Abstract:To develop a rapid and non-destructive method for detecting the internal quality of the “Shenzhou Peaches”, the SACMI near-infrared analyzer was used in the diffuse reflection for non-destructive measurements of the soluble solid content (SSC), firmness, and pH of fruits ready for harvest. The results were compared with those obtained by traditional methods. The results reveal that, after excluding outliers, the correlations between the predicted SSC values by the non-destructive method and the measured values using traditional methods (R2=0.79, p<0.01, SEP=0.47) are better than those of firmness (R2=0.47, p<0.01, SEP=2.01) and pH (R2=0.40, p<0.01, SEP=0.14). The SSC model (RPD=2.15, RMSEP=0.79%, RSD=6.2%) exhibits better prediction performances and can enable rapid detection. Meanwhile, the pH model (RPD=1.29, RMSEP=0.16, RSD=3.1%) and the firmness model (RPD=1.37, RMSEP=2.37 kg/cm2, RSD=39.4%) gave less satisfactory prediction results. This research has shown that detecting the SSC of “Shenzhou Peach” fruits is feasible with a near-infrared analyzer. This is a real-time, fast and non-destructive method for the internal quality evaluation of fruits. This finding can provide a theoretical foundation and technical support for intelligent future grading and classification of fruits.