Efficacy of hexanal as a potential preservative of papaya (carica papaya l.) fruit.

Author: Ouko, John

Supervisors: Jesang M.; Jane Ambuko and Willis O.

Fruits are rich in vitamins and antioxidants that are required in our daily diets. Papaya fruit for instance, is rich in pro-vitamin A and vitamin C that provide humans with a protective effect against cancer and other health challenges associated with the scavenge harmful oxygen-free radicals. The preservation of papaya is therefore very important to ensure a sustained health benefit supplied by this fruit. However, huge post-harvest losses, estimated above 40% have been reported due to quick ripening and softening of Papaya. The objective of this study was to determine the effects of hexanal as a potential organic compound for use to enhance the postharvest shelf life of papaya in Kenya. Hexanal is a volatile component of many plant tissues that occurs in traces in plants like cucumber, beans and grasses. Experiments were done using a liquid formulation of hexanal (hereinafter referred to as Enhanced Freshness Formulation, EFF) applied as a pre-harvest spray or postharvest dip on mature papaya fruits. Experiments were conducted using two concentrations of hexanal on volume by volume (v/v) basis at 1% and 2% v/v with a plain water treatment as a control and, applied to papaya fruits at two timings of 2.5 and 5 minutes in two Agro-ecological zone II (Meru) and IV (Machakos). Laboratory analyses we conducted at Jomo Kenyatta University of Agriculture and Technology (JKUAT). The parameters tested include Papaya firmness, peel and pulp colour, % cumulative weight loss, respiration rates, amounts of ethylene evolved, Total Titratable Acidity (TTA), Total Soluble Solids (TSS), Vitamin C and Beta-carotene.