L. Ragni

Fruit Damage Assessment in Peach Packing Lines

In order to assess the effects of mechanical handling on peaches, the impacts measured in Italian packing lines using an instrumented sphere were emulated in the laboratory by means of a simple drop-test device. Samples of Big Top, Caldesi 2000, Centry, and Rich Lady peaches were subjected to impacts representative of the conditions observed at the critical points in packing lines: the drop onto the conveyor belt from the dry bin dumper, the entrance into the counter-basket filler, and at the beginning of the filling of the mini-bin. A test was also carried out to assess the effects on the damages of repeated drops onto the same point of the surface of the fruits. At the highest impact level (180 g, 2.20 m/s), at the beginning of the filling of the mini-bin, damaged fruit did not exceed 18% and the average dimension of the flesh damages did not exceed 10 mm in diameter (Big Top) and 6 mm (Centry) in depth. In general, repeated drops did not seem to cause substantial additional damage. However, they did cause an increase in percentage of damaged fruits for Centry and for the dimension of the alterations for Rich Lady. Considering the severity of the test, the low number of fruits subjected to high impacts by the mini-bin filler and the kind of the damages, the packing lines studied in the present research should not produce an appreciable commercial damage to the ready-to-eat fresh peaches.

Quality Evaluation of Shell Eggs During Storage Using a Dielectric Technique

This article reports on investigating the possibility of non-destructively predicting basic quality parameters of shell eggs using an open-ended coaxial probe dielectric measurement technique. The studied parameters include yolk index, thick albumen height, and Haugh unit as well as air cell size as a function of storage duration at room temperature. The probe was connected to an impedance analyzer from which the dielectric spectra (dielectric constant and loss factor) were collected using a data logger and analyzed by means of partial least squares (PLS) analysis. The tests were carried out in the 10 to 1800 MHz frequency band on shell eggs stored for 1, 2, 4, 8 and 15 days at 22°C, positioning the probe in three different points on the shell eggs. For storage duration, the results showed R2 values up to 0.985 and 0.980 in cross-validation and test-set validation, respectively, while the R2 for the air cell height was up to 0.927 and 0.921, respectively. Yolk index, thick albumen height, and Haugh unit were also predicted with R2 values ranging from 0.526 to 0.728 (test-set validation). No substantial differences in prediction power emerged by using the dielectric constant, loss factor spectra, or position of the probe on the shell egg. The best frequency band for prediction was from 10 to 700 MHz.

MECHANICAL BEHAVIOR AND DAMAGE OF PINK LADY APPLES

Research was conducted to investigate the type of damage and mechanical behavior of Pink Lady apples during post-harvest operations. Samples of apples of this new cultivar were subjected to drop tests to simulate the kind of impact recorded in Italian sorting and packing lines by means of an instrumented sphere. A simple device with an acceleration transducer mounted on the apple and an acquisition system were used to cause an impact and to describe the mechanical behavior of the fruit. Data were treated statistically employing logistic regression and multiple linear regression analyses to determine correlations between probability, characteristics of damage and parameters describing impact and characteristics of the apples. A logit model was used to assess the probability of damage occurring to fruit. In this model (R2 L = 0.380) the characteristics of the impact and the firmness of the flesh of the fruit were found to be significant. The kind of damage appeared to be significantly influenced by the impact level and, in general, by the mass, the sugar content and the curvature radius at the point of impact on the apples. Coefficients of determination of the models to predict characteristics of damage were from 0.104 to 0.312. The curvature radius was correlated with peak acceleration of the apples, too (R2 = 0.210). Although the prediction power of the statistical models was low, they were useful to check significance and analyze correlations between parameters.