QUALITY EVALUATION OF PEACHES AND NECTARINES BY ELECTROCHEMICAL AND MULTIVARIATE ANALYSES - RELATIONSHIPS BETWEEN ANALYTICAL MEASUREMENTS AND SENSORY ATTRIBUTES

A propagation programme for peaches and nectarines has been targeted t o select genotypes having taste attributes such as high sugar levels a nd well-balanced sugar/acid ratios. The analytical measurements of som e soluble sugars and nonvolatile acids were carried out using innovati ve analytical procedures based on fast and selective devices which req uire very little or no sample pre-treatment whatsoever. These devices have found a unique application in detecting fructose, glucose and mal ic acid for the improvement of fruit genetics. The present study exami nes relationships between the analytical measurements of sugars and no n-volatile acids and the sensory attributes (sweetness and sourness) o f 21 peach and nectarine cultivars. Certain chemical parameters were c orrelated with the organoleptic acceptance of common commercial cultiv ars and recently introduced high and low-acid genotypes. Multivariate statistical analyses were found to be useful in describing the variabi lity of the chemical and sensory parameters which characterise peach q uality, as they enabled the identification of sets of variables that c ould be used to classify peaches and nectarines into high and low-acid categories. Malic and citric acids, minor components of these fruits, were important taste attributes as they contributed to the sensory pe rception of sourness. (C) 1997 Elsevier Science Ltd.