The hypoglycemic effect of Porphyra is well known. Based on in vitro digestion and metabolomics, the bioaccessibility, antidiabetic activity and phenolic conversion of P. haitanensis were investigated at different harvests. Total polyphenol content (TPC), α-glucosidase inhibition and oxygen radical absorbance capacity (ORAC) increased with harvesting and digestion stages, reaching maximum at the fourth harvest. TPC and α-glucosidase inhibition after digestion reached 130–150 mg/g and 50–90 %, ORAC was 8.7–13.5 times higher than the undigestion. However, bioaccessibility in the first and second harvests was 10–80 % higher than other harvests. The phenolic content in the fourth harvest was up-regulated to 2–30 times than the first and mostly were citrus flavonoids. Redundancy analysis indicated significant correlation between phenolic metabolites and bioactivities in different harvests of P. haitanensis during digestion, with the strongest correlation coefficients were apigenin and genistein. This study provides reference for the application of P. haitanensis in treating type 2 diabetes.

紫菜的降血糖作用是众所周知的。基于体外消化和代谢组学，研究了P的生物可利用性、抗糖尿病活性和酚类转化。在不同的收获期对坛花进行了调查。总多酚含量（TPC）、α-葡萄糖苷酶抑制作用和氧自由基吸收能力（ORAC）随着收获和消化阶段的增加而增加，在第四次收获时达到最大值。消化后TPC和α-葡萄糖苷酶抑制达到130-150mg/g和50-90%，ORAC比未消化时高8.7-13.5倍。然而，第一次和第二次收获的生物可利用性比其他收获高 10-80%。第四次收获的酚类物质含量比第一次增加2-30倍，且主要是柑橘类黄酮。冗余分析表明不同采收的坛紫菜消化过程中酚类代谢物与生物活性存在显着相关性，相关系数最强的是芹菜素和金雀异黄酮。本研究为P的应用提供参考。坛黄芪治疗2型糖尿病。