835 50 automatic amino acid analyzer

The methods of the Association of Official Analytical Chemists were employed to explore the WOP chemical composition. Protein, lipids, ash, moisture, and contents of WOP were determined according to AOAC Official Method 979.09, 996.06, 923.03, and 2001.12⁶³ . An 835-50 automatic amino acid analyzer (Hitachi, Ltd., Tokyo, Japan) was applied to determine the amino acid composition in accordance with the approaches of Yang et al.^{64 (link)}.

An LGJ-12 vacuum freeze-dryer was purchased from Songyuan Huaxing Technology Develop Co., Ltd. (Beijing, China). A TU-1901 spectrophotometer was purchased from Purkinje General Instrument Co., Ltd. (Beijing, China). An 835-50 automatic amino acid analyzer was purchased from Hitachi, Ltd (Tokyo, Japan), and a NoVAA400P flame atomic absorption spectrometer (F-AAS) was purchased from Analytik Jena AG Company (Jena, Germany). A FE20K electronic handheld pH meter was purchased from Mettler Toledo Company (Zurich, Switzerland). In the experiments, the ultrapure water used was produced from a Milli-Q integral water purification system (Millipore Corp., Billerica, MA, United States).
Bromothymol blue (BTB, cas#: 34722-90-2), lactose (cas#: 63-42-3), glucose (cas#: 50-99-7), rutin (cas#: 153-18-4), and gallic acid (cas#: 149-91-7) were purchased from Aladdin Bio-Chem Technology Co., Ltd. (Shanghai, China). The hollow cathode lamp and standards (purity ≥99%) of different mineral elements were purchased from Guobiao Testing and Certification Co., Ltd. (Beijing, China). All of the reagents used in the pretreatment of mycelial samples for automatic amino acid and F-AAS analyses were of guaranteed purity.