Near infrared quick non-destructive detection method for sodium benzoate in fruit juice

The near IR rapid NDT method for sodium benzoate in juice comprises: 1) collecting and mixing juice sample; 2) preparing the modeling sample set; 3) detecting the near IR of said sample: leading the sample from low-concentration to high-concentration into the detection pond of near IR detector, and selecting optical path with 0.2~60mm and 800~2500mm near infrared light to scan and obtain juice absorption spectrum chart; 4) building Maths model between the sodium benzoate content in sample and the absorption spectrum by multielement correction method; 5) validating the model; 6) analyzing the program sample. This invention has simple pretreatment, cuts detection time to within one minute, and has reliable result with error less than 10%.