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 ×
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.