T/GZSX 081-2021 Active Group standards

T/GZSX 081-2021 Determination of total flavonoids content in goji juice

Publish Date: 2021-09-26 Implement Date: 2021-10-10 For services related to genuine standard inquiry, procurement, translation, and other related services in China, please Contact Us

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Basic Information

Standard Code: T/GZSX 081-2021

Standard Type: Group standards

Standard Status: Active

is_force_gb: no

CCS Name: -

ICS Name: Food processing

Publish Date: 2021-09-26

Implement Date: 2021-10-10

Scope

Scope: This document specifies the ultraviolet spectrophotometric method for the determination of total flavonoid content (expressed as rutin) in prickly pear juice. This document is applicable to the determination of total flavonoid content in prickly pear juice and concentrated juice. The detection limit of total flavonoids in this document is 0.63 mg/100 g; the quantification limit is 7.0 mg/100 g. Main technical content: 3. Principle: Flavonoid compounds, due to their structural characteristics, exhibit maximum absorption at around 360 nm. Within a certain concentration range, the concentration and absorbance comply with the Lambert-Beer law. By comparing with rutin standard, the total flavonoid content in the sample is quantitatively determined. 4. Reagents and materials 4.1 Reagents 4.1.1 Rutin (C27H30O16) standard (content ≥ 97%). 4.1.2 Anhydrous ethanol: analytical grade. 4.1.3 Methanol: analytical grade. 4.2 Preparation of standard solutions 4.2.1 Rutin standard stock solution: Weigh 25 mg (accurate to 0.1 mg) of rutin, dissolve in methanol, and dilute to 25 mL to obtain a 1 mg/mL standard stock solution. 4.2.2 Rutin standard intermediate solution: Extract 2.5 mL of rutin standard stock solution with methanol and dilute to 100 mL to obtain a 25 μg/mL standard working solution. 5. Instruments and equipment 5.1 Balance: with a sensitivity of 0.1 mg. 5.2 Ultrasonic cleaner. 5.3 Ultraviolet spectrophotometer. 6. Analysis steps 6.1 Sample preparation: Weigh 1 g (accurate to 0.1 mg) of the sample into a 25 mL volumetric flask, dilute with ethanol, shake well, extract with ultrasound for 20 minutes, and let stand at room temperature for 30 minutes. 6.2 Standard working curve: Accurately extract 1.0 mL, 2.0 mL, 3.0 mL, 4.0 mL, and 5.0 mL of rutin standard intermediate solution into 25 mL colorimetric tubes, add methanol to the mark, shake well, and prepare a series of standard solutions with concentrations of 1.0 μg/mL, 2.0 μg/