ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Maturity and storage of Jonagold apples.

Lau, O. L.;

Tree Fruit Postharvest Journal Year: 1992 Vol: 3 Issue: 4 Pages: 10-13 Ref: 2 ref.

1992

บทคัดย่อ

Fruits of Jonagold trees on MM.111 rootstock planted in 1974 were used to identify practical harvest indices and to determine storability of fruits in air and controlled atmosphere (CA) storage in relation to harvest maturity. The results indicate that Jonagold fruits are ready to be picked for long-term storage when the fruits have acquired some of the following characteristics (in order of importance): starch index 6.5-less than or equal to 7.5 starch index number in a 1-9 system, flesh firmness more than or equal to 16.0-17.0 pounds pressure, water core 0-less than or equal to 12% of fruits affected, yellow ground colour 4.0-4.5 (lower for high N fruits) on the Golden Delicious Colour Meter, internal ethylene concentration 0.1-less than or equal to 1.5 p.p.m. or 0-less than or equal to 40% of fruits with an IECmore than or equal to 1 p.p.m., titratable acidity more than or equal to 0.6-0.7% malate, and soluble solids more than or equal to 12.5-14.5%. Fruits harvested at an optimal maturity (within one week of the first acceptable picking date) kept well in air at 0 deg C until Feb. Fruits kept for longer than 4 months, especially those picked late in the season, were soft, bland in taste and prone to breakdown and core flush. Fruits picked at an optimal maturity could be held in 1.5% O2 + 1-5% CO2 at 0 deg until June without any breakdown or fruit injury symptoms. CA-stored fruits retained better quality than air-stored fruits.