Food Science Students Find a New Life for Walnut by-product

The WALL-E Walnuts, Kim Shanks, Nethania Handoko, and Hayley McMillan (from left to right)

The WALL-E Walnuts, a team of three food science students, Kim Shanks, Hayley McMillan and Nethania Handoko, are developing a walnut nut butter from “tank solids”, a by-product of the walnut oil extraction process produced from a New Zealand walnut processing facility. This project is part of 311 Food Product Development (FOSC311), a project-based paper that puts students into small teams to design, develop and test product concepts and prototypes to deliver on a client's brief as part of their food Science degree.

Team leader Kim Shanks, weighting out samples for sensory analysis

Trickett’s Grove, the sponsoring company, wanted to create a new product from 30% of the typically discarded walnut ‘tank solids’, a by-product from the walnut oil extraction process. The students identified a gap in the walnut nut butter and upcycled food market and developed three nut butter variants: smooth, crunchy and sweet honey-flavoured. Their process involved separating the ‘tank solids’ to obtain a thick, oily mix, which served as the foundation for their nut butter. The team successfully tackled challenges such as inconsistent raw materials, achieving the desired thickness for the nut butter, and balancing the bitter walnut taste. They are now conducting sensory analysis to assess consumer acceptance before finalising their product for potential commercialisation. 

The final product has the potential to enter a competitive market, challenging other alternative nut butters, such as cashew and almond, while providing a source of omega-3 and fibre. To keep the product fresh and add a point of difference they will use amber glass packaging.

For more information about sponsoring a 311 student project, please contact Fiona Nyhof.

Email: fiona.nyhof@otago.ac.nz