Novel ECL Method for the Determination of Skatole in Porcine Adipose Tissue.

A new method for the determination of skatole present in porcine adipose tissue samples utilizing the electrochemiluminescence of skatole is presented. It has been observed that oxygen radicals produced at a high cathodic voltage can react with oxidized skatole to create an excited intermediate molecule that then relaxes, generating peak photon emission at around 480 nm. A strong electrochemiluminescence or electrogenerated chemiluminescence (ECL) signal using boron-doped diamond (BDD) electrodes was observed optimally when a reduction potential of -1.8 V was applied, held for 40 s, before holding an oxidation potential of 0.8 V for 10 s. Using this principle, a calibration curve using known concentrations of skatole showed good linearity (range 0.025-2 µM) and a very low detection limit (LOD, 0.7 nM). A method that demonstrates for the first time an approach that utilizes this ECL reaction, and has the potential to be developed into an analytical device for use in the slaughterhouse, has been developed. This was achieved by extracting skatole out of the porcine adipose tissues into acetonitrile - giving an extraction efficiency of 67.6%. This method was then validated by analyzing the skatole content of 33 pig fat samples that had been previously tested using a standard technique, high-performance liquid chromatography (HPLC), containing a range of concentrations (0.02-2.58 µg/g). This ECL method exhibited excellent reliability and correlation with HPLC, giving a R2 coefficient of 0.911, thus demonstrating the potential for this method to be developed for an on-line skatole detector.

Development of an analytical method for the determination of sterol compounds in boars' saliva.

"Boar taint" compounds influence the sexual behavioral responses of sows and stimulate their reproduction. This paper reports a fast, easier, and a non-invasive analytical method for the analysis of three "boar taint" compounds in boar' saliva samples: androstenone, androsten-3α-ol, and androsten-3ß-ol. This method was developed and validated based on solid-phase extraction (SPE) and multidimensional gas chromatography-mass spectrometry (MDGC-MS). All the compounds were detected without derivatization. This method affords good reproducibility (4%-8%), accuracy (80%-105%), precision (5.5%-9.1%), linearity (R2 = 0.98-0.99), and lower limits of quantitation (LLOQ) (0.1-0.2 µg/L). Although the presence of these compounds in saliva has been known for a long time, no simple and easy analytical method has been developed.

Genomic background and genetic relationships between boar taint and fertility traits in German Landrace and Large White.

BACKGROUND: Due to ethical reasons, surgical castration of young male piglets in their first week of life without anesthesia will be banned in Germany from 2021. Breeding against boar taint is already implemented in sire breeds of breeding organizations but in recent years a low demand made this trait economically less important. The objective of this study was to estimate heritabilities and genetic relationships between boar taint compounds androstenone and skatole and maternal/paternal reproduction traits in 4'924 Landrace (LR) and 4'299 Large White (LW) animals from nucleus populations. Additionally, genome wide association analysis (GWAS) was performed per trait and breed to detect SNP marker with possible pleiotropic effects that are associated with boar taint and fertility. RESULTS: Estimated heritabilities (h2) were 0.48 (±0.08) for LR (0.39 ± 0.07 for LW) for androstenone and 0.52 (±0.08) for LR (0.32 ± 0.07 for LW) for skatole. Heritabilities for reproduction did not differ between breeds except age at first insemination (LR: h2 = 0.27 (±0.05), LW: h2 = 0.34 (±0.05)). Estimates of genetic correlation (rg) between boar taint and fertility were different in LR and LW breeds. In LR an unfavorable rg of 0.31 (±0.15) was observed between androstenone and number of piglets born alive, whereas this rg in LW (- 0.15 (±0.16)) had an opposite sign. A similar breed-specific difference is observed between skatole and sperm count. Within LR, the rg of 0.08 (±0.13) indicates no relationship between the traits, whereas the rg of - 0.37 (±0.14) in LW points to an unfavorable relationship. In LR GWAS identified QTL regions on SSC5 (21.1-22.3 Mb) for androstenone and on SSC6 (5.5-7.5 Mb) and SSC14 (141.1-141.6 Mb) for skatole. For LW, one marker was found on SSC17 at 48.1 Mb for androstenone and one QTL on SSC14 between 140.5 Mb and 141.6 Mb for skatole. CONCLUSION: Knowledge about such genetic correlations could help to balance conventional breeding programs with boar taint in maternal breeds. QTL regions with unfavorable pleiotropic effects on boar taint and fertility could have deleterious consequences in genomic selection programs. Constraining the weighting of these QTL in the genomic selection formulae may be a useful strategy to avoid physiological imbalances.

Effects of dietary stachyose levels on caecal skatole concentration, hepatic cytochrome P450 mRNA expressions and enzymatic activities in broilers.

Effects of dietary supplemental stachyose on caecal skatole concentration, hepatic cytochrome P450 (CYP450, CYP) mRNA expressions and enzymatic activities in broilers were evaluated. Arbor Acre commercial mixed male and female chicks were assigned randomly into six treatments. The positive control (PC) diet was based on maize-soyabean meal, and the negative control (NC) diet was based on maize-non-soyabean meal. The NC diet was then supplemented with 4, 5, 6 and 7 g/kg stachyose to create experimental diets, named S-4, S-5, S-6 and S-7, respectively. Each diet was fed to six replicates of ten birds from days 1 to 49. On day 49, the caecal skatole concentrations in the PC, S-4, S-5, S-6 and S-7 groups were lower than those in the NC group by 42·28, 23·68, 46·09, 15·31 and 45·14 % (P < 0·01), respectively. The lowest pH value was observed in the S-5 group (P < 0·05). The stachyose-fed groups of broilers had higher caecal acetate and propionate levels compared with control groups, and propionate levels in the S-6 and S-7 groups were higher than those in the S-4 and S-5 groups (P < 0·001). The highest CYP3A4 expression was found in the S-7 group (P < 0·05), but this was not different from PC, S-4, S-5 and S-6 treatments. There was no significant difference in CYP450 (1A2, 2D6 and 3A4) enzymatic activities among the groups (P > 0·05). In conclusion, caecal skatole levels can be influenced by dietary stachyose levels, and 5 g/kg of stachyose in the diet was suggested.

Reduction of androstenone perception in pan-fried boar meat by different masking strategies.

BACKGROUND: Consumers highly sensitive to androstenone María (AND) will probably reject meat from entire male pigs, which tends to have high levels of this hormone. To avoid this, the effect of different masking strategies (sprinkling with mixed spices or fennel, marinating and breading with garlic-parsley or curry) on the sensory parameters of pork loin chops obtained from entire animals with high levels of AND (1.0-2.9 mg kg-1 AND in fat) and castrated animals (<0.4 mg kg-1 AND in fat), both with low levels of skatole (<0.1 mg kg-1 skatole in fat) was investigated. RESULTS: The garlic-parsley breadcrumbs led to the highest reduction in the perception of AND compared with the other masking strategies used, and preserved the juiciness of the product. There was a negative correlation between AND and fat content. CONCLUSION: AND odor and flavor can be reduced in meat from entire male pigs by using suitable strategies, the best strategy being the garlic-parsley breadcrumbs. © 2017 Society of Chemical Industry.

Fine mapping of a QTL affecting levels of skatole on pig chromosome 7.

BACKGROUND: Previous studies in the Norwegian pig breeds Landrace and Duroc have revealed a QTL for levels of skatole located in the region 74.7-80.5 Mb on SSC7. Skatole is one of the main components causing boar taint, which gives an undesirable smell and taste to the pig meat when heated. Surgical castration of boars is a common practice to reduce the risk of boar taint, however, a selection for boars genetically predisposed for low levels of taint would help eliminating the need for castration and be advantageous for both economic and welfare reasons. In order to identify the causal mutation(s) for the QTL and/or identify genetic markers for selection purposes we performed a fine mapping of the SSC7 skatole QTL region. RESULTS: A dense set of markers on SSC7 was obtained by whole genome re-sequencing of 24 Norwegian Landrace and 23 Duroc boars. Subsets of 126 and 157 SNPs were used for association analyses in Landrace and Duroc, respectively. Significant single markers associated with skatole spanned a large 4.4 Mb region from 75.9-80.3 Mb in Landrace, with the highest test scores found in a region between the genes NOVA1 and TGM1 (p < 0.001). The same QTL was obtained in Duroc and, although less significant, with associated SNPs spanning a 1.2 Mb region from 78.9-80.1 Mb (p < 0.01). The highest test scores in Duroc were found in genes of the granzyme family (GZMB and GZMH-like) and STXBP6. Haplotypes associated with levels of skatole were identified in Landrace but not in Duroc, and a haplotype block was found to explain 2.3% of the phenotypic variation for skatole. The SNPs in this region were not associated with levels of sex steroids. CONCLUSIONS: Fine mapping of a QTL for skatole on SSC7 confirmed associations of this region with skatole levels in pigs. The QTL region was narrowed down to 4.4 Mb in Landrace and haplotypes explaining 2.3% of the phenotypic variance for skatole levels were identified. Results confirmed that sex steroids are not affected by this QTL region, making these markers attractive for selection against boar taint.

Temperature-dependent Henry's Law constants of 4-alkyl branched-chain fatty acids and 3-methylindole in an oil-air matrix and analysis of volatiles in lamb fat using selected ion flow tube mass spectrometry.

RATIONALE: 4-Alkyl branched-chain fatty acids and 3-methylindole are characteristic flavor compounds associated with sheep meat. Determining their partitioning behavior between the gas and condensed phase and ultimately developing a correlation between the compound's headspace concentration and sensory descriptive grouping are important for high-throughput characterization and grading classification. METHODS: The headspace concentrations of 3-methylindole, 4-methyloctanoic acid, 4-ethyl-octanoic acid, and 4-methylnonanoic acid above corn-oil-based standard solutions and lamb fat samples were measured using selected ion flow tube-mass spectrometry (SIFT-MS). The standard solutions were equilibrated at 80, 100, 110 and 125°C while the fat samples were equilibrated at 125°C. Statistical evaluation, linear and polynomial regression analyses were performed to establish the compound-specific and temperature-dependent Henry's Law constants, enthalpy (ΔH) and entropy (ΔS) of phase changes. RESULTS: The Henry's Law constants (kHcp ) were calculated from the regression analysis with a high degree of confidence (p < 0.05) and linearity (r2  > 0.99). The kHcp increased with increase in equilibrium temperature. The empirical calculation of ΔH and ΔS at different temperatures confirmed the temperature-dependence of the Henry's Law constants. The headspace concentrations of the lamb-flavor compounds were determined above actual lamb fat samples and the corresponding condensed-phase concentrations were successfully derived. CONCLUSIONS: The temperature-dependent Henry's Law constants, ΔH, and ΔS of phase changes for 3-methylindole, 4-methyloctanoic acid, 4-ethyloctanoic acid, and 4-methylnonanoic acid in an air-oil matrix were empirically derived. The effectiveness of SIFT-MS for the direct, real-time, and rapid determination of key flavor compounds in lamb fat samples was established.

Development of recombinant antibody-based enzyme-linked immunosorbent assay (ELISA) for the detection of skatole.

The occurrence of boar taint and the European Commission recommendation to discontinue the surgical castration of pigs by the year 2018 creates an urgent need for new analytical methods that are simple, affordable, and suitable for field testing. We describe the generation and engineering of a skatole-specific antibody derived from a synthetic antibody library and the development of ELISA for its detection. The immunoassay is capable of detecting skatole with IC50 of 222 µg L(-1), which is within the analytical threshold level suggested for skatole, and with low cross-reactivity interference from other indolic compounds.

Simultaneous quantification of the boar-taint compounds skatole and androstenone by surface-enhanced Raman scattering (SERS) and multivariate data analysis.

This study investigates the feasibility of using surface-enhanced Raman scattering (SERS) for the quantification of absolute levels of the boar-taint compounds skatole and androstenone in porcine fat. By investigation of different types of nanoparticles, pH and aggregating agents, an optimized environment that promotes SERS of the analytes was developed and tested with different multivariate spectral pre-processing techniques, and this was combined with variable selection on a series of analytical standards. The resulting method exhibited prediction errors (root mean square error of cross validation, RMSECV) of 2.4 × 10(-6) M skatole and 1.2 × 10(-7) M androstenone, with a limit of detection corresponding to approximately 2.1 × 10(-11) M for skatole and approximately 1.8 × 10(-10) for androstenone. The method was subsequently tested on porcine fat extract, leading to prediction errors (RMSECV) of 0.17 µg/g for skatole and 1.5 µg/g for androstenone. It is clear that this optimized SERS method, when combined with multivariate analysis, shows great potential for optimization into an on-line application, which will be the first of its kind, and opens up possibilities for simultaneous detection of other meat-quality metabolites or pathogen markers. Graphical abstract Artistic rendering of a laser-illuminated gold colloid sphere with skatole and androstenone adsorbed on the surface.

Efficiency of genomic prediction for boar taint reduction in Danish Landrace pigs.

Genetic selection against boar taint, which is caused by high skatole and androstenone concentrations in fat, is a more acceptable alternative than is the current practice of castration. Genomic predictors offer an opportunity to overcome the limitations of such selection caused by the phenotype being expressed only in males at slaughter, and this study evaluated different approaches to obtain such predictors. Samples from 1000 pigs were included in a design which was dominated by 421 sib pairs, each pair having one animal with high and one with low skatole concentration (≥0.3 µg/g). All samples were measured for both skatole and androstenone and genotyped using the Illumina SNP60 porcine BeadChip for 62 153 single nucleotide polymorphisms. The accuracy of predicting phenotypes was assessed by cross-validation using six different genomic evaluation methods: genomic best linear unbiased prediction (GBLUP) and five Bayesian regression methods. In addition, this was compared to the accuracy of predictions using only QTL that showed genome-wide significance. The range of accuracies obtained by different prediction methods was narrow for androstenone, between 0.29 (Bayes Lasso) and 0.31 (Bayes B), and wider for skatole, between 0.21 (GBLUP) and 0.26 (Bayes SSVS). Relative accuracies, corrected for h(2) , were 0.54-0.56 and 0.75-0.94 for androstenone and skatole respectively. The whole-genome evaluation methods gave greater accuracy than using only the QTL detected in the data. The results demonstrate that GBLUP for androstenone is the simplest genomic technology to implement and was also close to the most accurate method. More specialised models may be preferable for skatole.

Enhanced HPLC Method for Boar Taint Quantification.

Boar taint is an unpleasant odour found in the carcasses of entire male pigs, resulting from androstenone and skatole accumulation during pubertal development, and impacting pork quality. This study proposes the validation of an adapted chromatographic method for quantifying skatole and androstenone in the pigs' liquid fat using fluorescence detection. A good chromatographic separation was achieved, with skatole (SKA) and androstenone (AND) elution at 4.4 and 9.9 min., respectively. An external calibration method was applied, with calibration curves correlation coefficient of 0.9999 for both analytes. Detection limit values were 1.53 and 16.02 ng/g for SKA and AND, respectively. SKA recovery was 99.72±2.34 % (2.34 % RSD) and 102.84±1.62 % (1.57 % RSD) for AND. Results showed good precision values (repeatability <2.46 % RSD for SKA, <6.85 % RSD for AND; intermediate precision <2.87 % RSD for SKA, <6.98 % RSD for AND). The method's robustness was tested and the values were within the reference ranges. The validation results proved that the adaptation of an existing method resulted in good assessments of robustness, reliability and accuracy.

Development and validation of a classification model for boar taint detection in pork fat samples.

This study aims to characterize a complete volatile organic compound profile of pork neck fat for boar taint prediction. The objectives are to identify specific compounds related to boar taint and to develop a classification model. In addition to the well-known androstenone, skatole and indole, 10 other features were found to be discriminant according to untargeted volatolomic analyses were conducted on 129 samples using HS-SPME-GC×GC-TOFMS. To select the odor-positive samples among the 129 analyzed, the selection was made by combining human nose evaluations with the skatole and androstenone concentrations determined using UHPLC-MS/MS. A comparison of the data of the two populations was performed and a statistical model analysis was built on 70 samples out of the total of 129 samples fully positive or fully negative through these two orthogonal methods for tainted prediction. Then, the model was applied to the 59 remaining samples. Finally, 7 samples were classified as tainted.

An overlooked compound contributing to boar taint and consumer rejection of meat products: 2-Aminoacetophenone.

Mainly skatole and androstenone have so far been considered causative for boar taint. Using a mixed methods approach it is shown herein that 2-aminoacetophenone (AAP) affects human perception of pork, too. We explored the importance of AAP in four trials: (1) chemical analyses of 221 fat samples from boar carcasses revealed that AAP occurs, on average, in similar quantities as skatole while the levels of androstenone being four-fold. (2) ranking tests with mixtures of androstenone and/or skatole with AAP presented on smell strips to trained sensory assessors showed that AAP amplifies boar odour. In order to study AAP's importance in meat products, four experimental variants of Lyon type sausage were then produced: a control, a product with added skatole (0.075 µg/g fat tissue), with added AAP (0.075 µg/g fat tissue), and with addition of both compounds. (3) results of a consumer discrimination test panel (n = 71) showed that, when added to a sausage system, APP causes a sensory difference of similar size as skatole while the methodology chosen affects the effect size: tetrad tests proved to be more sensitive than duo trio difference tests, in the tetrad test a sensory difference expressed as d' (d-prime) of 1.0 was reached. (4) a hedonic consumer test (n = 121) finally revealed that APP decreased consumer liking of the APP-spiked sausage - even to a stronger extent than skatole. APP caused significant drops in smell, taste, mouth-feel, after-taste and overall liking in Lyoner. Overall the findings suggest that, in the context of pork meat, AAP is of similar olfactory importance as skatole.

Theoretical exploration of the phenolic compounds' inhibition mechanism of heterocyclic aromatic amines in roasted beef patties by density functional theory.

The ability of spices (bay leaf, star anise, and red pepper) and their characteristic phenolic compounds (quercetin, kaempferol, and capsaicin) to inhibit Heterocyclic aromatic amines (HAAs) in roasted beef patties were compared. Density functional theory (DFT) was used to reveal phenolic compounds interacting with HAAs-related intermediates and free radicals to explore possible inhibitory mechanisms for HAAs. 3 % red chili and 0.03 % capsaicin reduced the total HAAs content by 57.09 % and 68.79 %, respectively. DFT demonstrated that this was due to the stronger interaction between capsaicin and the ß-carboline HAAs intermediate (Ebind = -32.95 kcal/mol). The interaction between quercetin and phenylacetaldehyde was found to be the strongest (Ebind = -17.47 kcal/mol). Additionally, DFT indicated that capsaicin reduced the carbonyl content by transferring hydrogen atoms (HAT) to eliminate HO·, HOO·, and carbon-centered alkyl radicals. This study provided a reference for the development of DFT in the control of HAAs.

Voltammetric discrimination of skatole and indole at disposable screen printed electrodes.

In this work, we study the electrochemical behaviour of skatole, one of the compounds responsible for the offensive smell in pork meat that is known as boar taint, at different metal and carbon electrodes. We then demonstrate for the first time that skatole and indole, the main electroactive interferent potentially present in real samples, can be discriminated and separately quantified using cheap and disposable screen printed electrodes (SPE). This implies significant progress compared to the colorimetric method reported by Mortensen in 1983.

Suppression of boar taint in cryptorchid pigs using a vaccine against the gonadotropin-releasing hormone.

Thirteen unilaterally cryptorchid Large White pigs, which had been immunized at 4 and 8 weeks of age and a third time at 64 ± 4 kg body weight against the gonadotropin releasing hormone with the vaccine Improvac®, were slaughtered at the age of 170 ± 9 days at a body weight of 102 ± 12 kg. Twelve pigs tested negative in the olfactory test of the salivary gland; their descended testicles were small and their fat androstenone concentration was low compared to normally developed boars of a previous experiment which had been vaccinated twice with Improvac® according the manufacturer's recommendation. One cryptorchid boar, which tested positive in the olfactory test and whose testicular weight and fat androstenone concentration corresponded to values of unvaccinated boars of the same age, obviously had not responded to the vaccination. It is an open question if the vaccination protocol for normal boars is sufficient to prevent boar taint in the majority of cryptorchid pigs, too.

Treize verrats de la race Grand Porc Blanc ayant une cryptorchidie unilatérale, immunisés contre la gonadolibérine à l'aide du vaccin Improvac® à l'âge de 4 et 8 semaines et une troisième fois à un poids vif de 64 ± 4 kg, ont été abattus à l'âge de 170 ± 9 jours à un poids vif de 102 ± 12 kg. Le test de cuisson de la glande salivaire s'est révélé négatif chez 12 animaux. Ces 12 verrats avaient de petits testicules descendus et une faible concentration d'androsténone dans le tissu adipeux en comparaison à des verrats normalement développés qui, lors d'une étude antérieure, avaient été vaccinés 2 fois selon les recommandations. Un seul verrat cryptorchide a eu une réponse immunitaire insuffisante au vaccin Improvac®, ce qui s'est manifesté par un test de cuisson positif ainsi qu'un poids du testicule descendu et une teneur en androsténone dans le tissu adipeux correspondant aux valeurs observées chez des verrats non immunisés du même âge. La question reste ouverte de savoir si le protocole de vaccination pour verrats normaux est suffisant pour empêcher le développement de l'odeur de verrat chez la plupart des verrats cryptorchides.

Can sensory boar taint levels be explained by fatty acid composition and emitted volatile organic compounds in addition to androstenone and skatole content?

This study aimed at understanding which molecules were responsible for the differences existing in boar taint sensory evaluation. The latter was therefore linked to the results of skatole and androstenone chemical analyses, fatty acid composition and VOC profiles of heated backfat. This study confirmed that some discrepancy exists between chemical analysis and sensory evaluation of tainted backfats. Significant correlations between human nose scores and fatty acid composition were not revealed. Strong correlations between emissions and contents in skatole and androstenone were found. Oxidation products of polyunsaturated fatty acids, with fatty odor descriptors, were found to be more present in the VOC profiles of boar fat considered untainted through the human nose methodology. Weak coefficient of determination for partial least square regression indicates that other factors, yet unknown, are responsible for sensory evaluation outcomes. These findings hence support the idea that high human nose score is mainly due to boar taint compounds rather than general differences in VOC profiles.

Consumer perception of entire male pork coated with spiced edible films as a new product to mask boar taint.

Pork production has undergone a shift towards the rearing of entire male pigs, however, its meat might carry with the presence of boar taint and it would be considered "unfit for human consumption". To offer a new alternative to the pork sector tailored to the needs of consumers, a viable option would be the use of edible spiced gelatin films to help minimize boar taint and improve its marketability. The responses of 120 regular meat consumers to entire pork with high levels of boar taint and castrated pork free of boar taint, both coated with spiced gelatin films were evaluated. They showed a similar response between entire and castrated male pork coated with spiced films, regardless of whether consumers usually detected unpleasant odours (as farm/animal) when consuming pork or not. Therefore, the new spiced films offer a new range of products to consumers as they contribute to the improvement of the sensory quality of entire male pork, especially among consumers who tend to buy new products.

Novel gels and films to mask boar taint in entire male pork.

Boar taint masking strategies were developed using hydrocolloids and spices to produce edible gels and films. Carrageenan (G1) and agar-agar (G2) were used for the gels and gelatin (F1) and alginate+maltodextrin (F2) for the films. The strategies were applied to both castrated (control) and entire male pork with high levels of androstenone and skatole. The samples were evaluated sensorially by a trained tasting panel through quantitative descriptive analysis (QDA). Lower hardness and chewiness of entire male pork, with high levels of boar taint compounds object of study, were found with the carrageenan gel, due to the better carrageenan gel adherence to the loin. The films showed that the gelatin strategy tended to have a certain "sweet" taste, and a higher overall masking than the alginate+maltodextrin film. In conclusion, a trained tasting panel found that gelatin film masked boar taint the most, followed by the alginate+maltodextrin film and the carrageenan-based gel.

Clinical utility of a novel colorimetric chair side test for oral malodour.

AIM: The aim of this study was to evaluate the utility of a simple colorimetric chair side test detecting amines in saliva as an adjunct test in the oral malodour diagnosis. MATERIAL AND METHODS: Non-stimulated saliva samples were collected from 100 volunteers with different degrees of oral malodour. The amount of amines detected by the test was estimated clinically (colorimetric test), confirmed semi quantitatively in the laboratory (standard addition method) and consequently compared with (i) the organoleptic score (OLS); (ii) the volatile sulphur compounds (VSCs) levels (OralChroma(™)) and (iii) the amount of amines detected by means of gas chromatography - mass spectroscopy. RESULTS: The chair side test correlated well (Spearman correlation coefficient: 0.46-0.77), with the OLS, the level of VSCs, and the amines determined by using gas chromatography - mass spectroscopy. The results of the new test for patients with and without oral malodour were significantly different (Mann-Whitney U-test, p < 0.0001). The sensitivity, specificity, and positive and negative predictive value of this chair side test were similar to those of the VSCs evaluations. CONCLUSIONS: These results support the "fit for purpose" of the new chair side test as adjunctive diagnostic tool for oral malodour.