Arrowhead (Sagittaria sagittifolia L.) as one of the aquatic starchy vegetables is widely consumed in China, America, India, Canada, etc. (Guo et al., 2025; Raza et al., 2021). Arrowheads are usually roasted and fried in cooking, which are loved owing to their special taste and flavor (Ghifari & Lasekan, 2023). Multiple biological activities such as antioxidant activity, immunological activity, antitumor activity, and immune activity of arrowheads have been reported (Feng, Qiu, et al., 2022; Gu et al., 2020), indicating arrowheads are a potential high-value food resource for diet preparation and functional food manufacturing.

As an important starch resource, arrowheads mainly comprise 54.6 % starch in dried edible tuber (Raza et al., 2023;Wang et al., 2013), and they are commonly refrigerated to inhibit quality degradation caused by moisture loss, enzyme activities, and microbial growth (Li & Sun, 2002). Freezing is a feasible method to preserve arrowheads but the formed ice crystals will induce severe mechanical damage to the microstructure, resulting in irreversible effects on the quality (Guan et al., 2024). In the storage and transportation of arrowheads, freeze-thaw cycles (FTC) inevitably caused by temperature fluctuation further accelerate quality deterioration such as texture collapse, water loss, and unpleasant odor formation (Bai et al., 2023; Fan et al., 2005), which lowers the buying inclination of consumers. To alleviate damages induced by FTC treatment, some additives such as polysaccharides are commonly used as protective agents to enhance the resistance of fresh foods against mechanical damage caused by ice crystals (Klinmalai et al., 2024). However, the safety and cost of additives limit their application. Recently, electric field (EF) as a non-contact physical technique has shown enormous potential for freezing and thawing of fresh foods such as meat (Yang et al., 2024) and vegetables (Chen et al., 2023). The mechanism of EF applied to accelerate freezing is that EF greatly lowers free energy needed in water realignment and the formation of ordered clusters, and then induces the premature formation of ice nuclei, finally forming small ice crystals with uniform sizes in a short time (Jiang et al., 2023). For the thawing process, the external air can be ionized via corona discharge with EF treatment and generate enormous momentum of ions, breaking the hydrogen bonds in ice crystals (Li et al., 2020). Starch as the main component of arrowheads play important roles in holding moisture and maintaining structure, which significantly influence the storage properties of arrowheads. Previous studies reported that FTC treatment significantly destroyed the gel structure and increased the compactness, crystallinity, and hardness of starch-based foods (Cheng et al., 2024). Alvarez and Canet (2001) found that FTC treatment broke the inner cell and tissue structure of frozen starchy vegetable purees, resulting in a coarse structure due to the aggregation of starch granules. It can be seen that starch are sensitive to repeated freezing and thawing and finally caused negative effects on structural and physicochemical properties of starch-based foods. We hypothesize that EF assistance can inhibit the quality deterioration of arrowheads induced by FTC treatment. Meanwhile, it is necessary to figure out the relationship between arrowheads' quality and starch variations, thus fully utilizing this starch resource.

Therefore, this study aims to figure out the effects of EF assistance on the structural and physicochemical properties of arrowhead starch, as well as the physical features of arrowheads after repeated freezing and thawing, thus revealing the relationship between quality deterioration and structural variations of arrowhead starch during storage at low temperature.