Evaluation On Six Characteristic Marks Of Commercial Orange Juices And Main Juice Oranges Produced In China

The six characteristic compositions of 38 main juice orange varieties including Hamlin,Bingtangcheng,Valencia,Jincheng,Xuegan and so on produced in China were studied to determine juice content acoording to a national standard GB/T 16771-1997 "Determination of juice content in orange,mandarin and tangerine juice and their drinks",and also the such study with 24 commercial orange juice products sampled from main orange juice produces in Chongqing,Sichuan,Hunan and Fujian was carried out..The six characteristic marks and juice content of COJ and Reconstituted OJ were compared to learn the influence of juice dilution.The results are below:1.The six characteristic mark content and juice content of almost hundred OJ samples from main production area in China were determined to establish primarily a data pool,of the six characteristic marks of juice oranges,that provid value information to study further characteristic compositions in OJ.2.The juice content detected by using the national standard "GB/T 16771-1997" had big difference from the reality,by the way there are significant difference between content of the six characteristic marks tested and the relative standard values of the national standard "GB/T 16771-1997".Therefore,the standard values and their weight values of the six marks regulated in the national standard would be verified and conferred further.3.According to a correlation test,the coefficients of content of the six marks and juice content of all samples both of fruits and commercial juices tested was less 0.66, and even less 0.5 from fresh fruit juices that most had around 0.2 between juice content and the mark content.Comparison with that of most commercial juices,there were higher probably due to blending with vary juices,but the coefficients of L-proline (0.2629) and D-isocitric acid(0.4475) were not higher than 0.5,and slao it was big defference with coefficients of same characteristic mark between fresh juices and commercial juices.Therefore,it would be reconsidered and verified to determine the juice content depending on the "GB/T 16771-1997".4.It is not reasonable that varieties,rootstocks,planting regions,harvest time,tree cares,processing procedures and storage effected obviously juice contents of concentrated juices and single strength juices according to "GB/T 16771-1997"5.There were differences,but not significant on juice contents with diluting proportion from concentrated juices and single strength juices made of same variety planting at same area tested by "GB/T 16771-1997".