Effect of Infrared Heat-Moisture Treatment and Cooling Rate on the Material Properties of Amylose–Lipid Complex Nanomaterials

There are limited food-compatible nanomaterials to be used in foods, or most of them are not considered as edible or clean label. Isolated amylose–lipid complex (ALC) nanomaterials were subject to infrared heat moisture treatment (IR-HMT) at 110°C for 1, 2, and 3 h continuously or IR-HMT for 1 h followed by different cooling systems (room temperature, refrigeration temperature, and liquid nitrogen) and repeated two more times. Differential scanning calorimetry (DSC) revealed that IR-HMT and an increase in cooling rates resulted in ALC nanomaterials with higher endothermic peak temperatures (T_p) (109–112°C) and the presence of Type II crystallites. Notably, IR-HMT and cooling with room temperature resulted in Type IIa ALC (T_p = 109°C), while cooling with refrigeration temperatures and liquid nitrogen resulted in Type IIb ALC nanomaterials (110–112°C). X-ray diffraction (XRD) revealed higher crystallinity (up to 21%) for IR-HMT ALC with different cooling systems compared to their untreated counterparts (13%). Furthermore, faster cooling resulted in ALC nanomaterials with higher crystallinity compared to slower cooling rate. IR-HMT resulted in ALC nanomaterials with lower viscosity compared to untreated ALC as observed from flow properties. Furthermore, they displayed lower water absorption and solubility indices, suggesting that IR-HMT and different cooling systems led to molecular changes in ALC nanomaterials that affected their properties.