Size, shape, and identity of surface crystals and their relationship to sensory perception of grittiness in soft smear-ripened cheeses

New Insights into Cheese Microstructure

Microscopy is often used to assist the development of cheese products, but manufacturers can benefit from a much broader application of these techniques to assess structure formation during processing and structural changes during storage. Microscopy can be used to benchmark processes, optimize process variables, and identify critical control points for process control. Microscopy can also assist the reverse engineering of desired product properties and help troubleshoot production problems to improve cheese quality. This approach can be extended using quantitative analysis, which enables further comparisons between structural features and functional measures used within industry, such as cheese meltability, shreddability, and stretchability, potentially allowing prediction and control of these properties. This review covers advances in the analysis of cheese microstructure, including new techniques, and outlines how these can be applied to understand and improve cheese manufacture.

Invited review: Crystals in cheese: More than a curiosity

Scientific interest in cheese crystals extends back more than a century. However, starting around the 1970s, industry interest, and interest on the part of cheese scientists, grew dramatically as changes in cheesemaking technology and market changes caused the presence of crystals in the marketplace to increase; advanced analytical capabilities enabled new crystalline species to be identified, their origins and causative factors to be elucidated, and their contributions to cheese texture to be better understood. It is now evident that a host of organic- and inorganic-based crystals occur in natural cheeses. Some crystals form preferentially at the surface of rindless or rinded cheeses, others in the irregular openings or spherical eyes that occur within the body of some cheeses, and still others embedded within the cheese matrix. It is also evident that crystals may profoundly influence cheese texture, both as a direct consequence of their abundance, size, shape, and hardness, and as an indirect result of cascading physiochemical events initiated by crystal formation. Consumer response to increased incidence of crystals in the marketplace has been mixed. On the one hand, surface crystals of calcium lactate pentahydrate on Cheddar cheese came to be viewed quite negatively in some markets, often being mistaken for mold growth and spoilage. This triggered industry concern and led to considerable research to determine the underlying causes and to develop strategies to limit or prevent calcium lactate pentahydrate formation. At the same time, other forms of crystallization increasingly came to be viewed as positive features in the growing market dedicated to artisanal and traditional cheeses, giving rise to a bifurcated consumer response to cheese crystals that is evident today. Traditional artisanal cheesemakers perhaps have the most to gain from advances in cheese-crystal research. Traditional artisanal cheeses rely heavily on stories that are weaved around their identity to create uniqueness and add value. A challenge and opportunity for these cheesemakers in the United States and globally will be to translate the fascinating science of their cheese crystals into engaging narratives that capture the imagination, add value to their cheese, and enhance the enjoyment of their cheese by consumers.