Characterization of the microstructure of dairy systems using automated image analysis

A sound understanding of the microstructure of dairy products is of great importance in order to predict and control their properties and final quality. The aim of this study was to develop an automated image analysis procedure to characterize the microstructure of different dairy systems. A high pressure freezing coupled with freeze-substitution (HPF-FS) protocol was applied prior to transmission electron microscopy (TEM) in order to minimize any modification of the microstructure of the dairy systems investigated. The developed image analysis procedure was first validated on synthetic images of suspensions, and then on two types of concentrated milk suspensions. Microstructural data relating to casein micelles in milk suspensions were taken from the literature. The established procedure was then applied to the two corresponding rennet-induced milk gels, prepared from the same milk concentrates used for suspensions preparation. The automated image analysis procedure allowed the reliable estimation of several characteristic microstructural parameters including area fraction, porosity, boundary length per unit area, particle aggregate size, inter-particle aggregate distance and tortuosity. The relative ease of estimating these microstructural parameters from the automated image analysis method could make it useful for routine measurements of milk gels. Moreover, the method enabled a useful discrimination between two different types of milk gels. This novel approach can contribute to a better understanding of the effects of processing on the structure-property relationships in dairy products, and may be applied to other food systems.

[1]  G. Licitra,et al.  Proteolysis and microstructure of Piacentinu Ennese cheese made using different farm technologies. , 2006, Journal of dairy science.

[2]  Sundaram Gunasekaran,et al.  Three-Dimensional Characteristics of Fat Globules in Cheddar Cheese , 1999 .

[3]  Frank Mücklich,et al.  Statistical Analysis of Microstructures in Materials Science , 2000 .

[4]  D. Legland,et al.  Changing the isoelectric point of the heat-induced whey protein complexes affects the acid gelation of skim milk , 2012 .

[5]  J. Cuq,et al.  Influence of pH on Protein Interactions and Microstructure of Process Cheese , 1997 .

[6]  J. Thapon,et al.  Préparation de fromage à partir de " pré-fromage liquide " obtenu par ultrafiltration du lait , 1971 .

[7]  G. Impoco,et al.  Quantitative analysis of nanostructures' shape and distribution in micrographs using image analysis , 2012 .

[8]  D. McMahon,et al.  Rethinking casein micelle structure using electron microscopy , 1998 .

[9]  M. Duduković,et al.  Tortuosity model for fixed beds randomly packed with identical particles , 2010 .

[10]  Ravi J. Suman,et al.  Formation factor and tortuosity of homogeneous porous media , 1993 .

[11]  Pierre Soille,et al.  Morphological Image Analysis: Principles and Applications , 2003 .

[12]  M. Corredig,et al.  Colloidal properties of concentrated heated milk , 2013 .

[13]  R. Dagastine,et al.  The effect of pH at renneting on the microstructure, composition and texture of Cheddar cheese , 2012 .

[14]  F. Malcata,et al.  Ripening-related changes in Serra da Estrela cheese: a stereological study. , 2011, Journal of dairy science.

[15]  F. Wolfe,et al.  Effect of Ultrafiltration of Skim Milk on Casein Micelle Size Distribution in Retentate , 1991 .

[16]  J. Sheehan,et al.  Analysing cheese microstructure: A review of recent developments , 2014 .

[17]  M. Corredig,et al.  The structure of the casein micelle of milk and its changes during processing. , 2012, Annual review of food science and technology.

[18]  Zhangxin Chen,et al.  Critical review of the impact of tortuosity on diffusion , 2007 .

[19]  Marie-Françoise Devaux,et al.  COMPUTATION OF MINKOWSKI MEASURES ON 2D AND 3D BINARY IMAGES , 2011 .

[20]  D. McMahon,et al.  Water Partitioning in Mozzarella Cheese and Its Relationship to Cheese Meltability , 1999 .

[21]  B. Cabane,et al.  Rheology and phase behavior of dense casein micelle dispersions. , 2009, The Journal of chemical physics.

[22]  H. Deeth,et al.  Characteristics of a calcium–milk coagulum , 2013 .

[23]  Yuming Li,et al.  Effect of pH on the association of denatured whey proteins with casein micelles in heated reconstituted skim milk. , 2003, Journal of agricultural and food chemistry.

[24]  P. Walstra,et al.  Effect of chymosin action on the hydrodynamic diameter of casein micelles. , 1981, Biochimica et biophysica acta.

[25]  R. Ipsen,et al.  Dynamic visualization and microstructure of syneresis of cheese curd during mechanical treatment , 2011 .

[26]  José Miguel Aguilera,et al.  MODELING THE EFFECT OF MICROSTRUCTURE ON FOOD EXTRACTION , 2001 .

[27]  J. Maubois,et al.  Application of Membrane Ultrafiltration to Preparation of Various Types of Cheese , 1975 .

[28]  S. Torquato,et al.  Reconstructing random media , 1998 .

[29]  M. Rudemo,et al.  Identification of the three‐dimensional gel microstructure from transmission electron micrographs , 2007, Journal of microscopy.

[30]  L. V. van Vliet,et al.  The determination of relative path length as a measure for tortuosity in compacts using image analysis. , 2006, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[31]  W. Buchheim.  Aspects of Sample Preparation for Freeze-Fracture/Freeze-Etch Studies of Proteins and Lipids in Food Systems. A Review , 1982 .

[32]  Philippe Andrey,et al.  Free-D: an integrated environment for three-dimensional reconstruction from serial sections , 2005, Journal of Neuroscience Methods.

[33]  S. Lortal,et al.  Nisin quantification by ELISA allows the modeling of its apparent diffusion coefficient in model cheeses. , 2011, Journal of agricultural and food chemistry.

[34]  S. Lortal,et al.  Transport phenomena in a model cheese: the influence of the charge and shape of solutes on diffusion. , 2013, Journal of dairy science.

[35]  J. R.,et al.  Quantitative analysis , 1892, Nature.

[36]  J. Lucey,et al.  ADSA Foundation Scholar Award. Formation and physical properties of milk protein gels. , 2002, Journal of dairy science.

[37]  A. Brodkorb,et al.  The casein micelle: Historical aspects, current concepts and significance , 2008 .

[38]  Harjinder Singh,et al.  Influence of denaturation and aggregation of β-lactoglobulin on rennet coagulation properties of skim milk and ultrafiltered milk , 1996 .

[39]  Sandra E. Kentish,et al.  Microstructure of milk gel and cheese curd observed using cryo scanning electron microscopy and confocal microscopy , 2011 .

[40]  H. Falentin,et al.  RNA extraction from cheese for analysis of in situ gene expression of Lactococcus lactis , 2008, Journal of applied microbiology.

[41]  Z Jiang,et al.  Efficient 3D porous microstructure reconstruction via Gaussian random field and hybrid optimization , 2013, Journal of microscopy.

[42]  R. Dagastine,et al.  The effect of calcium chloride addition on the microstructure and composition of Cheddar cheese , 2013 .

[43]  Harjinder Singh,et al.  Influence of heat treatment of milk on cheesemaking properties , 2001 .

[44]  G. Impoco,et al.  Quantitative Analysis of Cheese Microstructure using SEM Imagery , 2007 .

[45]  A. Bell,et al.  Effects of gelation temperature on Mozzarella-type curd made from buffalo and cows' milk. 1: rheology and microstructure. , 2012, Food chemistry.

[46]  H. Goff,et al.  A study of fat and air structures in ice cream , 1999 .

[47]  Confocal scanning laser microscopy and quantitative image analysis: application to cream cheese microstructure investigation. , 2008, Journal of dairy science.

[48]  David Legland,et al.  Structural mechanisms leading to improved water retention in acid milk gels by use of transglutaminase , 2013 .

[49]  W. Curtin,et al.  Using microstructure reconstruction to model mechanical behavior in complex microstructures , 2006 .

[50]  R. Ipsen,et al.  Relationship between physical properties of casein micelles and rheology of skim milk concentrate. , 2005, Journal of dairy science.

[51]  Enrique Iglesia,et al.  The effects of diffusion mechanism and void structure on transport rates and tortuosity factors in complex porous structures , 2004 .

[52]  D. Legland,et al.  Cartography of cell morphology in tomato pericarp at the fruit scale , 2012, Journal of microscopy.

[53]  M. Mellema,et al.  Structure and scaling behavior of aging rennet-induced casein gels examined by confocal microscopy and permeametry , 2000 .

[54]  G. Impoco,et al.  Microstructural properties of milk fat globules , 2013 .

[55]  Liu Yang,et al.  Interaction between β-casein micelles and imidazolium-based ionic liquid surfactant , 2013 .

[56]  T. Jeurnink,et al.  Changes in milk on heating: viscosity measurements , 1993, Journal of Dairy Research.

[57]  F. Mariette,et al.  Impact of casein gel microstructure on self-diffusion coefficient of molecular probes measured by 1H PFG-NMR. , 2007, Journal of agricultural and food chemistry.

[58]  D. Dalgleish,et al.  Interaction between casein micelles and whey protein/κ-casein complexes during renneting of heat-treated reconstituted skim milk powder and casein micelle/serum mixtures. , 2011, Journal of agricultural and food chemistry.

[59]  I. Sam Saguy,et al.  New approach to model rehydration of dry food particulates utilizing principles of liquid transport in porous media , 2005 .

[60]  K. B. Qvist,et al.  Effect of coagulation conditions on the microstructure and the large deformation properties of fat-free Feta cheese made from ultrafiltered milk , 2003 .

[61]  B. Bergenståhl,et al.  Milk membrane lipid vesicle structures studied with Cryo-TEM. , 2003 .

[62]  S. Torquato,et al.  Random Heterogeneous Materials: Microstructure and Macroscopic Properties , 2005 .

[63]  H. Goff,et al.  Changes in protein and fat structure in whipped cream caused by heat treatment and addition of stabilizer to the cream , 2000 .

[64]  B. Bergenståhl,et al.  Cryo-TEM of isolated milk fat globule membrane structures in cream , 2004 .

[65]  M. Kaláb,et al.  Microscopy and other imaging techniques in food structure analysis , 1995 .

[66]  Dominique Jeulin,et al.  3D MORPHOLOGICAL ANALYSIS OF COMPOSITE MATERIALS WITH AGGREGATES OF SPHERICAL INCLUSIONS , 2011 .

[67]  N. Otsu.  A threshold selection method from gray level histograms , 1979 .

[68]  José Miguel Aguilera,et al.  New dimensions in microstructure of food products , 2000 .

[69]  Partha P. Mitra,et al.  Pore-Size Distributions and Tortuosity in Heterogeneous Porous Media , 1995 .

[70]  J. Laencina,et al.  Hot topic: microstructure quantification by scanning electron microscopy and image analysis of goat cheese curd. , 2011, Journal of dairy science.