ANALYSIS OF VARIATION AND MULTIVARIATE RELATIONSHIPS AMONG ANALYTICAL AND SENSORY CHARACTERISTICS IN WHOLE APPLE EVALUATION

Sources of variation affecting assessment of whole apple fruit quality were identified and multivariate relationships between analytical and sensory characteristics examined. Fourteen analytical measurements (pH, soluble solids (SS), titratable acidity (TA), flesh L, flesh b, flesh a, flesh hue angle, weight, internal ethylene, skin L, skin a, skin b, starch skin hue-angle) and six sensory characteristics (juiciness, crispness, firmness, fruit flavour, sweetness and sourness) were evaluated on samples from the same apple quarters. Variation in fruit quality among apples of three red categories (15-25%, 50-60%, 85-95%) and within apples due to side-to-side (blush versus non-blush) and top-to-bottom were documented. Highly coloured 'McIntosh' apples (85-95% red) were significantly heavier, sweeter, and had a higher pH than those with less colour development. The non-blush sides of the apples were significantly more crisp and less sweet than the blush sides. Highly coloured 'Jonagold' apples (85-95%) were significantly sweeter and fruitier. The bottom sections of both the 'McIntosh' and 'Jonagold' apples had significantly lower pH than the top. The bottom sections of 'McIntosh' apples were sweeter; whereas the bottom sections of 'Jonagold' were less crisp and more fruity. For 'McIntosh' and 'Jonagold' cultivars, canonical correlation analyses elucidated three and two underlying dimensions, respectively, that characterised the relationships among the analytical and sensory variables. For both cultivars, discriminant analysis was successful in differentiating the red classifications using the analytical and sensory variables.