Strawberry fruit (Fragaria AT13387 research buy x ananassa Duch.), cv. Camarosa, were harvested from a commercial plantation located in Pelotas (Rio Grande do Sul State, Brazil), at five developmental stages based on fruit colour and weight: 1 (green, 3.0 g ± 0.9), 2 (white, 8.6 g ± 0.5), 3 (50% red, 14.2 g ± 0.7), 4 (75% red, 16.6 g ± 1.0) and 5 (red, 16.2 g ± 1.2). From each developmental stage three experimental units of approximately

60 strawberries were collected. Half of an experimental unit was immediately utilised for firmness determination and the remaining was frozen and stored at −80 °C for further analysis. Firmness was measured using a texture analyser (Texture Analyzer, TA.XT plus, Stable Micro Systems Texture Technologies) fitted with a 2 mm (diameter) flat probe.

Each fruit was penetrated 50% at a speed of 1.0 mm s−1 and the maximum force developed during the test was recorded. Three measurements were taken per fruit at different points of the equatorial zone and 30 berries at each stage were assayed. Results were expressed in Newtons (N). Total anthocyanin content was determined according to the method described by Lees and Francis (1972). One gram of strawberry ground to screening assay a powder in liquid nitrogen was suspended in 25 ml of acidic ethanol (0.01% HCl), for 1 h in the dark. Absorbance readings were performed in a spectrophotometer at 520 nm. Anthocyanin content was expressed Loperamide as mg of cyanidin-3-glucoside per 100 g of fruit fresh weight (fw). Total phenolic compounds were determined using the Folin–Ciocalteau reagent. One gram of ground flesh

was suspended in 60 ml of deionized water and 5 ml of Folin–Ciocalteau reagent. After eight minutes, the solution was neutralised with 20 ml of a saturated sodium carbonate solution and kept in the dark for 2 h. Absorbance was measured at 725 nm and results were expressed as mg of gallic acid equivalents per 100 g of fruit fw (mg GAE 100 g−1 fw). Ascorbic acid was measured using a reverse-phase HPLC (high-performance liquid chromatography), according to Vinci, Botre, Mele, and Ruggieri (1995). Total AA was extracted with metaphosphoric acid (1% w/v) and analysed in a Shimadzu HPLC system, using a Shim-Pak CLC-ODS column (3.9 cm × 150 mm × 4 μm), coupled to a UV SPD-10AV detector. The mobile phase consisted of 0.1% acetic acid in water (A), and methanol (B). An elution gradient started at 100% A, then linearly reduced to 98% of A and 2% B after five minutes; then held for two minutes and returned to the initial conditions at ten minutes. Flow rate was 0.8 ml min−1 and the detector was set at 254 nm. Quantification was based on an external standard calibration curve using l-(+)-ascorbic acid (Sigma–Aldrich).