Converting post-consumer food waste into fish feed.

Abstract

More than 40percent of human food produced is wasted and much of it in restaurants. Hence, food waste remains a serious environmental challenge facing the world today, with sizable quantities generated and disposed of in landfills. Accordingly, exploring solutions to mitigate the detrimental impacts of such waste becomes vital. Aquaculture, a rapidly growing industry in rural areas of developing nations, offers the potential of using this waste productively to partially replace commercial feed, which is often absent or expensive. The first experimental setup consisted of two 8-week feeding experiments performed to evaluate the suitability of using restaurant food waste to supplement commercial feed (CF) in the aquaculture of Nile tilapia Oreochromis niloticus. In the first experiment, five feeding regimens in which CF was substituted by waste-based feed at 0, 25, 50, 75 and 100percent of daily offering were evaluated. Results show that 25percent of the CF can be replaced with waste-based feed without any significant effect on survival, growth, feed conversion, hepatosomatic, viscerosomatic indices, hemoglobin, hematocrit and total plasma protein. In the second experiment, seven feeding treatments were evaluated in which daily offerings of CF were alternated with waste-based feed in 6-day cycles. Results suggest that replacement between 25percent and 33percent is feasible without significantly affecting survival or growth. Again, no significant differences were observed in growth, feed conversion ratio, VSI, hemoglobin, hematocrit and TPP. Findings suggest that around 25percent replacement of CF with Lebanese restaurant waste-based feed can be utilized in the culture of O. niloticus thus improving financial returns of farmers while reducing the environmental impact of food waste. The present work also assessed the effect of using post-consumer food waste as feed on the amino acid and fatty acid profiles of Nile tilapia, Oreochromis niloticus. Whole body protein proportion decreased, and amino acid composition changed significantly with increase of