STRATEGIES TO REDUCE WASTE IN THE DAIRY INDUSTRY: IMPROVING PRODUCT STABILITY AND UPCYCLING COPRODUCTS
The gap between food waste and food insecurity continues to urge the government, industry, and academia to propose, examine, and develop approaches to mitigate this critical challenge. The present work presents two main strategies to alleviate food waste and loss in the dairy supply chain. The mitigation of food waste was explored in the Ultra High Temperature (UHT) milk supply, while the reduction in food loss was examined in the valorization of liquid coproducts post-manufacturing.The first strategy aimed to investigate the role of a natural enzyme (lactose oxidase) as a clean-label alternative to control the growth of Pseudomonas spp., the heat-stable proteases (HSP) of which are responsible for gelation defects in UHT milk; an approach that aims to improve this product’s stability and reduce dairy waste. The second strategy focused on studying, optimizing, and applying fermentation technologies, combined with distillation and freeze-drying, to create new products and ingredients derived from dairy coproducts: Greek-style yogurt whey and dairy permeates. Through this research, we learned that adding lactose oxidase at 0.24 g/L delayed the proliferation of a cocktail comprised of HSP-producing Pseudomonas that had been introduced into raw milk at 1 x 105 cfu/mL. This action successfully delayed UHT milk gelation for up to a year under normal storage conditions, thus providing an opportunity to extend this product’s shelf-life. This alternative could be crucial in ensuring access to dairy nutrients in countries where UHT milk is the primary dairy product consumed and where the microbiological quality of raw milk is less than ideal. In addition, we uncovered the fermentation versatility of a commercial strain of Brettanomyces claussenii in dairy coproducts. This organism was demonstrated to create a diverse array of bioproducts containing either ethanol, acetic acid, galactose, or the combination of the three, by controlling its fermentation parameters: oxygen availability and degree of lactose hydrolysis. We optimized this organism’s anaerobic fermentation in dairy permeates to obtain the highest galactose and ethanol concentrations, and applied this approach to propose novel lactose-free, low-in-glucose, and galactose-rich products. This alternative could remediate the effects of dairy food loss in terms of both environmental and economic impacts.