Abstract:

In order to improve the extraction yield of fruit phenolics and evaluate the comparability of total phenolics content determination method, total phenolics content of jujube fruit was comparatively determined by using Folin Ciocalteu (FC) and UV-spectrophotometric methods, respectively. Meanwhile, the influence of different extraction systems on the testing results from the two methods was studied. Results from this study indicated that linear range of UV-spectrophotometric method was 1375-12500 mg/kg, linear range of FC method was 7500-15000 mg/kg. The detection limit and the quantifying limit of UV-spectrophotometric method were significantly lower than those of FC method. Precision and accuracy of the two methods were acceptable by detecting the recovery rate. The results also showed that appropriate solution for extracting total phenolics from jujube fruit was 60%-80% (v/v) methanol-water or ethanol-water system. Moreover, the extraction yield of the former was significantly (P<0.001) higher than the latter. Total phenolics content of jujube fruit determined by FC was significantly higher than that determined by UV-spectrophotometric method. The linear regression was: Y (FC) =1.538x+1221 (UV-spectrophotometric), r=0.956. The results would provide the theoretical guidance and reference methods for the research of total phenolics in fruits and vegetables.