INSTRUMENTAL AND SENSORY EVALUATION OF THE FLAVOR OF DRIED FRENCH BEANS (PHASEOLUS-VULGARIS) INFLUENCED BY STORAGE-CONDITIONS

The influence of storage conditions on the flavour of stored French beans after rehydration was evaluated by gas chromatography-sniffing port analysis (GC-SP) and GC-mass spectrometry of volatile compounds, and by quantitative descriptive analysis (QDA) and hedonic sensory evaluation. The dried beans were stored at three water activities (a(W)), two different temperatures and in presence or absence of light. In French beans 18 odour active volatile compounds were detected and a common odour profile of 10 compounds was shown. At elevated temperature and a(W) 0.3 and 0.5, GC-SP showed an increase in the number of assessors perceiving chemical, rotten odours at the sniffing port. The number assessors perceiving chemical odours at the sniffing port was increased by light exposure at a(W) 0.1. QDA revealed a significant decrease in intensities for the attributes 'French bean' and 'sweet', and an increase for 'chemical', 'burned', 'musty' and 'bitter' at the elevated temperature and a(W) 0.3 and 0.5. Exposure to light at a(W) 0.1 decreased 'French bean' scores and increased scores for 'chemical' and 'burned'. French beans stored at 20 degrees C in absence of light and at a(W) 0.3 were more appreciated by the hedonic panel than those stored at 40 degrees C. GC-SP and QDA revealed relationships between differently stored French beans, sensory attributes and volatile compounds. Therefore, volatile compounds are expected to be responsible for the change in flavour and appreciation of dried French beans by storage conditions.