| Abstract
| - The baking expansion properties of sour cassava starch (Polvilho azedo) are attributable tophotochemical starch degradation induced by heterolactic fermentation after sun-drying. This studyinvestigated the effects of UV irradiation on the different structural levels of cassava starch ascompared to those of corn starch and dextrins. Photosensitive compounds excited at 360 and 290nm in cassava starch were photodegraded when starch was exposed to sunlight or 360 nm irradiation.UV irradiation depolymerized cassava and corn starches, inducing modifications due, at least inpart, to a mechanism involving free radicals. Lactic acid was also photodegraded. Photodegradationinduced by UV absorption could have been due to fluorescent chromophores found in starches andnonfluorescent chromophores present in glucosidic units. Keywords: Sour cassava starch; photodegradation; UV irradiation; lactic acid; Polvilho azedo
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