Selecting and Training a Panel to Evaluate the Metallic Sensation of Meat

Abstract

The objective was to select and train assessors to evaluate metallic sensations in beef. The detection threshold of FeSO 4 .7H 2 O was determined using the method of limits. Twenty-six undergraduates participated in the test, and a single detection threshold was determined. Candidates with a threshold lower than or equal to the general value threshold were accepted. Next, the performance of the accepted candidates was evaluated using meat from the semimembranosus muscle of bovines at an internal cooking temperature of 65, 72 or 75℃. The metallic sensation in the meat was evaluated using the ranking test and an unstructured 9.0 cm line scale. The extremes of the scale have the expression not perceptible and highly perceptible. The assessors were selected to help the team analyze the discriminative power, reproducibility and overall use of scale. The results demonstrated that the processes for selecting and training assessors to evaluate the metallic sensation in meat were adequate.

Metallic Sensation—Just an Off-Flavor or a Biologically Relevant Sensing Pathway?

“…16 For coffee, several compounds related to either roasting parameters or unfavorable concentrations in the green beans may lead to metallic offflavors, such as dicaffeoylquinic acids. 17 On the other hand, metallic perceptions are used as valuable flavor descriptors to assess product quality, e.g., for beef 18 or freshwater fish. 19 Even though the biological mechanisms behind metallic sensations are not fully understood, for most of the mentioned products, at least the source inducing the unwanted loss in sensory quality is known, mainly either through the addition of salts or non-nutritional sweeteners or as a side effect of lipid oxidation.…”

“…For coffee, several compounds related to either roasting parameters or unfavorable concentrations in the green beans may lead to metallic off-flavors, such as dicaffeoylquinic acids . On the other hand, metallic perceptions are used as valuable flavor descriptors to assess product quality, e.g., for beef or freshwater fish…”

Selecting and training a panel to evaluate the rancid defect in soybean oil and fish hamburgers

“…Elortondo et al (2007) and Mitterer-Daltoé et al (2012) validated the sensory panel with a product that recalled the sensation by which the panel had been trained. Elortondo et al (2007) didn't use ANOVA for this purpose, only the percentage, where a sensation mentioned by 66.6% of assessors was considered a parameter, in which they were trained afterwards.…”

“…The samples were cut into uniform sizes of about 1.5 cm³, and maintained at 75 ºC (internal center) to the time of delivery (Mitterer-Daltoé et al 2012) using plastic cups coded with three-digit random numbers. Water at room temperature was provided to clean the mouth between samples.…”

Metallic: A Bivalent Ambimodal Material Property?

“…Intriguingly, however, consumers apparently got used to this particular metallic taint, with some even complaining when improvements in packaging design eventually eliminated this fault, or taint (Rosenbaum, 1979, p. 81). One also finds metallic characteristics reported in the assessment of various species of freshwater fish (Chambers & Robel, 1993), not to mention metallic sensations appearing in the panel rating of fresh red meat (Mitterer-Daltoe et al, 2012). Metallic is sometimes also mentioned as a sensory descriptor in the evaluation of coffee (Bicho et al, 2012), and occasionally in the dysguesia that has come to be known as pine nut syndrome (Ballin, 2012).…”