Chemical, microbial and sensory changes during the anaerobic cold storage of beef inoculated with a homofermentative Lactobacillus sp. or a Leuconostoc sp.

Slices of beef were inoculated with about 3.5 log cfu/cm2 of Lactobacillus sp. 93 SMRICC 235 (homofermentative) or Leuconostoc sp. 89 SMRICC 189 and stored in 5% CO2 + 95% N2 at 4 degrees C. The microbial, chemical (glucose, L-lactate, D-lactate, acetate, formate, ethanol, H2S) and sensory changes of the beef slices were studied. For beef inoculated with Lactobacillus sp. 93 the flavour score started to decrease when the maximum bacterial count was reached. Leuconostoc sp. 89 caused a rapid decrease in the flavour score before reaching the maximum bacterial count. Concentrations of acetate and D-lactate increased while glucose and L-lactate decreased in beef slices inoculated with Lactobacillus sp. 93. In the presence of Leuconostoc sp. 89 ethanol and D-lactate increased while glucose decreased. Lactobacillus sp. 93 formed the highest level of H2S, and a sulphurous off-odour was noted only in the presence of this strain. D-Lactate and acetate indicated high numbers of Lactobacillus sp. 93 on the meat surface, while D-lactate and ethanol indicated high numbers of Leuconostoc sp. 89. More studies are needed in order to correlate levels of D-lactate, acetate and ethanol with sensory changes.

Sensory and technological meat quality in carriers and non-carriers of the RN(-) allele in Hampshire crosses and in purebred Yorkshire pigs.

The effect of the dominant RN(-) allele on technological and sensory meat quality of loin and ham from pigs, crossbred from Landrace × Yorkshire sows and one Hampshire sire heterozygous for the RN(-) allele was studied. The non-carriers of the RN(-) allele and the purebred Yorkshire pigs were similar regarding most of the technological traits. In comparison with the RN(-) carriers, they had higher values for pH(u), Napole yield, dry matter and protein content, but lower values for drip loss, filter paper wetness, cooking loss, internal reflectance, residual glycogen and glycolytic potential. The three groups did not differ concerning lactate content, intramuscular fat or ash content. Shear-force values did not differ between the two RN genotypes, but both genotypes had lower shear-force values than the purebred Yorkshire pigs. Non-carriers had higher processing yield for cured cooked ham than RN(-) carriers. The RN(-) allele had little effect on the sensory attributes, as assessed by a trained panel using a descriptive test, but there was a tendency to lower chewing time for meat from the crossbreds compared to the purebred Swedish Yorkshire. RN(-) carriers produced more acidic fresh loin than non-carriers and purebred Yorkshire pigs, and juicier cured cooked ham than non-carriers.

Effect of Brussels sprouts and inulin/rape seed cake on the sensory profile of pork M. longissimus dorsi.

The objective of the present study was to evaluate the influence of two diets containing either Brussels sprouts or inulin/rape seed cake, compared with a standard diet (control) for slaughter pigs on flavour and odour attributes and sensory profile of cooked pork. Three weeks prior to slaughter 24 female pigs were allocated to three diets: (1) a standard grower-finishing diet (control) for slaughter pigs containing barley, wheat and soy-bean meal, (2) the control diet containing 11 energy percent Brussels sprouts and (3) a diet containing 25% inulin and 55% rape seed cake. The odour and flavour of the cooked meat from inulin/rape seed cake-fed pigs differed significantly from the other two diets, showing reduced meat odour, increased pig and acrid odour, increased pig flavour, reduced fresh flavour and total impression. Meat from the Brussels sprouts-fed pigs deviated only slightly from the control-fed pigs.

Consumer and sensory investigations in relation to physical/chemical aspects of cooked pork in Scandinavia.

The present study addresses sensory quality and liking for pork (eight samples) varying in quality due to adrenaline injection resulting in elevated ultimate pH post-slaughter (24h), meat ageing, cooking temperature and warmed-over flavour (WOF) among consumers (n=288) in Scandinavia. The consumers preferred meat with higher pH (pH(24h)=6.0), cooked to the lowest temperature (65 °C versus 80 °C). Consumers least preferred samples with WOF described as metallic, acidic and off-flavour by a trained panel. "Elevated pH(24h) meat" cooked to 65 °C resulted in a more sweet and tender meat. Juiciness, tenderness and the absence of off-flavour were the most important characteristics for consumers' liking of pork. Consumption frequency and liking of pork were positively related. The consumers that were most satisfied with pork quality reported highest consumption frequency. Elderly people and males expressed the highest liking score and consumption frequency, respectively.

An international study on the importance of androstenone and skatole for boar taint: II. Sensory evaluation by trained panels in seven European countries.

The aim of the present study (part of an EU AIR programme on boar taint) was to make objective the perception of boar taint in entire male pork, and to relate the perception to skatole and androstenone levels. Trained analytical sensory panels in seven European countries assessed pig meat with known levels of androstenone and skatole. The panels performed a sensory profiling using the attributes pig, urine, manure/stable, naphthalene/mothballs, rancid, sweet, sweat and abnormal, both for odour and flavour in separate sessions. It turned out to be difficult to harmonise sensory methodology for seven sensory panels throughout the EU, especially with respect to the exact level of training the panellists received. Sensory panels in general were able to differentiate between the two compounds and between different levels of the compounds, though substantial differences between the panels in the different countries existed. Androstenone was found to relate mostly to the urine attribute, while skatole related mostly to manure and, to a lesser extent, to naphthalene.

An international study on the importance of androstenone and skatole for boar taint: III. Consumer survey in seven European countries.

There has long been debate over the relative importance for consumer acceptability of androstenone and skatole. The objective of this study was to investigate consumer reaction to pig meat of varying levels of androstenone and skatole in seven member states of the European Union. Over 4000 entire male pigs (and 233 gilts as a control) were produced in six European countries, and a sub-sample of 420 were selected to represent a range of androstenone and skatole levels. Loin samples from these pigs were distributed to the seven participating countries. Samples were prepared and cooked according to standardised procedures in each of the countries and presented to pork consumers. Each consumer rated samples from five pigs for liking of flavour and liking of odour. Although there were significant differences between country panels in their liking of meat from entire males generally, there was a greater degree of dislike as both androstenone and skatole increased. This reaction was stronger for skatole than androstenone and consumers reacted more negatively in terms of odour than flavour.

An international study on the importance of androstenone and skatole for boar taint: IV. Simulation studies on consumer dissatisfaction with entire male pork and the effect of sorting carcasses on the slaughter line, main conclusions and recommendations.

An international study has been conducted in order to determine the respective contributions of androstenone and skatole to boar taint and their possible variations according to production systems and consumer populations. The presentation of the study and the main results concerning skatole and androstenone levels and data from sensory evaluation or consumer surveys are reported in companion papers. The present paper summarises the main conclusions of the study and gives tentative recommendations. A simulation study was conducted, based on the skatole and androstenone levels currently observed in European populations of entire male pigs and on the results of the consumer surveys. The first part of the simulation study demonstrated that, overall, 6.5% (odour) and 3.0% (flavour) more consumers were dissatisfied with entire male than with gilt pork. The differences were, however, very variable according to countries. Consumer dissatisfaction for the odour of entire male pork was mostly associated with high skatole levels, while androstenone had little influence on it. On the other hand, androstenone and skatole had similar contributions to the level of dissatisfaction for flavour. From the present study it is not possible to determine clear cut-off levels for androstenone/skatole. The regression equations presented in [Matthews, K. R., Homer, D. B., Punter, P., Béague, M. P., Gispert, M., Siret, F., Leask, H., Fonti i Furnols, M., & Bonneau, M. (2000). An international study on the importance of androstenone, skatole for boar taint: III. Consumer survey in seven European countries. Meat Science, 54, 271-283] provide a basis for decision making. However, due to methodological limitations, the results may underestimate consumer reaction to entire male pork. The second part of the simulation study demonstrated that sorting carcasses on the basis of androstenone/skatole would reduce, but not eliminate, differences in consumer dissatisfaction between entire male and gilt pork. For odour, taking androstenone into account did not improve the efficiency obtained from sorting using skatole only. For flavour, sorting using both compounds was more efficient than sorting using skatole only. Sorting out 15% of the entire males, on the basis of skatole only, would result in a difference in the proportion of dissatisfied consumers of 4.2% (odour) or 2.0% (flavour) between entire male and gilt pork. The results of the last part of the simulation study demonstrated that decreasing skatole in entire male pig populations, to levels as low as 0.10 ppm, would still result in a difference in the proportion of dissatisfied consumers of 3.2% (odour) or 1.6% (flavour). To reduce this difference further, the levels of both compounds would have to be reduced still further. The lowest difference that can be achieved is 2.3% (odour) or 0.4% (flavour). The conclusions of the present study may differ according to whether immediate commercial applications or long-term goals are considered. On the basis of the skatole and androstenone levels currently observed in entire male pig populations, sorting out procedures based on skatole is the easiest way to rapidly achieve a significant decrease in consumer dissatisfaction with entire male pork. In most countries, however, this will not be sufficient to obtain the same level of acceptability as with gilts. In the long term, a sharp reduction in both skatole and androstenone would have to be achieved in entire male pig populations to obtain low differences in acceptability between entire male and gilt pork.