A Green Analytical Method for Differentiating Fresh and Stored Green Teas via Determining Their Tricarboxylic Acid Organic Acids.

TEA IS A POPULAR NONALCOHOLIC BEVERAGE; NEVERTHELESS, SOME TRADERS UTILIZE STORED TEA AS A SUBSTITUTE FOR FRESH TEA, A PRACTICE THAT HAS HAD A NASTY EFFECT ON THE MARKET. THEREBY, IT IS NECESSARY TO DEVELOP AN OBJECTIVE METHOD TO DISTINGUISH BETWEEN FRESH AND STORED TEA SAMPLES.: METHODS: IN THIS WORK, A SIMPLE METHOD HAS BEEN DEVELOPED FOR THE DETERMINATION OF EIGHT ORGANIC ACIDS OF THE TRICARBOXYLIC ACIDS (OTCAS), INCLUDING CITRIC ACID, MALIC ACID, Α-KETOGLUTARIC ACID, CIS-ACONITIC ACID, SUCCINIC ACID, MALONIC ACID, AND FUMARIC ACID, IN 38 TEA SAMPLES. THE EXTRACTION AND PRETREATMENT OF OTCA IN TEA WERE CONDUCTED USING A 0.1% FORMIC ACID SOLUTION AND ACTIVATED CARBON.: RESULTS: THE LOQ (10 S/N) OF THE METHOD IS BETWEEN 0.47 AND 0.9 NG/ML, THE METHOD RSD ≤ 10%, THE SURFACE METHOD IS STABLE AND RELIABLE, AND THE AGREEPREP SCORE, WHICH CORRESPONDS TO THE METHOD'S PERFORMANCE, WAS CALCULATED TO BE 0.59, INDICATING THAT THE METHOD ALIGNS WITH THE PRINCIPLES OF GREEN ANALYTICAL CHEMISTRY. THEN, THESE OTCAS IN 38 TEA SAMPLES WERE SIMULTANEOUSLY DETERMINED BY LC-MS ANALYSIS OF THE EXTRACT.: CONCLUSION: IT IS NOTEWORTHY THAT DISTINCTIVE DIFFERENCES IN THE CONCENTRATION HAVE BEEN OBTAINED FOR MALIC ACID, SUCCINIC ACID, AND Α-KETOGLUTARIC ACID IN THE FRESH TEA VERSUS THE STORED TEA, RESPECTIVELY, INDICATING THAT THESE OTCAS CAN BE SELECTED AS THE POTENTIAL BIOMARKERS FOR THE DIFFERENTIATION OF STORED TEA SAMPLES FROM FRESH ONES.