肉类弹性测定方法的研究

文章阐述了使用高精密度的TZ-XTZi物性仪测定肉类弹性的方法。比较了不同测定方法的弹性数据与感官对照之间的相关性，试验结果表明一次压缩过程中的最在力来表示肉的弹性较为恰当。     

Prevalence of Campylobacter species in meat, milk and other food commodities in Pakistan

A surveillance study was carried out to determine the prevalence of Campylobacter in meat, milk and other food commodities in Pakistan. Over a period of 3 years (January 2002-December 2004), a total of 1636 food samples of meat, milk and other food commodities were procured from three big cities of Pakistan (Faisalabad, Lahore and Islamabad) and were analysed. Among meat samples, the highest prevalence (48%) of Campylobacter was recorded in raw chicken meat followed by raw beef (10.9%) and raw mutton (5.1%). Among other food commodities, the highest prevalence was observed in vegetable/fruit salad (40.9%), sandwiches (32%), cheese (11%) and raw bulk milk samples (10.2%). The overall prevalence of Campylobacter was found to be 21.5%, out of which 70.6% were identified as Campylobacter (C.) jejuni and 29.4% as C. coli. The study reported that the prevalence of Campylobacter spp. was significantly higher in the food commodities, which included raw/undercooked ingredients.     

Molecular detection of meat animal species targeting MT 12S rRNA gene

The efficacy of PCR-RFLP analysis of mt 12S rRNA gene in identification of animal species from meat samples of known and unknown origin and adulterated meat samples was evaluated. In PCR, all the samples generated an amplicon of 456 bp. Restriction enzyme digestion of the PCR product with AluI, HhaI, BspTI and ApoI revealed characteristic RFLP patterns. Of the samples of unknown origin few were identified as cattle, few as buffalo and some were admixtures of two, suggesting adulteration. The RFLP pattern of one did not match any of species included in the study, which on sequencing was confirmed as camel meat. Application of this technique on adulterated meat samples could detect both animal species in proportion of 50:50 and 75:25 (except in case of goat+cattle). The technique however could not detect any of the two species when proportion of mixture was 90:10 (except in case of cattle+buffalo).     

Suitability of three commercially produced pig breeds in Germany for a meat quality program with emphasis on drip loss and eating quality

This study aimed at characterising 606 crossbred pigs of three commercially available breed types in terms of their carcass and meat quality. Breed G and H were German Large White (LW) × German Landrace (LR) sows sired with Pietrain (PI) boars, i.e. PI × (LW × LR). Breed S was 25% Duroc (DU), i.e. PI × (DU × LR). Most of the parameters were affected by breed and/or date of slaughter. The meat of crossbred pigs with 25% Duroc proportion appeared most favourable because of higher intramuscular fat content, lower drip loss and higher sensory liking scores. Conductivity is closely related to drip loss while the data suggests that the relationship is dependent on breed and carcass weight. The application of conductivity and lean meat yield thresholds to select carcasses with uniform and superior meat quality effectively decreased drip loss and increased intramuscular fat content as well as sensory liking scores. The variation of meat quality traits remains high, though.     

Effects of dietary supplementation of vitamins D(3) and E on quality characteristics of pigs and longissimus muscle antioxidative capacity

The effects of addition of vitamin D₃ and vitamin E to pig diets on blood plasma calcium concentration, meat quality (longissimus muscle) and antioxidative capacity were investigated. Two treatments consisted of supplementation with vitamin D₃ (500,000 IU/d) for 5 days separately (group D) and a combination of vitamin E (500 mg α-tocopheryl acetate/kg diet) for 30 days and vitamin D₃ (500,000 IU/d) for 5 days (group D + E) to growing-finishing pigs before slaughter. Pigs fed with vitamin D₃ had higher (P < 0.01) plasma calcium concentration compared with control pigs. Dietary supplementation of vitamin E significantly (P < 0.05) increased the concentration of α-tocopherol in meat (longissimus muscle). Vitamin D₃ supplementation resulted in higher (P = 0.07) a^∗ values of loin chops at 5 days of storage. Vitamin D₃ and vitamin E supplementation did not affect other meat quality characteristics or tenderness (quantified by Warner–Bratzler shear force). Antioxidative capacity (measured as MDA production after incubation of longissimus muscle homogenates with Fe²⁺/ascorbate) was improved by vitamin E and partly by vitamin D₃ supplementation.     

Association of PPARGC1A and CAPNS1 gene polymorphisms and expression with meat quality traits in pigs

This study aimed to investigate the genes PPARGC1A (peroxisome proliferator-activated receptor gamma-coactivator 1A) and CAPNS1 (calpain small subunit 1) as candidate genes affecting meat quality traits in pigs. Four polymorphisms were identified in PPARCG1A and three in CAPNS1. The PPARGC1A polymorphism c.1288T>A was associated with pH and cooking loss in a F2 Duroc×Pietrain experimental cross (DuPi, n=313) and with pH values in Italian Large White (ILW, n=380) and Italian Landrace (ILA, n=158) populations (P<0.05). The CAPNS1 polymorphism c.429A>C was associated with pH and conductivity in DuPi and with meat color in ILA (P<0.05). PPARGC1A mRNA expression associated with drip loss (P<0.01) and the same tendency was found for CAPNS1 (P=0.06). The promoter methylation profiling suggested that methylation is not involved in CAPNS1 expression regulation. In conclusion, porcine PPARGC1A and CAPNS1 genes may affect meat quality traits, with breed-specific differences, and they could be used as markers for the improvement of meat quality in pigs.     

Elucidation of a basic protein, glyceraldehyde-3-phosphate dehydrogenase, as a contributing factor to raise Mg-ATPase activity of myofibrils during meat conditioning

We investigated the factor which increased the maximum value of the Mg-ATPase activity of myofibrils existing at low KCl concentrations during meat conditioning. On the treatment of myofibrils with the solution extracted with the buffer of pH 7.2 from muscle, the Mg-ATPase activity in the presence of 0–0.15 M KCl increased time-dependently. This change was most remarkable in the range of pH 5.6–7.0. Trypsin treatment of the extract abolished such effect, suggesting that the responsible factors were proteins. The fractionation of the extract with isoelectric focusing demonstrated that the factors were basic proteins (pI 8.3–9.6). The treatment of myofibrils with those basic proteins under various conditions suggested that the time-dependent adhesion of those basic proteins, through a denaturation at around pH 5.5, to myofibrils was assumed to raise the Mg-ATPase activity. Analysis of myofibrils prepared from rabbit muscles stored at 0°C for 12 days postmortem showed the appearance of the 35,000 Da protein, accompanied the increase in the Mg-ATPase activity. Therefore, the adhesion of this protein to myofibrils in situ probably caused the increase in the Mg-ATPase activity. Successive treatment with the basic protein and the crude cathepsin increased the dependency of the Mg-ATPase activity on KCl concentrations and the maximum value of the Mg-ATPase activity. Therefore, the coordinate action of a basic 35,000 Da protein and cathepsins was presumed to induce the changes in the Mg-ATPase activity of myofibrils during meat conditioning. The basic protein was concluded to be glyceraldehyde-3-phosphate dehydrogenase (its subunit molecular mass: 35,000 Da), since the incubation of myofibrils with its commercial preparation raised the Mg-ATPase activity of myofibrils.     

Cadmium intake of moose hunters in Finland from consumption of moose meat, liver and kidney

Although the average cadmium intake in Finland is about 10 μg day^-1, some risk groups can be identified. This study assessed cadmium intake from the consumption of moose meat, liver and kidneys by moose hunters. Consumption data from a postal questionnaire were combined with a representative database on moose cadmium concentrations. Cadmium intakes were calculated as point estimates for all respondents (n = 711), for those consuming moose meat, liver and/or kidneys, and for the highest decile of those. Probabilistic modelling using the Monte Carlo technique was used to simulate the distribution of dietary cadmium exposure. Of the respondents, 69% consumed moose liver and only 23% moose kidneys. The consumption of moose liver or kidneys significantly increased cadmium intake, whereas moose meat (median consumption 17 kg year^-1 person^-1) contributed only slightly (0.16 μg day^-1 person^-1) to the daily total cadmium intake. In the simulation, 10% of the moose hunters had an intake of > 8.76 μg day^-1 (14.6% of PTWI for a 60-kg person) from moose. Point estimates provided only a partial understanding of the potential exposure. Simulated distributions of intake were more useful in characterizing exposure. The study revealed that heavy users of moose organs have a relatively narrow safety margin from the levels of cadmium probably causing adverse health effects.     

利用ArcObjects和ArcSDE实现DEM的裁剪与存取

为了提高加载DEM教据的地图的显示、刷新、响应效率，需要将DEM栅格数据进行分块显示。在这种目的下，本文利用ArcObjects和ArcSDE，对DEM栅格数据进行裁减，并通过有效的方法实现栅格DEM数据面向ArcSDE数据库的存储和提取。     

Effect of usage Urtica dioica L. on microbiological properties of sucuk, a Turkish dry-fermented sausage

The effect of dried-ground Urtica dioica L. on microbiological characteristics of Turkish dry-fermented sausage (sucuk) were investigated. Dried-ground Urtica dioica L. was added to sucuk batters by the rate of 0%, 1%, 3% and 5%, and microbiological analysis were made on the 0, 3, 7, 10 and 14 days of ripening period.

According to the results, both the level of Urtica dioica L. and ripening time had a significant effects on the total aerobic mesophylic bacteria, lactic acid bacteria, Micrococcus/Staphylococcus, yeast-mould and Enterobacteriaceae counts (p<0.01). It was determined that the interactions ripening time × the levels of Urtica dioica L. had a significant effects on the counts of total aerobic mesophylic bacteria, lactic acid bacteria, Micrococcus/Staphylococcus, yeast-mould and Enterobacteriaceae (p<0.01). Enterobacteriaceae count were also found to be under the detectable level (<100 cfu/g) in sucuks (in day 14 of ripening) containing 3% and 5% Urtica dioica L.