Prediksi Umur Panen Pepaya Berdasarkan Total Padatan Terlarut, Kandungan Protein dan Kadar Air dengan NIR Spektroskopi

Abstract

Papaya is a climacteric fruit that usually harvested in green mature. The method of determination of papaya’s picking time can help the farmer to determine the harvest time. NIR (near infrared) can measure the content of an organic and non organic materials without affect them. Maturation level of papaya is correlated to the content of materials in the papaya. The objective of this experiment was to develop the method of determination of papaya’s picking time using NIR. Water content, protein and total soluble solid were used as internal parameter quality. Spectra of papaya was measured using NIR spectroscopy. Data of spectra were then used to develop calibration and validation model of NIR spectroscopy measurement based on the reference method. Partial Least Square (PLS) is a method used to determine the relation between chemistry composition of papaya and reflectant spectra and the absorbance. Spectra NIR was analyzed using 5 treatments: smooth average 3 points, normalization between 0 to 1, second derivative Savitzky-Golay 9 points, combination between smooth average 3 points and normalization between 0 to 1 and combination of smooth average 3 points, normalization between 0 to 1 and second derivative Savitzky-Golay every 9 points. The best model was selected according to coefficient of determination (R2), standard of error (SE), coeficient of variability (CV), ratio of standard error prediction to standard deviation (RPD) and model consistency (SEC/SEP). The best calibration models that selected based on the high accuration and consistency value by validation models with coefficient of determination (R2), SEC and SEP of 0.900 0.62 and 0.76 for water content; 0.837, 0.1 and 0,1 for protein content and 0.876, 0.90 and 1.06 for total soluble solid.