The high and significant
weighted regression coefficients (BW) obtained from the estimated
PLS models identified the X-variables that mostly contributed to
the differences observed in the corresponding sensory attribute
(Table 6). Concentration of organic acids was confirmed to be a
good predictor of sour taste in apples, as previously observed
(Harker et al., 2002). The range of treatment mean values for the
sum of acids found in the second year samples, approximately
1.0 mg/g, exceeded the magnitude of concentration change that
was determined to be required to produce a perceptible sourness
difference in apples, 0.8 mg/g (Harker et al., 2002).