Assoc. Prof. Pornnapa Kasemsiri, Ph.D., from Department of Chemical Engineering; Asst. Prof. Jetsada Posom, Ph.D., from Department of Agricultural Engineering; and Miss Artjima Ounkaew, a doctoral degree student in chemical engineering; have conducted a research study on bioactive substances to delay fruit ripening, including tapioca flour, glycerol, silver nitrate, and green tea extract, which they used to synthesize silver nono-particles, that were in turn used to coat a filtering paper sheet. The result was bioactive paper that can degrade Ethylene under visible light. Ethylene gas is the fruit hormone that accelerates fruit ripening. The bioactive substance coated on the filter paper can deter bacterial growth and retain the taste quality of the ripened fruit for 3-5 days without rotten. Maintaining fruit quality by slowing down the ripening period means the consumer can consume quality fruit as well as reducing cost incurring from rotten fruit. The substance can be used for delaying the ripening of fruits that have high export values.