Controlled and accelerated cheese ripening: the research base for new technologies

Research has already provided enough information on the contribution to maturation made by the major milk components when they are broken down by enzymes of rennet, milk and cheese microorganisms to control the overall intensity of flavour in most cheese varieties. This information has been converted into techniques and technologies including enzyme addition, control over the ripening flora, and the use of attenuated or genetically modified starters cultures. Although these represent a significant advance in ripening control, the next-generation of technology will be more sophisticated. It will be based on increasingly detailed research data on the role of starter and non-starter cultures in converting the products of the hydrolytic enzymes in cheese (amino acids, fatty acids and reducing sugars) to potent and diverse aroma compounds via their metabolic pathway enzymes. If permitted, genetic modification (GM) technology, specially developed by the dairy research base to be safe and food compatible, will play a vital role in proving the efficacy of this metabolic, rather than enzymatic approach. GM research is also capable of delivering the technology to make cultures tailored to specific cheese flavour and texture profiles. Cheese ripening technology has long been held back by the lack of detailed knowledge of flavour chemistry to emerge from a rather traditional and neglected research base. Such knowledge is absolutely vital as part of the development of new flavour cultures and enzyme formulations. In the last few years, this area of flavour chemistry research has been rejuvenated by new analytical techniques that combine sensory and chemical analysis, and by the development of faithful cheese model systems to test out new cultures and culture interactions quickly without expensive and long-term cheese trials. Combinatorial chemistry is the latest recruit to the army of cheese chemistry techniques and this has already an impact on our understanding of complex sulphur compounds in cheese.