Development of new chip products from Brewer's Spent Grain

Abstract

Brewer's Spent Grain (BSG) is a processing waste generated in large quantities by the brewing industry. It is estimated that over 38 million tons of BSG is produced worldwide each year, and is usually used as animal feed, composted, or thrown into landfills. BSG contains valuable nutritional components, including protein, fiber, and antioxidants. Due to its brittle texture, strong nutty flavors, and dark color profiles from the presence of barley, BSG has seen limited use in food products for human consumption. The objective of this study was to develop a palatable snack product containing varying percentages of brewer's spent grain.

BSG samples were provided by Iron Monk in Stillwater, and were evaluated for nutrients and potential antioxidant capacity. The samples were dried at a low temperature, then milled into flour. Two different formulations were developed, with one containing sweet potatoes. Varying percentages of BSG were incorporated into each formulation.

This project involved further evaluation of water activity, color, and texture (fracture force) in BSG chips. An informal sensory evaluation was performed, evaluating flavor, texture, and probability of purchase using a 5-point hedonic rating scale. It was expected to observe visual changes in color as BSG levels increased. However, there were no significant differences between the many percentages. The texture fracture force levels decreased as BSG inclusion increased in both formulations. This is largely due to the fact that higher levels of BSG created a more brittle texture, allowing the chips to break sooner than the chips made with lower levels of BSG, which resulted in a more 'leathery' texture. The results observed from the informal sensory testing indicated that chips with higher levels of BSG were more appealing to customers despite being dark in color.

Results from this work could be economically beneficial for our local Iron Monk business as well as breweries nationwide. Development of an alternative value-added product represents an opportunity to turn a processing waste into a future asset.