Quantification of Antioxidants and Metabolites

A commercial kit (BC1230, Solarbio) was applied to determine AsA content based on the oxidation rate of AsA catalyzed by AAO (ascorbic acid oxidase) (spectrophotometric measurement at OD_{265 nm}). A commercial kit (BC1240, Solarbio) was applied to determine DHA content based on the production rate of AsA from DHA by DTT (1,4-dithiothreitol) (spectrophotometric measurement at OD_{265 nm}). A commercial kit (BC1170, Solarbio) was applied to determine GSH content based on spectrophotometric measurement of the product from the reaction between GSH and DTNB (5,5’-dithiobis-2-nitrobenoic acid) (OD_{265 nm}). A commercial kit (BC1180, Solarbio) was applied to determine GSSG content based on the production rate of GSH (measurement of OD_{265 nm} for the reaction between GSH and DTNB) from GSSG catalyzed by GR (GSH reductase). A commercial kit (BC0290, Solarbio) was applied to determine proline content based on spectrophotometric measurement of the product from the reaction between proline and ninhydrin (OD_{520 nm}). A commercial kit (BC0035, Solarbio) was applied to determine plant soluble sugar content based on anthrone colorimetric method (OD_{620 nm}). A commercial kit (BC0700, Solarbio) was applied to determine starch content based on the separation of starch with 80% ethanol and acid hydrolyzation to glucose, followed by anthrone colorimetric method (OD_{620 nm}) (Chen et al., 2020b (link)).