Effect of Harvesting Stage, Form and Duration of Storage on Some Physico-Chemical Properties of Korarima ( <i>Afframomum</i> (Braun) P.C.M. Jansen) Collected From Masha Woreda, Sheka Zone, Southwestern, Ethiopia

Abstract

Korarima, also called Ethiopian cardamom, is cultivated in the forest areas of southwestern part of Ethiopia. It is an underutilized spice crop with minimal research attention in the past. Moreover, no tangible data is available regarding the harvesting stage, form and duration of storage in relation to the quality. Hence, a study was undertaken to determine the appropriate harvesting stage, form, and duration of storage for an optimum quality of korrorima. Fully mature green and mature red capsules were collected from Masha woreda of the southwestern Ethiopia at peak harvesting time, mid-September and October. The capsules were evaluated for different physico-chemical parameters within laboratory of Jimma university college of Agriculture and Veterinary Medicine (JUCAVM). Dual harvesting stages (fully mature green and mature red), three forms of storage (capsule, seed and powder) and three storage durations (0/without storing, 3 months storage and 6 months storage time) were arranged in factorial combination in randomized complete block design with three replicates. Results indicated that harvesting korrorima at different harvesting stages showed significant differences on physical and biochemical compositions. Fresh weight of capsules (FWC), dry weight of seeds (DWS), and seed to husk ratio (STHR) were highly significantly affected by harvesting stages (P<0.01). Significant (P<0.05) to very highly significant (P<0.001) variation was also observed for seed quality traits such as volatile oil, oleoresin contents and proximate compositions. The mean values of the fresh weight of capsule for mature green were 24.55% and 23.28 for mature red; dry weight of seed for mature green were 4.59 and 6.45% for mature red; and seed to husk ratio for mature green was 2.65% and 3.38% for mature red. Hence, moisture content ranged between 15.08 to 17.86; crude protein between 7.43 to 9.39; Volatile oil content ranged from 2.50 to 4.80 (v/w %) and oleoresin from 5.06 to 9.93 (w/w %). Therefore, physical, volatile oil and oleoresin compositions showed a significant reduction due to the interaction effect of the three factors. The variation may be linked to the moisture content and accumulation of different assimilates. Furthermore, level of exposure to higher temperature and free reactive oxygen might have created a significant variation between samples. Harvesting at fully mature green stage was found more recommendable and acceptable but fails to retain its intrinsic quality during long storage. Contrarily, prolonged harvesting reduces most of the intrinsic quality of the crop. Storing for extended time in the form of powder may lead consumers to loss most quality traits than storing in the form of capsule.