Effect of annealing temperature on morphology and physicochemical properties of cornstarch complexed with oleic acid and molecular dynamics simulation

Abstract

Background and objectives Annealing treatment (ANN) as a mild hydrothermal method to improve the complexation between starch and lipids has scarcely been studied. Moreover, the mechanism of starch pretreated by ANN on the complexation between starch and fatty acid still has not been investigated. Therefore, the object of this research was to investigate the effect of ANN pretreatment temperature (50, 55, and 60°C) on the morphology, crystal structure, and thermal properties of CSANN‐OA complex by using confocal laser scanning microscope (CLSM), X‐ray diffraction (XRD), and DSC. The mechanism of the complexation between starch and OA was simulated by the molecular dynamics simulation (MDS) method. Findings The results of complex indexes (CI) indicated that CSANN was easier to complex with OA than CSU, and the optimal ANN pretreatment temperature to promote the complexation between CSANN and OA was 50°C. The CLSM displayed that ANN pretreatment at 50°C caused more and stronger fluorescence fragments in CSANN‐OA than that of ANN pretreatment at 55 or 60°C. XRD of both CSU‐OA and CSANN‐OA changed to V‐type crystalline. The relative crystallinity (RC) and gelatinization enthalpy (ΔH) of the complex were decreased with increasing ANN pretreatment temperature, but the gelatinization temperature range (Tc–To) remains unchanged. According to results of MDS, Van der Waals might be dominate driving force between AM and OA. Conclusions These results suggest that ANN pretreatment is an effective method to promote the complexation of ANN starch with more polar or nonpolar components. Significance and novelty This result can provide available information about the complexation effect and complexation mechanism between starch subjected to ANN pretreatment and fatty acid.

Effect of freezing‐assisted treatment on the formation of stable VII‐type complex of fried sweet potato starch and its mechanism

“…The X‐ray diffraction data can be used to investigate the interaction between external oil and starch molecules (X. Zhang, Wang, et al., 2019). The X‐ray diffraction patterns and relative crystallinity values of native and fried SPS are presented in Figure 2b.…”

“…(2011) observed that the stearic acid‐treated cornstarch showed the bright fluorescence spot areas on the surface of the starch granules. The authors previously observed more pores, cracks, and accessible structure produced in the starch granules by the freezing treatment (Li et al., 2021), which could introduce more RSO into the starch granules and complex with the intragranular amylose (X. Zhang, Wang, et al., 2019). The fluorescence of fried SPS changed from light green to bright green with decreasing the treating‐assisted temperature.…”

“…X. Zhang, Wang, et al. (2019) reported that the annealing‐assisted treatment obviously increased the amount of cornstarch–oleic acid complexes by 2%−23%, which might be related to the improvement in the mobility of amylose. De Pilli et al.…”

“…To improve the formation of the starch–lipid complexes, extrusion (De Pilli et al., 2012), heat treatment (Y. Zhang, Li, et al., 2019), annealing (X. Zhang, Wang, et al., 2019), ultrasonic treatment (Ding et al., 2020), and high‐pressure homogenization (Meng et al., 2014) were adopted. X. Zhang, Wang, et al.…”

Computational strategies for the discovery of biological functions of health foods, nutraceuticals and cosmeceuticals: a review

“…Systems formed with cornstarch (CS) and fatty acids were simulated for 1 ns using Gromacs [ 104 ]. These results revealed that the total and potential energy were higher (in magnitude) for the lipids-CS complex when compared to CS alone, which led to the inference that more energy is necessary to damage the complex since it has more stability than CS alone [ 109 ].…”