Study on the rapid detection method of determining raw juice content in refrigerated orange juice from concentrated

Juice content was one of the main quality indicators of refrigerated orange juice from concentrated(ROJFC) and also the important basis for authenticity assessment. The result showed that the soluble substances in orange juices from different origins and orange juices with different raw juice content had characteristic absorption in the wavelength of 325 nm,which had clear distinction with the ultraviolet absorption of 22 kinds of common additives. The soluble substances were separated by self-developed rapid detection equipment and continuously detected in the wavelength of 325 nm. By this method,the absorption peaks of soluble substances which were separated according to the molecular weight size were obtained. The peak area was positively related with orange juice content. With 100% Brazil orange juice as standard reference,the raw juice content of orange juices were calculated by the external standard method. The sample pretreatment was simple,samples were detected just after filtration and ultrasonic degassing. Column separation and the325 nm detection wavelength could effectively avoid the interference of 22 kinds of common additives. This method had high precision(RSD<6.0),good linear relationship(R2=0.9988),strong anti-interference ability and could be used to detect the raw juice content of orange juice(raw juice content≥10%) fast and in large scale.