Effect of acid treatments and drying processes on physico-chemical and functional properties of cassava starch

Abstract

The effects of acid treatments (HCl or organic acids) and drying processes (oven or sun) on the physico‐chemical and functional properties of cassava starch have been studied. The objective was to obtain modified starches with expansion properties similar to those of sun dried fermented cassava starch (polvilho azedo) as produced by an empirical process. Expansion was evaluated using a baking test. Independent of the drying method, organic acid‐hydrolysed cassava starch presented the same X‐ray diffraction patterns (changes from C to A) and similar intrinsic viscosity values. SEM observations showed no differences between granule surfaces of sun dried and oven dried samples. However sun dried organic acid‐hydrolysed starches presented lower paste consistency values at 30°C when compared with oven dried ones. HCl‐modified cassava starches were oven or sun dried, giving biscuits with low specific volumes (2·5–3·1 ml g−1). Similar behaviour was obtained using oven dried organic acid modified cassava starches. When submitted to sun drying, organic acid modified starches showed great improvements in biscuit expansion (5–10 ml g−1). The highest average specific volumes were obtained using lactic acid modified starches. © 1998 SCI.

Características físico-químicas de amidos modificados com permanganato de potássio/ácido lático e hipoclorito de sódio/ácido lático

“…A propriedade de expansão em amidos também pode ser obtida através da modificação fotoquímica, como estudado por vários autores (NUNES, 1994;NUNES;CEREDA, 1994;PLATA-OVIEDO;CAMARGO, 1994;VATANASUCHART et al, 2005).…”

“…O desenvolvimento de féculas de mandioca autoexpansíveis poderá resultar em novos ingredientes para uso na elaboração de biscoitos, pães de queijo e em outros produtos panificáveis livres de glúten (DEMIATE, 1999). O processo fermentativo apenas fragmenta as cadeias amiláceas produzindo ácidos orgânicos, sendo a exposição à luz ultravioleta do sol o tratamento responsável pela propriedade de expansão (CEREDA; LIMA, 1985;CEREDA, 1983a;1981;DEMIATE, 1999;DEMIATE et al, 1999;DUFOUR et al, 1996;LEONEL;GARCIA;REIS, 2004;MESTRES;ROUAU, 1997;NUNES, 1994;NUNES;CEREDA, 1994;PLATA-OVIEDO;CAMARGO, 1998;. Polvilho azedo foi utilizado em algumas misturas com derivados de soja, obtendo-se um produto panificado de valor nutritivo superior quando comparado com o pão de trigo tradicional (SHEN et al, 1999).…”

The Effect of Emulsifier and Hydrocolloid on Baking Expansion and Texture of Bread from Modified Cassava

“…However, acidification of cassava starch, using lactic, acetic, or butyric acid and followed by oven drying, was unsuccessful to produce any great expansion ability after baking [20]. Additionally, amylase depolymerisation or natural lactic fermentation also did not provide the better expansion properties [13,19].…”

“…Additionally, amylase depolymerisation or natural lactic fermentation also did not provide the better expansion properties [13,19]. In the other hands, some researcher suggested to modify the cassava starch using combination of fermentation and sun drying method for better expansion baking properties [13,20,21].…”

“…The previous studies used lactic acid solution as acidifying agent [22][23][24]. The combination processes of UV irradiation and lactic acid solution followed by sun drying process represented the increase of specific volume of tested biscuits [20]. However, these better properties did not show in sour cassava starch treated by oven-drying method [20].…”