2 2 azino bis 3 ethylbenzothiazoline 6 sulfonic acid diammonium salt

Ovalbumin (OVA, albumin from chicken egg white, nitrogen content ≥ 12.5%, total protein on a dry basis ≥ 80%, relative molecular mass less than 1000 ≥ 80%, pI: 4.43–4.66; purity ≥ 80%), sodium alginate [SA, viscosity, 10 g L⁻¹, 20 °C, (Pa s) ≥ 0.02], LB broth, LB nutrient agar, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and water-soluble vitamin E Trolox were purchased from Solarbio Technology Co., Ltd. (Beijing, China). Kaempferol (KAE, a polyphenol from brown algae, purity ≥ 97%), tannic acid (TA), potassium persulfate, potassium ferricyanide, and iron(iii)chloride anhydrous were purchased from Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). The Folin-phenol reagent was purchased from Bomei Biotechnology Co., Ltd. (Hefei, China). All other chemicals used were analytical grade, and purchased from Sinopharm Chemical Glass Co., Ltd. (Jinzhou, China).

Gallic acid (GA), catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), epicatechin-3-O-gallate (ECG,), epigallocatechin gallate (EGCG), epicatechin gallate (ECG), gallocatechin gallate (GCG and ellagic acid (EA) were purchased from Sigma-Aldrich (Saint Louis, MO, USA) with a purity of > 98 %. Folin-Ciocalteu phenol reagent, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,4,6-tri-(2-pyridyl)-1,3,5-triazine (TPTZ), dinitrosalicylic acid (DNS), 4-nitrophenyl-a-d-glucopyranoside (pNPG), porcine pancreatic α-amylase (10 U/mg), Saccharomyces cerevisiae α-glucosidase (100 U/mg), porcine pancreatic lipase (30 U/mg) and porcine pancreatic cholesterol esterase (100 U/mg) were obtained from Beijing Solarbio Science & Technology Co. Ltd. (Beijing, China). All other reagents were of analytical grade and were commercially available.