Boric acid

Folinol, gallic acid, and rutin were purchased from Shanghai Yuanye Biological Co., LTD (Shanghai, China). Phenol was purchased from Aladdin Biotechnology Inc (Shanghai, China). Formic acid was obtained from Thermo Fisher Technologies Co., Ltd. (Waltham, MA, USA), and methanol was purchased from Merck Chromatographic Reagent Co., LTD (Darmstadt, Germany). Hydrochloric acid, sulfuric acid, petroleum ether (30~60 °C), copper sulfate, potassium sulfate, boric acid, sodium nitrite, sodium carbonate, aluminum chloride, sodium hydroxide, and other chemical reagents were analytical-pure and purchased from Xilong Scientific Co., Ltd. 1, 1-diphenyl-2-trinitrophenylhydrazine (DPPH) was purchased from Sigma Company in the United States. RRAP and ABTS kits were obtained from Biyuntian Biotechnology Co., Ltd. (Shanghai, China). The total starch assay kit was obtained from Megazyme International Ireland, Bray Business Park, Bray, Co. Wicklow, Ireland.

Red swamp crayfish (P. clarkii, n = 475, 11 ± 1 cm long and 32 ± 4 g in weight) were purchased from Qianjiang City, Hubei Province, China. A plastic foam box was used to transport the crayfish on ice to the Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety. The carapaces of the cephalothoraxes were collected, washed in ice water, and placed overnight in a cold room (4 °C) to remove surface moisture. Following this, they were intermittently ground into a fine powder (6.35 mm mesh) with an LD-T400 food blender (Dingshuai Electric Appliance Inc., Shanghai, China) to avoid degrading the heat-labile components.
Boric acid, Tris, sodium dihydrogen phosphate, disodium hydrogen phosphate, ethylenediaminetetraacetic acid (EDTA), sodium hydroxide, ammonium sulphate, and sodium chloride were of analytical grade and purchased from Xilong Scientific Co., Ltd., Shantou, China.