Evaluation of the freshness of fresh-cut green bell pepper (Capsicum annuum var. grossum) using electronic nose

Abstract

This study investigated a freshness assessment method utilizing electronic nose (e-nose) for fresh-cut green bell pepper (Capsicum annuum var. grossum) stored at 7 ± 1 °C. Physicochemical results showed that the fresh-cut green bell peppers were fresh until 5 days and became spoiled at 7 days, particularly as evidenced by a surge in aerobic plate count and malondialdehyde content on subsequent days. The e-nose data combined hierarchical cluster analysis (HCA) can preliminarily distinguish between fresh (days 0, 1, 3 and 5) and spoiled (days 7 and 9) samples. Principal component analysis (PCA) result showed that days 0 and 1 samples were mixed together in PCA plot, and the other different groups can be obtained according to the different sampling days. Partial least squares (PLS) statistical model (R2 = 0.9783, RMSE = 0.3317) was used to correlate the e-nose data with the aerobic plate counts. The results suggested the promising possibility of e-nose system for monitoring freshness of fresh-cut green bell pepper.