Muscle glycogen level and meat quality in pigs of different halothane genotypes

The halothane genotype of 22 Polish landrace pigs was determined using halothane test and blood typing. Eight homozygous normal (NN), eight hetero-zygotes (Nn) and six homozygous recessive (nn) were identified. The levels of glycogen and lactate were measured in biopsy samples taken from the longissimus lumborum using a shot biopsy technique. pH (pH(1)) and IMP/ATP ratio (R) were determined at 30 min after slaughter, while pH, meat colour and water holding capacity were determined on the day after slaughter. The halothane genotype did not affect intra vitam glycogen level. The nn pigs had a higher R value and lower pH(1) than both Nn and NN animals. Heterozygous animals were intermediate between both homo-zygotes for biopsy lactate level and meat colour. The lactate content of biopsy samples was significantly correlated with pH(1) (r = -0·68; P < 0·01), R (r = 0·68; P < 0·01), meat colour (r = 0·57; P < 0·01) and water holding capacity (r = 0·45; P · 0·05).     

Identification of halothane genotypes by calcium accumulation and their meat quality using live pigs

The three halothane genotypes (NN, Nn, and nm) were identified by measuring the capacity for Ca²⁺ accumulation by sarcoplasmic reticulum in whole muscle homogenate preparations of M. longissimus dorsi with a Ca²⁺ specific electrode at 35°C. Significant differences (P < 0·001) in deterioration (%) of Ca²⁺ accumulation, 12% for NN, 35% for Nn, and 81% for nn pigs, were observed after ageing the whole muscle homogenate preparations for 24 h in ice.

Predictions of meat quality in live pigs (n = 34) based on the values for water-holding capacity, assessed as fluid (g/0·5 g wet wt LD), and pH (fluid) by using small biopsy LD samples (Cheah et al. 1993) were performed on all the halothane genotypes. The halothane genotype NN (n = 11) showed a fluid value of 0·37 ± 0·01 and a pH (fluid) value of 6·62 ± 0·03 as compared with 0·61 ± 0·02 and 5·84 ± 0·04, respectively, for the halothane genotype nn (n = 13). The Nn pigs (n = 10) showed fluid (0·49 ± 0·03) and pH (fluid) (6·19 ± 0·11) values between those values observed for the two homozygotes (NN and nn). Predictions of meat quality in live pigs from biopsy LD muscles were confirmed from assessments on post-mortem LD muscles based on pH₁ and fibre optic probe (FOP) measurements.

The extent of deterioration (%) in Ca²⁺ accumulation showed high correlations with fluid (r = −0·861) and pH (fluid) (r = −0·831) in the biopsy LD samples, and with pH₁ (r = 0·663), FOP (r = −0·812), and drip (%) loss (r = −0·777) in the post-mortem LD samples.     

Texture and rheological properties of meat from pigs of different halothane genotypes

The effects of halothane genotype (NN, Nn and nn) in pigs on meat texture, rheological properties, fibre diameter, area of intramuscular fat, pH, colour, drip loss, cooking loss and yield of cooked and of smoked loin were examined. Cooked and smoked meat of NN pigs exhibited lower hardness, gumminess, chewiness, elasticity moduli, greater cohesiveness and a longer relaxation time compared to meat from pigs with genotype Nn or nn. Meat from pigs of the nn genotype exhibited the greatest hardness and elasticity, the shortest relaxation time and the lowest viscosity and cohesiveness, while meat from genotype Nn was intermediate regarding these parameters. Significant correlations were found between parameters of texture, and rheological properties and pH, structure, drip and cooking loss. © 1998 SCI.     

Influence of porcine stress on blood composition and early post-mortem meat quality in pigs of different halothane genotypes

The purpose of this study was to investigate porcine stress, blood serum values and early post-mortem (pm) meat quality in pigs of unknown and known halothane genotype. Collection, transportation and slaughtering of the pigs were studied from the farm up to the carcass chilling (45 min pm). Reactors (nn) had the highest creative kinase (CK) activity. CK activity increased most prominently during transport in reactors, and at the abattoir in non-reactors (Nn or NN). The content of serum glucose was highest in non-reactors and lowest in non-carriers (NN, P<0·01). Serum glycerol level was highest in reactors and lowest in carriers (Nn, P < 0·05). Differences in serum lactate and pH values were not significant. Carriers had the highest and non-reactors the lowest carcass temperature, 0 min pm (P = 0·001). Temperature of non-reactors increased most rapidly (9·4%) and that of carriers increased most slowly (0·9%) during scalding. Reactors had the most rapid (3·1%) and carriers the slowest (0·3%) fall in carcass temperature between scalding and chilling. No significant differences were found between halothane genotypes in the rate of glycogen breakdown and lactate formation, 45 min pm. PSE (pH(1) ≤ 5·8) frequencies of reactors, non-reactors, non-carriers and carriers were 100·0, 14·3, 13·0 and 12·5, respectively.     

Muscle fibre characteristics and metabolic response at slaughter in pigs of different halothane genotypes and their relation to meat quality

Muscle samples for histochemical and biochemical analyses were taken immediately at slaughter from M. longissimus dorsi of pigs with different halothane genotypes (NN and nn). Fibre type composition was similar between groups but the nn-genotype had larger mean fibre areas and lower capillary density than the NN-genotype. At exsanguination the nn-genotype had lower muscle pH (pH(e)), higher lactate and ammonia and lower glycogen and phosphagen (ATP and CP) concentrations and twice as many glycogen-depleted type IIA and IIB fibres as compared with the NN-genotype. Muscle pH(e) was correlated positively to capillary density, glycogen and phosphagen concentrations and negatively to mean fibre area, ammonia and lactate concentrations. Ammonia concentrations were correlated negatively to ATP concentrations and positively to the percentage of glycogen-depleted IIB fibres. The highest reflectance and drip loss values were seen in the nn-genotype. The reflectance values were correlated positively to the percentage of glycogen-depleted type IIB fibres in muscle and the values for drip loss were correlated negatively to pH(e). These data show that fibre size and capillary density in muscle seem to be important factors that influence the metabolic response at slaughter and thus meat quality.     

Influence of loading method and stocking density during transport on meat and dry-cured ham quality in pigs with different halothane genotypes

The effect of loading method and stocking density in transit on meat and dry-cured ham quality was investigated in pigs with different halothane genotypes. A total of 507 Italian heavy pigs, supplied by two farms, were loaded by ramp or lift and transported unmixed for 35–55 min to the abattoir at a stocking density of either <0.4 or >0.6m² per 100 kg pigs. After overnight lairage in separate pens with free access to water, the pigs were slaughtered. Halothane genotype was assessed post mortem. Four hundred and thirty-nine pigs had a homozygous dominant (NN) genotype and 68 pigs were heterozygous (Nn). Carcass skin damage, meat quality traits and ham curing parameters were evaluated. Loading method and stocking density showed a negligible effect on meat and dry-cured ham quality while the predominant factor affecting these was the halothane genotype. Nn pigs produced meat with a faster rate of pH fall and lower water holding capacity as well as ham with higher weight losses in salting and greater incidence of defects in the dry-cured product. There were insignificant interactions between halothane genotype and loading method or stocking density. Overall, irrespective of pre-slaughter treatment, the Nn pigs were less suitable for the production of high quality products such as dry-cured ham.     

Antioxidant capacity and phenolic content of different solvent extracts from banana (Musa paradisiaca) and mustai (Rivea hypocrateriformis)

In the present study, chloroform, acetone, and methanol extracts from stem and flower of banana (Musa paradisiaca) and leaves, stem, and flowers of mustai (Rivea hypocrateriformis) were evaluated for their in vitro antioxidant activity using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH^•), 2,2′azinobis (3-ethylbenzothiozoline-6-sulfonic acid) diammonium salt (ABTS^•+), iron chelation, and antihemolytic activity. Among the solvents used, methanol gave the maximum yield in banana, whereas in night glory acetone was reported to having higher extractive value. The total phenolic content was also higher in these extracts. The antioxidant potential of the extracts was well established with their DPPH^• and ABTS^•+ radical scavenging activities and ferric reducing antioxidant capacity. The potential of multiple antioxidant activity of samples can be further evidenced by inhibition of reactive oxygen mediated erythrocyte cell lysis and metal ion chelating activity. However, this is the first report on the antioxidant property of mustai and this plant is having excellent antioxidant potential over banana. In conclusion, the results implied that the leaves, stem, and flowers of banana, and mustai could be considered as health supplements and nutraceuticals/functional foods.     

Extractives, acidity, buffering capacity, ash and inorganic elements of black locust wood and bark of different clones and origin

Chemical properties of black locust wood and bark from Greece, Bulgaria and Hungary (clones NY, U and J) were investigated. Disks at breast height were taken from 25 black locust trees (five trees per origin and clone) and were divided into separate biomass components (juvenile heartwood, mature heartwood, sapwood and bark). Hot water soluble (HWSE) and dichloromethane soluble extractives (DSE), acidity (pH), buffering capacity, ash content and inorganic elements were determined according to standard laboratory techniques. Bark had the highest extractive content for both HWSE (9.25–13.49%) and DSE (3.09–4.03%). Differences of extractive contents in wood were found to exist between trees of different origin and between the three clones and ranged in heartwood between 5.04–10.10% for HWSE and 0.53–1.83% for DSE and in sapwood between 3.33–6.76% for HWSE and 0.48–1.47% for DSE. The higher values of pH occurred in sapwood (4.92–5.35), while the differences between bark (4.44–5.12) and heartwood (4.35–4.92) were small. Acid (ABC) and base (BBC) buffering capacities from the initial to pH 10 for ABC and to pH 3 for BBC were greater in bark (ABC 0.0172–0.0219 ml/ml and BBC 0.0079–0.0141 ml/ml) than in the other wood components (for heartwood ABC 0.0069–0.0159 ml/ml and BBC 0.0022–0.0096 ml/ml and for sapwood ABC 0.00330.0066 ml/ml and BBC 0.00330.0049 ml/ml). The total ash content was greater in bark (7.24–8.56%) than in other biomass components (for heartwood 0.34–0.89% and for sapwood 0.72–1.24%). The content of the main inorganic elements (Ca, K, Mg, Na, P) were also found to be much higher in bark while sapwood values were greater than heartwood.     

The effect of washing water parameters (pH, hardness and sodium pyrophosphate content) on the water-holding capacity and gelation characteristics of sardine (Sardina pilchardus) mince

In order to determine the effect of washing water parameters [pH, hardness and tetrasodium pyrophosphate (TSPP) content] on the water-holding capacity (WHC) and gelation properties of sardine (Sardina pilchardus) mince, two experiments designed by response surface methodology were carried out. The WHC of the mince was maximum when washed in the pH range of 6.5–7.0, with TSPP>1.7?g???l^-1, and CaCO₃ between 30 and 60?mg???l^-1. With the exception of breaking deformation and the folding test, where the highest values were obtained at 60?mg???l^-1 CaCO₃, the variation of water hardness did not induce any significant changes in the other rheological parameters. The use of relatively high concentrations of TSPP in the leaching water contributed to the achievement of high values of breaking deformation, though beyond 2.5?g???l^-1 a detrimental effect on breaking force was observed, and consequently also on gel strength.     

Ruminal buffers: temporal effects on buffering capacity and pH of ruminal fluid from cows fed a high concentrate diet.

In vitro characteristics of several buffers and alkalinizing agents commonly utilized to reduce ruminal acid load were evaluated. Ruminal fluid was collected from five cows consuming a diet containing concentrate and sorghum silage in a 68:32 ratio (DM basis). This fluid was incubated with either NaHCO3, a natural sodium sesquicarbonate, a multielement buffer or MgO (7.1 g/L of ruminal fluid), or no buffer for 48 h; flasks were removed and analyzed for pH, buffering capacity, and buffer value index every 12 h during the 48-h incubation. The buffer value index accounts simultaneously for alterations in pH and buffering capacity. Compared with the unbuffered control, all buffering compounds increased ruminal fluid buffer value index. However, the buffer value index separated these buffering compounds into two categories. The NaH-CO3 and sodium sesquicarbonate exhibited similar buffer value indexes; both were markedly higher than those for the multielement buffer and MgO. Although NaHCO3 and sodium sesquicarbonate each increased both ruminal fluid pH and buffering capacity sharply, the multielement buffer only increased pH and buffering capacity moderately. The increase in buffer value index for MgO primarily was due to an increase in pH. Both NaHCO3 and sodium sesquicarbonate were fully active within the first 12 h of incubation; activity of multielement buffer and MgO reached a plateau at 24 h. Compared with the multielement buffer and MgO, NaHCO3 and sodium sesquicarbonate should be more beneficial in preventing short-term postprandial increases in ruminal fluid hydrogen ion concentration; because of their slower release rates, the multielement buffer and MgO should help stabilize ruminal acid-base status, but efficacy might be reduced because of passage out of the rumen.     

不同品种蓝莓酚类物质组成特征及抗氧化能力比较分析

以高丛、矮丛、兔眼蓝莓为研究对象,比较了其总酚、花色苷、原花色素、单体酚以及抗氧化力差异。超高效液相色谱检测结果表明,绿原酸为3种蓝莓中含量最多的酚酸;表没食子儿茶素是高丛蓝莓和兔眼蓝莓含量最丰富的黄烷醇,表儿茶素没食酸酯则是矮丛蓝莓含量最高的黄烷醇;在3种蓝莓中含量最高的黄酮醇均为芦丁;矮丛蓝莓单体酚总量显著高于高丛蓝莓和兔眼蓝莓。抗氧化分析结果则表明,无论从DPPH、ABTS还是FRAP测定结果来看,矮丛蓝莓均具有最强的抗氧化能力。相关性分析结果表明,3种蓝莓总酚、总花色苷和原花色素含量均与抗氧化能力存在明显的正相关性。     

Muscle pH(60), colour (L, a, b) and water-holding capacity and the influence of post-mortem meat temperature

The use of the pH(60) and colour parameters (L, a, b) as chilled pork drip loss predictors 24 h post-mortem as well as the influence on this meat characteristic of an early blast cooling regime (90 min post-mortem) were investigated. Despite the best correlation found with pH(60) (-0·647), both indicators were found to be poor for this purpose, it being impossible to use them alone for pork quality classification (PSE/DFD status). Comparing the evolution between the drip losses on chilled and early deep frozen (-60°C) longissimus dorsi pork cuts, the results indicate that both the thawing regime and the time the samples stay in refrigeration, influence the observed trends significantly. The general drip loss enhancement seen after thawing as well as the increasing meat toughness, judged subjectively, must be due to cold-shortening and/or thaw rigor phenomena.     

Comparative study of the histochemical properties, collagen content and architecture of the skeletal muscles of wild boar crossbred pigs and commercial hybrid pigs

The histochemical properties, collagen content and architecture of Musculus longissimusthoracis (LT), Musculus pectoralis profundus (PP) and Musculus biceps femoris (BF) were compared in F(1) (half blood) and F(2) (quarter blood) wild boar crossbred pigs and commercial hybrid pigs, and Japanese wild pigs. F(1) pigs showed the lowest growth rate, followed by F(2) pigs. The most rapid growth was shown by the commercial pigs. The percentage weights of LT and PP muscle to body weight were larger in the wild boar crossbred pigs than commercial pigs. The muscles of the crossbred pigs contained type I and IIA myofibers at higher frequency and type IIB at lower frequency than the commercial pigs, except for LT muscle of F(2) pigs. The myofiber diameter in each type of muscle did not differ between pigs except for the smaller type IIA in BF muscle in commercial pigs. The total amount of intramuscular collagen was less in LT muscles than the others. More intramuscular collagen was found in the wild boar crossbred pigs than the commercial pigs in LT and PP muscles. With an increase of collagen content, the perimysial collagen architecture developed but not the endomysial architecture. Traits characteristic of the crossbred pigs seem to be inherited from the wild boar. Our results clarify that cross breeding with wild boar results in pigs with distinctive muscle characteristics in terms of histochemical properties, collagen content and architecture.     

Colour,phenolic content and antioxidant capacity of some fruits dehydrated by a combination of different methods

The objective of this study was to improve product quality of dehydrated fruits (apple, pear, papaya, mango) using combined drying techniques. This involved investigation of bioactivity, colour, and sensory assessment on colour of the dried products as well as the retention of the bio-active ingredients. The attributes of quality were compared in regard to the quality of dehydrated samples obtained from continuous heat pump (HP) drying technique. It was found that for apple, pear and mango the total colour change (ΔE) of samples dried using continuous heat pump (HP) or heat pump vacuum-microwave (HP/VM) methods was lower than of samples dried by other combined methods. However, for papaya, the lowest colour change exhibited by samples dried using hot air–cold air (HHC) method and the highest colour change was found for heat pump (HP) dehydrated samples. Sensory evaluation revealed that dehydrated pear with higher total colour change (ΔE) is more desirable because of its golden yellow appearance. In most cases the highest phenol content was found from fruits dried by HP/VM method. Judging from the quality findings on two important areas namely colour and bioactivity, it was found that combined drying method consisted of HP pre-drying followed by VM finish drying gave the best results for most dehydrated fruits studied in this work as the fruits contain first group of polyphenol compounds, which preferably requires low temperature followed by rapid drying strategy.     

Polyphenols content and antioxidant capacity of thirteen faba bean (Vicia faba L.) genotypes cultivated in Tunisia

In vitro antioxidant capacity of thirteen genotypes of faba bean (Vicia faba L.) collected during three different growing stages (vegetative, reproductive and maturity) have been evaluated. For the vegetative stage (VS) and reproductive stage (RS) the whole plant (WP) has been used for the analysis while for the maturity stage (MS) the plant was divided and analyzed in different parts, the whole seed (WS), seed coat (SC), cotyledons (Cot) and pod (Pod). The antioxidant capacity has been evaluated by means of the total phenolic and total flavonoid contents (TPC and TFC respectively), the ferric-reducing/antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assays. The results showed different antioxidant properties for the same genotype when considering the different parts or stages of the plant. High content of both total phenolics (> 92.85 mg as gallic acid equivalent (GAE)/g of dried plant) and flavonoids contents (> 11.87 mg as rutin equivalent (RE)/g of dried plant) were found for all genotypes during the vegetative and the reproductive stages, which also showed the highest antioxidant activity (FRAP value ≥ 1.157 mmol/g and DPPH radical-scavenging capacity > 43.49%), indicating their potential as natural sources of antioxidant foods. For the maturity stage, the highest values for the TPC, TFC, FRAP and DPPH scavenging capacity were observed for the pods and the lowest for the cotyledons.The results of this study indicate that faba beans are a good source of natural antioxidants independently to their genotype. The quantification of the antioxidant capacity according to the stage and the plant part could be suitable for applications on the food industry in relation to production and preservation of faba bean food products.     

Evaluation of halothane sensitivity and prediction of post-mortem muscle metabolism in pigs from a muscle biopsy using (31)P NMR spectroscopy

Phosphorus nuclear magnetic resonance (³¹P NMR) measurements were made on biopsy samples from pig muscles. Two experiments were performed, one in France and one in Czechoslovakia. In experiment 1, the muscle samples were obtained by surgery from the Biceps femoris muscle of 10 pigs with various genetic types (5 Large White, 1 Large White × Landrace, 4 Pietrains). In experiment 2, the muscle samples were obtained by shot biopsy from the Longissimus dorsi muscle of 11 Belgian Landrace × Duroc pigs, of which 6 were halothane-negative and 5 halothane-positive. The pigs were slaughtered by electrostunning and exsanguination respectively 3 weeks and 1 week after the biopsy, and meat quality traits (pH₁, reflectance and water holding capacity) were determined. The changes in adenosine triphosphate (ATP), creatine phosphate (CP), inorganic phosphate (P_i) and pH, as deduced from NMR, were faster in Pietrains than in Large Whites, and in halothane-positive than in halothane-negative pigs. The value of the CP/P_i ratio at 40 min after taking biopsy allowed discrimination between halothane-positive and halothane-negative pigs. The values of pH, creatine phosphate and adenosine triphosphate, as measured at definite times on the biopsies, were correlated with the rate of post-mortem metabolism (r approx 0·8) and with meat quality traits. ³¹P NMR measurements combined with a rapid and efficient biopsy technique appear as an alternative tool for assessment of both halothane sensitivity and prediction of meat quality in pigs.     

Conjugated Linoleic Acid (CLA) content of meat from three muscles of Massese suckling lambs slaughtered at different weights

Eighteen Massese male lambs, fed mainly maternal milk were slaughtered at 11, 14 and 17kg. Samples of Longissimus Dorsi (LD), Triceps Brachii (TB) and Semimembranosus (Sm) muscles were collected. Milk from the lamb's dams was sampled weekly. Fatty acid composition of milk and meat was determined. TB was the fattest muscle, Sm the leanest one and LD showed an intermediate value of total lipids, while the weight at slaughter did not influence total intramuscular fat content in any muscle. Although slaughter weight slightly affected overall fatty acid composition of muscles, rumenic acid and total CLA content in TB and Sm, but not in LD, significantly increased with slaughter weight. As regard milk fatty acid composition, the contents of total CLA, RA and others minor CLA isomers decreased during the first four weeks after lambing and then increased at the last control (five weeks). The animals slaughtered at a live weight of 14 and 17kg showed a greater SCD enzyme activity (estimated by product/substrate ratio) and a higher rumen activity (estimated by means of branched chain and odd chain fatty acid content in meat) than animals slaughtered at 11kg. Cis-7, trans-9 CLA content significantly increased with the slaughter age in TB and SM, while trans-7, trans-9 CLA, only increased in TB, and cis-8, cis-10 CLA, only increased in SM. Further studies are needed in order to verify weather the different behaviour of RA in LD muscle may be due to differences in muscle metabolism or fatty acid utilisation.     

Effect of pH(24), NaCl content and proteolysis index on the relationship between water content and texture parameters in biceps femoris and semimembranosus muscles in dry-cured ham

The aim of the present study was to determine the effect of pH level and NaCl content on the relationship between water content and texture parameters in semimembranosus and biceps femoris muscles in dry-cured ham. The experiment was undertaken using 18 hams, selected in a commercial slaughterhouse. Half of the hams had a pH<5.7 and the rest a pH>6.2, measured in the semimembranosus muscle at 24-h post mortem (pH(SM24)). The hams were treated with 20, 50 or 80g of NaCl per kg of ham. At the end of the aging process nine samples from semimembranosus and biceps femoris muscles were dried to different levels of water content covering the range from 22.4% to 58.5%. At the end of the drying period, a Texture Profile Analysis was used to determine textural parameters. Samples from biceps femoris muscle and samples from hams with low pH(SM24) showed a higher proteolysis index (100×non-protein nitrogen/total nitrogen) than samples from semimembranosus muscle and samples from hams with high pH(SM24), respectively. The proteolysis index decreased when the added NaCl amount increased. The proteolysis index was the parameter that best explained the modifications in the relationship between water content and the texture parameters (hardness, cohesiveness and springiness) of dry-cured ham muscles and it would be considered in order to predict the texture in dry-cured ham at different drying levels. Dry-cured hams with a lower proteolysis index were more prone to present harder texture at low water contents, which is typical of hams with crustiness problems.