Physico-Chemical Analysis of Internal Bruise of Selected Fruits Using Chemical Shift Imaging

摘要

Chemical shift imaging (CSI) is a spectroscopic imaging technique which provides both spatial and spectroscopic information of internal physico-chemical properties of test samples and, thus, it is a useful tool for assessing the distribution of internal characteristics of fruits or vegetables. In this study, CSI was applied in detecting the internal properties of bruises in apples and plums subjected to mechanical impact. MR spectroscopic correction and image fusion were employed in correcting fieldinhomogeneity and displaying CSI experimental results. The result images reflected the variation of some phenolic compounds and water content in the bruised and fleshy parts of the fruits on the first day and the seventh day after bruising. The quantityof phenolic compounds in the bruised part in apples and plums decreased after 7 days, but it in the fleshy part increased after 7 days. Water content in apple has the similar result of phenolic compounds, it reduced in bruised part after 7 days later. HPLC experiments were applied to support the CSI results, in HPLC analyses, phenolic compounds would increase in bruised and fleshy parts in apples and plums by the 7th day, and on the 7th day, phenolic compounds in fleshy part in apples were more than that in the bruised part. However, phenolic compounds in the bruised part of plums were more than that in the fleshy part. The results of 7th day between CSI and HPLC are consistent. This study demonstrates that CSI is a feasible method for non-invasive assessment of internal physico-chemical properties of biological materials.