Determination of physicochemical and antioxidant properties of fruit extracts of two lemon varieties (Cook Eureka and Khoushehi) during ripening and shelf life.

In this research, physicochemical and antioxidant properties of two varieties of lemon (Cook Eureka and Khoushehi) were evaluated during two years by sampling from October 17 to November 16, every 10 days (four times) from trees and at the end of shelf life period. The results showed, generally, the size and volume of fruit of Cook Eureka was large and Khoushehi lemon was small. The fruit weight and juice percentage in Cook Eureka did not change significantly (p<0.05) during harvesting time and shelf life. The TSS/TA ratio also increased during ripening and shelf life, with the exception of the Khoushehi fruits which harvested on November 16. Although the technology index in Cook Eureka was not significantly change during harvesting times, but the peel thickness of Khoushehi fruits decreased during shelf life. In general, the values of L*, a* and b* color indices in both varieties and experiment were high from first to last harvest times. Also, amount of Chroma and CCI showed an increase pattern during shelf life. Fruits picked at the last harvest (Nov. 16), which had the highest amount of vitamin C (28.31 mg/100gFW), also had the highest vitamin C levels at the end of shelf life (42.64 mg/100gFW). Totally, the total phenol and antioxidant content of fruit were increased during shelf life period in both varieties.