Variability of health and bioactive compounds in strawberry (Fragaria x ananassa Duch.) cultivars grown under an Indian temperate ecosystem

Introduction. Strawberry is rich in health as well as bioactive compounds, and benefits resulting from the use of natural products rich in bioactive substances are receiving increased interest from the pharmaceutical, food and cosmetic industries. Materials and methods. Twenty-two cultivars of strawberry (Fragaria x ananassa Duch.) grown under a temperate ecosystem were screened for ascorbic acid, phenolic compounds, flavonoids, anthocyanins and antioxidant activities (DPPH and FRAP assays). The phenolic content was measured by Folin-Ciocalteu reagent using gallic acid as the standard. Antioxidant activity was determined in terms of DPPH and FRAP assays and expressed as ascorbic acid equivalent. Total anthocyanins and total flavonoid content were determined using a colorimetric method. Titratable acidity (citric acid) was determined by the titration method. The average data of two years was analyzed using SAS 9.2 software. Results and discussion. Significant differences in the health and bioactive compounds were detected among the cultivars. The range of ascorbic acid of the tested samples was (51.03 to 89.40) mg.100 g(-1) fresh weight. Titratable acidity varied between 0.73% and 1.44%; however, total anthocyanins ranged between (28.24 and 43.32) mg cyanidin-3-glucoside Eq.100 g(-1) fresh weight. Total phenols varied from (380.10 to 888.10) mg gallic acid Eq.100 g(-1) and total flavonoids from (31.26 to 55.16) mg catechin Eq.100 g(-1). The total antioxidant activity ranged between (203.13 and 471.10) mg ascorbic acid Eq.100 g(-1) fresh weight for DPPH, and between (326.06 and 701.13) mg ascorbic acid Eq.100 g(-1) fresh weight for FRAP. Total phenols, DPPH and FRAP showed close association; however, PCA clearly categorized the selected cultivars into two broad groups. All of the diverse cultivars were clustered into two clusters which could be exploited for future qualitative breeding programs based on average cluster distance and can act as gene sources for making health foods. Conclusion. The importance of our findings would be significant for farmers, breeders, consumers and industries concerning food quality, disease prevention and healthcare.