Acoustic impulse response of young coconut (Cocos nucifera L.) fruits in relation to maturity

Abstract

Acoustic impulse responses of young coconut fruits were analyzed using Fourier analysis and the correlation of signal characteristics with the mucous-like stage, cooked rice-like stage and leather-like stage maturity levels was determined. Analyses of sound signals of unshaved and shaved fruit samples were performed to determine if the difference in acoustic response could help enhance the differentiation of the fruits at different maturity levels. Results of statistical analysis showed that the frequency of the impulse response of the unshaved fruits increases with maturity levels and are significantly different from each other, while those of the shaved fruits are not. Also, results of regression analysis showed that as the fruits mature and the meat or kernel of the fruit thickens, sweetness of the juice also increases.