Use of Mechanically Separated Spleen in Frankfurters

Beef and pork frankfurters were produced with 0, 5, 10, and 15% of the meat block being mechanically separated spleen (MSS). No fatting or peelability problems were experienced. Frankfurters were held at 2°C and evaluated at 2-wk intervals for 6 wk. Consumer panelists rated all products acceptable. A bi-monthly laboratory taste panel evaluated all frank furters (except the 15% product) acceptable during storage. Allo-Kramer shear values decreased with increased MSS, Frankfurters with 5, 10, and 15% MSS had 2.2, 3.9, and 4.9 times more iron than the control, respectively. Level of MSS did not influence bacterial numbers.     

DIVERSITY OF PERCEPTIONS OF MEAT TENDERNESS AND JUICINESS BY CONSUMERS: A TIME-INTENSITY STUDY

Seven judges, untrained in sensory assessment, were trained in the use of Time Intensity (TI) and asked to monitor the tenderness and juiciness of a range of cooked beef and pork samples. The subjects were given no definitions concerning sensory cues to monitor in their assessments, nor did they confer with each other. The shapes of the TI curves they recorded for tenderness and juiciness differed between individuals, although there were similarities in the curve shapes for the 2 attributes for each individual. Correlations between the intensity parameters of the curves (maximum intensity and area under curve) and the chewing time were not significant for the subjects as a group for tenderness, although significant correlations were found for some of the subjects when examined individually. The results indicate that subjects differ in their concepts of sensory tenderness and juiciness, and that perceived tenderness does not correlate with chewing time for all subjects. In more general terms the study supports the use of TI assessments for interpreting individual differences in sensory perceptions.     

METHOD TO INVESTIGATE DIFFERENCES IN CHEWING BEHAVIOUR IN HUMANS

This study examines whether the patterns of muscle activity measured from the masticatory muscles during a chew are sufficiently reproducible to form the basis of a characterisation of chewing behaviour, and whether they express the degree of variation evident between individuals. Electromyograph (EMG) readings of the repetitive activity involved in chewing gum were analyzed for 10 subjects, each on three separate occasions. For each individual the temporal aspects of the chew cycle (duration of the activity burst, period between bursts of activity and duration of the complete cycle) were reproducible between EMG recording sessions. Consistency was also found for amplitude aspects of the EMG record: mean voltage within the activity burst, maximum voltage, and the area under the EMG trace. For all six parameters there was significant variation between subjects. The study showed that variations in the chewing pattern, as occur for chewing on opposite sides of the mouth, were reflected in the 6 EMG parameters examined, and that the changes elicited were different for each individual. Moreover, encouraging subjects to concentrate on the act of chewing caused them to modify their chewing pattern, highlighting the importance of avoiding such attention when assessing habitual chewing behaviour.     

CHARACTERISATION OF PATTERNS OF CHEWING BEHAVIOUR IN HUMAN SUBJECTS AND THEIR INFLUENCE ON TEXTURE PERCEPTION

Electromyography was used as a noninvasive and unobtrusive technique to characterise chewing patterns for a range of foods. Differences between subjects for a variety of aspects of chewing sequence are recorded for a range of foods (carrot, apple, roast pork, salami, biscuit and toast). Identifiable subgroups of subjects differing in chewing behaviour existed within the random sample of 52 dentate subjects. The five subgroups accounted for 52%, 21%, 11%, 10% and 6% of the sample population. Major discriminating factors between the behavioural groups lie in their chewing time and the muscle work rate during chewing. Sensory ratings for firmness and rubberiness of model foods differed significantly between the subjects exhibiting different chewing behaviours. Chewing behaviour may influence consumers' perceptions about the texture of a food.     

Immobilized α-amylase from Bacillus licheniformis: a potential enzymic time—temperature integrator for thermal processing

Biphasic and nth-order models were tested as to their usefulness to fit experimental inactivation data of Bacillus licheniformis α-amylase, immobilized on glass beads, and were discussed with respect to their suitability to characterize the considered enzymic system as a time—temperature integrator (TTI) to evaluate heat processes. Both isothermal and non-isothermal inactivation experiments were carried out. Model (kinetic) parameters (rate constant k, activation energy E_A and reaction order n) were estimated using a non-linear regression procedure. The results obtained, especially the activation energy of about 293 kJ mole^–1, indicated a potential use of this system as a TTI for heating processes in the temperature range of 96–108°C.     

A SURVEY OF THE PREVALENCE OF SALMONELLA AND OTHER ENTERIC PATHOGENS IN A COMMERCIAL POULTRY FEED MILL

A study of the prevalences of Salmonella, Listeria and thermophilic campylobacters in a dedicated commercial poultry feed mill was undertaken. Salmonella was frequently recovered in samples taken in the preheat and postheat treatment areas of the mill with the overall percentage of samples positive found to be 18.8% and 22.6%, respectively. Feed ingredients and dust collected in the preheat treatment locations within the mill were frequently contaminated with Salmonella (11.8% and 33.3% of samples, respectively). High prevalences of Salmonella were also detected in dust samples (24.2%) obtained from the postheat treatment area of the mill and from feed delivery vehicles (57.1%).
Listeria was also recovered from samples at pre- and postheat treatment areas within the mill with overall isolation rates of 14.1% and 18.5% observed, respectively. The most frequently observed species of Listeria recovered from samples in both areas within the mill was L. innocua, L. monocytogenes, L. grayi and L. welshimeri.
No thermophilic campylobacters were recovered from any of the samples analyzed in the current study.     

Structural Aspects of the Lattice Thermal Expansion of Hexagonal Cordierite

The mechanism of lattice thermal expansion in pure hexagonal cordierite prepared by glass devitrification was investigated by time-of-flight neutron powder diffraction at temperatures from 22° to 750°C under vacuum. Full matrix least-squares refinement of the diffraction spectra was carried out in space group P6/mcc using the Rietveld method. The structural data from the refinements were resolved into components parallel and normal to the c axis. The negative c axis expansion results from two effects: (1) increasing distortion of the T₂ tetrahedral (ring tetrahedra) with temperature, primarily due to displacement of the T₂ cations toward the c-axis channels in the structure; (2) decreasing distortion of the T₁/M tetrahedra/ octahedra with increasing temperature, due to octahedral I (M-O₁) bond expansion and an associated decrease in torsional distortion of the T₁ tetrahedra.