In conclusion, it has been argued in this chapter that synchrotron radiation allows the determination of structural kinetics of food processes. In addition to the application reviewed here, there are other obvious applications. One such broad area is emulsion science. Thus synchrotron radiation experiments already have been reported in the literature, which investigate the structures of monolayers on the surface of a Langmuir trough.

A second broad area is the kinetics of aggregation of macromolecules during processing. The intense synchrotron radiation beams at APS naturally are highly collimated, owing to the high particle beam energy selected (7 GeV), and the X-ray beams therefore will be very well suited for ultra-small angle experiments (Shenoy et al., 1988). Recalling once again the reciprocal relation between diffraction angle and spacings inferred, such beams can be used to probe dimensions as large as 2 microns, and rapid kinetics will be accessible owing to the high beam intensity. Note that, while XRD requires regular structure, the structure need not be strictly crystalline.

A phenomenon that might be called facilitated nucleation is well recognized: new crystals nucleate near the surfaces of existing crystals (summarized in Avrami, 1939). Based on this fundamental understanding, it is clear that the way in which a food formulation is sheared, while nucleation and crystallization are under way, can be expected to have profound consequences for texture of the final product. The study of such a process using synchrotron radiation techniques can be expected to yield valuable insights.

This chapter necessarily is speculative since the potential of synchrotron radiation in the food industry remains largely to be demonstrated. Nonetheless, the application to fat crystallization shows that this potential is real and not "academic". What actually happens in future may depend on the will of various food companies to pursue long-term, fundamental research, a pursuit to which historically there has been limited commitment. Note that industrial work is welcomed and encouraged at the various synchrotron sources. The food and agricultural industries are represented at these sources, but as yet they are minor users (see e. g., Barnes et al., 1991).

For further information on synchrotron radiation experimentation, the reader is referred to other sources such as the "Handbook on Synchrotron Radiation", which is a series of volumes edited by Ernst-Eckhard Koch and published by North Holland Press; volume 1(a) and (b) were published in 1983. There is also a three volume series referred to as the "Hercules course" and published together by Springer-Verlag and Les editions du physique.

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