Internal Validation of Rapid and Performant Method for Carotenoids Determination in Tomato Waste Powder by HPLC

Abstract

An analytical method was developed and validated for separation, detection and quantification of carotenoids (all-trans lutein, β-carotene and all-trans lycopene) in tomato waste powder by high-performance liquid chromatography (HPLC-DAD). Extraction of carotenoids was achieved in acetone under nitrogen atmosphere and magnetic stirring. Carotenoids were separated on a reverse-phase C30, 3 μm column (250 �4.6 mm) coupled to a 20 � 4.6 mm C30 guard column using mobile phases consisting of (A) methanol/ water (98:2, v/v), (B) methanol/water (95:5, v/v) and (C) methyl tert-butyl ether.The method has a good sensitivity (LOD = 0.161 �0.333 μg/mL and LOQ = 0.484 � 1.000 μg/mL) and a good precision (RDS (r) = 0.67 � 1.15% for injection repeatability; RSD (r) = 1.02 � 2.14% for analysis repeatability intra-day; RSD (r) = 1.23 � 2.43% for intermediate precision; RSD (R) = 1.57 � 3.07 % for intra-laboratory reproducibility. The method was applied byanalyzing 8 tomato waste powders, obtained through tomatoes processing as juice. Their carotenoids content varied in the following ranges: 1.474 � 2.452 mg/100g for all-trans lutein; 9.645 � 11.587 mg/100g for β-carotene; 60.150 - 64.855 mg/100g for all-trans lycopene.