Firmness of Mandarin at Different Picking Dates

Abstract

The objective of this work was to characterise the firmness of ‘Satsuma’ mandarin fruit ( Citrus reticulate) at different picking dates. The firmness of mandarin was monitored using non-destructive impulse response (I-R) and traditional compression test. The dominant frequency (f), stiffness coefficient (SC) and elasticity coefficient (EC) as a function of picking date were expressed. The mandarin at different picking dates is characterised for a decrease in the f, SC and EC. The higher f, SC and EC corresponded to the firmer mandarin. A good correlation was established between the impulse response parameters (SC and EC) and compression force (CF) and determination coefficients were 0.89 and 0.90, respectively. The low correlation was found between SC (or EC) and sugar content (or pH). SC and EC were better firmness prediction, and the results implied that these two parameters could be used to distinguish different picking dates and firmness.

Pattern recognition of eggshell crack using PCA and LDA

“…The development of low-cost, lightweight, and flexible piezoelectric film sensors, reported by Shmulevich, Galili, and Rosenfeld (1996) and Galili, Shmulevich, and Benichou (1998), added new possibilities for dynamic testing of agricultural products. The measuring technique of fruit firmness with the piezoelectric film sensors has been found to be simple, fast, and repeatable (Gomez & Wang, 2005;Gomez, Wang, & Pereira, 2006;Wang, Ying, & Cheng, 2007). However, in the area of eggshell crack detection, there is little research using piezoelectric film sensors.…”

Maturity classification of cacao through spectrogram and convolutional neural network

“…Most of these acoustic techniques utilize an accelerometer, microphone, piezoelectric sensors, in testing fruits such as kiwi [10], mandarin [11], peach [12], melon [13], apple [14], and pomelo [15]. On the other hand, an acoustic tester with a mechanical plunger was found in a study to determine the ripeness of Juan canary melon [16].…”

On the quality of acoustical measures when evaluating fruits quality

“…In the last decades, different acoustic techniques have been developed in order to measure the quality of fruits: firmness, external and internal defaults, diseases, changes during the shelf life, etc. Thus, acoustic techniques have been applied for measuring the firmness of several fruits such as apples [1], pears [2], melons [3], kiwifruits [4], tomatoes [5], pineapples [6] and mandarins [7]. Acoustic measurements have also allowed to identify external defects on egg [8] or pistachio [9] and internal defaults in pears [10], watermelons [11], cheese [12] and potatoes [13].…”