bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of left ventricular diastolic function and the Tei index by tissue Doppler imaging in patients with primary hyperparathyroidism
Authors: Baykan Merih , Erem Cihangir , Erdogan Turan , Ersöz Halil Önder , Gedikli Ömer , Korkmaz Levent , Kücükosmanoglu Mehmet , Haclhasanoglu Arif , Kaplan Sahin , Çelik Sükrü
Published: January 2007

Background  The aim of this study was to assess left ventricular (LV) systolic and diastolic function and myocardial performance (the Tei index) by tissue Doppler imaging (TDI) in patients with primary hyperparathyroidism (PHPT).

Methods  We prospectively evaluated 21 patients with PHPT [nine women, 12 men; aged 50 ± 11 years, serum calcium 2·9 ± 0·17 mmol/l, intact PTH (iPTH) 51·5 ± 52·1 pmol/l] and 27 healthy control subjects (13 women, 14 men; aged 49 ± 10 years, serum calcium 2·35 ± 0·12 mol/l, iPTH 2·9 ± 0·9 pmol/l). LV systolic and diastolic function was assessed by conventional echocardiography and by TDI. Early diastolic (Em), late diastolic (Am) and peak systolic (Sm) mitral annular velocities, the ratio Em/Am and the Tei index were calculated from TDI measurements. Mitral inflow velocities, colour M‐mode flow propagation velocity (Vp), relative wall thickness (RWT) and LV mass index (LVMI) were assessed by two‐dimensional echocardiography.

Results  Em and Em/Am were lower in patients with PHPT than in healthy controls (11·2 ± 1·5 cm/s vs. 13·5 ± 2·5 cm/s, P = 0·005; 0·94 ± 0·27 vs. 1·36 ± 0·44, P = 0·02, respectively). In patients with PHPT, the Tei index was significantly higher than that in controls (0·45 ± 13·6 vs. 0·33 ± 8·1, P = 0·02). Peak (E) velocity and the ratio of E to peak late (A) velocity (E/A) were lower in those with PHPT than in those without (59 ± 15 cm/s vs. 72 ± 19 cm/s, P = 0·02; 0·8 ± 0·15 vs. 1·1 ± 0·33, P = 0·001, respectively). Patients with PHPT had significantly higher RWT (0·50 ± 0·02 cm vs. 0·41 ± 0·02 cm, P = 0·0001), isovolumetric relaxation time (IVRT) (115 ± 13 ms vs. 103 ± 11 ms P = 0·04) and A velocity (79 ± 16 cm/s vs. 68 ± 13 cm/s P = 0·05) than controls. Vp was lower in PHPT patients than in healthy subjects (42 ± 9·98 cm/s vs. 54 ± 19·01 cm/s P = 0·04). There were no significant differences between the two groups regarding LV end‐diastolic and end‐systolic dimensions, LVMI, deceleration time of the mitral E wave, Am and Sm.

Conclusion  TDI analysis of mitral annular velocities, Em/Am and the Tei index is useful for assessing LV diastolic dysfunction in patients with PHPT. The parameters obtained from the lateral mitral annulus by TDI can be used for the identification of LV diastolic dysfunction in PHPT patients.
The aryl hydrocarbon receptor‐interacting protein gene is rarely mutated in sporadic GH‐secreting adenomas
Authors: Iwata Takeo , Yamada Shozo , Mizusawa Noriko , Golam Hossain MD. , Sano Toshiaki , Yoshimoto Katsuhiko
Published: January 2007

Background  Recently, germline mutations of aryl hydrocarbon receptor‐interacting protein (AIP) gene located on 11q13 were identified in patients with pituitary adenoma predisposition.

Aim/patients and methods  We investigated the involvement of the AIP gene in one family with isolated familial somatotropinomas (IFS). To investigate the role of AIP in sporadic GH‐secreting adenomas, we first analysed somatic mutations in 40 tumours. Second, DNA from corresponding leucocytes was analysed in tumours showing genetic changes of the AIP gene.

Results  Germline mutation of AIP was found in an IFS family. Bi‐allelic inactivation of AIP by a combination of germline mutation and loss of heterozygosity were confirmed in two pituitary adenomas. Mutation analysis of the AIP gene in the 40 sporadic GH‐secreting adenomas showed no mutations except for a missense mutation, suggesting that germline mutations in patients diagnosed with sporadic acromegaly or gigantism were rare. In a patient with gigantism, a missense mutation of V49M was identified at the germline level.

Conclusion  Based on these results, we conclude that the loss of function of AIP contributes to IFS, but not for most Japanese sporadic GH‐secreting adenomas.
Management options for river conservation planning: condition and conservation re‐visited
Authors: LINKE SIMON , PRESSEY ROBERT L. , BAILEY ROBERT C. , NORRIS RICHARD H.
Published: January 2007

1. Systematic conservation planning is a process widely used in terrestrial and marine environments. A principal goal is to establish a network of protected areas representing the full variety of species or ecosystems. We suggest considering three key attributes of a catchment when planning for aquatic conservation: irreplaceability, condition and vulnerability.

2. Based on observed and modelled distributions of 367 invertebrates in the Australian state of Victoria, conservation value was measured by calculating an irreplaceability coefficient for 1854 subcatchments. Irreplaceability indicates the likelihood of any subcatchment being needed to achieve conservation targets. We estimated it with a bootstrapped heuristic reserve design algorithm, which included upstream–downstream connectivity rules. The selection metric within the algorithm was total summed rarity, corrected for protected area.

3. Condition was estimated using a stressor gradient approach in which two classes of geographical information system Layers were summarised using principal components analysis. The first class was disturbance measures such as nutrient and sediment budgets, salinisation and weed cover. The second class was land use layers, including classes of forestry, agricultural and urban use. The main gradient, explaining 56% of the variation, could be characterised as agricultural disturbance. Seventy‐five per cent of the study area was classified as disturbed.

4. Our definition of vulnerability was the likelihood of a catchment being exposed to a land use that degrades its condition. This was estimated by comparing land capability and current land use. If land was capable of supporting a land use that would have a more degrading effect on a river than its current tenure, it was classified vulnerable (66% of the study area). 79% of catchments contained more then 50% vulnerable land.

5. When integrating the three measures, two major groups of catchments requiring urgent conservation measures were identified. Seven per cent of catchments were highly irreplaceable, highly vulnerable but in degraded condition. These catchments were flagged for restoration. While most highly irreplaceable catchments in good condition were already protected, 2.5% of catchments in this category are on vulnerable land. These are priority areas for assigning river reserves.
Alternative states in the phytoplankton of Lake Kinneret, Israel (Sea of Galilee)
Authors: ROELKE DANIEL L. , ZOHARY TAMAR , HAMBRIGHT K. DAVID , MONTOYA JOSÉ V.
Published: January 2007

1. Through analyses of a 34‐year record of phytoplankton, zooplankton and physicochemical parameters from Lake Kinneret, Israel, we show that distinct and persistent phytoplankton assemblage states occurred from winter to summer.

2. The most obvious characteristic of these states was the presence or absence of a spring bloom of the dinoflagellate, Peridinium gatunense.

3. Analyses of the data within the framework of the alternative states model revealed a possible complex triggering mechanism, and system hysteresis.

4. A change in zooplankton biomass and body size coincident with changes in predation pressure associated with the collapse of the Kinneret Bleak, Acanthobrama terraesanctae, fishery appeared to be the ‘slow changing’ variable in the context of the alternative states model. Alternative phytoplankton states were only possible after this variable crossed a threshold in 1993–94, following the collapse of the fishery.

5. When alternative states were possible, some physicochemical parameters and the structure of the zooplankton assemblage appeared to control which phytoplankton state emerged in a given year. In years without a P. gatunense bloom, important physicochemical parameters in winter included low NO3 loading, high water temperature, high water level, a deeper thermocline, low transparency, high concentrations of NO3 and Cl in the epilimnion, and low concentration of epilimnetic total phosphorus. In addition, the cladoceran Chydorus sphaericus and adults of the copepod Mesocyclops ogunnus were observed in winter in years without a bloom.

6. Zooplankton biomass and body size of some taxa have recovered since the 1993–94 collapse of the fishery, yet incidence of both phytoplankton states in Lake Kinneret was still possible. Within the framework of the alternative states model, this suggests that the slow changing variable threshold where alternative states became possible is different from the threshold where alternative states will no longer be possible. In other words, the system is characterised by a hysteresis.
Riverine invertebrate assemblages are degraded more by catchment urbanisation than by riparian deforestation
Authors: WALSH CHRISTOPHER J. , WALLER KYLIE A. , GEHLING JANELLE , NALLY RALPH MAC
Published: January 2007

1. Restoration of riparian forests has been promoted as a means of mitigating urban impacts on stream ecosystems. However, conventional urban stormwater drainage may diminish the beneficial effect of riparian forests.

2. The relative effects of riparian deforestation and catchment urbanisation on stream ecosystems have rarely been discriminated because urban land use and riparian degradation usually covary. However, land use at three scales (channel canopy cover along a 100‐m site, riparian forest cover within 200 m of the channel for 1 km upstream, and catchment imperviousness) covaried only weakly along the lowland Yarra River, Victoria, Australia.

3. We tested the extent to which each land use measure explained macroinvertebrate assemblage composition on woody debris and in the sediments of pools or runs in the mainstem Yarra River in autumn and spring 1998.

4. Assemblage composition in both habitats and in both seasons was most strongly correlated with proportion of catchment covered by impervious surfaces. Sites with higher imperviousness had fewer sensitive taxa (those having a strong positive influence on indicators of biological integrity) and more taxa typical of degraded urban streams. Sensitive taxa rarely occurred in sites with >4% total imperviousness. However, within sites of similar imperviousness, those with more riparian forest cover had more dipteran taxa. Channel canopy cover did not explain assemblage composition strongly.

5. Riparian forest cover may influence richness of some macroinvertebrate taxa, but catchment urbanisation probably has a stronger effect on sensitive taxa. In catchments with even a small amount of conventionally drained urban land, riparian revegetation is unlikely to have an effect on indicators of stream biological integrity. Reducing the impacts of catchment urbanisation through dispersed, low‐impact drainage schemes is likely to be more effective.
Precipitation pulses and soil CO2 flux in a Sonoran Desert ecosystem
Authors: SPONSELLER RYAN A.
Published: January 2007

Precipitation is a major driver of biological processes in arid and semiarid ecosystems. Soil biogeochemical processes in these water‐limited systems are closely linked to episodic rainfall events, and the relationship between microbial activity and the amount and timing of rainfall has implications for the whole‐system carbon (C) balance. Here, the influences of storm size and time between events on pulses of soil respiration were explored in an upper Sonoran Desert ecosystem. Immediately following experimental rewetting in the field, CO2 efflux increased up to 30‐fold, but generally returned to background levels within 48 h. CO2 production integrated over 48 h ranged from 2.5 to 19.3 g C m−2 and was greater beneath shrubs than in interplant spaces. When water was applied on sequential days, postwetting losses of CO2 were only half a large as initial fluxes, and the size of the second pulse increased with time between consecutive events. Soil respiration was more closely linked to the organic matter content of surface soils than to rainfall amount. Beneath shrubs, rates increased nonlinearly with storm size, reaching an asymptote at approximately 0.5 cm simulated storms. This nonlinear relationship stems from (1) resource limitation of microbial activity that is manifest at small time scales, and (2) greatly reduced process rates in deeper soil strata. Thus, beyond some threshold in storm size, increasing the duration or depth of soil moisture has little consequence for short‐term losses of CO2. In addition, laboratory rewetting across a broad range in soil water content suggest that microbial activity and CO2 efflux following rainfall may be further modified by the routing and redistribution of water along hillslopes. Finally, analysis of long‐term precipitation data suggests that half the monsoon storms in this system are sufficient to induce soil heterotrophic activity and C losses, but are not large enough to elicit autotrophic activity and C accrual by desert shrubs.
Applicability of Time‐Temperature Indicators as Shelf Life Monitors of Food Products
Authors: TAOUKIS P.S. , LABUZA T.P.
Published: January 2007

A systematic approach that allows the correlation of the response of a Time‐Temperature Indicator (TTI) to the consumed and remaining shelf life of a food product exposed to the same variable temperature conditions was developed. The approach was based on kinetic principles and is applicable to a TTI‐food system without necessitating side by side testing. The applicability of three major TTI types to the developed scheme was studied. Experiments under several isothermal conditions were conducted and kinetic parameters for the three TTI were determined. All TTI showed an Arrhenius temperature dependence and their calculated activation energies ranged from 10 to 40 kcal/mol.
Reliability of Time‐Temperature Indicators as Food Quality Monitors Under Nonisothermal Conditions
Authors: TAOUKIS P.S. , LABUZA T.P.
Published: January 2007

Application of time temperature indicators (TTI) is based on response information or kinetic models from isothermal testing. The reliability of such models under variable temperature conditions was systematically studied. Nonisothermal experiments of two types were conducted involving prolonged exposures to high temperatures followed by storage at low temperatures to study the “history effect,” and storage at controlled, sinusoidaly varying temperatures. Three major types of commercial TTI were studied. Results showed that, although some types of TTI exhibit a significant “history effect,” the prediction models can be applied satisfactorily for the variable temperature storage.
Total Sterols in Seafoods: Iatroscan TLC/FID Versus the Kovacs GLC/FID Method
Authors: WALTON C. G. , RATNAYAKE W. M. N. , ACKMAN R. G.
Published: January 2007

THE TOTAL STEROLS of selected seafood samples were determined, after saponification, by latroscan TLC/FID and the results were compared with those obtained by the more common technique of gas‐liquid chromatography which gives individual sterols. No significant difference was found between the techniques in terms of quantitative accuracy for total sterols. In many products the sterol compositions were known or specific compositional details were not important. Thus, in most finfish and Crustacea species, cholesterol constituted over 90% of the sterols and, therefore, the Chromarodlatroscan TLC/FID with or without inclusion of an internal standard would give an accurate estimation of the cholesterol in fish products.
Paramyosin‐Myosin‐Actin Interactions in Gel Formation of Invertebrate Muscle
Authors: SANO TAKESHI , NOGUCHI SATOSHI F. , TSUCHIYA TAKAHIDE , MATSUMOTO JUICHIRO J.
Published: January 2007

Even when actomyosin dissociated into myosin and actin in the paramyosin‐natural actomyosin system, the indices of gel properties increased on increasing the paramyosin content; however, their increases were smaller. Also, in the paramyosin‐myosin system gels, the indices of gel properties increased on increasing the paramyosin content; however, the increases were smaller than those for the paramyosin‐natural actomyosin system gels. In both systems, a high linearity was observed between each index of gel properties and paramyosin. It was likely that the paramyosin‐myosin interaction did not bring about the characteristic texture of invertebrate muscle gel directly, but the binding of myosin and actin might be indispensable if the contribution of paramyosin was to occur.
Role of F‐actin in Thermal Gelation of Fish Actomyosin
Authors: SANO TAKESHI , NOGUCHI SATOSHI F. , MATSUMOTO JUICHIRO J. , TSUCHIYA TAKAHIDE
Published: January 2007

The thermal gelation processes of the myosin‐natural actomyosin system were investigated to determine the role of F‐actin in thermal gelation of actomyosin. The dynamic viscoelastic behavior during thermal gelation changed considerably depending on the (F‐actin)/ (myosin) ratio. F‐actin gave the viscosity to an actomyosin sol but did not affect the elasticity development occurring in the 30 ‐ 46°C range. The decrease in storage modulus in the 46 ‐ 53°C range was directly induced by the presence of F‐actin. The gel of myosin alone showed the highest elasticity, while that of myosin containing a small amount of F‐actin had the highest elastic modulus.
Heat‐induced Gelation of Minced Rainbow Trout (Salmo gairdneri:) Effect of pH, Sodium Chloride and Setting
Authors: AUTIO K. , KIESVAARA M. , POLVINEN K.
Published: January 2007

The structure formation of minced rainbow trout was monitored during heating from 30°C to 85°C by a dynamic rheological method. The maxima of storage modulus (G') were found at 37°C and in the range of 45°C to 60°C. The largest differences in rigidity resulted from seasonal variations. Firmest protein matrix was obtained by using well‐fed fish as raw material, by setting the gels at 35°C and using a pH value around 6.1. Sodium chloride in the range 1–2% had little effect on the final rigidity of the minced rainbow trout gels.
Lipid Peroxidation Protection Factors in Rainbow Trout (Salmo gairdnerii) Muscle Cytosol
Authors: HAN T.J. , LISTON J.
Published: January 2007

Two types of lipid peroxidation protection factors were found in rainbow trout white muscle cytosol. One type of protection factor is heat‐labile and nondialyzable. This type of protection factor could be superoxide dismutase, catalase, or a yet uncharacterized proteinaceous factor. The other type is heat‐resistant but dialyzable. Iron chelating reagent, such as inorganic phosphate could belong to this type of protection factor. Both types are glutathione (GSH)‐independent and preserve polyunsaturated fatty acid in fish muscle microsomes. This indicates that these protection factor are able to prevent the initiation of lipid peroxidation of polyunsaturated lipids.
Denaturation of Cod Myosin during Freezing after Modification with Formaldehyde
Authors: ANG JIT F. , HULTIN HERBERT O.
Published: January 2007

Formaldehyde at concentrations occurring in frozen fish increased the extent of denaturation as measured by loss in solubility, decrease in ATPase activity and increase in surface hydrophobicity, of partially purified cod myosin stored at ‐25°C or ‐80°C. Most denaturation occurred during the freezing/thawing process. Formaldehyde caused some crosslinking of myosin, but crosslinking and insolubilization appeared to be relatively independent. The presence of diamines led to some increase in crosslinking but had little effect on protein solubility.
Changes in Electrophoretic Patterns of Gadoid and Non‐gadoid Fish Muscle during Frozen Storage
Authors: RAGNARSSON KARL , REGENSTEIN JOE M.
Published: January 2007

Sodium dodecyl sulfate polyacrylamidc gel electrophoresis of fish muscle during frozen storage showed that a crosslinked protein of 280,000 daltons formed with gadoids, whereas this band did not occur with non‐gadoid fish species. For cod, 20 days at ‐7°C are needed for the crosslink to appear, whereas for whiting only 3 days arc needed. Formaldehyde (FA) may be responsible for the crosslinking. Adding ascorbic acid to cod mince prior to freezing accelerated dimcthylamine and FA formation during frozen storage and accelerated the formation of the crosslinked protein, while leaving cod fillets on ice for 10 days prior to freezing, reduced the Instron hardness and the crosslinked protein did not appear with 50 days of frozen storage at ‐7°C.
Texture Changes of Frozen Stored Cod and Ocean Perch Minces
Authors: HSIEH YIN LIANG , REGENSTEIN JOE M.
Published: January 2007

During frozen storage, minced cod and ocean perch were examined by expressible moisture (EM), water binding potential (WBP) and computerized texture profile analysis (TPA). The results suggested that a microcomputer interfaced with the Instron efficiently performed TPA. The texture and water loss of all fish minces changed more rapidly at ‐7°C storage than at ‐20°C and ‐40°C. Furthermore, cod, a gadoid with the ability to degrade trimethylamine oxide to dimethylamine and formaldehyde, deteriorated faster than ocean perch, which did not have this ability. EM was useful for examining the water loss of frozen fish at ‐ 7°C only during the first two weeks of storage. The WBP at ‐7°C storage showed a good correlation with storage time for cod and ocean perch. This suggests that WBP might be a good indicator for examining water holding ability of fish proteins.
Separation of Cod (Gadus morhua) Fillet Proteins by Electrophoresis and HPLC after Various Frozen Storage Treatments
Authors: LeBLANC EILEEN L. , LeBLANC RAYNALD J.
Published: January 2007

Myofibrillar, sarcoplasmic (SAR) and total extractable proteins (TEP) were isolated from the same lot of frozen cod (Gadus morhua) fillets stored at ‐30°C, ‐22°C, ‐15°C, and ‐12°C and a simulated industrial fluctuating temperature (SIFT) program. HPLC and SDS‐PAGE showed that myofibrillar and SAR of the fillets stored at ‐12°C and ‐15°C exhibited low and high molecular weight changes similar to the SIFT. A new indicator of myofibrillar frozen storage quality was developed using SDS‐PAGE. TEP profiles by HPLC were time and temperature dependent. These observations by SDS‐PAGE and HPLC were further evidence that changes in frozen stored cod muscle were partially due to covalent S‐S crosslinking.
Microbiological Studies of the Cause of Discoloration of Common Dolphin (Coryphaena hippurus) Fillets
Authors: CHEN H.C. , HU C.C.
Published: January 2007

The effect of killing method of common dolphins aboard vessels on green pigment formation, and the microbiological survey of the green meat were studied. Eight bacterial strains which produced H2S in peptone iron agar at both 4 and 25°C were isolated from green meat samples. They constituted one strain of Alteromonas putrefaciens and seven strains of Proteus vulgaris. Discoloration occurred when each of the eight isolates was reinoculated in normal fillets at 4°C. The bleeding operation has little effect on reducing green discoloration of the dolphen meat. Discoloration of the meat could be prevented by icing the fish and keeping them cold until they could be filleted and frozen.
Selection of Mixed Cultures for Meat Fermentation
Authors: HOULE J.‐F. , LAFRANCE M. , JULIEN J.‐P. , BROCHU E. , CHAMPAGNE C.P.
Published: January 2007

Strains of Pediococcus cerevisiae, Pediococcus acidilactici, Lactobacillus plantarum, Lactobacillus casei and Micrococcus varians were studied with the aim of preparing mixed cultures of compatible strains for meat fermentations. Addition of 0.18% nitrite was slightly inhibitory while addition of 7% of a spice mix proved stimulatory. Antibiosis was observed between lactobacilli and pediococci. Micrococcus varians did not produce inhibitory substances toward other cultures and was insensitive to bacteriocins produced by the lactobacilli or the pediococci. Antibioses observed using disk assays were confirmed in mixed acidification trials, and mixes of some fast‐acidifying strains were unsuccessful.
Effects of Blade Tenderization, Vacuum Massage Time and Salt Level on Chemical, Textural and Sensory Characteristics of Precooked Chuck Roasts
Authors: SHACKELFORD S. D. , REAGAN J. O. , MANN T. F. , LYON C.E. , MILLER M. F.
Published: January 2007

The influence of blade tenderization (T), vacuum massage time (2, 3 hr) and salt level (SL) (1.0, 1.25%) on the chemical, textural, and sensory characteristics of precooked chuck roasts prepared from Triceps brachii (TRI) and Supraspinatus (SUP) muscles was investigated. Cooking losses decreased and total yields increased with higher SL, while T increased product fat content. T decreased Warner‐Bratzler shear values for the bind site (junction between the two muscles) and the edge of the roast. Instron values for hardness and chewiness of the muscle tissue were decreased by blade tenderization. Sensory panel evaluation showed that TRI had a more intense beef flavor and was more tender than SUP, while T improved first impression tenderness.
Lipid Oxidation and Sensory Analysis of Cooked Pork and Turkey Stored under Modified Atmospheres
Authors: NOLAN NANCY L. , BOWERS JANE A. , KROPF D. H.
Published: January 2007

Precooked pork and turkey were stored at 4°C for 18 hr and at ‐ 20°C for 3 months in vacuum and in atmospheres of air, carbon dioxide, and nitrogen. For both short‐term refrigerated storage and long‐term frozen storage, vacuum‐packaging of precooked turkey and pork resulted in more meaty and less warmed‐over flavor and aroma than the other packaging treatments. Samples stored in carbon dioxide and nitrogen atmospheres were less “oxidized” as indicated by sensory scores and TBA values than those stored in air but were more “oxidized” than vacuum‐packaged meat. Warmed‐over and rancid flavor and aroma scores correlated highly and consistently with TBA values, but inconsistently with the less sensitive fluorescence method. Vacuum‐packaged turkey was darker and redder than other samples after frozen storage.
Effect of Heating Rate and Protein Concentration on Gel Strength and Water Loss of Muscle Protein Gels
Authors: CAMOU J.P. , SEBRANEK J.G. , OLSON D.G.
Published: January 2007

The effects of heating rates (17, 38 and 85°C/hr) and protein concentration (10, 20, 30, 40, and 50 mg/mL) on gels made of extracted salt‐soluble proteins were evaluated. Gel strength decreased when heating rate was increased. A greater water loss from compressed gels occurred at protein concentrations of 10 and 20 mg/mL than at 30 to 50 mg/mL Protein loss in the expelled water, after compression, was less for the slower heating rates while the total amount of protein in the expelled water increased with increasing protein concentration in the system. SDS gel electrophoresis demonstrated a change in some of the expelled proteins at different heating rates.
Improved Tenderness of Restructured Beef Steaks by a Microbial Collagenase Derived from Vibrio B‐30
Authors: MILLER A.J. , STRANGE E.D. , WHITING R.C.
Published: January 2007

To reduce connective tissue toughness Vibrio B‐30 collagenase was evaluated for its ability to degrade muscle collagen in a restructured beef (RSB) product. Dissected muscles pooled from clods of 4 USDA choice chucks were made into three RSB products: untrimmed control (C), hand trimmed of epimysium (T) and untrimmed and treated with 0.01% collagenase (E). RSB products were held for 24 hr at either 2°C or 11°C and were analyzed cither raw or after heating (40°C for 1 hr). Aerobic microbial load remained low (1–2X102 cfu/g) during the 24 hr 11°C incubation. Heated samples of enzyme treated RSB had lower Lee‐Kramer shear values than controls. In both raw and heated samples enzyme treatment increased hydroxyproline solubility. An enzyme treatment of 24 hr at 11°C followed by heating produced maximum tenderization. Although optimum treatment conditions need to be defined by further research, Vibrio B‐30 collagenase appeared to be efficacious for the tenderization of RSB products.
Improvement of Pigment and Lipid Stability in Holstein Steer Beef by Dietary Supplementation with Vitamin E
Authors: FAUSTMAN C. , CASSENS R.G. , SCHAEFER D.M. , BUEGE D.R. , WILLIAMS S.N. , SCHELLER K.K.
Published: January 2007

Pigment and lipid oxidation was investigated in fresh ground sirloin from control and vitamin E‐supplemented (370 I.U./head/day) Holstein steers. Alpha‐tocopherol levels were higher (P<0.05) in muscle from supplemented animals than from controls. During 6 days storage at 4°C, metmyoglobin accumulation and lipid oxidation (TBA) were greater (P<0.05) in beef from control versus supplemented animals. TBA value and % metmyoglobin were highly correlated in the control (r = 0.91) and supplemented (r = 0.72) groups. TBA values of cooked sirloin slices subsequently stored for 2 days at 4°C, and for frozen ground sirloin patties stored at ‐18°C for 1.5 and 3 months, were lower (P<0.05) in beef from supplemented animals than from controls. Meat which contained in excess of ca. 0.3 mg α‐tocopherol/100 g tissue displayed the least oxidation of both pigments and lipids.
Film Sealant and Vacuum Effects on Two Measures of Adhesion at the Sealant‐Meat Interface in a Cook‐in Packaging System for Processed Meat
Authors: ROSINSKI M.J. , BARMORE C.R. , DICK R.L. , ACTON J.C.
Published: January 2007

The adhesion of meat to five chemically different plastic sealant materials was determined for a vacuum‐packaged, cook‐in‐the‐film, processed meat product. Measures of adhesion strength at the sealant‐meat interface and quantity of film residue deposits resulting from adhesion were evaluated for product initially vacuum‐packaged at 63.5, 69.8 or 75.9 cm Hg. Films with nylon, nylon‐Surlyn blend or Surlyn sealants had higher adhesion strengths at each vacuum level compared to films with sealants of linear low density polyethylene or polypropylene. Adhesion strengths and quantities of residue generally decreased with increases in vacuum although individual sealant responses differed due to vacuum when adhesion was measured by meat residue deposits left on the film.
Emulsion Stability and Sensory Quality of Beef Frankfurters Produced at Different Fat or Peanut Oil Levels
Authors: MARQUEZ E.J. , AHMED E.M. , WEST R.L. , JOHNSON D.D.
Published: January 2007

Frankfurters were produced at 12, 20 and 29% fat levels using beef fat or 60% substitution with peanut oil. Less emulsion stability, lower smokehouse yield and lower sensory juiciness scores were found as final fat content of beef frankfurters was lowered to 12%. Firmness, darkening of external color, and flavor intensity were enhanced in the low fat product. Frankfurters with 60% fat as peanut oil exhibited comparable emulsion stability and sensory quality parameters with no rancid flavor development over a period of 6 weeks at 4°C. They were as acceptable to sensory panels as the 29% beef fat frankfurters. Substitution of 60% of the beef fat with peanut oil resulted in a product with significantly (P < 0.05) less cholesterol content.
Effect of Storage Temperature, Time, and Method of Slicing on Microbial Population and White Film Development in Vacuum Packaged, Dry‐Cured Ham Slices
Authors: KEMP J.D. , LANGLOIS B.E. , AKERS K. , AARON D.K.
Published: January 2007

Aged ham slices, bone‐in or boneless, were vacuum‐packaged and stored at 2°C or 24°C for 8 wks. White film was more abundant on bone‐in slices. Color was not affected by treatment. Aroma remained normal at 2°C for all slices but abnormal aromas developed in some 24°C packages by 2 wk and in all packages by 8 wk. Aerobic and staphylococci counts on bone‐in and boneless slices at 24°C were high at 2 wk and remained high, while lactobacilli counts were highest at 2 wk, decreased to initial levels by 4 wk and increased again to 8 wk. Yeast and mold counts at both temperatures decreased with storage but at a faster rate in bone‐in hams.
Effects of Prolonged and Adverse Storage Conditions on Levels of Cholesterol Oxidation Products in Dairy Products
Authors: SANDER B.D. , SMITH D.E. , ADDIS P.B. , PARK S.W.
Published: January 2007

The effects of normal and adverse environmental holding conditions on the formation of cholesterol oxidation products (COPS) in powdered cheeses and salted and unsalted butteroil were investigated. Little or no change in COPS levels was noted in a variety of powdered dairy products stored at 4, 21, or 38°C for up to 6 months. Storage for 18 mo at 4°C resulted in a three‐fold increase in the levels of COPS. Cheddar cheese powder continuously exposed to light (1611 lx) displayed increases in α‐epoxide and 7‐ketocholesterol through week 3, thereafter declining to a level at week 9 of about one‐half of that seen at week 3. Continuous heating of butteroil (110°C) caused large increases in COPS' levels, with unsalted butteroil exceeding levels found in salted butteroil by 2‐ to 3‐fold.
Development of Hydrolyzed and Hydrolyzed‐lsomerized Syrups from Cheese Whey Ultrafiltration Permeate and Their Utilization in Ice Cream
Authors: ARNDT E. A. , WEHLING R. L.
Published: January 2007

Hydrolyzed lactose syrup (HLS) was produced from cheese whey ultrafiltration permeate by treatment with immobilized β‐galactosidase, deionization, and evaporation. The degree of hydrolysis was 97.2%. Hydrolyzed‐isomerized lactose syrup (HILS) was produced from hydrolyzed, deionized ultrafiltration permeate by treatment with immobilized glucose isomerase, deionization and evaporation. The degree of isomerization was 34.8%. HLS and HILS were substituted for 25% or 50% of the sucrose (on a solids basis) in vanilla ice cream. The mix freezing time increased when HLS or HILS was substituted for sucrose at a level of 50%. There were no significant differences in melting rates (P < 0.05) and few differences in sensory quality.
Evolution of Free Amino Acids during the Ripening of Cheddar Cheese Containing Added Lactobacilli Strains
Authors: PUCHADES R. , LEMIEUX L. , SIMARD R.E.
Published: January 2007

Cheddar cheese was produced with different lactobacilli strains added to accelerate ripening. The concentration of proteolytic products was determined as free amino acids in the water‐soluble fraction at two, four, seven and nine months of aging and at two different maturation temperatures (6°C, 15°C). All amino acids increased during ripening and were higher in the Lactobacillus‐ added cheeses than in the control cheese, and higher in cheeses ripened at 15°C than at 6°C. Glutamic acid, leucine, phenylalanine, valine and lysine were generally in higher proportion in all cheeses. The cheeses with added L. casei‐casei L2A were classified as having a “strong Cheddar cheese” flavor after only seven months of ripening at 6°C.
Radiolabelling Study of the Heat‐induced Interactions Between α‐Lactalbumin, β‐Lactoglubulin and K‐Casein in Milk and in Buffer Solutions
Authors: NOH BONGSOO , RICHARDSON TOM , CREAMER LAWRENCE K.
Published: January 2007

Radiolabeled α‐lactalbumin, β‐lactoglobulin and κ‐casein were added to milk prior to heating it at 95°C for up to 20 min. The distribution of these proteins between the micellar and serum phases and between various sized aggregates were determined chromatographically. The results from these and other supplementary experiments were consistent with a model of whey proteins denaturing in milk during heat treatment and using κ‐casein as a nucleation site for the formation of heat‐induced complexes involving disulfide bonding. These heat‐induced complexes, like κ‐casein itself, remained associated with the external surface of the casein micelle and continued to enlarge with additional heat treatment.
Rheological Changes During Slow Acid Induced Gelation of Milk by D‐glucono‐δ‐lactone
Authors: KIM BYUNG Y. , KINSELLA JOHN E.
Published: January 2007

Alteration in the rheological behavior of milk during acidification were studied. Structure formation during gelling was monitored by a small strain rheological scanner. Dynamic viscoelastic properties were monitored as a function of time and temperature. Time of onset of gelation, rate of network formation and development of the elastic component during acidification were accelerated at higher temperatures (55°C). Addition of calcium (0–40 mM) facilitated gelation. Preheating milk at 90°C for 5 min prior to acidification enhanced gelation and induced protein‐protein network formation. The number or strength of elastically effective bonds between protein molecules were reduced and gels of lower firmness were obtained with preheated milk, compared to gels made from unhealed milk.
Stabilization of Lactase (Escherichia coli) by Milk Components and Related Compounds
Authors: MAHONEY R.R. , WILDER T.
Published: January 2007

Thermal stability of lactase was 170‐fold greater in milk than in phosphate buffer at 60°C. Enhanced stability was due primarily to casein, whose effect was largely substrate dependent. Casein or lactose alone had little or no effect, but together they stabilized the enzyme more than 400‐fold at 60°C. The relative effectiveness of other proteins, as stabilizers, was: bovine serum albumin >caseinate>ovalbumin>soy isolate>α‐lactalbumin>lysozyme. Galactose was much less effective than lactose in promoting stability; sucrose and glucose were ineffective. Stability was dependent upon both lactose concentration and casein concentration, and decreased with increasing enzyme concentration. Dithioerythritol increased stability in buffer but had relatively little effect in milk.
Salmonella Inactivation in Liquid Whole Egg by Thermoradiation
Authors: SCHAFFNER D.F. , HAMDY M.K. , TOLEDO R.T. , TIFT M.L.
Published: January 2007

Salmonella enteritidis in liquid whole egg (LWE) was inactivated using heat, radiation and thermoradiation (combined heat and radiation). Rates of Salmonella inactivation were determined as a function of radiation dose, temperature, initial cell number and pH. Thermoradiation caused a greater reduction in viable cell number than either heat or radiation alone. This effect was more pronounced at pH 6.5 than at pH 7.0, and more so at 60°C than at 50°C. The lower the initial cell number, the faster the rate of Salmonella inactivation. Physical denaturation of LWE was not apparent after thermoradiation below 60°C, and endogenous egg white lysozyme was not affected by thermoradiation (19.5 krad, 60°C) treatment.
Thermal Denaturation of Hen Egg White Studied by Chromatographic and Immunochemical Techniques
Authors: SAJDOK JIR̂Í , POŽÁRKOVÁ DANA , RAUCH PAVEL , KÁŠ JAN
Published: January 2007

The course of thermal denaturation of hen egg white at 70°C was studied in detail by fast gel chromatography on Superose 12 and by immunochemical techniques. The mechanism of thermal denaturation differed depending on the pH of the environment. The aggregation of protein at the beginning of heat treatment was typical at pH 5 while at pH 9 the breakdown to smaller fragments prevailed. The chromatographic method for the determination of thermally undamaged (native) ovalbumin correlated well with the immunochemical method.
1H and 23Na NMR Relaxation Studies of the NaCl/β‐Lactoglobulin System Equilibrated at Various Water Activities
Authors: FANNI J. , CANET D. , ELBAYED K. , HARDY J.
Published: January 2007

NMR relaxation times (T1) of 1H and 23Na were determined at 8, 14, 60, MHz and at 14, 52 MHz, respectively, in the NaCl/β‐lactoglobulin system equilibrated at water activities ranging from 0.11 to 0.97. A two‐state model was used for both nuclei which allowed the calculation of proportions of bound and free species. It was shown that bound water and Na+ increased at medium water activities in the presence of increasing NaCl. The discrepancy with adsorption isotherms data was explained by (1) limitations of the mass balance equation used to calculate interacting salt by gravimetry and (2) the fact that NMR probed the totality of ions in the vicinity of the protein, whereas adsorption isotherms were indicative of sodium choride tightly bound to the protein. It was also shown that the protein and Na+ shared available water molecules at medium and low water activity.
Effect of Water Activity aw of Milk on acid Production by Streptococcus thermophilus and Lactobacillus bulgaricus
Authors: LARSEN RAÚL F. , AÑÓN MARÍA CRISTINA
Published: January 2007

Rate of acid production by Lactobacillus bulgaricus ATCC 11842 and Streptococcus thermophilus ATCC 19258 was measured at temperatures between 30°C and 50°C in milks which had been adjusted from 0.992 to 0.943 aw with glycerol. Data were fitted with a nonlinear mathematical model of the Arrhenius type. Decrease of aw inhibited acid production by both organisms. Range of temperatures, within which the rate of acid production was higher than 50% of the optimal rate, was also narrowed with both species. Optimal temperatures of acid production were unaffected by changes of aw. Minimum aw for acid production was always lower when aw of milk was adjusted with glucose or sucrose than with glycerol.
Interaction of Antibiotics and Water Activity on Streptococcus thermophilus and Lactobacillus bulgaricus
Authors: LARSEN RAÚL F. , AÑÓN MARÍA CRISTINA
Published: January 2007

Acid production was determined in cultures of Streptococcus thermophilus and Lactobacillus bulgaricus in the presence of penicillin and gentamycin in milks with water activity adjusted between 0. 992 and 0.943 by adding glycerol, glucose or sucrose. Resistance of S. thermophilus A TCC 19258 and CRL 410 to penicillin increased when aw was lowered with glycerol from 0.992 to 0.995, and from 0.992 to 0.985 in L. bulgaricus ATCC 11842. Susceptibility to gentamycin increased in both species with reduction of aw. Susceptibility of S. thermophilus CRL 410 to penicillin increased in most cases when aw was adjusted with glucose, while acid production at a aw of 0.985 was always higher than that of the controls (aw 0.992) when sucrose was used. With L. bulgaricus CRL 420, lower acid production was observed at all penicillin concentrations, whether glucose or sucrose was used as the humectant.
A Factorial Approach to Modeling aw of a Multicomponent Food in the High Moisture Range (aw 0.90–1.00)
Authors: NIETO M.B. , TOLEDO R.T.
Published: January 2007

Water activity (aw) depression in a multicomponent food such as fish sausage was investigated using a 4x3x3 factorial design on combinations of NaCl, nonfat dry milk (NFDM) and lard added to a fixed amount of minced fish. The effects of NaCl, NFDM, lard and the interaction NaCl x NFDM, were significant. The responses across levels of the above factors were linear. From the magnitude of effect of each factor, two extended models for predicting aw were derived in terms of molal salt concentration and two empirical parameters called water activity depressing capacity, di, and water binding capacity, WBC, respectively. Both were demonstrated to predict accurately aw of newly formulated fish sausage.
Activity and Mobility of Water in Sweetened Whole Soy Concentrates and Their Rheological Properties
Authors: KHAN RAFIULLAH , STEHLI D. , WEI L.S. , STEINBERG M.P.
Published: January 2007

Intermediate moisture systems were formulated with dehulled, blanched soybeans and four nutritive sweeteners (sucrose, glucose, fructose, sucrose/glucose). Soy content and sucrose/water ratio were varied. Water activity, water mobility (NMR) and rheological properties were determined. All three parameters were strongly influenced by the sweetener. All samples showed non‐Newtonian behavior. Soy content and sucrose/water ratio had a stronger influence on rheology than on water properties.
Combined Effect of Sucrose and Heat Treatment Temperature on the Thermal Resistance of Staphylococcus aureus MF‐31
Authors: TUNCAN ERDAL U. , MARTIN SCOTT E.
Published: January 2007

The combined effect of sucrose and heat treatment temperature on the thermal resistance of Staphylococcus aureus MF‐31 was examined by determining the relationships between the D value, temperature and each of three parameters (water activity, osmotic pressure and water binding energy) related to sucrose‐water binding. The results showed that sucrose and temperature had a significant interactive effect on thermal resistance. More specifically, sucrose increased the heat resistance, and this effect was greater at lower temperatures than at higher temperatures. The effect of sucrose on the Z value was slight compared to its effect on the D value.
Factors Affecting Amine Production by a Selected Strain of Lactobacillus bulgaricus
Authors: CHANDER HARISH , BATISH V. K. , BABU S. , SINGH R. S.
Published: January 2007

Lactobacillus bulgaricus‐52 showed maximum growth and amine production in MRS broth in 24 hr at 37°C. The optimum pH for the production of histamine, tyramine, and tryptamine by L. bulgaricus‐52 was 5.0. Highest yields of the different amines were obtained in the absence of NaCI in the growth medium. A concentration of even 0.5% NaCI had a slight inhibitory affect on the synthesis of amines. A similar trend was observed in terms of amine production by L bulgaricus‐52 in milk samples held at 37°C for different time intervals.
Effect of Calcium Level on Bread Iron Utilization by Iron‐Deficient Rats
Authors: RANHOTRA G. S. , GELROTH J.A.
Published: January 2007

Utilization of iron in bread containing variable amounts of calcium was examined using iron‐deficient rats as the test model. Iron was added to the bread at the normal enrichment level. Calcium, however, was added at levels up to 9 times the normal level. Iron utilization efficiency (IUE) was calculated based on collective increases observed in hemoglobin and liver iron. Compared to a diet low in both calcium and phosphorus (IUE = 100%), IUE averaged 98% when the diet was high in calcium but moderate in phosphorous, and 78% when the diet was very high both in calcium and phosphorous. Viewed collectively, the data suggested that excessive intake of both calcium and phosphorus would adversely affect the utilization of iron in bread, but some excess of calcium alone would not.
Mathematical Characterization of the Compressive Stress‐Strain Relationships of Spongy Baked Goods
Authors: PELEG M. , ROY ISABELLE , CAMPANELLA O.H. , NORMAND M.D.
Published: January 2007

The compressive stress‐strain relationships of selected breads, English muffins and sponge cake were determined with a Universal Testing Machine and described mathematically in terms of a three‐parameter empirical model. These parameters gave account of the overall mechanical resistance of the sponge, the existence of a shoulder in its stress‐strain curve and the strain level at which densification of the sponge becomes the dominant deformation mechanism. They were also sensitive indicators of the changes that were observed in the stress‐strain relationship as a result of successive compression and could be used to distinguish between the deformation patterns of the various products.
Properties and Structure of Amylose‐Glyceryl Monostearate Complexes Formed in Solution or on Extrusion of Wheat Flour
Authors: GALLOWAY G. I. , BILIADERIS C. G. , STANLEY D. W.
Published: January 2007

Differential scanning calorimetry (DSC), alpha‐amylolysis, and gel filtration chromatography (GFC) were used to characterize the lamellar morphology of solution‐grown amyloseglyceryl monostearate (GMS) complexes. The complexes grown at 60°C and 90°C had melting temperatures of 100°C and 114°C, respectively. Both enzyme digested complexes had broad overlapping GFC chromatographs; however, the amylose‐GMS‐90°C complex had chain lengths 25% to 40% larger than the lower temperature complex. Assuming the main GFC peak was representative of the ordered lamellar regions, the complexes grown at 60°C and 90°C had helical chain segments of 104 Å and 145 Å, respectively. The influence of GMS addition on the twin screw extrusion of soft wheat flour was also investigated. Formation of a complex during extrusion, characteristic of the amylose‐GMS‐90°C polymorph, decreased the starch solubility, water holding capacity, enzyme susceptibility and degree of expansive‐puffing of the extrudate.