Effect of storage conditions on the chemical composition of Actinidia kolomikta fruits

Abstract

Actinidia kolomikta fruits are evaluated as a healthy fruits because of high content of ascorbic acid and their antioxidant activity. But the fresh fruit can be stored for only two weeks in the refrigerator. Storage time are prolonging on creating optimal conditions. Investigations were carried out at the Aleksandras Stulginskis University, Lithuania, in 2015. Object of the research was fruits of Actinidia kolomikta (Maxim. & Rupr.) Maxim.) cultivars ʽLankėʼ, ʽLandėʼ, ʽLaibaʼ, ʽPaukštės Šakarvaʼ. The aim of the research was to analyse the changes in basic chemical parameters of Actinidia kolomikta fruits during ripening in the controlled atmosphere chambers. Fruits were stored in controlled atmosphere chambers for 6 weeks in the same temperature (0 ºC) and humidity (90 %), but in different air composition (No. 1. – 21 % O2, 78 % N2; No. 2. – 0,5 % O2, 98,5 % N2, 1 % CO2; No. 3 – 1,5 % O2, 95,5 % N2, 3 % CO2; No. 4. – 2 % O2, 93 % N2, 5 % CO2, 0,03 ppm C2H4). Dry matter content was determined by drying the samples to constant mass at 105 °C; soluble solids content – by refractometric method; ascorbic acid – by titration with 2.6-dichloroindophenol sodium salt; chlorophylls and carotenoids – by two-ray UV spectrophotometer. The largest amounts of ascorbic acid and pigments were identified in Actinidia kolomikta fruits just after harvest whereas the levels of dry matter and soluble solids increased during storage. Ascorbic acid content decreased during storage, the biggest amount remained in ʽLandėʼ fruits. After 6 weeks ‘Paukštės Šakarva’ fruits, stored in 3rd chamber, were the most ripe.