Starch and lipids, being pivotal nutrients in food, assume a significant role in the realm of food processing [1]. Starch and lipids play crucial roles in determining food texture, viscosity, digestion, flavor, and shelf life [2]. During the food processing procedure, the taste and quality of the end product are influenced by the intricate physical and chemical interplay between starch and lipids [1]. Starch can be classified into two main components (amylose and amylopectin). Amylopectin consists of both α-1, 4-glucoside bonds and α-1, 6-glucoside bonds. Amylose is composed of glucose units linked by α-1, 4-glucoside bonds [3]. Despite what is often thought, it is well established that amylose is slightly branched [4]. Amylose exhibits the capacity to establish starch-lipid complexes with lipids owing to its distinctive helical configuration and hydrophobic cavities. Conversely, amylopectin is characterized by numerous short branches that restrict the formation of helical structures and result in weaker interactions with lipids [5,6]. In the case of starch mixed with lipid, the water solubility of starch is observed to decrease, accompanied by an increase in gelatinization temperature and a reduction in enzyme sensitivity. These changes can be attributed to the formation of a starch-lipid complex resulting from the coating of lipids with starch molecules [7,8]. Several factors affect the interaction between starch source origin, chemical structure, addition ratio, and processing method [6,8].

Compared to glutinous rice starch, rice starch, tapioca starch, and potato starch, the complex index, structural order degree, and resistant starch (RS) content of myristic acid complex in maize starch and high amylose maize starch were found to be the highest [9]. Compared to other cereals, oats exhibit a high starch content (60 %) and lipid content (2 % to 12 %), starch and lipid significantly influence product properties [10]. Previous studies have demonstrated that reducing lipid content in oat flour leads to increased peak viscosity and gel strength, the rheological properties of oat starch are influenced by the presence of oat lipid [11]. The heating process of oats leads to the disruption of starch crystalline structure and dissociation of double helix structure, thereby promoting the formation of hydrophobic cavities through hydrophobic forces. The hydrophobic cavity facilitates the formation of a starch-lipid complex, enclosing the lipid through robust hydrogen bonding and intermolecular forces [12,13]. Wheat flour cooking induces a shift from A-type to V-type starch configuration, indicating the formation of starch-lipid complexes [15].

Endogenous lipids present in rice flour as well as within maize and tapioca starches impede the process of in vitro digestion of starch by acting as barriers against hydrolytic enzymes [16]. Lipids and starch combine to form a complex, which increases the content of RS. When subjected to heat, food undergoes a reaction with various fatty acids resulting in the formation of starch-lipid complexes. These complexes exhibit an enhanced resistance towards enzymatic hydrolysis and significantly impact the structural characteristics, physicochemical properties, and digestive mechanism [6]. The complexation between corn starch and lauric acid was accomplished via the establishment of hydrogen bonds and hydrophobic interactions. This complex facilitated the development of an ordered structure in corn starch, leading to a decline in starch digestibility and an increase in RS level [17]. The enhancement of ordered structural arrangement and thermal stability can effectively enhance the resistance to enzymatic digestion [17].

During the processing of oat products, the interaction between starch and lipids plays a crucial role in determining their quality. To provide a comprehensive understanding of this phenomenon, we simulated the cooking process to investigate the interaction between oat starch and oat lipid. This study serves as a theoretical foundation for comprehending the changes in both the quality and characteristics of oat products during cooking. However, it is important to note that our investigation solely focused on examining the interplay between starch and lipid in oats, while neglecting the potential influence of oat protein. Therefore, future research endeavors will aim to explore the intricate relationship among oat starch, lipid, and protein components within these products. This study does not reflect this. This study was conducted to investigate the effects of oat lipids on the structure and function of oat starch. The crystalline and ordered structures of starch were analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Scanning electron microscopy (SEM) was used to observe the micromorphology of starch. Additionally, pasting, thermal properties, viscoelasticity, and gel strength were assessed through RVA analysis, differential scanning calorimetry (DSC), rheology measurements, and texture analyzer assays. The digestibility of starch in vitro was determined by the amylase and glucose oxidase/peroxidase (GOPOD) method. Furthermore, correlation analyses between different lipid additions and each index were conducted for the starch samples. This study has established a solid theoretical foundation for the processing and utilization of oats.