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Biomedical subjects

H J Swatland

Publications and source records attributed to H J Swatland.

At least 19 recordsLinked to original sources
PubMed1998

Meat quality variation in the robotic sorting of pork loins.

A robot was used to make fiber-optic reflectance measurements from 400 to 700 nm in 10-nm increments at six sites, 10 cm apart, along the length of 48 pork loins. Meat quality was assessed in the longissimus dorsi near the thoracolumbar junction using 1) a bag-drip method for fluid loss, 2) a subjective evaluation of wetness, 3) a colorimeter measurement of paleness (CIE L), and 4) a subjective evaluation for Japanese pork color scores (JPCS). Sorting of the loins in the commercial plant from which they originated was correlated (P < .01) with fluid loss (r=.57), with wetness scores (r=-.57), with CIE L* (r=.71), and with JPCS (r=-.64). Laboratory measurements of pH at the site of meat quality assessment were correlated (P < .01) with fluid loss (r=-.61), with wetness scores (r=.65), with CIE L* (r=-.74), and with JPCS (r=.77). Average spectra obtained robotically were correlated (P < .01) with fluid loss (r=.56 at 670 nm, and R=.76 adding 560 and 540 nm), with wetness score (r=-.65 at 480 nm, and R=.75 adding 530 and 570 nm), with CIE L* (r=.76 at 480 nm, and R=.82 adding 690 and 520 nm), and with JPCS (r=-.70). In sorting loins that were all categorized as normal at the plant, mean reflectance data collected robotically were correlated with fluid loss, r=.42 (P > .05) at 700 nm and R=.58 (P > .05) adding 430 nm; with wetness score, r=.25 (P > .05); with CIE L*, r=.58 (P < .025) at 700 nm; and with JPCS, r=-.71 (P < .01) at 700 nm. Thus, as well as detecting obvious PSE loins, the robotic probe also had a limited capability to sort loins all categorized as normal at the plant.

Animals↗
PubMed1997

Observations on rheological, electrical, and optical changes during rigor development in pork and beef.

Electrical and optical changes were measured in bovine sternomandibularis and porcine sternocephalicus strips tested sinusoidally in a rigorometer up to 3 h postmortem. Rigor development was detected by decreased muscle elongation, decreased stress-strain hysteresis area, and increased elastic modulus. Elastic modulus was affected by loading rate (r = .98, P < .005) from loading rates of 3.6 to 13.3 kPa/s. Capacitance decreased and resistance increased at 120 Hz, 1 kHz, and 10 kHz as rigor developed. Sometimes changes were irregular at one frequency but steady at another. The most consistent electrical predictors of rigor development were capacitance at 120 Hz and resistance at 10 kHz. Electrical impedance changed as muscle strips were stretched in the rigorometer, so that dimensional effects could be a source of error if testing causes muscle contraction. The dominant fiber-optic reflectance changes during rigor development were increases toward 400 nm and decreases toward 700 nm, although transient increases were sometimes detected toward 700 nm. Optical changes generally were later than electrical changes. All these complex changes are an obstacle to the early prediction of pH-dependent aspects of meat quality from electrical and optical measurements.

Abattoirs↗
PubMed1994

A review of probes and robots: implementing new technologies in meat evaluation.

Changes in function from fat-depth measurement to meat quality measurement, and vice versa, have occurred in the history of electrical and optical meat probes. In the future, robotic systems might use ultrasonics to measure subcutaneous fat depth while at the same time positioning a fiber-optic probe relative to the skeleton to measure meat quality. There is a major distinction between probes that make a measurement at a single site within the carcass and those that produce a vector of measurements as they move through the carcass. Vector measurements were introduced to find subcutaneous fat thickness, but they may be used for meat quality measurements to deal with intra- and intermuscular variation. Replacement of hand-held probes by robots is in progress and could change meat distribution and marketing, perhaps replacing conventional meat grading by lowering the unit cost of grading and improving reliability for consumers. The feasibility of using ultrasonics to find probe measuring sites in the thoraco-lumbar region of pork carcasses has been proven. This requires new types of carcass morphometry data, such as rib angles and curvatures, and intercostal dimensions.

Abattoirs↗
PubMed1993

Developing a fiber-optic probe to combine subcutaneous fat depth and meat quality measurements.

This feasibility study demonstrates that the boundary between porcine subcutaneous fat and longissimus muscle can be detected with a probe using optical fibers to illuminate and detect anatomical boundaries. A relatively large optical window (approximately 3 mm2) seemed to give the best resolution of fat to muscle boundaries, whereas a smaller window gave a better resolution of marbling. Scattered, obliquely sectioned optical fibers gave reflectance spectra of fat and muscle that were relatively flat and parallel (fat > muscle). Thus, white light may be used with optical fibers to detect fat to muscle boundaries, although the greatest monochromatic separation was at 820 nm. In comparing measurements made as the probe penetrated the meat with those made as the probe was withdrawn, structures appeared to be deeper on the way in than on the way out, because of compression of the meat. Multichannel operation allowed tissue transmittance to be measured as well as reflectance and channels to be averaged to improve performance. These observations will be useful in developing new apparatus to measure fat depth and meat quality in one operation using optical fibers.

Adipose Tissue↗
PubMed1992

Effect of wavelength on spatial measurements of light scattering for the measurement of pork quality.

White light from a xenon arc was focused onto the upper surface of 25-mm-thick transverse sections of pork longissimus muscle. A servo motor moved an optical fiber across the lower surface of the muscle to collect transmitted light, which then was passed through a grating monochromator and onto a photomultiplier for spatial measurements of scattering (SMS) and transmittance spectra. The SMS were calculated as the slope of the logarithm of transmittance relative to path length through the sample (which was calculated trigonometrically). Pale, soft, exudative (PSE) pork was measured with an index that included a subjective evaluation of meat color and objective measurements of reflectance, drip loss, and centrifugation fluid loss. The strongest correlation of SMS with PSE was at 610 nm (r = .86, P less than .005) and the strongest correlation of transmittance with PSE was at 650 nm (r = -.95, P less than .005). This supports the use of a red laser at 633 nm for the detection of PSE pork.

Abattoirs↗
PubMed1991

Evaluation of probe designs to measure connective tissue fluorescence in carcasses.

Three probes were evaluated for their effectiveness in measuring connective tissue fluorescence within carcasses or primal cuts: 1) a quartz-glass rod, 2) a light guide formed from bundles of optical fibers, and 3) a single optical fiber. The shape of the fluorescence emission spectrum of tendon was altered by the method of measurement, probably because of differences in the intensity of excitation. The single optical fiber design provided the best solution to the problem caused by the irregular distribution of connective tissue in meat, and a modified fat-depth probe was tested as a prototype. Beef shank had more fluorescence peaks per millimeter (P less than .01), a greater area above minimum fluorescence (P less than .01), and a greater mean peak intensity (P less than .005) than did psoas major.

Animals↗
PubMed1989

Morphometry of pectoral development in turkey breeding stock.

1. Musculo-skeletal development was measured in males and females of two genetic lines of turkey breeding stock: one line had been selected mainly for egg production (E-line) while the other had been selected for meat production as well as egg production (M-line). 2. The M-line had a more rapid growth of body weight and breast muscle weight than the E-line but breast muscle yield (breast muscle weight/body weight) did not differ between lines. 3. From an early age, breast length and keel length were longer in the M-line than in the E-line. 4. In older birds, keel depth was greater in the M-line than in the E-line. 5. No differences between lines were detected for depth of the pectoralis muscle, number of muscle fibres in the depth of the pectoralis, or muscle fibre cross sectional areas.

Animals↗
PubMed1989

Fluid distribution in pork, measured by x-ray diffraction, interference microscopy and centrifugation compared to paleness measured by fiber optics.

Moderately PSE (pale, soft, exudative) and moderately DFD (dark, firm, dry) pork was examined by x-ray diffraction for interfilament separation, by differential interference contrast microscopy for interfiber area, and was centrifuged to measure water holding capacity (WHC). Internal reflectance spectra were measured by fiber optics. For PSE to DFD pork, filament separation ranged from 39 to 48 nm, interfiber area from 42 to 3%, and WHC from 49 to 64%, respectively. The correlation of reflectance with interfilament separation varied considerably with wavelength (reaching r = -.83 at 680 nm, P less than .005). The correlation of reflectance with interfiber area was more uniform across the spectrum (reaching r = .90 at 450 nm, P less than .005), as was the correlation of reflectance with WHC (reaching r = -.80 at 400 nm, P less than .005). At 24 h postmortem, fiber-optic spectrophotometry may be used as a rapid, nondestructive method to predict WHC and potential fluid losses from commercial pork with a moderate range from PSE to DFD. Interfiber area was correlated negatively with filament lattice area and WHC, but no significant correlation was found between filament lattice area and WHC. Filament separation was decreased only slightly by centrifugation. These results indicate that at 24 h postmortem the extra fluid released from PSE pork already has been lost from the myofilament lattice and is awaiting release from compartments downstream such as interfiber and interfascicular spaces.

Animals↗
PubMed1988

X-ray diffraction measurements of postmortem changes in the myofilament lattice of pork.

Postmortem changes in the lateral spacing between filaments of the longissimus muscle in pork were examined by small-angle x-ray diffraction. Samples that were fixed in glutaraldehyde as soon as they were collected showed a rapid decrease in filament spacing from 1 h to 3 h and then a further, slower decrease to 24 h. Samples that were examined immediately or were kept prior to examination in buffered Ringer's solutions at pH values similar to those expected in the carcass showed a rapid decrease in filament spacing from 1 h to 3 h and then little further change to 24 h. In contrast, samples taken at various times postmortem and stored in Ringer's solutions at pH 7.2 for several hours before examination showed little postmortem change in lattice spacing. Fixed samples showed similar changes to those of unfixed samples, but the lattice spacing always was less in fixed than in unfixed samples. These results support the classic theory that much of the water that may be lost by drip and evaporation from meat originates from the spaces between the filaments. The major factor that caused shrinkage of the filament lattice and loss of water from the fibrils was pH.

Actin Cytoskeleton↗
PubMed1988

Autofluorescence of bovine ligamentum nuchae, cartilage, heart valve and lung measured by microscopy and fibre optics.

The fluorescence of bovine tissues was measured post mortem by microscopy of frozen sections and by using optical fibres to excite fluorescence and to measure fluorescence emission spectra. Mechanical disruption of the tissue (by comminution or sectioning) did not appreciably change tissue fluorescence spectra. Ligamentum nuchae had the strongest fluorescence and lung tissue had the weakest. In samples measured with a minimum prior exposure to ultraviolet light, the peak fluorescence emission was at 410 or 420 nm (with excitation at 365 nm). Exposure to ultraviolet light for about 1 minute shifted the fluorescence peak to 450 to 470 nm. Further exposure (about 30 minutes) caused a loss of the 450 to 470 nm fluorescence peak, while emissions above 530 nm were maintained or strengthened. Microscopy showed that the fluorescence that was measured by fibre optics from intact connective tissues originated mostly from collagen and elastin fibres.

Animals↗
PubMed1987

Fluorimetry of bovine myotendon junction by fibre-optics and microscopy of intact and sectioned tissues.

The autofluorescence of tendon, epimysium and endomysium at the myotendon junction of the deep digital flexor in the bovine forelimb was measured with a fluorescence microscope and with a bifurcated light guide composed of quartz optical fibres. Data were adjusted for spectral variation in the radiance of the halogen illuminator used to standardize the photometer. Samples of myotendon junction were examined intact, in slices several millimetres thick and after being frozen in liquid nitrogen and sectioned at 20 micron. Sections were examined with and without a mounting medium and with and without immersion oil objectives. Type I collagen fibres were identified by their scarcity of branching, relatively large size and yellow staining with silver. Type III collagen fibres were identified by their extensive branching, small size and black staining with silver. Purified Types I and III collagen were also examined. Type I collagen fibres had a strong fluorescence emission peak between 410 and 450 nm and a shoulder at 510 nm. For the strong peak, results obtained by fibre-optics were positively biased relative to those obtained by microscopy. Type III collagen reticular fibres lacked a strong emission peak at 410 to 450 nm. Although their overall fluorescence was weaker than that of Type I collagen fibres, Type III collagen fibres had similar or slightly stronger emissions around 510 nm. The Type I emission spectrum of collagen fibres was converted to a spectrum similar to the Type III spectrum by conditions that caused the fading of fluorescence (storage as dry or mounted sections and exposure of sections to UV light).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Measurement of the gristle content in beef by macroscopic ultraviolet fluorimetry.

Ultraviolet light (365 nm) was directed at an angle of 45 degrees onto meat samples in a circular aperture (3 cm diameter). Fluorescence emissions were measured with a monochromator and a photomultiplier tube. Intact tendons and elastic ligaments had a strong fluorescence emission peak around 440 to 450 nm and only weak fluorescence around 510 nm. Tissues such as lean meat and adipose tissue that contain a matrix of reticular fibers (Type III collagen) had very low fluorescence around 440 to 450 nm so that their peak emittance was the weak fluorescence peak at 510 nm. The 510/440 nm ratio of fluorescence emissions was measured in comminuted meat samples containing varying mixtures of lean meat and gristle and varying mixtures of muscles with a high and low gristle content. The 510/440 nm ratio was correlated with the ratio of lean meat/gristle (r = .96, P less than .005). The 510/440 nm ratio was correlated with the ratio of longissimus/shank meat (two trials; r = .93, P less than .01; and r = .94, P less than .005). Results were only slightly changed when samples had dry surfaces or when samples were mixed with adipose particles. The relationship between the area of gristle in the samples and the 510/440 nm ratio was curvilinear with the greatest sensitivity to the fewest gristle fragments.

Animals↗
PubMed1985

Fibre-optic spectrophotometry of immature bovine skeletal muscles and the cellular distribution of myoglobin and succinate dehydrogenase.

Samples of diaphragm and pectoralis profundus were taken from nine calves with a range of blood haemoglobin levels of 4 to 8.5 g/100 ml. In both muscles, fibres with strong succinate dehydrogenase activity contained myoglobin, but in the pectoralis there were many fibres with strong alkaline ATPase activity and weak succinate dehydrogenase activity that had low or undetected levels of myoglobin. The whole cross-sectional area of individual fibres was scanned to map the distribution of succinate dehydrogenase activity. Among fibres with similar levels of ATPase activity, those from the diaphragm had greater succinate dehydrogenase activity than those from the pectoralis. Subsarcolemmal succinate dehydrogenase activity was greater than the axial succinate dehydrogenase activity, and radial gradients of succinate dehydrogenase activity were steepest in the diaphragm. For pectoralis fibres with weak ATPase, the mean and the axial succinate dehydrogenase activities were correlated with blood haemoglobin levels (r = 0.62 and r = 0.61, respectively; P less than 0.05 with a Student's t-test). Muscle colour was measured directly by fibre-optic spectrophotometry and correlations of absorbance with succinate dehydrogenase activity were obtained. Absorbance at 620 nm 24 h post-mortem was correlated with succinate dehydrogenase activity in pectoralis fibres with weak ATPase (r = 0.81; P less than 0.005).

Adenosine Triphosphatases↗
PubMed1985

Growth-related changes in the intracellular distribution of succinate dehydrogenase activity in turkey muscle.

The intracellular distribution of succinate dehydrogenase (SDH) activity was measured and mapped in iliotibialis cranialis muscle fibers of growing turkeys. Two weeks after hatching, fibers with strong myofibrillar adenosine triphosphatase (ATPase) were larger in cross sectional area than fibers with weak ATPase, but fibers with weak ATPase subsequently exhibited more rapid relative growth. At two weeks, both types of fibers had stronger SDH activity in their central axis than in the subsarcolemmal region. At ten weeks this gradient was reversed so that SDH activity declined from the periphery to the axis (a negative centripetal gradient of SDH activity). Fibers with strong ATPase developed the steepest negative gradients of SDH activity. Fibers with weak ATPase tended to have more uniformly distributed SDH activity, even when fibers had grown quite large.

Adenosine Triphosphatases↗
PubMed1984

The radial distribution of succinate dehydrogenase activity in porcine muscle fibres.

A microscope photometer with a computer-controlled scanning stage was used to map the distribution of succinate dehydrogenase (SDH) activity in transverse sections of skeletal muscle fibres of pigs from 9 to 29 weeks of age. Absorbance due to SDH activity was measured in successive concentric zones that converged on the central axis of the muscle fibre. In all fibres, there was less SDH activity in the axis of the fibre than in the periphery of the fibre. In fibres with strong adenosine triphosphatase (ATPase) activity and weak overall SDH activity, the radial gradient of SDH activity remained constant as fibres grew in cross-sectional area. However, in fibres with weak ATPase and strong SDH and in fibres with strong ATPase and strong SDH, the radial gradient of SDH activity increased as fibres grew larger. Changes in radial gradients were due to both decreased SDH activity in the axis and to increased SDH activity in the periphery. In all three fibre types, the overall SDH activity per fibre increased with age.

Adenosine Triphosphatases↗
PubMed1984

Optical characteristics of deep pectoral myopathy in turkey carcasses.

When eviscerated turkey carcasses are illuminated with white light from a 100 W lamp in the body cavity dorsal to the sternum, about 90% of carcasses with deep pectoral myopathy can be detected subjectively. With this method, subjective detection is more reliable than photometric detection. When a fiber-optic probe is placed in direct contact with a lesion, the absorbance spectrum of reflected light is radically different to the spectrum from normal muscle, and three types of lesions can be identified (red-purple, green, and yellow). However, the presence of lesions is masked by even a shallow depth (approximately 1 cm) of normal muscle between the lesion and the probe. A combination of both optical methods might enable carcasses to be inspected without slashing the breast muscles of all the carcasses from flocks of suspect birds, but the whole length of the supracoracoideus on each side would have to be traversed by the fiber-optic probe. For a fiber-optic detection system in the abattoir, the simplest diagnostic characteristic would be the ratio of two wavelengths (480/550 nm). The average ratio for normal muscle was .68. The average ratios for lesions were from 1.17 to 1.38.

Abattoirs↗
PubMed1983

Aerobic activity in the axis of growing myofibers in the porcine biceps femoris.

Twenty-four pigs between 9 and 29 wk of age were slaughtered at intervals of 4 wk. A microscope photometer was used to measure the staining intensity of histochemical types of myofibers. Biceps femoris myofibers were categorized as either strong-ATPase or weak-ATPase. The growth in cross sectional area of strong-ATPase myofibers was greater than that of weak-ATPase myofibers (allometric growth ratio, k = 1.36, P less than .005). Among strong-ATPase myofibers of animals at each different age, myofibers with a large diameter tended to have weaker succinate dehydrogenase (SDH) activity in their central axis than myofibers with a small diameter. Hence, correlations of cross sectional area with axial SDH staining (transmittance) ranged from r = .27 at 9 wk to r = .43 at 29 wk (all correlations significant, P less than .005). When the means for strong-ATPase myofibers of pigs at different ages were compared, SDH staining in the central axis of strong-ATPase myofibers tended to decrease as myofibers grew larger in cross sectional area. On this basis, myofiber cross sectional area was correlated with SDH transmittance, r = .85 (P less than .025). Among weak-ATPase myofibers of animals at each different age, large diameter myofibers sometimes tended to have weaker axial SDH activity than small myofibers, but no significant decrease in axial SDH activity was detected as myofibers grew larger.

Adenosine Triphosphatases↗