45Ca mobility and distribution during ripening and maturation of Rutgers and RIN tomatoes

Authors

• L. R. Howard University of Arkansas, Department of Food Science, Route 11, Fayetteville, AR, 72703
• A. Uusi-Rauva University of Helsinki, Faculty of Agriculture and Forestry, Instrument Centre, Viikki, SF-00710 Helsinki, Finland
• J. J. Laine University of Helsinki, Department of Food Chemistry and Technology SF-00710 Helsinki, Finland

DOI: https://doi.org/10.23986/afsci.72217

Abstract

Radioisotope 45Ca was used to examine changes in levels of bound and soluble calcium during tomato fruit ripening, and the distribution of calcium in different regions of Rutgers and Rin (non-ripening) tomato tissue. Levels of cell wallmiddle lamella bound 45Ca decreased readily in pericarp tissue during ripening of Rutgers tomatoes with only as mall decrease being observed in RIN fruit. No significant increase in soluble 45Ca was observed for either genotype during ripening. Decreasing levels of bound and soluble 45Ca were observed from calyx to blossom end of pericarp tissue in Rutgers and RIN fruits. Low levels of bound 45Ca were found in the inner locular walls at an early stage of tomato ripening. The implication of low levels of cell wall bound calcium in relation to catabolic changes associated with ripening are discussed.