Determination of the diffusion coefficients of small solutes in cheese: A review

Abstract

-In cheese technology, the mass transfer of small solutes, such as salt, moisture and metabolites during brining and ripening, is very important for the final quality of the cheese. This paper has the following objectives: (i) to review the data concerning the diffusion coefficients of solutes in different cheese types; (ii) to review the experimental methods available to model the mass transfer properties of small solutes in complex matrices such as cheese; and (iii) to consider some potential alternative approaches. Numerous studies have reported the transfer of salt in cheese during brining and ripening. Regardless of the type of cheese and its composition, the effective diffusion coefficients of salt have been reported to be between 1 and 5.3 × 10 −10 m 2 ·s −1 at 10-15°C. However, few papers have dealt with the mass transfer properties of other small solutes in cheese. Most of the reported effective diffusion coefficient values have been obtained by macroscopic and destructive concentration profile methods. More recently, some other promising techniques, such as nuclear magnetic resonance, magnetic resonance imaging or fluorescence recovery after photobleaching, are currently being developed to measure the mass transfer properties of solutes in heterogeneous media at microscopic scales. However, these methods are still difficult to apply to complex matrices such as cheese. Further research needs to focus on: (i) the development of nondestructive techniques to determine the mass transfer properties of small solutes at a microscopic level in complex matrices such as cheese; and (ii) the determination of the mass transfer properties of metabolites that are involved in enzymatic reactions during cheese ripening. cheese / mass transfer / diffusion / modelling / solute Article published by EDP SciencesRésumé -Détermination des coefficients de diffusion de petits solutés dans le fromage : une synthèse. En technologie fromagère, le transfert de petits solutés, tels que le sel, l'eau et les métabolites au cours du saumurage et de l'affinage, joue un rôle majeur sur la qualité finale du fromage. Cette revue bibliographique a pour objectifs principaux : (i) de faire le bilan des valeurs publiées des coefficients de diffusion de différents solutés dans les fromages ; (ii) de passer en revue les méthodes expérimentales disponibles pour déterminer les propriétés de transfert des petits solutés dans des milieux complexes comme le fromage ; (iii) de considérer les méthodes alternatives potentiellement applicables aux fromages. Dans la littérature, de nombreuses études ont été publiées au sujet du transfert de sel dans les fromages au cours du saumurage et de l'affinage. En fonction du type de fromage et de sa composition, les coefficients de diffusion effectifs du sel sont compris entre 1 et 5,3 × 10 −10 m 2 ·s −1 à des températures comprises entre 10 et 15°C. Très peu d'études concernant les propriétés de transfert d'autres petits solutés dans les fromages ont été publiées. La plupart des coefficients de diffusi...

Spatial Distribution of Bacterial Colonies in a Model Cheese

“…It is therefore very important to quantify these distances, as they also influence the interaction between bacterial colonies of the same species or of different species, such as lactic acid bacteria and pathogens (34) or ripening species in cheese. Very little data are available regarding the diffusion of small solutes in cheeses (10). Whatever the diffusion rate, the closer the colonies are, the less the matrix microstructure influences the diffusion between colonies.…”

“…relies on the metabolic activities of bacterial colonies, leading to the formation of flavors and textures of cheese (11,25). So far, ripening has always been described with average processes on the cheese scale with destructive techniques like grinding (5,12,23) or slicing (10), and microgradients of nutrients and metabolites are thus assumed to occur between colonies in the cheese matrix. Ripening process kinetics should then depend not only on the activities of colonies but also on the spatial organization of colonies inside the matrix.…”

Determination of Aroma Volatile Diffusion Coefficients in Set‐Type Acidified Dairy Matrices of Different Composition and Microstructure by Means of the Concentration Profile Technique in Combination with Headspace Gas Chromatography

“…The methodological approach to the determination of small compound mobility, i.e., diffusion phenomena in food matrices, is largely determined by the matrix composition, the matrix texture properties and the microbiological, physical and chemical stability of the matrix (Floury et al 2010). In the present study, the apparent diffusion coefficient Da was determined via concentration profiling following the so-called "touching semi-infinite cylinders" method.…”

The influence of cheese composition and microstructure on the diffusion of macromolecules: A study using Fluorescence Recovery After Photobleaching (FRAP)

“…Floury, Jeanson, Aly, and Lortal (2010) reported a significant lack of published data on diffusion coefficients of macromolecular solutes in cheese, most of the existing papers dealing only with the diffusion of NaCl and small solutes during the salting and ripening processes. They also noted that most diffusion coefficients for these solutes were obtained from a method based on spatio-temporal concentration profiles, which has the drawback of being macroscopic, destructive and time-consuming.…”