Effect of Annealing on Structural, Physicochemical, and In Vitro Digestive Properties of Starch from Castanopsis sclerophylla

Abstract

Annealing is a hydrothermal treatment that changes the structural and functional properties of starches. This study investigates and compares the effects of one‐step annealing for 24 and 48 h, respectively, and two‐step annealing on the structural, physicochemical, and digestive properties of Castanopsis sclerophylla starch (CaS). Annealing has no effect on CaS morphology, crystalline pattern, and short‐range ordered structures. However, annealing decreases the swelling power, solubility, setback, and peak viscosity of CaS and increases its crystallinity and thermal stability. Post annealing, the rapidly digestible starch (RDS) of CaS decreases, the slowly digestible starch (SDS) increases while the resistant starch (RS) content of CaS remains unchanged. Comparing with One‐step annealing for 24 h, one‐step annealing for 48 h and two‐step annealing does not further change the RDS and SDS content of annealed CaS.

The Influence of Temperature Changes on the Rice Starch Structure and Digestive Characteristics: One and Two-Step Annealing

“…The gelatinization characteristic curve and corresponding parameters of rice starch before and after annealing are presented in Figure 4 and Table 2 . According to Figure 4 , the peak viscosity of starch after annealing decreased by varying degrees, which was consistent with the findings of Shi et al [ 2 ]. The internal crystallization of starch increased, and the interactions between the starch chains were strengthened after annealing, thereby inhibiting the formation of hydrogen bonds between starch and water, reducing the degree of hydration in the amorphous region and limiting the swelling capacity, resulting in a decrease in peak viscosity.…”

“…Compared with one-step annealing, the surface folds of the two-step annealed starch granules ( Figure 1 (A4,A5)) were significant, of which the surface folds of ANN−60−50 were slightly more than those of ANN−50−60, possibly resulting from the temperature changes in the two-step annealing that aggravated the dissolution of amylose in the hydrothermal effect. Shi et al [ 2 ] found that annealing at different temperatures and times had no effect on the morphology of starch from Castanopsis sclerophylla . These results showed that changes in the morphological characteristics caused by annealing modification might depend on starch source and treatment conditions.…”

“…Starch is a semi-crystalline polymer composed of glucose, which is deposited in the form of granules in the roots, stems, and leaves of green plants and widely used in foods, medicines, and cosmetics [ 1 , 2 ]. However, natural starch is poor in functionality and prone to aging, which reduces the viscoelasticity of the product and causes poor gel stability and transparency [ 3 , 4 ].…”

Influence of Annealing Process Combined with Enzymatic Modification with Transglucosidase on Black Rice Starch

“…[ 30 ] According to studies by Shi et al. [ 31 ] and Wang et al. [ 32 ] starch is not fully gelatinized, so digestibility is little affected during the process.…”

“…The increase in firmness indicates that there was a strengthening of the bonds between the gelatinized starch granules, indicating greater interactions between amylose and amylopectin, thus forming a more stable structure and reducing amylose leaching. [ 31 ]…”