The keratin in wool is a highly crosslinked protein. The high molecular weight, crosslinked structure prevents its shaping into films without extensive decomposition. Since the crosslinks are —S—S— bridges, reducing agents can break them up. resulting temporarily in lower molecular weight polymers. In this work, wool fibers are pretreated with an aqueous solution of various reducing agents to open the disulfide bonds, and then pressed into films at 130-150°C and pressures of 41.7-66.7 MPa in a hydraulic press. The optimum conditions to obtain clear, transparent films include using Na2SO3 in aqueous alcohol solutions before pressing 135°C and 55.6 MPa.

Greek yogurt (GY), a high-protein-low-fat dairy product, particularly prized for its sensory and nutritional benefits, revolutionized the North American yogurt market in less than a decade, bringing with it new sustainability challenges. Standard GY production generates large volumes of acid whey, a co-product that is a potential source of environmental pollution if not recovered. This study aims to assess the environmental performance of different technologies and identify the main factors to improve GY production. A complete life cycle assessment (LCA) was performed to compare the standard technology (centrifugation) with two new technologies (fortification and ultrafiltration) to reduce acid whey volumes. Three milk protein concentrate alternatives were also assessed. Results show that technology choice is not a clear discriminant factor. However, minimizing losses and wastage (accounting for 23 to 25% of the environmental impacts for all indicators) beyond the processing plant and selecting milk ingredients (accounting for 63 to 67% of the impacts) with low environmental impacts are key factors to improve the environmental performance of GY systems. From a methodological perspective, the results also highlight a shortcoming in the current LCA guidelines (2015) issued by the International Dairy Federation to treat the multifunctionality of GY systems.

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Greek yogurt (GY), a high-protein-low-fat dairy product, particularly prized for its sensory and nutritional benefits, revolutionized the North American yogurt market in less than a decade, bringing with it new sustainability challenges. The standard production of GY generates large volumes of acid whey, a co-product that is a potential source of environmental pollution if not recovered. This study aims to assess the environmental performance of different technologies and identify the main factors for improving GY production. A complete life cycle assessment (LCA) was performed to compare the standard technology (centrifugation) with two new technologies (fortification and ultrafiltration) to reduce acid whey volumes. Three milk protein concentrate alternatives were also assessed. Results show that the technology choice is not a clear discriminant factor. However, minimizing losses and wastage (accounting for 23 to 25% of the environmental impacts for all indicators) beyond the processing plant and selecting milk ingredients (accounting for 63 to 67% of the impacts) with low environmental impacts are key factors in improving the environmental performance of GY systems. From a methodological perspective, the results also highlight a shortcoming in the current International Dairy Federation LCA guidelines (2015) for treating the multifunctionality of GY systems.