjuncts tested increased the WHC by comparison with the full‐fat (23% fat) control, which had the lowest WHC (26.15%). Sensory analysis showed that there was a trend for higher fat beef burgers to have increased tenderness, however, no significant differences were found between the low‐ and full‐fat controls. Beef burgers containing pectin, micro‐crystalline cellulose, oat fiber and carrageenan scored high in flavor and overall quality. In contrast the burger formulated with blood protein had poor overall quality and flavor attributes. Burgers containing tapioca starch, modified food starch derived from waxy maize, and oat fiber significantly reduced Instron shear values.
A COMPARISON OF THE QUALITY CHARACTERISTICS OF PALE, SOFT AND EXUDATIVE BEEF AND PORK1
Authors: AALHUS J.L. , BEST D.R. , MURRAY A.C. , JONES S.D.M.
Published: May 2007

Beef and pork carcasses of normal quality were compared to those subjectively scored as PSE (pale, soft, exudative) postslaughter. Compared to normal meat, the PSE samples from both beef and pork exhibited a lower pH45and glycogen content early postmortem while lactate concentration, L*, hue angle and chroma values were elevated (P<0.05). Drip loss for both PSE beef and pork was also higher than normal meat with a 2.8‐fold increase for PSE beef and a 1.3‐fold increase for PSE pork. Shear values for PSE beef were over 1 kg lower than control beef whereas shear values for PSE pork were over 1 kg higher compared to normal pork (P<0.05). It is clear from these data that rapid pH drops during early postmortem do not always result in similar changes in tenderness. A more complete understanding of the underlying cellular mechanisms of tenderization, electrical stimulation and the PSE condition should help to elucidate the paradox.
SENSORY AND PHYSICOCHEMICAL CHARACTERISTICS OF PRECOOKED, MICROWAVE‐REHEATABLE STEAKS
Authors: MCWATTERS K. H. , RESURRECCION A. V. A. , CARPENTER J. A.
Published: May 2007

Precooked, small‐portion, microwave‐reheatable steaks were processed from three grades (US Choice, US Select+, and US Select‐) of top round beef. Marinated/tenderized samples were compared to nonmarinated/nontenderized controls from each grade. Untrained consumers (n=102) rated the sensory attributes, overall acceptability, and willingness to purchase the steaks at various settings (fast food, restaurant/cafeteria, supermarket). Marination and tenderization improved the sensory attributes, overall acceptability, and consumers' willingness to purchase the steaks, regardless of the grade from which they were prepared. Marinated/tenderized steaks from the US Select grade were more acceptable than nonmarinated/nontenderized steaks from the US Choice grade. Marinated/tenderized steaks from each grade required less force and energy to cut, contained about 3% more moisture and 0.5% less fat, and had more cooking loss than their control counterparts. However, consumers rated the marinated/tenderized products as being more tender, juicy, flavorful and more acceptable overall than controls.
CURRENT STATUS OF BOVINE SPONGIFORM ENCEPHALOPATHY‐A REVIEW
Authors: BREWER M.S.
Published: May 2007

Bovine spongiform encephalopathy (BSE) is a fatal brain disease of cattle which is presumed to have originated from feeding meat and bone meal (MBM) manufactured from rendered scrapie‐infected sheep. More than 170,000 cases of BSE have been identified in UK cattle since it was specifically diagnosed in 1986. Most are in dairy herds. This paper reviews the background of the disease, changes in rendering in the United Kingdom which appear to have led to the development of BSE in cattle, characteristics of the disease, the disease‐causing agent (prions), related prion diseases in other species, the impact of genetics on prion disease, prion strains, species barriers to transmission, risk of Creutzfeld‐Jakob disease to humans, inactivating prion infectivity, and tallow and gelatin production and safety. Efforts at controlling the disease in the United Kingdom and preventing the disease in the United States are also discussed.
THE INFLUENCE OF GENOTYPE ON BEEF PALATABILITY AND COOKING PROPERTIES. AN EVALUATION OF WAGYU F1 CROSSES AND OTHER GENOTYPES UNDER NORTH AMERICAN FEEDLOT CONDITIONS1
Authors: JEREMIAH L.E. , GIBSON L.L.
Published: May 2007

Beef strip loins (100) were evaluated from steers of 10 different genotypes fed under North American feedlot conditions for 150 days. Significant (P<0.05) but small numerical differences were observed in thaw‐drip losses from roasts and cooking losses from steaks. Roast flavor and texture profiles revealed important differences in both individual flavor and texture character notes. However, these differences were of insufficient magnitude to influence the appropriateness balance, and blend of individual character notes. Although differences were not observed (P>0.05) in mean palatability ratings, lower proportions of steaks from Angus were rated tough initially and overall than steaks from any other breed or breed combination. Therefore, incorporation of Wagyu genetics at the F1 level did not improve but was not detrimental to cooking and/or palatability attributes, except in the case of Wagyu x Angus crosses, which were not as acceptable in tenderness as Angus.
TEXTURAL AND SENSORY PROPERTIES OF REDUCED‐FAT FRANKFURTERS CONTAINING ANTIOXIDANT‐WASHED BEEF HEART SURIMI1
Authors: WANG B. , XIONG Y.L.
Published: May 2007

Textural and sensory properties of frankfurters prepared with or without beef heart surimi were evaluated. Addition of 15% beef heart surimi increased the rupture force and cooking‐yield of frankfurters by 80% and 3%, respectively (P<0.05). Frankfurters treated with beef heart surimi received higher juiciness and binding scores than the control (P < 0.05). Beef heart surimi with or without an antioxidant did not cause any detectable off‐flavor of the frankfurters. These results indicated that beef heart surimi can be used as an effective binding agent for cured comminuted meat products.
CONSUMER ACCEPTANCE OF HONEY MARINATED CHICKEN
Authors: HASHIM I.B. , McWATTERS K.H. , HUNG Y.‐C.
Published: May 2007

Chicken bone‐in breast quarters marinated through injection with lemon‐pepper poultry marinade containing 20 or 30% honey were compared to that marinated without honey and commercial marinated chicken. The objectives were to determine (1) consumer acceptance and willingness to buy and the amount to pay for marinated chicken and (2) the effect of honey on instrumental measurements of color and texture. Chicken was roasted at 177C for 1 h to an internal endpoint temperature of 80C and evaluated for acceptance by 67 untrained consumers. All experimental test products had similar hedonic ratings for appearance, color, flavor, taste, tenderness, juiciness, and overall liking. All samples, both experimental and commercial, were acceptable, and most consumers would be willing to buy chicken marinated with the formulations used in this study for the same price that they were paying for similar products.
GENDER AND DIET INFLUENCES ON PORK PALATABILITY AND CONSUMER ACCEPTANCE. I. FLAVOR AND TEXTURE PROFILES AND CONSUMER ACCEPTANCE1
Authors: JEREMIAH L.E. , SATHER A.P. , SQUIRES E.J.
Published: May 2007

Ninety intact male, 89 castrated male, and 60 female pigs were slaughtered at a mean market weight of 95.7 kg and a mean age of 151.5 days. All pigs were housed in groups of four and were fed ad libitum either a corn or wheat based ration, until 24 h preslaughter, at which time feed, but not water was withheld. Six percent of the samples from castrated and 30% of the samples from intact male pigs were perceived to have an inappropriate barnyard aromatic at a relatively high intensity. Only 2% of the samples from castrates, as opposed to 27% of the samples from intact males were perceived to have an inappropriate sex taint aromatic at a relatively high intensity. Although samples from females were perceived to have an inappropriate barnyard aromatic at a relatively high intensity, no sex taint aromatic was detected from these samples. There was no effect of diet on either palatability or consumer acceptance traits.
SENSORY CHARACTERISTICS AND PROCESSING YIELD OF BONELESS HAMS OBTAINED FROM GILTS ADMINISTERED EXOGENOUS PORCINE SOMATOTROPIN
Authors: BRYAN K.A. , KUECKER W.G. , HENNING W.R. , MILLS E.W. , HAGEN D.R.
Published: May 2007

Two studies were conducted to evaluate effects of administration of porcine somatotropin (pST) to growing gilts on subsequent processing and sensory characteristics of porcine ham muscles. The Semimembranosus muscle was separated from the other major muscles prior to pumping to 120% of green weight with a brine solution. Treatment with pST in vivo increased the weight of Semimembranosus compared with controls (P < 0.05). The muscle weight gains associated with pST treatment were retained during ham processing, resulting in heavier hams from gilts administered pST. However, pST treatment did not affect ham processing yields (%), smoked ham color, final product proximate composition or important palatability characteristics of hams (P > 0.05).
DISPLAY LIFE OF FRESH BEEF CONTAINING DIFFERENT LEVELS OF VITAMIN E AND INITIAL MICROBIAL CONTAMINATION
Authors: ZERBY H.N. , BELK K.E. , SOFOS J.N. , MC DOWELL L.R. , WILLIAMS S.N. , SMITH G.C.
Published: May 2007

Strip loins from beef cattle fed diets supplemented or not supplemented with α‐tocopheryl acetate (vitamin E; 500 IU·animal−1·d‐1) were fabricated into steaks inoculated at three initial levels (1.7 to 1.9; 2.3 to 2.5; 6.4 to 7.1 log CFU/cm2) of bacterial contamination (from over aged retail steaks) and evaluated for psychrotrophic plate counts (PPC), overall appearance and color during 6 days of simulated retail display (0 to 4C). Initial contamination affected changes in PPC (P < 0.05) during display, while the highest level of initial contamination eliminated benefits of high vitamin E concentrations on product color within 4 days of retail display. However, increased vitamin E concentrations in steaks were associated with higher (P < 0.05) CIE a* values appearance scores when the level of initial contamination was less than 2.5 CFU/cm2. Results indicated that vitamin E supplementation does not mask high levels of bacterial contamination.
GARLIC IN CHINESE SAUSAGE1
Authors: SUN Y.M. , OCKERMAN H.W. , MARRIOTT N.G.
Published: May 2007

Boneless pork shoulders were formulated with flavor adjuncts for the production of a semidry sausage. Nitrite was added as 75 or 150 ppm of the formulation and 5% fresh garlic, 1.2% garlic powder, or 0.006% garlic essential oil was incorporated. The samples with 150 ppm added nitrite were only slightly higher in pH than those with 75 ppm added nitrite, and this value decreased with storage time. TBA and TPC numbers indicated that the sausage samples did not spoil during storage. Garlic addition did not produce lower thiobarbituric acid (TBA) total plate count (TPC, or aerobic plate count, APC) numbers. Fresh garlic had a stronger flavor than garlic powder and garlic essential oil in the quantities used. Addition of 150 ppm nitrite resulted in a brighter color, and better antimicrobial ability than 75 ppm nitrite. Sensory evaluation revealed little differences between samples with 75 ppm and 150 ppm added nitrite.
EFFECTS OF LIVE ANIMAL SAMPLING PROCEDURES AND SAMPLE STORAGE ON THE GLYCOLYTIC POTENTIAL OF PORCINE LONGISSIMUS MUSCLE SAMPLES
Authors: MILLER K.D. , ELLIS M. , SUTTON D.S. , McKEITH F.K. , WILSON E.R.
Published: May 2007

Eight hybrid gilts of Hampshire descent were selected at 110 kg live weight, grouped together in one pen and given a one‐week adaption period prior to sampling. Longissimus samples (approximately 0.5 g) were taken using spring‐loaded biopsy equipment with animals either unrestrained and free to move in the pen or, 3 h later, restrained with a nose snare for two minutes prior to sampling. There was no difference among the two handling approaches for glycolytic potential (P > 0.05). Animals were slaughtered and four longissimus samples (0.5 g) were taken from each carcass immediately following exsangination to evaluate four sample storage methods. Two viable storage methods, freezing in liquid nitrogen followed by freeze drying or immediate homogenization in perchloric acid, yielded relatively high and similar values for muscle glycolytic potential.
FACTORS AFFECTING COLOR PROPERTIES OF BEEF PATTIES COOKED ON AN OUTDOOR GAS GRILL
Authors: BERRY B.W. , BIGNER‐GEORGE M.E.
Published: May 2007

Visual and instrumental color properties were obtained on beef patties cooked on an outdoor gas grill. Factors evaluated as to their influence on color were fat content, (20–28% vs 6–10%) patty handling prior to cooking (fresh, thawed either as patties or bulk ground beef), endpoint in cooking (57, 66, 71C, slit in outer edge of patty during cooking showing brown color), lighting conditions and evaluation time post‐cooking. Factors resulting in less pink/red color and more brown color in cooked patties were (1) higher fat content, (2) cooking bulk frozen, thawed, then pattied product, (3) higher endpoint temperature and longer time postcooking before evaluation. Termination of cooking by observing brown color in slits in patties cooked on a gas grill was not synonymous with a safe internal temperature.
SHEAR FORCE ANALYSIS AS AN INDICATOR OF CHANGES IN MECHANICAL STRENGTH OF ISOLATED BEEF INTRAMUSCULAR CONNECTIVE TISSUE DURING AGING
Authors: NORDYKE J.G. , KUBER P.S. , MARTIN E.L. , DE AVILA D.M. , REEVES J.J. , DUCKETT S.K.
Published: May 2007

Intramuscular connective tissue (IMCT) was isolated from bovine semitendinosus (ST) muscles aged 3, 5, 7, 10, 14, 21, 28, and 35 days postmortem. Shear force values were collected from raw ST muscle and IMCT preparations to determine changes in mechanical strength (resistance to shearing) of the connective tissue fibers during postmortem aging. Statistical analysis indicated significant differences in mean shear force values of isolated IMCT preparations between aging periods (P < 0.001) but no consistent pattern of change in shear force values was detected. No significant change in shear force values of raw ST muscle during postmortem aging (P > 0.05) was observed. Other investigators have incorporated the same procedure and reported decreasing shear force values with increased aging times for IMCT preparations and raw ST samples. Our results were not in agreement with these findings.
FAT THICKNESS AND LOIN EYE AREA EFFECTS ON PORK CARCASS QUALITY MEASURES
Authors: PRINGLE T.D. , WILLIAMS S.E.
Published: May 2007

Pork carcasses (n = 133), varying in fatness and muscling, were selected to evaluate the relationship between pork carcass cutability and pork meat quality. Carcasses were selected with three levels of 10th rib fat (TRBF: < 2.03 cm, n = 60; 2.03 ‐ 2.54 cm, n = 31; and > 2.54 cm, n = 42) and three levels of loin eye area (LEA: < 35.5 cm2, n = 33; 35.5 – 41.9 cm2, n = 52; and > 41.9 cm2, n = 48). Data were collected on the longissimus muscle of ribbed carcasses. Carcasses in the leanest TRBF group had less (P < 0.05) marbling, and softer (P < 0.05) and more watery (P < 0.05) lean than the fatter categories. Carcasses in the leanest category were also redder in color (P < 0.05; higher a* values) than the fattest category. Carcasses in the smallest LEA group had higher (P < 0.05) marbling and firmness scores than the largest LEA group and carcasses in the largest LEA group had more (P < 0.05) exudative loin muscles than the remaining LEA groups. Collectively, these data indicate that selection for reduced carcass fatness and increased carcass muscling, in swine, has significant negative effects on pork meat quality.
ELASTIC DEFORMATION IN PROBE MEASUREMENTS ON BEEF CARCASSES
Authors: SWATLAND H.J.
Published: May 2007

Beef carcasses were probed through the forelimb flexors, the triceps brachii, the width of the M. longissimus thoracis et lumborum (LD), and the depth of the LD. The objective was to measure elastic deformation from the distortion of optical signals. Strong reflectance at 550 nm combined with weak ultraviolet fluorescence indicated adipose tissue, while strong reflectance combined with strong fluorescence indicated connective tissue. Connective and adipose tissue peaks were examined relative to depth in the carcass. Elastic deformation was detected when way‐in (insertion) peaks were deeper in the carcass than way‐out (withdrawal) peaks, indicating tissue compression in advance of the probe tip. Connective tissue was deformed more than adipose tissue. Whether or not this method can be used to assess meat softness or tenderness on‐line remains to be seen.
TUMBLING REGIME EFFECTS ON THE PROCESSING CHARACTERISTICS AND TENDERNESS OF COOKED ROAST BEEF
Authors: BOLES J.A. , SHAND P.J.
Published: May 2007

Tumbling prior to injection and different tumbling regimes was investigated to improve the processing characteristics of beef mini roasts. Six inside round muscles (semimembranosus muscle, with adductor and gracilus removed) were cut into six 700 ± 50 g roasts. The roasts were injected 125 or 150% over original weight. The tumbling regime incorporated tumbling prior to injection (pretumbling) and two postinjection tumbling regimes (continuous versus intermittent). Tumbling prior to injection improved (P < 0.05) injection pick up, retention, yield and tenderness, however, with mini roasts there were no differences between continuous and intermittent tumbling. Further research is needed on processing technologies to improve efficiencies in producing these mini roast beef.
THE DEGRADATION OF MYOFIBRILLAR PROTEINS IN BEEF AND LAMB USING DENATURING ELECTROPHORESIS ‐ AN OVERVIEW
Authors: HOPKINS D.L. , THOMPSON J. M.
Published: May 2007

Degradation of specific myofibrillar proteins has been followed in many studies using SDS‐PAGE (denaturing) electrophoresis and these have shown that proteins such as titin, nebulin, troponin‐T, desmin, filamin and vinculin are degraded at different rates during postmortem storage of meat. Although informative, electrophoresis is usually restricted to qualitative interpretation of the gels and there have been few studies that have quantitatively linked the degradation of specific proteins to changes in toughness. Improved quantitative methods (including scanning densitometry, image analysis, and modeling approaches) will be necessary to determine the protein and/or protein alterations that cause postmortem tenderization. This approach is complementary to other measurements of proteolysis where the objective is to more adequately explain the variation in toughness.
THE INFLUENCE OF COMPOSITIONAL CHANGES IN BEEFBURGERS ON THEIR TEMPERATURES AND THEIR THERMAL AND DIELECTRIC PROPERTIES DURING MICROWAVE HEATING
Authors: LYNG J.G. , SCULLY M. , McKENNA B.M. , HUNTER A. , MOLLOY G.
Published: May 2007

This study focused on a microwavable bunburger consisting of a precooked burger in a bread bun. The objective was to assess whether burger formulation changes would affect selected thermal and dielectric properties of the precooked burgers in addition to affecting bunburger temperatures during microwaving. Control burgers and those with elevated fat, water, rusk and salt levels were prepared. Proximal analysis of the raw and precooked burgers revealed a reduction in the fat and moisture content differences following deepfrying. However, burger formulation influenced (P<0.05) the measured thermal and dielectric properties of the precooked burgers in addition to affecting temperatures (P<0.05) from the burger edge and the top and bottom buns. Temperatures from the burger center were not affected (P< 0.05). Adjusting composition does offer the manufacturer a method to alter temperature during microwave heating through the magnitude of the temperature changes observed in this work were small.
RELATIONSHIP OF CHILLING RATE AND LOCATION WITHIN MUSCLE ON THE QUALITY OF HAM AND LOIN MUSCLES
Authors: OHENE‐ADJEI S. , ELLIS M. , McKEITH F.K. , BREWER M.S.
Published: May 2007

Halothane negative Durocs (n=36) were slaughtered, and subjected to: accelerated chill (AC: −30C for 2 h, with air circulation, followed by equilibration at 4C for 20–22 h), conventional chill (CC: 4C for 22–24 h with water sprayed every 2 h until 12 h postmortem), and slow chill (SC: 10–12C for 12 h followed by equilibration at 4C for 10–12 h). Color, pH, and drip loss were determined for the Semimembranosus (SM) Biceps femoris (BF), Longissimus thoracis (LT), and Longissimus lumborum (LL). In the ham muscles, AC decreased b* values and drip loss. Decreased drip loss was restricted to the outer sites. Ham muscles were darkest in the mid location and lightest in the inner locations. In the Longissimus, AC decreased pH but did not affect color or drip loss. Compared to SC, AC proved beneficial, however, AC had no advantages over CC in pigs with minimal predisposition to quality problems.
ENHANCEMENT EFFECTS ON SENSORY AND RETAIL DISPLAY CHARACTERISTICS OF BEEF ROUNDS
Authors: ROBBINS K. , JENSEN J. , RYAN K.J. , HOMCO‐RYAN C. , MCKEITH F.K. , BREWER M.S.
Published: May 2007

Beef round roasts were injected (to 110% of original weight) to result in 0.4% sodium chloride and 0.4% phosphate on a finished weight basis. Steaks from enhanced roasts were more (P<0.05) juicy, tender and salty than those from control roasts. However, enhancement had a detrimental effect on the color of the steaks during retail display. After two days in display, enhanced steaks had lower visual color scores indicating darkening and discoloration. At 4 days, a* and b* values were lower for enhanced steaks indicating that they were less red and yellow than controls. Aerobic plate counts suggested that enhanced steaks were more susceptible to microbial growth during retail display. Although enhancement positively affected sensory characteristics, the negative effect of a shortened shelf‐life was apparent.
WATER‐HOLDING AND COLOR CHARACTERISTICS OF BEEF FROM ELECTRICALLY STIMULATED CARCASSES
Authors: McKENNA D.R. , MADDOCK D. , SAVELL J.W.
Published: May 2007

Electrical stimulation (ES) was applied to the right sides of 15 beef carcasses and the corresponding left sides were used as nonstimulated (NS) controls. Data collected included: postexsanguination pH (0.5, 3, 6, 24 h), L, a, and b color values, drip loss, and expressible moisture. Muscles from ES carcasses tended to have more accelerated postmortem pH declines than the corresponding muscles from NS carcasses. M. triceps brachii had a lower pH at 0.5 h (P < 0.05), M. longissimus thoracis had a lower pH at 0.5 h (P =0.055) and 3 h (P < 0.05), and M. semimembranosus had a lower pH at 0.5 and 3 h (P < 0.05), respectively. Hunter L, a, and b values did not differ within ES and NS treated muscles. Additionally, ES did not influence color values of the M. semimembranosus. ES did not affect drip loss or expressible moisture in beef muscles.
ESTIMATION of MICROBIAL NUMBERS FROM PURE BACTERIAL CULTURES and FROM MINCED BEEF SAMPLES BY REFLECTANCE COLORIMETRY WITH OMNISPECTM 40001
Authors: MANNINEN M.T. , FUNG D.Y.C.
Published: May 2007

Tristimulus reflectance colorimetry (RC) is a rapid method with which microbial activities can be monitored by the mediation of dye pigmentation changes. Dyes that produce color changes because of shifts of pH and oxidation/reduction (O/R) potential or free amino groups can be used.

To estimate total microbial numbers from pure coliform and Listeria cultures and from minced beef samples, the appropriate color endpoint values were selected for each sample type (b*=+2 for coliforms, L*=+ 11 for Listeria, and a*=+ 4 and a*=+ 6 for minced beef samples) and used to estimate color detection times (CDTs). the regression lines of data between aerobic plate count (APC; conventional and also Spiral System with minced beef samples) and RC were calculated. Reliability of the calibration lines was good; r = 0.90–0.99 for bacterial cultures and r = 0.82 (0.80) for minced beef (a*=+ 4) and r = 0.80 (0.78) for minced beef (a*=+6) when RC was compared with APC (Spiral).

The calibration line for minced beef samples (1/10 dilution) could be used to classify samples above and below a certain specified microbial level (e.g., log 6.0 CFU/g) and to marginal samples. Using these scheme with a*=+4 as the color endpoint value, 70% of the tested 40 minced beef samples were correctly classified. the calibration line could also be used to approximate plate count determinations (e.g., CDT of 12 h will result in an estimated count of log 5.9 CFU/g).

Results were obtained in shorter time (ranging from 0–15 h for Enterobacter aerogenes and E. coli, from 2–17 h for H. alvei, from 1.5–25 h for Listeria monocytogenes ATCC 35152 and Scott A, from 6–39 h for slowly growing L. monocytogenes ATCC 19919, and from 2–15 h for minced beef, depending on the initial cell concentration) than required by conventional plate counting (24 h for coliforms, 24–48 h for Listeria, and 48 h for total counts). Time for further confirmation varies according to bacterial species. the RC technique was sensitive for low levels (as low as 1 CFU/mL) of microbes.

Colorimetric microtest plate technology provided in the OmnispecTM Bioactivity Monitor System simplifies the analysis, saves labor and materials, and provides high capacity.
TELLURITE REDUCTION BY FOODBORNE BACTERIA
Authors: PALUMBO S.A. , WILLIAMS A.C.
Published: May 2007

Using an agar overlay technique, we determined that colonies of both Gram‐positive and Gram‐negative bacteria could reduce tellurite. We also observed that under anaerobic conditions, the growth of Gram‐positive bacteria was inhibited if tellurite was present in the plating medium.
COMPARISON of ANALYTICAL SENSITIVITIES of THREE ENZYME IMMUNOASSAY PROCEDURES FOR the DETECTION of SALMONELLA LIPOPOLYSACCHARIDE
Authors: NIELSEN K.H. , TSANG R.S.W.
Published: May 2007

The analytical sensitivities of three different enzyme linked immunoassays (ELISA), two competitive and a capture format were assessed. the assay systems employed monoclonal antibodies to Salmonella lipopolysaccharide (LPS) outer core epitopes to detect crude LPS antigens from Salmonella typhimurium. the most sensitive ELISA was the capture procedure, being capable of detection 1.3 ng/ml of LPS. This technique, however also gave the greatest between‐test variation and as a result, the lowest amount that could be detected with a 95% confidence limit was actually 12.8 ng/ml and it took the longest time to perform (3 h, 30 min). A competitive ELISA using limiting monoclonal antibody to compete between solid phase antigen and soluble antigen in the sample, ranked second in sensitivity, and can detect 2.8 and 3.8 ng/ml of LPS when tested with two different monoclonal antibodies. However, because of the slight between test variation, the actual sensitivities that could be detected with a 95% confidence limit were 3.1 and 4.6 ng/ml, respectively. This test takes approximately 1 h and 30 min to perform.

The classical type of competitive assay, employing a labelled antigen, was the least sensitive being capable of detecting 5.8 ng/ml if the LPS was conjugated with horseradish peroxidase and 16.0 ng/ml if alkaline phosphatase was used as a label. to account for the between‐test variation, the sensitivities with a 95% confidence limit were 8.6 and 18.7 ng/ml for the respective assays, which take 2 h and 15 min to perform.

These sensitivities compare favorably with those published for similar assays, but all of the procedures were judged insufficiently sensitive for direct use on food samples to be tested for the presence of Salmonella species. However, the assays would be quite suitable for demonstration of Salmonella sp. after an enrichment procedure.
EFFECTIVE METHOD FOR DRY INOCULATION of BACTERIAL CULTURES
Authors: HOFFMANS CYNTHIA M. , FUNG DANIEL Y.C.
Published: May 2007

An effective way for inoculation of bacteria into dry foods/ingredients that gives a uniform mixture was developed. In the first part of this experiment, Salmonella typhimurium was successfully inoculated into chalk. Chalk tubes were weighed then soaked in a broth with S. typhimurium and allowed to dry back to their original weight. the dried chalk was made into a powder form. A viable cell count of this chalk, using a selective media for S. typhimurium, showed that the organism survived the drying while entrapped in the chalk. the “charged” chalk was used in an experiment as a dry inoculum where it was mixed with a low‐moisture poultry feed. In comparison to a liquid inoculum, the “charged” chalk was a superior way of inoculating into dry particles because it created a more homogenous mixture with the feed without altering any properties of the feed itself. the second part of this experiment entailed a shelf‐life study of the “charged” chalk. the same procedures for inoculating chalk were done using ten different cultures including Bacillus cereus, Clostridium perfringens, Escherichia coli, Enterobacter aerogenes, Lactobacillus plantarum, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, and Streptococcus faecalis. Data showed that the cultures are stable in the chalk for at least six months.
COMPARISON of FOUR LATEX AGGLUTINATION KITS to RAPIDLY IDENTIFY LANCEFIELD GROUP D ENTEROCOCCI and FECAL STREPTOCOCCI
Authors: KNUDTSON LINDA M. , HARTMAN PAUL A.
Published: May 2007

Enterococci isolated from water (50 strains), clinical material (50 strains), pork products (25 strains), and other foods (25 strains) as well as 50 known strains were used to compare the abilities of four latex streptococcal grouping kits to correctly identify group D isolates. the Streptex kit (Wellcome Diagnostics) was 98.5% accurate and easiest to interpret. the Slidex Strepto kit (Vitek Systems) and Strepslide kit (NCS Diagnostics) also were acceptable; they were 96.5% and 96.0% accurate, respectively. When the Bacto Strep Grouping kit (Difco Laboratories) was used, 99% of the group D isolates were positive for both group D and group B, including enterococcal strains that are group D‐negative.
COMPETITIVE ENZYME IMMUNOASSAY FOR the DETECTION of SALMONELLA LIPOPOLYSACCHARIDE1
Authors: NIELSEN K.H. , TSANG R.S.W. , GARCIA M.M. , SURUJBALLI O. , NEMEC M.
Published: May 2007

A competitive enzyme immunoassay for detection of Salmonella sp. was developed in order to provide a sensitive assay for same‐day identification of Salmonella sp. the assay could be performed in about 90 min and consisted of the following steps. Lipopolysaccharide derived from Salmonella typhimurium was used to passively coat polystyrene 96‐well plates and tubes. A titrated amount of monoclonal antibody specific for an outer lipopolysaccharide core epitope commonly found in Salmoneila sp. was mixed with the prepared test sample prior to adding the mixture to the antigen coated matrix. Antibody bound to the immobilized antigen was detected with horseradish peroxidase labelled goat antimouse IgG (H&L chain).

The analytical sensitivity of the assay was 3.1 ng and 5.6 ng of lipopolysac‐charide per ml for the plate and tube formats, respectively, if 25% inhibition or less was considered negative. This cutoff level was based on reactivity of unrelated monoclonal antibodies with S. typhimurium lipopolysaccharide and lipopolysac‐charide from E. coli with the Salmonella specific monoclonal antibody in the assay.
THE ANTIMICROBIAL PROPERTIES of LYSOZYME ALONE and IN COMBINATION WITH OTHER ADDITIVES IN VITRO and IN SELECTED MEAT PRODUCTS1
Authors: PROCTOR V.A. , CUNNINGHAM F.E.
Published: May 2007

Bactericidal properties of lysozyme alone and in combination with other antimicrobials were studied in vitro using the microtiter system and in hotdogs and hamburger with three pathogens: Salmonella enteriditis or typhimurium, Listeria monocytogenes ATCC# 35152, and Staphylococcus aureus ATCC# 69129. Lysozyme and nisin were found to be effective against L. monocytogenes and were bactericidal in vitro at 9.27 mg/ml and 212.8 μg/ml, respectively. Twelve and one‐half μg/ml nisin and 5 mg/ml lysozyme were synergistic on hotdogs, where they reduced L. monocytogenes counts on MOX agar by 3 log10 cycles on day 1, 3 log10 cycles on day 2, and 2 log10 cycles on day 3. No synergism was found in hamburger. the combinations of 5 mg/ml lysozyme and 12.5 μg/ml nisin and 5 mg/ml lysozyme, 12 μg/ml nisin, and. 02% EDTA acted synergistically on hotdogs to reduce S. aureus counts by 2 and 3 log10 cycles, respectively, over the 3‐day shelf‐life study.
POLYCLONAL ANTIBODIES IN AN ENZYME‐LINKED IMMUNOSORBENT ASSAY (ELISA) TO DETECT BACTERIAL SPORES1
Authors: FOEGEDING P.M. , CHANG Y.H.
Published: May 2007

The feasibility of broad detection of bacterial spores is illustrated using an enzyme linked immunosorbent assay (ELISA). The assay utilized polyclonal antibodies produced by immunizing rabbits and sheep with either inactivated Bacillus cereus T spores or Clostridium sporogenes PA 3679 spores. Using anti B. cereus T spore IgG, the ELISA detected, with varying sensitivity, spores of six Bacillus (including B. megaterium, B. subtilis, B. stearothermophilus, B. coagulans, B. subtilis var. globigii, and one unknown species) and C. botulinum 1304E spores. It did not detect other Clostridium spores (C. botulinum 62A, C. botulinum 12885A, C. botulinum 41B, C. perfringens NCTC8239 and C. perfringens ATCC3624). Using anti‐Clostridium IgG, the ELISA detected C. botulinum 41B but did not detect C. botulinum 62A, 12885A, or 1304E; C. perfringens NCTC8239 or ATCC3624; or spores of six Bacillus species. Vegetative cells did not react in the ELISA. The results suggest it may be feasible to develop a rapid and simple immunologically based test to estimate bacterial spore loads.
EFFECT OF OXYGEN REDUCING MEMBRANE FRAGMENTS ON GROWTH OF CAMPYLOBACTER SPP.1
Authors: NIROOMAND FAHIMEH , FUNG DANIEL Y.C.
Published: May 2007

The effect of different concentrations of Oxyrase in brucella broth supplemented with hematin solution and FBP supplement on growth of five strains of Campylobacter jejuni and one strain of C. coli at 42C under shaking and nonshaking condition was evaluated, and the generation times were calculated. The growth of Campylobacter increased as the amount of Oxyrase (0 to 0.8 unit/ml) in the broth increased. Fastest growth and shortest generation time were achieved with 0.6 unit/ml of Oxyrase in brucella broth both under shaking and nonshaking condition. All strains had higher growth and shorter generation times in the Oxyrase treated samples compared to nontreated controls.

Growth kinetics of 5 strains of C. jejuni and one strain of C. coli (different level of initial population of inocula) in brucella broth with (0.6 unit/ml) and without Oxyrase at 42C in a gyrotory water bath shaker were studied. Growth curves were constructed and generation times were calculated. For all strains, growth rates were significantly (P 0.05) higher and generation times were significantly (P 0.05) shorter in the Oxyrase treated samples (0.6 unit/ml) compared to controls (0 unit/ml). The effect of Oxyrase on growth of Campylobacter strains was more profound at low initial inoculum levels. Oxyrase had a greater stimulatory effect on growth of Campylobacter strains in exponential growth phase than in stationary phase of growth.
RAPID METHODS AND AUTOMATION IN FOOD MICROBIOLOGY: BEYOND DELPHI FORECAST1
Authors: VASAVADA PURNENDU C.
Published: May 2007

Routine microbiological analysis of foods has traditionally involved estimation of the total numbers of organisms by direct microscopy, viable counts or dye reduction, etc. The conventional methods have been fully or partially automated and alternative methods for estimation of microbial populations based on measurement of amplitude of selected parameter(s) have been introduced over the past two decades. The Delphi Technique is a method for technological forecasting helpful in planning future business activities, particularly in the areas of rapid technological development. In 1980–1981, a Delphi survey was conducted to develop a consensus view of future development in rapid and automated methods in food microbiology.

The survey predicted that traditional methods for enumeration organisms in foods, i.e., colony count methods will be superseded by automated and mechanized methods for colony count by the end of the century. However, prediction of acceptance of alternative methodologies for detection and characterization of food‐borne pathogens, including the gene probes and the PCR based methods have been introduced. This presentation is designed to review these new technologies as a summary of this symposium.
COMPARISON OF MODIFIED SALMONELLA‐TEK ENZYME IMMUNOASSAY AND MODIFIED GENE‐TRAK SALMONELLA ASSAY FOR RECOVERY OF SALMONELLA FROM SELECTED LOW‐MOISTURE FOODS
Authors: SHERROD PATRICIA S. , JUNE GERALDINE A. , ANDREWS WALLACE H. , AMAGUANA R. MIGUEL , HAMMACK THOMAS S.
Published: May 2007

The sensitivity of the original versus the modified Salmonella‐Tek enzyme immunoassay (EIA) was compared for recovery of Salmonella spp. from selected low‐moisture foods. Serial tenfold dilutions were inoculated into incubated post enrichment media (dilution‐to‐extinction approach). Results indicated no significant difference between the original and modified Salmonella‐Tek EIAs. A comparison of the modified Salmonella‐Tek EIA and the modified GENE‐TRAK Salmonella assay, using the same approach, also showed no significant differences.

The effectiveness of the assays was then compared using a second approach (dry bulk inoculation). A lyophilized culture was inoculated into bulk food. Replicate 25‐g test portions were used in a 3‐way comparison of the effectiveness of the modified Salmonella‐Tek EIA, the modified GENE‐TRAK Salmonella assay, and the standard culture method approved by the Association of Official Analytical Chemists (AOAC) International and recommended in the Food and Drug Administration's Bacteriological Analytical Manual. Of 460 test portions examined, 307 gave positive reactions with the modified Salmonella‐Tek EIA, 298 with the modified GENE‐TRAK Salmonella assay, and 292 with the AOAC/BAM culture method.
EFFECT OF ALCOHOL‐FLAMING ON MEAT CUTTING KNIVES 1
Authors: FUNG DANIEL Y.C. , PHEBUS RANDALL K. , KANG DONG HYUN , KASTNER CURTIS L.
Published: May 2007

Alcohol‐flaming to sterilize meat cutting knives is a common practice when microbiologically sampling meat surfaces. Often knives will be wiped with paper towels and repeatedly dipped for a short period in alcohol followed immediately by flaming. This investigation addressed the effectiveness of alcohol and alcohol‐flaming for sterilization of cutting knives. Additionally, the effect of high levels of residual meat particles in alcohol used for repeated dipping on sterilization was determined. Stainless steel knives were used to slice ground beef, wiped with a towel, submerged in alcohol for 2 s to 1 h, and flamed (wiping only and alcohol dipping only serving as control samples). Knives were microbiologically evaluated by placing into tubes of standard plate count (SPC) agar or Brain Heart Infusion (BHI) broth. Slight microbial growth was observed for agar and broth tubes from knives dipped into alcohol fór 2 s receiving no flaming. Agar tubes from knives dipped for 2 s to 1 h receiving flaming indicated no growth. The more sensitive broth assay indicated microbial growth in virtually all tubes, however, viable cell counts from these tubes demonstrated very low levels of contamination (1–4 CFU/cm2). Thus, the use of alcohol dipping with or without flaming provided effective microbial destruction on the knives. Knives repeatedly dipped into alcohol containing high levels of residual meat particles and flamed indicated that the alcohol remains an effective means of decontaminating knife surfaces even during prolonged usage.
DETECTION OF CLOSTRIDIUM BOTULINUM TYPE E TOXIN BY MONOCLONAL ANTIBODY ENZYME IMMUNOASSAY
Authors: WONG PHILIP C.K.
Published: May 2007

Botulinum type E toxin is a well recognized causative agent of seafood botulism poisoning. Underprocessing or postretort recontamination of preserved seafoods has resulted in sporadic cases of botulism. Currently, laboratory mice are being used to detect this toxin. However, it requires three to six days to obtain final results. A rapid method using monoclonal antibody (Mab) enzyme immunoassay was therefore developed. Hybridomas secreting specific Mab against the type E epitope were generated by fusion of SP/20‐Ag 14 myeloma cells with spleen cells from BALB/c mice immunized with botulinum type E neurotoxoid. Five potent, stable hybridomas were selected, cloned, propagated, and preserved in liquid nitrogen as cell lines. Immunoglobulin subisotyping showed these Mabs belonged to the IgG subclasses. No cross‐reaction was observed with culture supernatants of C. botulinum types A, B, and F or with crude toxins extracts of type C and D. Large quantities of Mabs were produced in ascites fluids, harvested, and affinity purified. A Mab‐based biotin‐avidin amplified double sandwich enzyme‐linked immunosorbent assay allowed detection of type E toxin in inoculated seafoods at levels equivalent to 1–10 MLDs/ml (5–10 pg/ml).
AN AUTOMATED METHOD FOR QUANTIFYING THE L‐ALANINE TRIGGER OF BACILLUS SUBTILIS SPORE GERMINATION AND COMPETITIVE INHIBITION BY D‐ALANINE
Authors: ROMICK THOMAS L. , THARRINGTON GEORGE
Published: May 2007

We developed an automated method for studying the germination kinetics of Bacillus subtilis spores using a microtiter plate (MP) reader. Phosphate buffer supplemented with L‐alanine was used to isolate the germination phase as determined by decrease in optical density (OD630). Using a standard 96‐well MP, L‐alanine triggered germination kinetics were measured by automatic OD measurement every 3 min until the maximum OD630 change (OD630) was determined. When OD630 values were plotted against L‐alanine concentration on a double reciprocal plot, a straight line (R2= 0.98) was produced. The addition of D‐alanine to the medium demonstrated classical competitive inhibition on double reciprocal plots. A 3‐dimensional representation of the untransformed data showed the response surface nature of competitive inhibition. The method automates the tedious task of determining loss of refractility associated with spore germination under defined conditions so that inhibitors to germination can be studied. Since 96 OD630 determinations can be done simultaneously in small volumes (200 μL) extensive data can be generated about inhibitors using relatively small spore crops in a single, short (1.4 h) incubation.
ELISA FOR DETECTING OKADAIC ACED IN MODEL SYSTEMS USING PURIFIED POLYCLONAL ANTIBODIES
Authors: DIXON LURLENE G. , HAMDY MOSTAFA K. , HAYDEN MARSHA A. , LANCETTE GAYLE A.
Published: May 2007

Polyclonal antibodies were produced in rabbits against okadaic acid (OA) following its coupling to bovine serum albumin using standard carbodiimide condensation procedure to form the immunogen. The immunogen was dialyzed against Tris buffer pH 7.45 at 4C and used to immunize two rabbits. Each rabbit received (at four sites) 0.5 mL immunogen (i.d.) together with adjuvant followed by three repeated injections of 0.3 mL emulsified immunogen‐adjuvant mixture at weekly intervals. The last injection was made 60 days after the fourth. The antiserum was collected, at intervals, the immunoglobulin fraction (IgG) isolated, purified and used in an ELISA system to capture the okadaic moiety of the immunogen. Antibody titers increased following repeated immunization and the IgG recognized low levels of OA. However, ELISA was more sensitive for detecting the immunogen than for pure OA, but using the biotinylated‐IgG enhanced the titration to both and the detection limit for OA was 0.63 ng per 0.1 mL buffer‐methanol and the assay linearity ranged from 0.63 to 5.0 ng OA.
MEDIA SUPPLEMENTATION TO SUPPORT GROWTH OF HELICOBACTER PYLORI1
Authors: GUIMARAES A.G. , FUNG D.Y.C.
Published: May 2007

Growth of Helicobacter pylori is better on solid medium than in liquid medium. This investigation studied the growth of H. pylori in Brain Heart Infusion Broth (BHI) with 10% Fetal Calf (FCS) only, 10% PCS + 0.5 unit/ml OxyraseTM and 0.5 unit/mL OxyraseTM incubated microaerobically and aerobically. High populations (ca. 5.5 log CFU/mL) could be detected in aerobic incubation in broth when OxyraseTM was added. However, in BHI media without OxyraseTM after incubation for 24 h aerobically the numbers of H. pylori decreased from log 7.3 CFU/mL to none detectable. BHI with 10% PCS and BHI were adequate liquid enrichment media for the growth of H. pylori under microaerophilic conditions.
A TWO‐HOUR, SINGLE‐STEP RT‐PCR PROTOCOL FOR DETECTION OF RNA‐VIRUS
Authors: WANG RONG‐FU , CAMPBELL WARREN , CERNIGLIA CARL E.
Published: May 2007

A rapid protocol of RT‐PCR for the detection of RNA‐Virus, Mouse Hepatitis Virus, was developed. An Idaho Air‐Thermal Cycler was used with 5 mM Mg CI2 in the buffer so that both RT and PCR steps can be run in one tube and the total detection time is less than two hours.