2.1.fruit source and ripening
Unripe green ‘Hass’ avocado fruit were harvested from three growers in the North Island,new Zealand,during march 2011 (late maturity).fruit were commercially packed and transported to the plant & food research laboratory in Auckland within 4 days of harvest and held in cool storage ( 5 °C) for 3 weeks. fruit were ripened using 100 μL L^(-1) ethylene for 24 h at 20°C and allowed to the target fruit firmness.fruit firmness was measured using Aweta AFS (AWETA Impact & Acoustic Firmness system,nootdorp,nootdorp,Holland),and fruit were selected in the range of 20-26 Acoustic Index (all) (equivalent to 0.6-0.8 kgf Effegi puncture 8-mm probe),or ‘firm-ripe’ on the hand-firmness scale ( rating of 3.5-4) (white,woolf,hofman,&arpaia,2005).