Development and Validation of an UV-Visible Method for the Determination of B-carotene in the Leafy Vegetables in Thailand
Determination of p-carotene content in four types of leafy vegetables, water morning glory, kale, lettuce and Chinese cabbage by using a simple, rapid and low cost of UV-Visible method. This study was in the concentration range of 0.5 to 12 mg/L, and showed the linear regression equation y = 0.0764X – 0.0008, and an excellent linearity with correlation coefficient (R2) was 0.9999. The accuracy of the method analysis was reported by percentage recovery of about 80-106%. The precision was reported by percent of relative standard deviation and varies for intra-day 3.92% and inter-day 3.99%* The limits of detection and limit of quantification were 0.004 and 0.013 mg/L, respectively. Acetone is the most suitable for extraction, ratio of weight of samples to solvent, and extraction time was 1:3 g/mL and 10 min. Moreover, the most appropriate storage temperature for leafy vegetable samples is 4°c. Evaluation of p-carotene content under the suitable conditions in the kale, Chinese cabbage, lettuce and water morning glory was found to be 27.96 ± 2.99, 19.35 ± 1.92, 18.78 ± 0.88 and 18.48 ± 1.86 mg/100 g, respectively.