Relationship between baking behavior of modified cassava starches and starch chemical structure determined by FTIR spectroscopy

Cassava sour starch is a typical food ingredient from some South American c ountries, produced mainly in Brazil and Colombia and it shows high expansio n when baked. It is known that sun-drying fermented starch is essential. Re cently degradative oxidation has been considered as possibly related to che mical changes on cassava starch and was evoked as a probable cause for baki ng property. We produced some chemically oxidized samples presenting baking property to be compared with lactic acidified and sun- or oven-dried ones, as well as with commercial cassava sour starch and native cassava starch. All the samples were analyzed by using FTIR spectroscopy associated with ch emometric data processing. Successful prediction of starch expansion value was achieved by partial least square regression of FTIR spectral data. The results of both qualitative and quantitative spectral analyses showed that presence of carboxylate groups (1600 cm(-1)) on cassava starch as well as s ome other changes in the region around 1060 cm(-1) of mean normalized spect ral data are essential for baking property. The degradative oxidation is as sumed to take place on the C-O bond relative to carbon 1 and oxygen 5 of th e cyclic part of glucose at 1060 cm(-1). (C) 2000 Elsevier Science Ltd. All rights reserved.