Upcycled Animal Feed: Sustainable Solution to Orange Peels Waste

Abstract

Currently, in an effort to increase their sustainability and reduce their carbon footprint, industries look for ways to valorise their waste instead of simply treating it. At the same time, food insecurity is increasing with alarming rates and thus solutions are sought. To this end, the main objective of this paper was to optimise an innovative valorisation strategy to turn orange juice industry by-products into high-value secondary feedstuff for animals. In this context, a valorisation strategy was designed where a saccharification step of the orange peels and an aerobic fermentation step of the liquid residue were included. Both processes were optimised via factorial deign. The saccharification process was optimised in terms of pectinolytic and cellulolytic enzymes and solid loading, whereas the aerobic fermentation method was optimised in terms of nutrients addition, the yeast to glucose ratio, and pH control. According to the optimised conditions, the final animal feedstuff should be formulated by mixing the solid residue of orange peels after the saccharification process under the optimum conditions (50 °C, 24 h, 7.5% solids loading, Pectinex 25 μL/g TS, CellicCTec3 25 μL/g TS), with the harvested yeast cultivated aerobically on orange peels hydrolysate (30 °C, 24 h, orange peels hydrolysate as sugar source, nutrients addition, yeast to glucose ratio equal to 0.02). Finally, the formulated feedstock should be dried in order to stabilise the product in terms of shelf life and feed safety. The final feedstuff presented 23.11% higher in vitro organic matter digestibility and threefold protein content.

Volume 12, No. 2, 2023

“…Additionally, the peel contains essential oils that can have antimicrobial and antioxidant properties, which can help improve animal health and welfare. Orange peel can be used as a partial replacement for traditional feed sources, such as corn or soybean meal, in ruminant and non-ruminant diets (Andrianou et al, 2023). In ruminants, the high fiber content of orange peel can stimulate rumen function and increase the production of microbial protein, which is an important source of protein for the animal.…”

Sequential Extraction and Characterization of Essential Oil, Flavonoids, and Pectin from Industrial Orange Waste

“…Therefore, alternative approaches to handling orange waste need to be considered. A typical of those approaches involves upcycling of orange waste to be used as animal feed; however, it lacks an adequate amount of protein and is low in pH and has been suggested to require modification to improve its suitability for feedstock . On the other hand, value-added ingredients for food, pharmaceutical, and cosmetic applications, such as essential oil (EO), polyphenols, and pectin, have been produced from orange peel (OP) obtained from orange processing for decades, well before “upcycling” was defined.…”

Fiber Enrichment of 3D Printed Apricot Gel Snacks with Orange By-Products

“…Orange peel is a by-product of the citrus sector with a significant content of fiber and bioactive compounds [6]. It is the main waste generated during orange juice processing, and between 8 and 20 million tons of orange waste are produced each year, with more than 50% in the form of peel [7,8]. Waste generated in the food industry can be put into other food uses such as the formulation of novel foods.…”