Table 2.

Method of protein selenization modification.

Selenization System	Principal Operating Parameter	Selenium Content/(mg/g)	Combination	Reference
Microwave-assisted Na2SeO3 selenization	5 g Morchella protein hydrolysate, 20 g Na2SeO3 dissolved in 500 mL H2O pH = 5.0 adjusted by 1 M HCl Microwave power was 250 W, irradiation time was 20 min Centrifugation at 4000× g for 15 min	59	Se-O Se=O	[45]
CH3COOH-Na2SeO3	0.2 g Nostoc commune glycoprotein 0.2 g Na2SeO3, 0.5 g BaCl2 50 mL 2% CH3COOH solution 2 mL 10% HNO3 solution The reaction was carried out in a 75 °C water bath for 7 h	1.403	\	[50]
Selenated sulfinic acid	10% selenated sulfinic acid solution buffer 6% H2O2 The reaction was carried out in a vacuum reactor at 40 °C for 5 h	75.85	Se=O	[51]
Dry-heat selenization	Egg white protein concentration of 2% The freeze-dried samples were kept at 60 °C for 5 d In the presence of H277SeO3, pH = 3.0, dry heating at 60 °C for 3 d	9.5	-O-SeHO2	[46]
Na₂SeO₃	Selenized ovalbumin 2% 2% Na₂SeO₃ buffer solution pH = 3.0 The freeze-dried samples were kept at 60 °C for 3 d	8.8	S-Se-S	[49]