Thermal and physicochemical characterization of seven Argentine rice flours and starches

ITURRIAGA, L. LOPEZ DE MISHIMA, B.; AÑÓN, M.C.

FOOD RESEARCH INTERNATIONAL

Año: 2004 vol. 37 p. 439 - 447

0963-9969

Abstract Di.erential scanning calorimetry (DSC) was used to evaluate phase transitions of rice .ours and starches from seven new argentine genotypes in systems with di.erent water content. Flours of high, medium and low TG (gelatinization temperature) were detected; DHG (total gelatinization enthalpy) showed two homogenous groups (8.1–9.2 and 10.1–10.4 mJ/mg). Amylose–lipid complex melting endotherm in waxy rice .ours was observed despite the low amylose content. It is suggested that this complex could be originated in the longest amylopectin branches and extra granular complexing lipids. Di.erential behaviour in waxy genotypes was found with decrease of water content, probably due to the highest water absorption capacity of the AP (amylopectin). Genotypes with high (26.8–28.6 g/100 starch), medium (19.6–20.7 g/100 g starch) and low total amylose (TAM) content was found (1.3–2.1g/100 g starch). In using X-ray di.raction, the relative crystallinity in waxy genotypes was found to be higher (48%) than that corresponding to the non-waxy ones (37–40%). A linear correlation between gelatinization process cooperativity and TAM was found to exist but no between DHG and TG with crystallinity and TAM. Glass transitions (Tg) of gelatinized starch–water systems were also determined by DSC. Results indicated higher values ()5.0 to 6.3
C) for .ours than for starches ()10
C).TG (gelatinization temperature) were detected; DHG (total gelatinization enthalpy) showed two homogenous groups (8.1–9.2 and 10.1–10.4 mJ/mg). Amylose–lipid complex melting endotherm in waxy rice .ours was observed despite the low amylose content. It is suggested that this complex could be originated in the longest amylopectin branches and extra granular complexing lipids. Di.erential behaviour in waxy genotypes was found with decrease of water content, probably due to the highest water absorption capacity of the AP (amylopectin). Genotypes with high (26.8–28.6 g/100 starch), medium (19.6–20.7 g/100 g starch) and low total amylose (TAM) content was found (1.3–2.1g/100 g starch). In using X-ray di.raction, the relative crystallinity in waxy genotypes was found to be higher (48%) than that corresponding to the non-waxy ones (37–40%). A linear correlation between gelatinization process cooperativity and TAM was found to exist but no between DHG and TG with crystallinity and TAM. Glass transitions (Tg) of gelatinized starch–water systems were also determined by DSC. Results indicated higher values ()5.0 to 6.3
C) for .ours than for starches ()10
C).DHG (total gelatinization enthalpy) showed two homogenous groups (8.1–9.2 and 10.1–10.4 mJ/mg). Amylose–lipid complex melting endotherm in waxy rice .ours was observed despite the low amylose content. It is suggested that this complex could be originated in the longest amylopectin branches and extra granular complexing lipids. Di.erential behaviour in waxy genotypes was found with decrease of water content, probably due to the highest water absorption capacity of the AP (amylopectin). Genotypes with high (26.8–28.6 g/100 starch), medium (19.6–20.7 g/100 g starch) and low total amylose (TAM) content was found (1.3–2.1g/100 g starch). In using X-ray di.raction, the relative crystallinity in waxy genotypes was found to be higher (48%) than that corresponding to the non-waxy ones (37–40%). A linear correlation between gelatinization process cooperativity and TAM was found to exist but no between DHG and TG with crystallinity and TAM. Glass transitions (Tg) of gelatinized starch–water systems were also determined by DSC. Results indicated higher values ()5.0 to 6.3
C) for .ours than for starches ()10
C).DHG and TG with crystallinity and TAM. Glass transitions (Tg) of gelatinized starch–water systems were also determined by DSC. Results indicated higher values ()5.0 to 6.3
C) for .ours than for starches ()10
C).Tg) of gelatinized starch–water systems were also determined by DSC. Results indicated higher values ()5.0 to 6.3
C) for .ours than for starches ()10
C).
C) for .ours than for starches ()10
C).