Fruit quality analysis

Service description

Quality of fruits. At this service, we evaluate different attributes that define the final fruit quality, and also the optimum time of harvest. The methods, parameters and assay protocols are: - Non-destructive determination of fruit maturity by the measurement of chorophyll degradation (DAmeter by Turoni) - Fruit  Color: the color coordinates L * a * b * are determined using a portable spectroradiometer (Minolta CM-700d / 600d spectrophotometer). - Fruit  Firmness Aweta (nondestructive method) was conducted by Acustic Firmness Aweta sensor, which is based on the acoustic response to a mechanical impulse transferred by a plunger to the fruit surface method. This equipment provides the weight of each fruit and two scales firmly parameter representing the entire fruit. - Fruit  Firmness Magness-Taylor (destructive method): The flesh firmness was measured by penetrometer Effegi, eliminating the skin in that area and entering the piston penetrometer, obtaining the force exerted in kg / cm2. The traditional penetrometer (Magness Taylor) only provides information on a localized fruit zone (in which pressure is exerted), whereas the previous method (Aweta) makes an overall assessment of fruit firmness, measuring the vibration of the whole fruit . - Fruit  Soluble Solids: for this determination the technique described in the Official Methods Analysis of Fruit Juices (AOAC-1984; nº8 method Fédération International des Producteurs Jus de Fruits., 1962)will be used. The measurement is performed on a drop of apple juice from 20 fruits of each batch to analyze and takes place in a digital refractometer Atago brand, model DBX 55, with automatic temperature correction (results are expressed in Brix at 20 ° C). - Fruit  Titratable acidity: natural total acid content is determined by titration with sodium hydroxide solution by the potentiometric method (Official Methods of Analysis, AOAC, 1990). The analysis was performed in triplicate for each batch by the following procedure: 10mL fruit juice diluted to 100 mL with distilled water, then the pH meter electrode is introduced and titrated with stirring with 0.1N sodium hydroxide to a pH of 8.1. To do an automatic titrator CRISON, Compact model is used. The acidity is expressed as malic g / L juice acid, since this is the major apple acid (Eskin, 1991).   - Fruit  Thiault index. Determining the optimal harvest time is essential from the standpoint of storage efficiency of the block. No working methods easy to use for determining the optimal harvest time "in situ" field. The determination of stochastic relationships between various characteristic parameters of the fruit provides a good opportunity to determine the most useful practical methods to establish the conditions of storage of the fruit in terms of the information obtained. Thiault index measures the evolution of ripening apples and other fruits. This index is a combination of sugar content and acidity, and is obtained by the following mathematical formula: Thiault Index (IT) = total sugars (g L-1) + total acidity (g malic acid L-1) × 10. - Fruit  Streif index. This is another index used for determining the optimal time to harvest the fruits. This index combines the strength of the pulp with the soluble solids content and the amount of starch in the fruit mesocarp, measured using the iodine test. Streif index (IS) = firmness (kg / cm2) / (soluble solids (° Brix) x index starch).