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This study aimed to determine how small heat shock proteins (sHSPs) protect myofibrillar proteins from µ-calpain degradation during ageing. Immunoprecipitation experiments with M. longissimus dorsi (LD) from Angus heifers (n = 14) examined the interaction between αß-crystallin, desmin, titin, HSP20, HSP27 and µ-calpain. Results showed that αß-crystallin associated with desmin, titin, HSP20, HSP27 and µ-calpain. Exogenous αß-crystallin reduced desmin and titin degradations in myofibrillar extracts and attenuated µ-calpain activity. In a second experiment, bull LD (n = 94) were aged at -1.5°C for up to 28 days post mortem. µ-Calpain autolysed faster in high ultimate pH (pH(u)) meat (pH(u)≥6.2) and this was concomitant with the more rapid degradation of titin and filamin in this pH(u) group. Desmin stability in intermediate pH(u) meat (pH(u) 5.8 to 6.19) may be due to the protection of myofibril-bound sHSPs combined with the competitive inhibition of µ-calpain by sHSPs.

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The eating quality of meat is a result of complex interactions between the biological traits and biochemical processes during the conversion of muscle to meat. It was hypothesised that muscles inevitably engage towards apoptotic cell death due to the termination of oxygen and nutrient supply to the muscle following exsanguination. Thus, factors that regulate the process of apoptotic cell death of muscle cells are believed to ultimately influence meat quality. Proteomic studies have associated the regulation of small heat shock proteins (sHSPs) with various meat quality attributes including tenderness, colour, juiciness and flavour. Due to the anti-apoptotic and chaperone functions of sHSPs, they are proposed to be involved with the eating quality of meat. In this review, we discuss the possible chaperone and anti-apoptotic role of sHSPs during the conversion of muscle to meat and consider the repercussions of this on the development of meat tenderness.

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Bull Musculus longissimus dorsi (n=63) were categorised into high (pH≥6.2), intermediate (pH 5.8-6.19) and low (≤5.79) ultimate pH (pHu) and aged up to 28 days post mortem at -1°C. High pHu samples were acceptably tender at 1 day post mortem and significantly more tender than low pHu meat at all ageing timepoints (p<0.05). Rapid autolysis of µ-calpain in high pHu meat was linked with the more rapid degradation of titin, nebulin and filamin in this pHu group. Desmin degraded faster in low pHu meat and was concurrent with an increase of cathepsin B levels. The results from this study support the hypothesis that beef tenderisation is pHu compartmentalised with tenderness in high and low pHu meat characterised by variable rate of degradation of high and low molecular weight myofibrillar proteins during ageing, which are in turn regulated by µ-calpain and cathepsin B activities.

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Bull M. longissimus dorsi (n=94) categorised into high (n=28), intermediate (n=14) and low (n=52) ultimate pH (pHu) were aged at -1.5°C for 28days. Shear force was higher and more variable (p<0.05) in intermediate pHu samples during ageing. Titin, filamin and desmin degradation was also less extensive in intermediate pHu samples compared to the other two pH categories. The extent of the decline of HSP20, HSP27 and αß-crystallin concentrations during post mortem ageing was pHu related such that high pHu meat maintained the highest concentration of small heat shock proteins followed by intermediate and low pHu meat. µ-Calpain autolysis was slowest in intermediate pHu and cathepsin B activities remained consistently low during ageing in this group (p<0.05). Meat toughness in the intermediate pHu group may be attributed to the combination of a larger pool of sHSP with a sub-optimal cathepsin B activity and intermediary µ-calpain activities.

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This study evaluated the effects of surgically implanted passive integrated transponder (PIT) tags on growth rate, survival and tag retention of yellow shortfin eels Anguilla australis with an initial mean mass of 101 g. There were no significant differences in body mass, total length, specific growth rate and survival between tagged and untagged A. australis in a 108 day laboratory trial. This tagging method was very reliable, with a tag retention of >95%.

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UNLABELLED: Goat milk fat includes several branched chain fatty acids (BCFAs), like 4-methyloctanoic acid, which when free, are responsible for goaty flavor. This flavor limits the market opportunities for goat milk. Prior research showed that cyclodextrins (CDs) can reduce goaty flavor, presumably by binding free fatty acids. This research extends that observation. In odor ranking trials in citrate buffer at pH 4.8, ß-CD concentrations between 0% and 0.35% were increasingly effective in reducing odor intensity due to 4-methyloctanoic acid, but only when present in high molar excess. α-CD was also effective, but γ-CD was not. In lipase-treated goat milk only ß-CD was effective but at much lower molar excess, a difference potentially explained by several factors. One was that BCFAs bind to CDs in marked preference to their straight chain isomers. Displacement experiments with phenolphthalein disproved that hypothesis. The ability of ß-CD to reduce goaty flavor intensity extended to yogurt. An analytical panel showed that flavor of goat yogurt was reduced by addition of ß-CD, but only if added before heating and fermentation. A hedonic trial showed that consumers preferred unsweetened and sweet/vanilla-flavored goat yogurt more when ß-CD was included, P = 0.004 and 0.016, respectively. Males liked all yogurts more than females (P < 0.01), but there was a treatment × gender interaction (P = 0.016) for sweet/vanilla yogurt: sweet/vanilla masked the goaty flavor for males but not females. This results parallels previously demonstrated gender effects for sheepmeat flavor caused by BCFAs. PRACTICAL APPLICATION: ß-Cyclodextrin masks goaty flavor in yogurt, and with its GRAS status means it could be used in commercial goat yogurts and similar products so the real or perceived nutritional advantages of goat milk are not lost to goaty flavor.

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The potential of near infrared (NIR) spectroscopy as an on-line method to quantify glycogen and predict ultimate pH (pH(u)) of pre rigor beef M. longissimus dorsi (LD) was assessed. NIR spectra (538 to 1677 nm) of pre rigor LD from steers, cows and bulls were collected early post mortem and measurements were made for pre rigor glycogen concentration and pH(u). Spectral and measured data were combined to develop models to quantify glycogen and predict the pH(u) of pre rigor LD. NIR spectra and pre rigor predicted values obtained from quantitative models were shown to be poorly correlated against glycogen and pH(u) (r(2)=0.23 and 0.20, respectively). Qualitative models developed to categorize each muscle according to their pH(u) were able to correctly categorize 42% of high pH(u) samples. Optimum qualitative and quantitative models derived from NIR spectra found low correlation between predicted values and reference measurements.

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The concept of geographical exclusivity prompted an exploratory survey with toasted woods other than oak to flavor wine. A total of 11 woods and oak (Quercus alba) were cut into chips 20 × 10 × 2.5 mm and toasted at 200 °C for 2 h (light toast) or 210 °C for 3 h (dark). Weight losses and changes in CIE color space were monitored. The toasted chips were infused in unoaked chardonnay (5 g L(-1)) for 2 wk. Parallel infusions were done with model wine (water, ethanol, tartaric acid) adjusted to pH 3.5. Ultraviolet absorbances due to infusion were recorded on the basis that that lignin compounds and their potential pyrolysates are based on phenolic structures that absorb in the ultraviolet range. Weight losses on light and dark toasting were highly variable between species as were color changes, suggesting potential for different flavor outcomes from chemical changes. Ultraviolet absorbance curves were also highly variable showing that different species yielded different quantities of potentially flavor-active phenolic compounds in real and model wine. More absorbing matter was extracted from the light toast treatments, and light toast oak, which demonstrated the greatest weight loss on light toasting, yielded the widest range of ultraviolet-absorbing matter. In an informal sensory trial with the 24 species/toast combinations infused in chardonnay all but one wood, Cupressus macrocarpa, resulted in flavors reminiscent of oaked wines. A hedonic consumer trial with 4 species and oak compared with uninfused chardonnay showed that each of the 4 had potential as a flavorant. Thus, woods unsuited to barrel construction could provide unrealized flavor opportunities in the wine industry, and could extend to flavoring spirits.

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The hygiene of chicken processing surfaces and retention of the wheat protein gliadin and of protein in general on those surfaces were compared in 15 trials after 3 increasingly rigorous cleaning steps. Eleven different chicken products with wheat derivatives as a batter were prepared on 3 processing lines in 15 production runs selected at random over 6 mo (5 runs were thus replicates). Using surface swabs, surface hygiene was monitored by adenosine triphosphate (ATP) bioluminescence, gliadin by immunoassay, and protein by the Coomassie dye method. Gliadin was monitored in 14 trials, protein in 5, and all trials were monitored by ATP bioluminescence. In a typical trial, gliadin values normalized to uncleaned values fell from 100000 arbitrary units, to 6000 after rinsing, to 30 (foam, rinse), to not detected (sanitize, rinse). Parallel ATP bioluminescence values also decreased, but crucially, the relative gliadin value was less than the relative ATP value after foam and rinse in all 14 trials, a result unchanged after sanitize and rinse. In trials comparing ATP and protein, the relative ATP values exceeded the relative protein values in 4 of 5 trials after foaming and after sanitizing. Thus, for these 11 products, ATP bioluminescence was a surrogate indicator of residual gliadin and probably of residual protein. Absolute gliadin concentration on an uncleaned processing line was also the basis of modeling the risk of cross-contamination of gliadin in follow-up product, where the line was hypothetically left uncleaned between production runs. The results show that all follow-up product could be declared "gluten-free" under proposed legislation, and suggest that some industrial cross-contamination risks are currently overestimated.

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This article reports the perception of cooked, nitrite-cured sheepmeat sausage that included 1.5% glucose, sucrose, xylose, or no sugar addition. The 4 sugar treatments were dry-cooked, vacuum packed, and stored chilled, and were hedonically assessed after 0, 1, and 2 mo. Consumers were advised that they could be eating any 1 of beef, chicken, lamb, pork, or turkey, in a salted cured preparation. Three-way analysis of variance (ANOVA) showed that liking of appearance, color, and texture were unaffected by sugar treatment, whereas liking of aroma, flavor, sweetness, and overall liking were markedly and significantly increased by xylose. Storage time as a factor had minimal effects on liking. In contrast, all attributes were liked more by male consumers (57%, P < 0.001). When asked to identify the meat species, lamb was correctly identified 50% of the time. With xylose, the observed frequency of lamb's misidentification as beef increased by 50% above the expected Chi-square frequency. This was largely at the expense of observed lamb selection frequency, which was 18% below expectation. When data were segregated by gender, the misidentification remained significant for males (P = 0.002), but was not significant for females (P = 0.32). The misidentification of beef for lamb may be due to the generation of Strecker aldehydes in the Maillard reaction between xylose and meat amino acids, which were shown to be greatly increased in the headspace above xylose-treated sausage. The restriction of significant misidentification to males is less easy to explain but may be associated with the possible greater sensitivity of females to volatile fatty acids, which are components of sweat.

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Five-carbon sugars affect cooked meat flavor by the Maillard reaction. This research extends to the effects ofpH and cooking temperature on meaty and species flavor, sweetness, barnyard, and rancid flavor in sheep-meat. Glucose and xylose were each blended into ground longissimus meat to 0%, 0.5%, or 1% and heated to 75 degrees C. Xylose treatments browned more than glucose treatments, and xylose flavor effects were more marked. With xylose, sheepmeat flavor declined significantly, but meaty flavor also declined. Differences were marked between pH 5.93 and 6.52, but pH effects at lower pHs were more subtle. Sweetness increased in many treatments, suggesting that 75 degrees C did not fully exploit the Maillard reaction. Therefore, pressure-cooked casserole treatments, chilled and frozen, were used to study the effects ofxylose, packaging, and storage time on flavor. There were no flavor differences due to chill packaging (foil laminate compared with barrier bag) (not significant). Xylose addition reduced sheepmeat flavor by 24% on the 1 to 9 intensity scale (P<0.001), while meaty flavor and sweetness were unaffected. Rancid flavor was reduced by xylose addition (P<0.01), and the reduction in barnyard flavor approached significance (P=0.07). Chilled storage time to 29 d did not affect any attribute. In the frozen casserole trial (stored exposed to air), xylose had no significant flavor effects (all P > or = 0.38). However, storage to 71 d increased the rancid flavor score from a negligible 0.06 to 0.60 (P=0.04), suggesting that rancidity development swamped more subtle effects.

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The functional properties of whole, diced or minced high and normal pH beef were determined after 0, 1, 2, 3 and 7 month's storage. There was no interaction between pH, degree of comminution and storage time for most of the attributes measured. Regardless of storage time or comminution method, high pH meat had significantly (P<0.001) higher sarcoplasmic protein solubility, water holding capacity, cooked batter torsion stress and strain, yield and emulsion stability than normal pH meat. Normal pH meat had significantly (P<0.01) higher myofibrillar protein solubility and hue angle than high pH meat. Water holding capacity significantly (P<0.01) decreased and hue angle increased with the increase in the degree of comminution. Protein solubility in raw meat and the cooked batter stress, strain, yield and emulsion stability of both high and normal pH meat deteriorated with time. However, this deterioration was faster in the normal pH meat compared to high pH meat except for total and myofibrillar protein solubility. Within the parameters of the present study, it is concluded that frozen high pH meat possesses superior functional attributes compared to normal pH meat regardless of the degree of comminution or storage time.

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Longissimus dorsi muscles from six normal- and six high-ultimate pH bulls were selected for fine mincing and subsequent pH adjustment with acid and alkaline pyrophosphate. Four pH treatments were prepared: initially high remains high (mean of pH 6.37), high becomes normal (5.62); initially normal remains normal (5.65), and normal becomes high (6.21). The addition level of phosphate as P(2)O(5) was the same in all replicates. Before pH adjustment, colour and water holding capacity (WHC) values were strongly affected by higher (initial) pH in expected ways: darker, lower chroma, higher capacity. After pH adjustment, these values were affected only by the final pH, not the initial pH (the pH history). Total protein solubility was likewise affected by final pH but not initial pH. In contrast, the combination high initial pH-high final pH improved sarcoplasmic protein solubility by 20% over the combination normal initial pH-high final pH. Sarcoplasmic protein solubility is an indicator of strain required to fracture cooked batters made from the minced meats; in the event, the rank order of the four treatments for strain-to-fracture matched that of sarcoplasmic protein solubility. Statistically, sarcoplasmic protein solubility and strain-to-fracture were both affected by initial pH (P<0.01) and final pH (P<0.001). However, stress required to fracture cooked batters was entirely controlled by initial pH (P<0.01). In other words, the stress-to-fracture advantage of initially high pH meat was not matched by upward pH adjustment of initially normal pH meat. Emulsion stability, which is better with higher pH meat, was affected by initial and final pH (both P<0.01). Cook yield, like WHC of pH-adjusted raw meat, was more due to final pH than initial pH, similarly cooked batter colour, whereas final pH had a significant effect on quality attributes (generally better when higher). An initially high pH history conferred an enduring advantage on three important batter attributes, stress-to-fracture, strain-to-fracture, and emulsion stability. Therefore, prior exposure of beef to normal pH conditions (pH 5.4-5.7) renders it less useful as a manufacturing grade product.

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A method to measure the approximate glycolytic potential of slaughter animals, and thus the ultimate pH, was applied for several months on the slaughter line of a cattle abattoir. The patented method (WO 00112844) determines a so-called glucose value from the hydrolysis of glycogen in a sample of Longissimus lumborum. The value is available before the dressed carcass is weighed and graded. The 13,700 cattle tested were pasture-fed bulls and 'prime' animals, the latter comprising steers and virgin females. The method was used to sort carcasses into two quality grades, table cuts and manufacturing, according to a threshold glucose value that in this application corresponded to an ultimate pH of 5.70. In frequency distributions the glucose value was roughly normally distributed for prime animals but for bulls was lower on average and strongly skewed to low values. The distributions showed that 19% of prime and 62% of bulls had an ultimate pH below 5.70. The results were consistent with prior survey work undertaken in New Zealand with conventional pH measurements made a day after slaughter. Error in the method is examined with respect to commercial outcomes. For most errors the method 'fails-safe', in that normal pH animals are more likely to be classed as high pH than vice versa. In a second phase of the study, meteorological and some abattoir data are related to mean daily glucose values and their variance. The more bulls slaughtered per day the lower the mean glucose value for bulls (r=-0.25, P<0.01), an effect presumably arising from mixing unfamiliar groups of bulls. There was a decrease in mean glucose value with higher maximum daily temperature (P<0.01). Periods of rainfall in the days leading to slaughter were positive for glucose value. For both bulls (especially) and prime, the lower the mean glucose value, the greater the percent variance (r=-0.81 and -0.56, P<0.001) but the cause of this could not be established.

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A patented method of rapidly determining the ultimate pH from approximate glycolytic potential of muscles of slaughtered animals has been devised. The method is based on the rapid hydrolysis of muscle glycogen to glucose by the enzyme amyloglucosidase and subsequent measurement of the liberated glucose. In acetate buffer at pH 4.5, glucose concentration can be determined in 30 s with domestic meters for diabetes control. The meter response differed from that of glucose in blood, but was linear with concentration. In slurries comprising homogenised meat in acetate buffer and added glucose, a similar linear response was obtained. Amyloglucosidase was capable of rapidly hydrolysing glycogen to glucose in such slurries. In the 24 h following slaughter, a decrease in glycogen, as determined by glucose, occurred in parallel with the decline in pH. At the same time, lactate progressively accumulated as expected. Values for the approximate glycolytic potential and (by calibration) ultimate pH, were obtained on prerigor muscle within 7 min of muscle sampling in an industrial environment. The method is suitable for on-line application in beef abattoirs particularly those employing hot boning where ultimate must be known at the grading point.

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This paper describes the colour properties of seven hot-boned, unstimulated beef striploins during rigor attainment at 9, 14 and 24°C, during blooming at 4°C, and after storage at -1°C for 0, 2 and 8 weeks. Immediately after rigor attainment (0 weeks of storage) full blooming, as judged by L* and chroma, took at least 12 h. After 2 and 8 weeks storage, blooming was complete within about 4 h. The exponential equations describing blooming were different for 0 weeks compared with 2 and 8 weeks. This difference can be explained in terms of oxygen consumption by meat freshly in rigor. At 0 weeks, meat that entered rigor at 24°C had the best bloomed colour, whereas at 2 and 8 weeks the 9°C treatment had the best and the 24°C the worst. The data set, which spanned a range of ultimate pH values and three rigor attainment temperatures, was used to estimate the value of early colour measurements (first 24 h post-rigor) in predicting colour during display several weeks later. As judged by correlation coefficients, early measurements of hue were the only ones useful. L* and chroma were poor predictors. This result, together with the knowledge that blooming is slow in the first 24 h post-rigor, casts doubt on the value of subjective or objective colour assessments made in chillers. Temperature of rigor attainment between 9 and 24°C did not affect the time of browning onset, nor the rate of browning. It was confirmed that meat with lower pH had higher chroma before and after blooming.

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Sixteen male Comisana lambs were divided into two groups of eight at age 45 days. One group received a commercial pelleted diet (control) and the other group (carob) received a diet in which 20% carob pulp was used in partial replacement of barley. The animals were slaughtered at 100 days. No significant differences were observed for live weight, although the carob group ate 14% more dry matter, showing a higher conversion index (2.68 and 3.22kg dry matter per kg weight gain respectively for control and carob). The dressing percentage was higher (p < 0.05) for the control group; however, the carcasses showed no differences in the European classification system. Lightness (lean colour) was the only meat quality parameter (p < 0.05) affected by diet treatment: the carob group lambs had a higher L (∗) value. This could not be attributed to ultimate pH, which was not significantly different between the two groups. In triangle tests, sensory panelists were unable to distinguish one diet treatment from the other. Instrumental tenderness was also unaffected by diet treatment.

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The effects of sheep age and diet on several odours and flavours are described. Ram lambs raised on ewe's milk then a corn-based diet were compared with lambs raised on milk and a pasture of grass/clover, six treatments in all. A seventh treatment comprised very old ewes maintained on pasture. Fat and lean from forequarters was minced and cooked together. Cooked lean was assessed for intensity by a sensory panel for 10 flavour attributes. Four showed significant (P < 0.01) treatment effects: 'sheepmeat', 'animal', 'liver', and 'poultry'. Sheepmeat flavour was highest in the slow-grown pasture-fed lambs. Animal flavour-the flavour associated with the odour of confined livestock-showed a similar pattern with treatment. Liver flavour was highest in ewe meat, and the biochemical origin of this flavour is discussed. Eleven related odour attributes were assessed on the rendered fat with a novel olfactometer. Five attributes showed highly significant treatment effects for intensity (P < 0.001): animal and sheepmeat odours showed a similar distribution to the equivalent flavours; likewise cabbage and rancid odours were associated with the two slow-grown pasture treatments. A comparison of the odour and flavour statistics showed that the sense of smell was the more discriminating in sheepmeat assessment, and also confirmed that fat was the true source of sheepmeat odour/flavour. In respect of sheepmeat production for effective marketing, the data showed that at 90 days, a pastoral diet resulted in slightly enhanced odours when compared with a corn-based diet. By 215 days, however, many undesirable odours were exacerbated. Since these older rams were more sexually developed, a sex rather than an age effect could not be excluded. Rendered fat from this work was further used in a companion study (Yang et al., 1997. Meat Sci., 45, 183-200) in an attempt to link individual volatile compounds to odour attributes.

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The effects of lamb age and diet on volatiles from fat are described. Rendered fat from ram lambs raised on ewe's milk then a corn-based diet was compared with that from lambs raised on milk and a pasture of grass/clover, six treatments in all. An additional treatment comprised very old ewes maintained on pasture. Helium-borne volatiles of rendered fat were resolved on a DB5 gas chromatographic column and the mass spectra obtained. Long chain alka(e)nes like neophytadiene were dominant in pasture treatments especially where the lamb growth rate was slow. Branch chain fatty acids (4-methyloctanoic, 4-methylnonanoic and an unidentified acid) were also highest in these treatments. Longer chain aldehydes like 2-undecenal were good indicators of a grain diet. Hexanal, commonly associated with rancid odours, was unaffected by treatment. The diketone 2,3-octanedione was an excellent indicator of a pasture diet, as was 3-methylindole (skatole). Phenols showed complex relationships to treatments, but were generally more common in pasture treatments. Benzenethiol (thiophenol) was unaffected by treatment. Inspection of principal component analysis plots identified 10 volatile compounds as contenders for the cause of sheepmeat odour; branch chain fatty acids were confirmed as the leading chemical class. There were indications that puberty or age caused an increase in the odorous 4-methylnonanoic acid. Animal odour-the odour of confined livestock-was clearly causally linked to 3-methylindole, a rumen breakdown product of tryptophan. 3-Methylindole was also responsible for rancid odour, rather than hexanal and its analogues. A hypothesis is advanced that links 2,3-octanedione formation to the enzyme lipoxygenase and linolenic acid, both abundant in green leafy tissue. Overall, the data confirm that sheepmeat odour/flavour is specifically linked to the branch chain fatty acids, and is probably exacerbated by pasture-derived 3-methylindole and alkyl phenols.

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The effect of dietary supplementation with clenbuterol for either 8 days or 55 days in lambs was studied. The 55-day treatment was combined with an immediate preslaughter exercise regime. The effect of these treatments on post-mortem calpain system activities, meat ageing and meat quality was studied. Neither short-nor long-term supplementation had an effect on the rate of pH fall post mortem. Short-term supplementation had no effect on the initial nor the final shear force values but these were higher at intermediate times. In contrast, prolonged supplementation increased shear force values at all times post mortem. Preslaughter exercise, while influencing the rate of pH decrease in both control and supplemented groups, did not affect meat tenderness. After short-term clenbuterol-supplementation, the in-vitro µ-calpain activity was significantly lower in the supplemented group at 6 and 24 hr post mortem, while m-calpain and calpastatin activities were largely unaffected. In contrast, 55-day clenbuterol supplementation resulted in significantly higher levels of calpastatin activity at all times post mortem. These data imply that clenbuterol results in toughened meat due to alterations in the calpain/calpastatin system, the mechanisms of which are dependent upon the duration of supplementation.