Interaction of Skatole and Androstenone in the Olfactory Perception of Boar Taint

Abstract

This study analyzed odor-odor interactions of two malodorous volatile substances, androstenone and skatole, that may accumulate in fat and meat of uncastrated male (boar) pigs. Therefore, fat samples were collected from 1000+ entire male pig carcasses for sensory evaluation and quantification of boar taint compounds using gas chromatography-mass spectrometry (GC-MS). Each sample was sniffed by 10 trained assessors, resulting in 11 000+ individual ratings, which were subjected to statistical analysis. Pearson correlations of chemical traits and sensory traits (panel average) were higher for skatole [r(1029) = 0.59; p < 0.001] than for androstenone [r(1029) = 0.44; p < 0.001]. Linear terms of androstenone and skatole as well as their interaction significantly (p < 0.05) contributed to perception of deviant smell (R(2) = 0.43). Standardized regression coefficients illustrate the higher importance of skatole (β = 0.68) than androstenone (β = 0.39). Interindividual differences in the responses of assessors to androstenone and skatole are confirmed. A new curved approach is suggested because it better accounts for the interaction of androstenone and skatole than the "safe box" approach. On the basis of these data, sorting strategies using instrumental measurements are discussed. An automated detection based on only skatole measurements is recommended because its performance is only slightly inferior to a sorting based on both androstenone and skatole. Sorting thresholds need to be calibrated against consumer acceptance though.

Sensory evaluation of meat from entire male pigs raised with different feeding and housing conditions

“…However, slaughtering entire male pigs implies the risk of having carcasses with the so-called boar taint (Aaslyng, Broge, Brockhoff, & Christensen, 2015) posing a risk to the entire pork supply chain therefore being a significant barrier to the banning of the undesirable practice of piglet castration (Mathur et al, 2012). Boar taint is described as a penetrating 'animal', 'urine', 'faecal' or 'sweat' like unpleasant odour which becomes especially intense when pork is cooked (Mathur et al, 2012), and is mainly associated with the presence of skatole and androstenone, but animal tissues contain varying levels of other compounds, such as indole and other steroids, that can influence the perceptions of the main contributors of boar taint (AnnorFrempong, Nute, Whittington, & Wood, 1997;Morlein et al, 2016). Skatole (3-methylindole) is a metabolite derived from the amino acid tryptophan produced in the lower gut by intestinal bacterial flora, and androstenone (5α androst-16-en-3-one) is a steroid produced in the testis (Aldal et al, 2005;Chen, Zamaratskaia, Andersson, & Lundstrom, 2007;Lunde et al, 2010).…”

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

“…The sample material was derived from a larger study aiming to validate genomic selection for reduced boar taint (STRAT-E-GER Project); for more detailed information see [15]. The samples were taken at a commercial abattoir (Tönnies Lebensmittel GmbH & Co. KG–Home; Long: 8.32240°E; Lat: 51.86262°N).…”

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“…vary a lot but also that there are other factors affecting this scent, for example, the fat content and matrix itself also differ between animals (Morlein et al, 2016). Results showed that panellists discriminate meat samples from animals with inulin addition in its feeding portions.…”

“…In this study, cooked belly meat from uncastrated pigs raised under different levels of housing and feeding, was analysed to verify if there was sensory perception of different levels of androstenone and skatole. There is little data available concerning boar taint evaluation with regard to assessor reliability (Morlein et al, 2016). However, to evaluate the repeatability of panellists, two samples of the same condition groups were served twice with different codes.…”