Innovative Olive Tree Leaves Shredder Prototype for the Valorization of Wasted Leaves: An Application to High-Quality Compost Production

Abstract

Extra virgin olive oil is considered worldwide as one of the most important products, a standard bearer of the Mediterranean diet. Despite this, the production chain of extra virgin olive oil generates four times more waste than quantity of oil. For this reason, the disposal of olive mill wastes represents a significant environmental problem in all the Mediterranean countries. In this direction, several innovations and improvement strategies were proposed in the literature to correctly manage these by-products and, in some cases, to valorize them by the recovery of polyphenols and other interesting substances. However, innovations and improvement strategies for the valorization of olive tree leaves are definitely neglected in the literature, thus motivating this work. The aims of this work are as follow: firstly, to develop and test an innovative olive tree leaves shredder prototype to help olive oil millers in the management of waste leaves deriving from pruning and olive oil production; secondly, to test the combination of the minced olive tree leaves with other by-products in the production of high-quality compost. The results showed the effectiveness of the tested olive tree leaves shredder in significantly reducing the volume occupied by the leaves by 40%. Moreover, the mixing of the minced olive tree leaves with other by-products lead to a high-quality compost which, in accordance with Italian legislation, could even be certified and labeled with this denomination. Future research will investigate the quantification of the benefits in terms of environmental impacts using life cycle assessment.

Evaluation of the Potential of Agro-Industrial Waste-Based Composts to Control Botrytis Gray Mold and Soilborne Fungal Diseases in Lettuce

“…A good number of studies have been made on the use of olive mill wastes as soil amendments; suppressive effects of olive mill waste-based composts on different phytopathogens have also been demonstrated [62]. Using olive leaves in composting is a new concept [63], and the results from this study fully endorse the potential of leavesbased composts as suppressive amendments against plant pathogens. A large number of microbes appeared in microbiological analyses of grape marc-based composts produced by Santos et al [49].…”

Should extra virgin olive oil production change the approach? A systematic review of challenges and opportunities to increase sustainability, productivity, and product quality

“…As highlighted in earlier work (Cappelli et al, 2021), the production of EVOO continues to increase. In particular, according to a European Commission report, approximately 3 million tons of olive oil are produced each year worldwide (European Commission, 2020;Cappelli et al, 2021).…”

“…As highlighted in earlier work (Cappelli et al, 2021), the production of EVOO continues to increase. In particular, according to a European Commission report, approximately 3 million tons of olive oil are produced each year worldwide (European Commission, 2020;Cappelli et al, 2021). Two million tons are produced in the EU; in particular, the leading member states involved are Spain (66% of EU production); Italy (15%); Greece (13%); and Portugal (5%) (European Commission, 2020;Cappelli et al, 2021).…”

“…In particular, according to a European Commission report, approximately 3 million tons of olive oil are produced each year worldwide (European Commission, 2020;Cappelli et al, 2021). Two million tons are produced in the EU; in particular, the leading member states involved are Spain (66% of EU production); Italy (15%); Greece (13%); and Portugal (5%) (European Commission, 2020;Cappelli et al, 2021). However, as reported by Espadas-Aldana et al (2019) and Cappelli et al (2021), 80% of the olive mass is composed of pulp, stones, and water; therefore, the production process of EVOO generates roughly four times more waste than the quantity of oil.…”

“…Two million tons are produced in the EU; in particular, the leading member states involved are Spain (66% of EU production); Italy (15%); Greece (13%); and Portugal (5%) (European Commission, 2020;Cappelli et al, 2021). However, as reported by Espadas-Aldana et al (2019) and Cappelli et al (2021), 80% of the olive mass is composed of pulp, stones, and water; therefore, the production process of EVOO generates roughly four times more waste than the quantity of oil. Consequently, the management and disposal of olive mill by-products represent the most significant environmental problem in all Mediterranean countries.…”