The objective of this study was to optimize the conditions to enhance the antioxidant property of sword bean (Canavalia gladiata) as a coffee substitute in two processing methods, roasting and grinding. The optimum condition to remove off-flavor of the bean and maximize functionality and efficiency was light roasting and cryogenic grinding (<53 μm). In this condition, extraction yield was 16.75%, total phenolic content (TPC) was 69.82 ± 0.35 mg gallic acid equivalents/g, and total flavonoid content (TFC) was 168.81 ± 1.64 mg quercetin equivalents/100 g. The antioxidant properties were 77.58 ± 0.27% for DPPH radical scavenging activity and 58.02 ± 0.76 mg Trolox equivalents/g for ABTS radical scavenging activity. The values of TFC and ABTS radical scavenging activity were significantly higher (p<0.05) than in other conditions, and TPC and DPPH radical scavenging activity were second highest in lightly roasted beans following raw beans. HS-SPME/GC-MS analysis confirmed that the amino acids and carbohydrates that are the main components of sword bean were condensed into other volatile flavor compounds such as derivatives of furan, pyrazine, and pyrrole during roasting. Roasted and cryogenic-ground sword beans showed higher functionality in terms of TFC, DPPH, and ABTS radical scavenging activities compared to those of coffee. Overall results showed that light roasting and cryogenic grinding are the most suitable processing conditions for enhancing the bioactivity of sword beans.

中文翻译：

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烘烤和低温研磨可增强剑豆 (Canavalia gladiata) 的抗氧化性能。

本研究的目的是优化条件以增强剑豆（Canavalia gladiata ）的抗氧化性能) 作为咖啡的替代品，采用两种加工方法，烘焙和研磨。去除咖啡豆异味并最大限度提高功能和效率的最佳条件是轻度烘焙和低温研磨 (<53 μm)。在此条件下，提取率为16.75%，总酚含量（TPC）为69.82±0.35 mg没食子酸当量/g，总黄酮含量（TFC）为168.81±1.64 mg槲皮素当量/100 g。DPPH 自由基清除活性的抗氧化性能为 77.58 ± 0.27%，ABTS 自由基清除活性为 58.02 ± 0.76 mg Trolox 当量/g。TFC 和 ABTS 自由基清除活性的值显着高于其他条件下 (p<0.05)，TPC 和 DPPH 自由基清除活性在轻度烘焙豆中仅次于生豆第二高。HS-SPME/GC-MS 分析证实，作为刀豆主要成分的氨基酸和碳水化合物在烘焙过程中被浓缩成其他挥发性风味化合物，例如呋喃、吡嗪和吡咯的衍生物。与咖啡相比，烘焙和低温磨碎的刀豆在 TFC、DPPH 和 ABTS 自由基清除活性方面表现出更高的功能。总体结果表明，轻度烘焙和低温研磨是提高剑豆生物活性的最合适加工条件。和 ABTS 自由基清除活性与咖啡相比。总体结果表明，轻度烘焙和低温研磨是提高剑豆生物活性的最合适加工条件。和 ABTS 自由基清除活性与咖啡相比。总体结果表明，轻度烘焙和低温研磨是提高剑豆生物活性的最合适加工条件。