Abstract:

The effect of postharvest heat treatment on fruit quality and reactive oxygen species (ROS) metabolism in
strawberry was investigated by using multivariate analysis in this study. The results of one-way analysis of variance showed
that 60-min heat treatment significantly reduced fruit decay rate, TSS-Acid ratio and MDA content, but increased the
contents of total acid and protein on the 14th day of storage as well as the activities of CAT, PPO and POD on the 14th day
and SOD activity on the 7th day. In contrast, 30-min heat treatment effectively reduced b* and L* values on the 7th day of
storage but markedly increased the contents of total flavonoids and GSH on the 14th day. A remarkable increase of FRAP on
the 7th day and total phenol content on the 14th day was observed in the fruit with 45 min heat treatment before storage. The
results of principal component analysis (PCA) indicated that 60-min heat treatment had a greater impact on b* value, total
acid, CAT, APX, and respiration. The results of path coefficient analysis and partial least squares regression (PLSR) showed
that fruit decay rate was significantly positively correlated with H2O2 content, solid/acid ratio and a* value, but significantly
negatively correlated with total acid, anthocyanin, pH and b* value.

Key words: strawberry, heat shock treatment, fruit quality, reactive oxygen species, multivariate analysis