At harvest, 20 marketable ripe fruits were selected at random from each plot and washed with distilled water. The tomatoes were then evaluated on the basis of a number of physical and nutritional attributes considered to be indicators of quality in processing tomatoes: fruit and juice color, fi rmness, juice content, dry matter, soluble solids, titratable acidity, pH, consistency and lycopene content.
The external color and fi rmness of the fruits were measured at two opposite equatorial surface locations on each fruit. Tomato color was measured in the Hunter Lab color space using a Minolta Chroma Meter CR400/410 (Minolta Corp., Osaka, Japan) with the CIE illuminant C. The L value indicates the ratio of white to black color; the a value the ratio of red to green color; and the b value the ratio of yellow to blue color. The a/b ratio (red to green component of color) is commonly used as a redness index to report the color quality (brightness of red color) of tomatoes and tomato products (Akdeniz et al., 2012) . This variable is also correlated with lycopene accumulation in tomatoes (Giovanelli et al., 1999) .
Fruit fi rmness was measured in the pericarp tissue by an
FT-327 penetrometer (Bertuzzi, Facchini, Italy) with a probe 8 mm in diameter, and was expressed as kg cm -2 . Then all fruits were divided into three equal parts: one part was used to determine the dry matter content in an oven set at 70 ºC until constant weight was achieved (units expressed as grams per 100 g fresh weight), the second part to determine the juice content by using a conventional juicer extractor, removing the seeds and skins and measuring the juice color as previously indicated for whole fruits (units expressed as grams per 100 g fresh weight); and the third part was homogenized and used for the remaining determinations.
Soluble solids were measured using a digital refractometer
ATAGO PR-32 (Atago Co. LTD, Tokyo, Japan) with automatic temperature compensation, which provides values as °Brix. pH was determined using a pH meter, and titratable acidity was quantifi ed by titrating 5 g of tomato paste with 0.1 mol L -1 NaOH to pH 8.1 with an automatic sample titrimeter (
TitroMatic 1S-2B, Crison, Barcelona, Spain). Acidity was expressed as grams of citric acid equivalent per 100 g fresh weight.
The consistency of the homogenate was determined by measuring the distance that the homogenate fl owed in 30 s under its own weight along a level surface (Barret et al., 1998) with a standard Bostwick consistometer (CSC Scientifi c, 1-800-458-2558, USA). Smaller Bostwick values indicate a thicker, higher-consistency tomato product; therefore, smaller values are preferable in tomato processing (García and Barret, 2006) .
Lycopene determination was based on a spectrophotometric analysis using a Lambda-Bio40 spectrophotometer (Perkin-Elmer, Waltham, MA, USA). Lycopene extractions were performed with 2 g of homogenate, which were shaken for 15 min in 50 mL of hexane, 25 mL of acetone and 25 mL of ethanol and then shaken for a further fi ve minutes after the addition of 5 mL of distilled water. Then, 5 mL of the upper layer was recovered and increased to 10 mL with hexane. The samples were shaken again, and measurements were immediately taken by the spectrophotometer. A calibration line relating standard concentrations and absorbance at 510 nm was used to obtain lycopene concentrations (Roselló et al., 2011) . Lycopene content was expressed as milligrams per 100 g fresh weight. With the exceptions of dry fruit matter and juice content, all assessments were carried out in duplicate.
Moreno C., Mancebo I., Tarquís A.M., & Moreno M. (2014). Univariate and multivariate analysis on processing tomato quality under different mulches. Scientia Agricola, 71(2), 114-119.
