A promising natural purple batter system with antioxidant activity for vacuum fried breaded shrimp

Abstract This study aims to develop a batter system with natural purple and functional quality for vacuum fried breaded shrimp. Purple sweet potato flour (PSPF), soy protein isolate (SPI), and xanthan gum were used as coating materials. The effect of the ratio of SPI and xanthan gum on the rheological properties, coating pick-up, color, moisture content, oil content, texture, anthocyanin content and antioxidant activity were investigated. Compared with the control group, it was observed that the batter system with PSPF, SPI and xanthan gum had better rheological properties. The result showed that a ratio of 2:1 for SPI to xanthan gum had the highest coating pick-up value (49.83%), the more attractive purple (a* = 3.07), less oil content (20.55%) and retained higher anthocyanin content (51.71 mg/100 g). Based on the results of anthocyanin content, vacuum fried shrimps were analyzed for antioxidant activity. In the 2,2-diphenyl-1-picrylhydrazyl (•DPPH), hydroxyl (•OH) radical-scavenging assay test, PSPF vacuum fried shrimps showed high free-radical scavenging activity (60.19% for •DPPH and 35.97% for •OH). Therefore, the batter system with PSPF, SPI and xanthan gum is a promising coating material, which is widely used for vacuum fried breaded products, such as pork chop, steak, chicken nuggets and fish fingers.

摘要 本研究旨在开发一款兼具天然紫色外观与功能品质的真空油炸裹粉虾面糊体系。研究采用紫薯粉（purple sweet potato flour, PSPF）、大豆分离蛋白（soy protein isolate, SPI）及黄原胶作为裹覆原料，探究了SPI与黄原胶的配比对体系流变特性、裹覆率、色泽、水分含量、含油率、质构特性、花色苷含量及抗氧化活性的影响。与对照组相比，添加PSPF、SPI及黄原胶的面糊体系流变性能更优。结果表明，当SPI与黄原胶配比为2:1时，体系裹覆率最高（49.83%），所得产品呈现更诱人的紫色（a*=3.07），含油率更低（20.55%），且保留了更高的花色苷含量（51.71 mg/100 g）。基于花色苷含量的检测结果，本研究进一步对真空油炸虾的抗氧化活性进行分析。在2,2-二苯基-1-苦基肼自由基（•DPPH）、羟基自由基（•OH）清除试验中，添加PSPF的真空油炸虾展现出优异的自由基清除活性：•DPPH自由基清除率为60.19%，•OH自由基清除率为35.97%。综上，以PSPF、SPI及黄原胶配制的面糊体系是一款极具应用前景的裹覆材料，可广泛应用于猪排、牛排、鸡块、鱼条等真空油炸裹粉类产品。