During the post-harvest period, the shelf life of tamarillos can be significantly affected by fungi such as Colletotrichum tamarilloi. Although incorporating fungicides such as lauric acid into packaging can prevent fruit loss, it is necessary to find more readily available sources of antifungal agents. This study demonstrated that incorporating coconut oil hydrolysis products (COHP) into packaging can prevent fungal growth in tamarillos (Solanum betaceum). We found that high-pressure hydrolysis of coconut oil produced COHP with 93.1% w/w organic phase recovery and a high concentration of lauric acid (43.3% w/w). Minimum inhibitory concentration assays of CHOP against four different fungi (Colletotrichum tamarilloi, Fusarium oxysporum f.sp. passiflorae, Fusarium solani, and Fusarium equisetti) confirmed their antifungal properties. Furthermore, we incorporated COHP as an additive in high-density polyethylene (HDPE) films and observed that it inhibited the growth of Colletotrichum tamarilloi by over 80%. Results from in vivo studies showed that the shelf life of both infected and healthy tamarillos was extended by up to three and more than four weeks, respectively.