Bioscience Evidence 2025, Vol.15, No.6, 260-269 http://bioscipublisher.com/index.php/be 264 5 The Influence of Sweet Potato Processing and Cooking Methods 5.1 Retention and loss of nutrients (boiling, steaming, roasting, frying) Different cooking methods can affect the nutrients in sweet potatoes. Generally speaking, steaming and boiling can better preserve beta-carotene and vitamin C. Especially steaming and microwave heating have the highest retention rate of vitamin C. Some studies can even reach 98.98%~102.36% (Eke-Ejiofor and Onyeso, 2019; Buratti et al., 2020; Yvonne and Pontsho, 2023). In contrast, frying and baking will cause more loss of these nutrients. Pressure cooking and boiling also have better retention of beta-carotene, while air frying and baking have the most severe loss (Fornazier et al., 2025). Cooking may also enhance polyphenols and antioxidant activity, among which steaming and microwave heating have the most obvious effects (Kamal and Golshany, 2024; Cao et al., 2025). Although frying is more popular in taste, it will increase a lot of fat and calories, so it is not very suitable as a daily healthy eating method. 5.2 The influence of different cooking methods on glycemic index The glycemic index (GI) of sweet potatoes varies depending on the cooking method. Generally, the GI of boiled sweet potatoes is lower than that of baked and fried ones. This is because during the cooking process, the starch structure changes and more resistant starch is formed, thereby causing the blood sugar to rise more slowly (Freitas et al., 2023). Baking and frying make starch easier to digest, so the GI value will rise. Studies also show that the starch breakdown rate and blood sugar response of boiled sweet potatoes are both lower than those of roasted sweet potatoes. For diabetic patients, boiling water is a more appropriate choice. 5.3 Effects on anthocyanins, carotenoids and vitamin C Anthocyanins and polyphenols are prone to loss during heating. However, steaming and microwave heating can retain them better. The anthocyanins in purple sweet potatoes have a relatively high retention rate when steamed or fried with the skin on. β -carotene retains its effect relatively well under steaming, boiling and microwave heating, but is significantly lost during frying and baking (Buratti et al., 2020). Vitamin C is highly sensitive to heat. The retention rate is the highest in steaming and microwave heating, while the loss is the greatest in baking and frying (Figure 2) (Cao et al., 2025). Figure 2 GC-MS analysis of volatile compounds in steamed sweet potato ‘Xinxiang’ and ‘Pushu32’ at different temperatures (A) Classes of volatile compounds. (B) Correlation network between different treatments and volatile compounds of steamed sweet potato. The inner nodes represent different treatments while the outer nodes represent volatile compounds. The thickness of the line is proportional to the content of volatile compounds. The color depth of the inner circle depends on the amounts of volatile compounds, while the color depth of the outer circle depends on the content of specific volatile components (Adopted from Cao et al., 2025) 6 Case Analysis: Examples of Sweet Potato Intake Promoting Health 6.1 Background Sweet potatoes (Ipomoea batatas) are believed to be highly beneficial to health due to their high dietary fiber content, rich vitamins and minerals, as well as some active components. In recent years, the role of sweet potatoes
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