Changes of ultrasound characteristics of mango juice during fruit ripening.
Valente M., Laux D., Prades A.
Author Affiliation: CIRAD, UMR Qualisud, TA B-95/16 - 73, rue JF Breton Montpellier, F-34398 Cedex 5, France.
Post Harvest, Food and Process Engineering. International Conference of Agricultural Engineering - CIGR-AgEng 2012: agriculture and engineering for a healthier life, Valencia, Spain, 8-12 July 2012 : C-0131
Abstract : Attenuation and propagation velocity of ultrasound signals at 25 MHz were measured on clear mango juice samples using a pulse echo method. Ultrasound characteristics were determined with other physico-chemical characteristics on juice samples extracted from fruits undergoing ripening for three weeks at 22°C and 80% RH and periodically removed every two or three days. During fruit ripening, the changes of biochemical composition induced more effect on velocity than attenuation. Velocity was positively correlated to soluble solids content (R=0.98), to sucrose content (R=0.80) and negatively correlated to titratable acidity (R=-0.59) and fruit firmness (R=-0.76). A linear model based on soluble solids content and a PLS model based on all the physico-chemical characteristics were built to predict ultrasound velocity. Finally, the results obtained in this study showed that velocity is a relevant parameter linked to the major biochemical changes occurring during controlled fruit ripening. Due to high attenuation of ultrasound waves in peel and mango flesh, confirmation of these results for whole fruit will be a challenge.