Application of Scanning Electron Microscopy and Confocal Laser Scanning Microscopy to the study of dough matrix microstructure

Abstract

Microscopy techniques are useful to study the interaction among different components of food systems. The knowledge ofmicrostructure contribute to understand macroscopic characteristics and even to predict typical behaviour. Amongmicroscopic techniques Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM) arefrequently used to study dough microstructure. SEM and CLSM provide complementary information to that obtained byothers microstructural methods. By means of SEM it is possible to study sample topology and the micrographs obtainedexhibit gluten strands arrangement and localization of starch granules inside it. When dough sample is observed by CLSM,dough is stained by fluorophores that compete for dough components depending of their affinity to them. Thus, differentcomponents of matrix are stained in different colours. The election of fluorophores and solvents in which they aredissolved are relevant to obtain information that contributes to elucidate matrix conformation. In this chapter, it is shownthe use of SEM and CLSM to study dough matrix microstructure. The selection of degree of magnification in SEM andCLSM and the election of different conditions by CSLM are discussed. Besides, it is shown that when CLSM is used it ispossible to perform a quantification of protein value and degree of matrix complexity by fractal index.