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

Abstract

SUMMARY:Due to its composition of unsaturated and polyunsaturated fatty acids, oils and fats are very susceptible to oxidation, with rancidity being one of the main defects. Among the several existing methodologies to monitor oxidation in foods, sensory analysis stands out because of the sensitivity of responses. Accordingly, this study aimed to select and train a panel of expert assessors to identify the rancid flavor, showing the statistical steps in the process. Assessors were selected according to their individual performance, statistically analyzed by ANOVA and Tukey's mean comparison, Wald Sequential Analysis and chi-square test. The validation of the trained panel was carried out with the sensory analysis of fish burgers and soybean oil. F Value and box-plot graphic methods were effective for better visualization of results when used along with the mean and standard deviation tables. The final trained panel consisted of seven assessors, who have been able to identify and differentiate rancid taste in both samples used for validation. KEYWORDS: Bioactive Phytochemicals; Fish; Flavors; Food Quality; Sensory AnalysisRESUMEN: Selección y entrenamiento de un panel para evaluar el defecto rancio en aceite de soja y hamburguesas de pescado. Debido a su composición en ácidos grasos insaturados y poliinsaturados, los aceites y grasas son muy susceptibles a la oxidación, siendo la rancidez uno de los principales defectos. Entre las diversas metodologías existentes para seguir la oxidación en los alimentos, el análisis sensorial destaca por la sensibilidad de las respuestas. Este estudio tuvo como objetivo seleccionar y capacitar a un panel de catadores entrenados para identificar el sabor rancio y se muestra estadisticamente los pasos del proceso. Los catadores fueron seleccionados de acuerdo a su capacidad individual y estadísticamente analizados por ANOVA comparando las medias mediante Tukey, análisis secuencial de Wald y prueba de chi-cuadrado. La validación del panel entrenado se realizó con el análisis sensorial de hamburguesas de pescado y aceite de soja. El valor F y la representación gráfica boxplot fueron eficaces para una mejor visualización de los resultados cuando se utilizan junto con las tablas de desviación media y estándar. El panel final estuvo formado por siete catadores que fueron capaces de identificar y diferenciar el sabor rancio en ambas muestras utilizadas para su validación.

Survival analysis and cut-off point to estimate the shelf life of refrigerated fish burgers

“…The burgers were prepared, 18 hours after slaughtering, in the Food Technology Lab at UTFPR (N008) according to the formulation described by (Marques et al, 2017). The fillets were removed from the freezer, ground in a food processor, basic washed, mixed in a sanitized bowl (Figure 1a), shaped into 125g units and sealed in a portable vacuum machine (Figure 1b).…”

“…A previously trained panel (Marques et al, 2017) of 7 assessors and evaluated the rancid flavor. The score form had a 10 cm unstructured scale to distribute the samples within this range, anchored in "no rancid flavor" and "pronounced rancid flavor".…”