“Greenleaves” – wet extraction of leaf protein from fresh broccolini and other green leafy vegetable waste
The challenge
Edible green leafy waste is removed for different reasons (such as quality, appearance, compliance) throughout the supply chain post-harvest. CSIRO data conservatively suggest the volume is at least 128kT of leafy green waste produced nationally every year (Ambiel et al., 2019). Perfection Fresh produce substantial amounts of broccolini leaf material, the majority being removed for cosmetic purposes. This material is composted, returned to the soil or fed to animals. Woolworths stores each collect a large variety of leafy green vegetable waste from stores including; outside leaves from lettuce, cabbage, cauliflower and broccoli that are removed by staff or customers pre-purchase. These are fed to animals, composted, or disposed of in landfill.
Our plan
Perfection Fresh, Woolworths and The Leaf Protein Co, in collaboration with South Australian Research and Development Institute (SARDI) and Fight Food Waste CRC, will assess the viability of recovering protein, fibre and other components from green leaf waste from new sources. The aim of this research project is to demonstrate whether a commercially scalable wet extraction process optimised to produce high quality, food-grade, leaf protein (RuBisCO) from other leafy green feedstocks can be used with fresh broccolini and mixtures of leafy greens collected from supermarkets.
Previous work has shown that up 50% of the dry weight of the leaf mass of certain vegetables is protein (Davys et al., 2011). If this material is quickly processed by wet extraction it results in high yield and quality of the protein powder which can be sold to food manufacturers as an alternative to animal sources of protein. Other components of the leaf material, such as fibre, can also be captured and sold. In this way, green leaves that would otherwise go to waste (landfill, compost) or animal feed are transformed into valuable food ingredients. This project brings together the Leaf Protein Co, with their proprietary wet extraction process optimised for sweet potato leaves and bibb lettuce, with Perfection Fresh, the largest producer of broccolini in Australia, and Woolworths with thousands of stores each producing green leafy waste every day.
References:
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- Ambiel C, Adell, A, Sanguansri P, Krause D, Gamage T, Garcia-Flores, R and Juliano P (2019) Mapping Australia fruit and vegetable losses pre-retail. CSIRO, Australia.
- Davys MNG, Richardier C, Kennedy D, de Mathan O, Collin SM, Subtil J, Bertin E and Davys MJ (2011). Leaf Concentrate and Other Benefits of Leaf Fractionation In: Combating Micronutrient Deficiencies: Food-based Approaches (eds B. Thompson and L. Amoroso). FAO.
