Study on measuring the ripeness level of the 'Crystal' guava fruit using NIR (near infrared) spectroscopy
'Crystal' guava is a cultivar of guava that is widely cultivated in Indonesia, recently. The crispy and sweet flesh of a mature 'Crystal' guava gives a different taste from some other cultivars of guava already known in the country. However, measurement of 'Crystal' guava maturity is still done manually, so that the results are less accurate and less objective. This study aims to study and determine the correlation of 'Crystal' guava ripeness parameters obtained by NIR spectroscopy as one of many common non-destructive methods with those obtained by destructive method. The destructive ripeness parameters tested were flesh hardness, total soluble solids, and moisture content. The sample used was 180 'Crystal' guava fruits with three different ripeness levels, 60 fruits for each level of ripeness. The equipment for spectroscopy measurement was N-500 spectrometer NIRFlex solids optical fiber at wavelengths of 1000-2500 nm. The NIR spectra data pre-processing was employed to improve the accuracy of prediction of the flesh hardness, total soluble solids, and moisture content, as three ripeness parameters using the NIR spectra. The results showed that the spectra could be used to predict total soluble solids and moisture content as the ripeness parameters with good accuracy, while they were less viable to predict the flesh hardness as the other ripeness parameter of the guava.
Ahmad, U., Purwanto, Y.A. and Cahyo, L.D. (2018). Study on measuring the ripeness level of the 'Crystal' guava fruit using NIR (near infrared) spectroscopy. Acta Hortic. 1210, 43-50
guava, NIR, total soluble solids, moisture, flesh hardness