MATERIAL SCIENCES

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 Polarizing Microscopy is effective to examine food products that exhibit optical anisotropy or  birefringence. Several food components are birefringent, notably starch granules, fat crystals, and protein fibers. Starch birefringence is clearly identified using polarized microscopy due to observation of high contrast ‘Maltese cross’ patterns in non-heat-treated specimens . The gelatinization temperature of native and modified starches is determined by following the loss of birefringence as a sample is progressively heated and gelatinization takes place. Fat crystal morphology  and size distribution, which correlate to stability and quality attributes in lipid-based products, are also easily characterized using polarized light  microscopy due to the birefringence of crystalized fats.