THERMODYNAMIC AND FUNCTIONAL-PROPERTIES OF MECHANICALLY COMPACTED FLOUR

Compaction of flour can be beneficial as it may prevent or slow down t he diffusion of oxygen into the flour and thereby reduce enzymatic act ivity within the flour and infestation by mites and microorganisms. Al so, the reduction in volume through compaction would facilitate relati vely easier mechanical handling and reduce the space requirement for s torage and transportation. The overall objective of this research was to determine whether mechanical compaction of flour would adversely ef fect its thermodynamic and functional properties. Two different grades of flour were used in this investigation: a low extraction (64%) pate nt flour and a high extraction (79%) straight grade flour. Loose flour was compacted mechanically, which corresponded to a reduction in flou r volume of 55%, and exposed to sorption desorption tests. Dough prepa red from treated (compacted and reconstituted) and loose flour was exp osed to standard empirical and imitative rheological tests. The analys is involved determination of the sorption desorption characteristics, the specific area of the absorption sites, heat of sorption and desorp tion, free energy changes, and rheological tests including farinograph , mixograph, viscoamylograph, alveograph, wet gluten content, short ba king tests, and capillary rheometer tests for the treated and control flours. In general, compaction and reconstitution of flour had no adve rse influence on the thermodynamic and rheological behaviour of the do ugh.