Panel calibration methods for sensory testing of food contact materials: Results of inter-comparison trials

Chantal Gilbert

Campden & Chorleywood Food Research Association, U.K.

 c.gilbertcampden.co.uk

EU legislation limits transfer of constituents from contact materials into foodstuffs in quantities that could cause an unacceptable deterioration in sensory characteristics. As part of the collaborative project ‘Calibsensory’, funded by the European Commission GROWTH Programme, calibration methods were developed for sensory analysis of foods in contact with paper and board. Calibration samples and panel training procedures were developed for use in conjunction with two existing European Standards (EN1230-1 for odour and EN1230-2 for off-flavour).

Previously within the project, calibration samples for testing odour, off-flavour in fatty food, and off-flavour in dry food were developed. Samples concentrations were developed to ‘match’ a given intensity on a selected 5-point sensory scale.

Inter-comparison trials were executed to evaluate the calibration procedures for the three types of evaluations. For each trial, the panel calibration procedure consisted of three steps:

A – Assessment of samples before training by a selected sensory panel

B – Training of the panel

C – Assessment after training using the same sensory panel

Data from the assessments conducted before and after training were submitted for analysis. For each participating panel, median scores for each sample were compared with the intended score on the 5-point scale, and confidence intervals from Mood’s median test were used to evaluate discrimination between adjacent samples.

For all trials, accuracy and discrimination improved after training, demonstrating that the calibration procedures improved panel performance. Results of post-trial questionnaires indicated that the feasibility of the trials decreased with increasing difficulty and time for preparation. Cost and difficulty in obtaining equipment also made some trials less feasible in practice.

These calibration procedures will help laboratories implement the procedures described in the EN standards, enabling reproducibility and repeatability of results obtained from sensory evaluation.

Partners: AINIA (Spain), CCFRA (Hungary, UK), CTP (France), Iggesund (Sweden), KCL (Finland), UNEW (UK), and VTT Biotechnology (Finland)

Key words: Calibration methods, Sensory panel, Packaging, Inter-comparison trials