2.2. Fruit Quality Parameters

Fruit firmness was determined in each individual fruit of each replicate by using a TX-XT2i Texture Analyser (Stable Microsystems, Godalming, UK) interfaced to a personal computer. A flat steel plate was mounted on the machine which measured the fruit equatorial diameter and applied a force that achieved a 5% deformation of the fruit diameter. Firmness results were expressed as the force-deformation ratio (N mm⁻¹). Skin colour was measured on three points of the equatorial fruit perimeter by using a Minolta colorimeter (CRC200, Minolta Camera Co., Kantō, Tokio, Japan) and colour was expressed as Hue (arctg b*/a*) according the CIELab coordinates. Pomegranate fruit were cut in two halves, and again, three colour readings were taken in the arils of each fruit to measure internal colour as Hue. Arils from the five fruit of each replicate and treatment were taken and combined to obtain a homogeneous sample in which the following parameters were measured. About 50 g of arils were squeezed through a cotton cloth and the juice used to quantify TSS and TA in duplicate. TSS was determined by using a digital refractometer, Atago PR-101 (Atago Co. Ltd., Tokyo, Japan), at 20 °C, and expressed as g kg⁻¹. One mL of the juice was diluted in 25 mL of distilled H₂O and used to measure titratable acidity (TA) by automatic titration (785 DMP Titrino, Metrohm) with 0.1 N NaOH up to pH 8.1, and results were expressed as g kg⁻¹ malic acid equivalent.