Identification method of natural caffeine in tea beverage
A technology for caffeine and tea beverages, which is applied in the field of authenticity and detection of food quality, and can solve problems such as application restrictions, inability to introduce, and restrictions on LC-IRMS
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0026] Embodiment 1: A preferred embodiment of the method for discriminating the true and false identification of natural caffeine in the tea beverage of the present invention
[0027] The method for discriminating the true and false identification of natural caffeine in the tea beverage of the present invention operates according to the following steps:
[0028] (1) Sample pretreatment
[0029] Grind tea leaves and coffee beans separately, accurately weigh 0.500g (±0.001g) of the sample into a 50mL centrifuge tube, add 25mL of ultrapure water, shake for 1min to mix evenly, ultrasonically extract for 30min, centrifuge at 10000r / min for 5min, and take approximately 1mL of the supernatant was passed through a 0.45μm aqueous filter membrane into a 1.5mL sample bottle, diluted 5 times with ultrapure water, and then tested by LC-IRMS.
[0030] Take 5mL tea beverage sample, put it into a 50mL centrifuge tube, add ultrapure water to the 50mL mark, centrifuge at 10000r / min for 5min, ...
Embodiment 2
[0053] Embodiment 2: the delta of caffeine in coffee bean, coffee 13 C Identification
[0054] Coffee beans and coffee samples from 44 different countries and regions were purchased in the market, extracted by ultrasonic pure water, and directly entered into LC-IRMS isotope mass spectrometry analysis.
[0055] The analysis results are shown in Table 1. Table 1 shows the δ of caffeine in the above-mentioned 44 kinds of coffee beans and coffee. 13 C value. It can be seen from Table 1 that the caffeine δ of coffee beans and coffee natural sources 13 The C value ranges from -25.322‰ to -30.930‰, and the t distribution is used to statistically analyze the caffeine δ of 44 samples 13 The mean value of C is -27.938‰, and the standard deviation s is 1.306‰. Simultaneous detection of δ of synthetic caffeine 13The C value is -35.794‰~-38.528‰. From this, it can be known that the δ of caffeine from natural sources 13 The value of C is larger.
[0056] This embodiment selects natu...
Embodiment 3
[0060] Embodiment 3: LC-IRMS detection of caffeine in tea
[0061] In this example, LC-IRMS was used to measure the δ of 68 tea samples and 5 synthetic caffeine samples. 13 C value. The results are shown in Table 2, and Table 2 is the δ of caffeine in tea 13 C value. It can be seen from Table 2 that the δ of natural caffeine contained in tea leaves 13 The C value is about -25‰ to -33‰, while the δ of synthetic caffeine 13 The C value is about -35‰ to -39‰, which is higher than the δ of natural caffeine 13 The value of C is lower.
[0062] Table 2
[0063]
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More 


