Comparison of Polyphenol, Sugar, Organic Acid, Volatile Compounds, and Antioxidant Capacity of Commercially Grown Strawberry Cultivars in Turkey

Abstract

The aim of this study was to compare certain important fruit quality parameters such as sugars, organic acids, total phenolic content, antioxidant capacity, and volatile compounds of 10 commercial strawberry cultivars grown in the research and experimental area in Yaltir Agricultural Company located in Adana provinces of Turkey. As for the sugar content of strawberry fruits, fructose was identified as the dominant sugar and the highest value (4.43%) was found in the cultivar "Rubygem". In terms of organic acid, among the examined strawberry cultivars, "Calinda" had the greatest level of citric acid (711.45 mg g^-1). Regarding vitamin C content, the highest amount was found in the cultivar "Sabrina" (25.08 mg 100 g^-1). Ellagic acid was the main phenolic acid in all examined cultivars (except the "Plared" cultivar), and the highest amount was detected in the "Fortuna" cultivar (3.18 mg 100 g^-1). We found that the cultivar FL-127 had the highest total phenolic content (158.37 mg gallic acid equivalent 100 g^-1 fresh weight base). Regarding antioxidant capacities, the highest value (88.92%) was found in the cultivar Victory among all the cultivars studied. The detailed analysis of volatile compounds was performed by gas chromatography/mass spectrometry (GC/MS) and 34 compounds were detected. Among them, esters, acids, and alcohols were found to be the major volatile compounds in strawberry fruits. In conclusion, strawberry fruits belong to ten cultivars showed abundant phenolic compounds and at the same time have high antioxidant activity.

Keywords: HPLC; SPME/GC/MS; organic acids; phenolic compounds; strawberry; sugars; volatile compounds.

Figure 1

Principal component analysis (PCA) for different varieties and phenolic profile (individual phenolic compounds, total phenols content, and DPPH).