Detektion von Ebergeruch mittels chemischer Analytik und Humansensorik bei Ebern aus ökologischer Mast

Die Mast intakter männlicher Schweine birgt das Risiko des sogenannten Ebergeruchs, welcher problematisch für die Konsumentenakzeptanz ist. Die Praktikabilität der Ebermast hängt daher von der Reduktion der ursächlichen Substanzen im Tier sowie der sicheren Detektion auffälliger Schlachtkörper am Band ab. Zugabe von roher Kartoffelstärke verringerte die Rate geruchsauffälliger Schlachtkörper. Die Übereinstimmung zwischen den chemischen Messwerten und der humansensorischen Beurteilung lag bei 84 %

Erste Ergebnisse eines Grundfuttervergleichs zur Senkung der Skatolbelastung in der ökologischen Ebermast

Skatole, one of the main causes of boar taint, derives from tryptophan in the large intestine and accumulates in the fat tissue of boars, thus decreasing meat quality. We hypothesize that energy of roughage promotes growth of skatole reducing microbes. Therefore, we compare the two roughages grass-clover-silage and straw, regarding the effect on concentrations of skatole and androstenone in the fat tissue. The experiments are currently ongoing and will help to evaluate special feeding strategies as an alternative to castration, thereby promoting animal welfare and product quality

Einfluss von Genotyp und Fütterung in der ökologischen Mast intakter männlicher Schweine. I: Ebergeruch

Fattening of entire male pigs is a useful alternative to piglet castration but the problem of boar taint is still unresolved. The object of the present study was to test the effect of (i) two different terminal sire lines (Danish Duroc, Du vs. Piétrain, Pi) and (ii) two different feeding strategies (without (-) vs. with (+) raw potato starch prior to slaughter) on the prevalence of boar taint in organic pork production. The results show that entire male growing-finishing pigs of Du origin have significantly higher androstenone concentrations in shoulder back fat than those of Pi origin whereas the feeding strategy has no significant effect. Concerning skatole, both genetic origin and feeding strategy significantly affect concentrations in shoulder back fat: Pi- entire male pigs are significantly 2.25 times above Pi+, Du-, and Du+ which are on an identically low level. The present results still do not justify a final recommendation

Correction: Noise and accustomation: A pilot study of trained assessors' olfactory performance.

[This corrects the article DOI: 10.1371/journal.pone.0174697.]

Carcass Quality, Meat Quality and Sensory Properties of the Dual-Purpose Chicken Lohmann Dual

Over 40 million day-old layer line cockerels are culled in Germany each year, due to economic reasons, leading to a recently instigated research focus on the potential of dual-purpose breeds as an alternative to conventional poultry husbandry, especially the practice of culling. This paper aims to explore and assess the dual-purpose chicken breed “Lohmann Dual” (LD) performance (n = 30) and sensory characteristics (n = 48). Carcass and meat quality traits are evaluated, and descriptive sensory analysis of breast muscles is conducted. To define the scope of characteristics, a market sample of “Ross” Line (n = 35) is adducted. LD carcasses are characterized by higher leg than breast yield; carcass, breast and leg weights are higher in Ross. LD meat has a lower pH, differs in color, has higher drip and thawing losses, but lower cooking loss. LD breast muscles are firmer as indicated by shear force measurements, which is confirmed through the sensory analysis. Appearance, odor and flavor differ between the lines. Overall, distinguishable differences are found between both breeds. Further research should focus on the marketing aspect of the dual-purpose line, as some characteristics could draw consumers to this product. Animal welfare and ethical concerns should further be considered when considering dual-purpose breeds as a feasible alternative to culling

Noise and accustomation: A pilot study of trained assessors’ olfactory performance

<div><p>While recent studies suggest an influence of noise on olfactory performance, it is unclear as to what extent the influence varies between subjects who are accustomed to noise and those who are not. Two groups of panelists were selected: a University panel usually working under silent conditions and an abattoir panel usually working on the slaughter line with abattoir noise. Odor discrimination, odor identification, and odor detection thresholds were studied. Furthermore, a sensory quality control task using 40 boar samples was performed. All tests were accomplished both with and without extraneous noise recorded at an abattoir (70 dB) using headphones. Contrary to the researchers’ expectations, abattoir noise hardly affected the olfactory tests nor was the quality control task impaired. Abattoir noise did not influence the perceived intensity of boar taint and the classification results of the testers, regardless of whether they were accustomed to such noise or not. The results indicate that sensory quality control can be conducted in a manufacturing environment with constant noise without diminishing the assessors’ performance.</p></div

Odor detection thresholds for androstenone and skatole of the university panel (left) and the abattoir panel (right) under noise (●) and silent conditions (○) including the panel average for the silent (- - -) and noisy condition (──).

<p>The scores in the threshold test can range between -3 and 20 and they represent a series of binary dilutions of the respective odorant; dilution step -3 corresponds to 8 mMol. That is, a higher dilution step indicates a lower detection threshold, i.e. higher sensitivity. Two assessors of the abattoir panel were obviously insensitive towards androstenone and thus excluded from this analysis. Abattoir noise (70 dB) was applied using headphones.</p

Comparison of averaged fat scores for each sample under noisy and silent condition.

<p>For the abattoir panel A the individual fat scores were either 0 (not tainted) or 1 (tainted). That is, the average score over assessors represents a probability that a given sample is tainted. For the University panel U the original scores ranged from 0 (standard pork fat odor) to 5 (strongly deviation from standard pork fat odor). Abattoir noise (70 dB) was applied using headphones.</p