Comparison of Texture Determination Method and Correlation Analysis with Sensory Evaluation of 5 Kinds of Apple

In order to compare different instrumental methods for determining the texture of 5 different kinds of apples, the texture of five different apple cultivars were determined by shear, penetrometer method and texture profile analysis (TPA), and influence of different test conditions on the characterization of apple texture was also studied. Meanwhile, the correlation between the instrumental parameters and sensory evaluation was analyzed. The hardness of apples could be measured and distinguished by shearing, puncturing and TPA compression. The results showed that hardness of peeled flesh ranked in order of Orin > Fuji > Ralls > Jonagold > Golden delicious. The puncture results showed that the peel had a significant effect on the texture of apple (P<0.05), and there was a significant difference in the texture of different puncture locations (P<0.05), the top part of apple showed the maximum hardness, followed by the part of shoulder and equator. The correlation analysis with sensory evaluation showed that the maximum puncture modulus was highly correlated with sensory crispness (r=0.638, P<0.01), which could be used to predict apple crispness. With the increase of deformation rate for TPA method, the tested value of apple hardness increased significantly (P<0.05), while the cohesivenss decreased significantly (P<0.05), and a 25% compression showed best correlation with sensory evaluation. This study indicated that both the puncture and TPA method were suitable for the determination of apple texture. The puncture test was significantly affected by the peel and puncture site, and the maximum puncture modulus could be used to characterize apple crispness. The TPA method had the best correlation with the sensory evaluation when the deformation rate was 25%.