(f) Determination of calcium content: This analysis was per- formed on frozen strawberries according to Fraeye et al. (2009). Homogenized strawberry samples were dried overnight at 105 °C. One gram of the dry sample was calcinated in a muffle furnace at 550°C during 4h. The residue was transferred to a 1 N HNO3 solution and incubated at 70 °C for 1 h. The volume was adjusted to 100 mL. The Ca2+ concentration was measured using atomic absorption spectrophotometer (SPY9).