There is considerable interest in alternatives to thermal processing. A recent review in the International Journal of Dairy Technology by Ahmad and his colleagues looks at the effects of non thermal processes on the activity of milk enzymes. I have included the abstract below.
Impact of nonthermal processing on different milk enzymes. Ahmad et al (2019) Available at https://doi.org/10.1111/1471-0307.12622.
Milk is highly perishable and deteriorates rapidly during storage. Although the thermal processing technologies successfully inactivate many enzymes and microorganisms up to a required level, they can negatively affect the natural flavour of dairy foods and decrease their nutritional value. Alternative nonthermal technologies have been established as an interesting approach to produce safe and healthy dairy products, without compromising their nutritional quality. These techniques have the ability to inactivate milk enzymes without affecting the milk quality. In addition, the combination of two different nonthermal techniques and mild heating has proven to be more effective to provide safety to milk when compared to the treatments alone. This review aims to evaluate the impact of nonthermal technologies, in particular, ultrasound, pulsed electric field, high‐pressure processing and ultraviolet irradiation on milk enzymes.