GC-MS SCREENING OF METABOLITES AND ANTIOXIDANT PROPERTIES IN FOUR VARIANTS OF SOLANUM LYCOPERSICUM (TOMATO)

Abstract

Consumption of Solanum lycopersicum or known as tomato has been associated with the decreased risk of some cancer types. Epidemiological findings confirmed the observed health effects due to the presence of varied antioxidants in tomato. This is due to variations of antioxidants presence in tomatoes. Therefore, it is important to know which types of tomatoes species contain the highest number of antioxidants and antioxidant activity. In this study, antioxidant content and antioxidant activity of four tomato variants was studied. The objectives of this research was to screen for metabolites and to compare number of metabolites by using two different extraction method. A comparison of the antioxidant activity and total phenolic content between four tomato variants was conducted based on the results. Tomatoes that are used in this study includes tomato, truss tomato, yellow cherry tomato and red cherry tomato. These tomatoes were subjected to metabolite extraction using two different solvents which is methanol and methanol-chloroform. Following that, screening of metabolites were performed using ­Gas Chromatography-Mass Spectrometry (GCMS) and metabolites were detected and analysed. The total antioxidant activity of the tomatoes was measured using 2,2’-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing power (FRAP) assays. The Total Phenolic Content (TPC) was determined spectrophotometrically according to the Folin-Ciocalteau procedure. The number of metabolites detected using GCMS are higher in methanol-chloroform extract as compared to methanol extract. Methanolic extracts of all four tomatoes were shown to have free radical scavenging activity. However, red cherry tomato showed to have the highest antioxidant activity with IC₅₀ value of 1.7 mg/ml, followed by truss tomato with IC₅₀ 2.1 mg/ml, yellow cherry tomato with IC₅₀ 4.0 mg/ml and finally tomato with IC₅₀ 5.6 mg/ml. The highest value of FRAP in Gallic Acid Equivalent was 4.3 mg/g in red cherry tomato, followed by 3.8 mg/g in truss tomato, 2.9 mg/g in yellow cherry tomato and 2.4 mg/g in tomato. The total phenolic content ranges from 0.44 to 3.73 mg/ml. In conclusion, red cherry tomato shown to have the highest total phenolic content and antioxidant activity compared to the other three variants. The findings of this research provide some valuable information to consumers when choosing the best type of tomatoes for good wellbeing and as well to set the basis of future research.