Determination of avocado maturity by ultrasonic attenuation measurements

Abstract

A non-destructive ultrasonic method was evaluated for the determination of avocado (Persea americana Mill.) maturity. Fruit of`Ettinger' and`Fuerte' avocado cultivars were sampled from tagged trees in the orchard throughout the fruiting season on six and five dates, respectively. Each fruit was subjected to ultrasonic measurements in which ultrasonic mechanical waves were excited in the avocado flesh, enabling the attenuation of waves to be calculated. The dry weight (DW) content of fruit was assessed for the determination of avocado maturity. The changes in attenuation of the ultrasonic signal and those in DW content, during the fruiting season, were functions of time in opposite tendencies: a monotonic decrease in attenuation and a monotonic increase in the DW content. The two cultivars yielded similar tendencies for attenuation and DW content. The relationship between attenuation and DW content suggested that the degree of avocado maturity can be determined by ultrasonic non-destructive technology. #

Firmness evaluation of watermelon flesh by using surface elastic waves

“…In the throughtransmission mode, the system consists of two ultrasonic transducers that are mounted in a structure that maintains a constant angle of 120°between the transducers' tips while in contact with a sample surface. The attenuation of ultrasonic waves with frequency of 50 kHz was found to change dramatically during storage, shelf-life, postharvest softening, and ripening of avocado, mango, and apple, whereas the change in ultrasonic velocity did not correlate with the physiochemical changes of the fruits (Mizrach et al, 1997(Mizrach et al, , 1999Kim et al, 2009).…”

Assessing plum fruit quality attributes with an ultrasonic method

“…The method is based on a patented system, which enables the fruit quality attributes to be determined by measuring the changes in ultrasonic sound waves passing through the peel and flesh (Mizrach, Galili, & Rosenhouse, 1995). Several models of devices based on this technique have been developed and successfully used for nondestructive determination of quality attributes of avocado during their shelf life , and of their maturity while on the tree (Mizrach, Flitsanov, El-Batsri, & Degani, 1999) and for determination of the quality parameters of mangoes during their shelf life (Mizrach, Flitsanov, & Fuchs, 1997). This technique has been successfully used to monitor the softening of avocadoes in low-temperature storage (Mizrach, Flitsanov, Akerman, & Zauberman, 2000).…”

3-D Model of sound pressure field in a meridinal section plane of fruit

“…This allows calculating the attenuation of the flesh in between the probes tips in contact with the peel. This method was used by Mizrach et al in several progressive studies; they measured ultrasonic wave attenuation in avocado and mango fruits [7][8][9][10][11] depends on the maturity, firmness and several other physiochemical parameters of the fruits. The spatial distribution of the ultrasonic waves within the fruit tissue needed to be studied in order to allow efficiency design of progressive type of ultrasonic fruit quality device.…”