1. Check the packaging of the betel nut: Observe the packaging of the betel nut to see if there is any damage or abnormality. If the package is damaged or incomplete, then it may have been won.
2. Scrape the silver film: There is a silver film on the package of betel nut, use a knife or other tools to scrape the film, if there is a word or a number under the film, then it may have been won.
3. Check the appearance of betel nut: Observe the appearance of betel nut, if the betel nut meat is brown or white, the base is gray or black, then it is genuine. If the color is opposite, then it may be an inferior betel nut.
4. Check for brine: Open the package of betel nut and smell if there is a brine flavor. If there is a strong brine flavor, then it is genuine. If there is no brine flavor, then it may be an inferior betel nut.
5. Try to chew: Take a small piece of betel nut and try to chew it, if a lot of dross (betel nut stems and fruits) will appear soon, then it is genuine. If there is no dross after chewing, then it may be a poor quality betel nut.
It should be noted that the above method is for reference only and cannot be guaranteed to be absolutely accurate. If you are in doubt about the quality of betel nut, it is recommended that you buy it from a regular store or consult your local betel nut producer or seller.