Available online www.jocpr.com Journal of Chemical and Pharmaceutical Research, 2015, 7(6):112-116 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 112 Measurement of starch and soluble solid content in papaya using near infrared spectroscopy Yohanes Aris Purwanto 1,2 , I. Wayan Budiastra 1 , Emmy Darmawati 1 and Nur Arifiya 1 1 Department of Mechanical and Biosystem Engineering, Bogor Agricultural University, Kampus IPB Darmaga Bogor, Indonesia 2 Center for Tropical Horticulture Studies, Bogor Agricultural University, Kampus IPB Baranangsiang Jl. Raya Pajajaran Bogor, Indonesia _____________________________________________________________________________________________ ABSTRACT Starch and soluble solid content in papaya are an important parameter for measuringthe maturity of fruit after harvesting. In this work, the application of near infrared (NIR) spectroscopy in measuring starch and soluble solid content in papaya wereevaluated. Samples of papaya were harvested at 135, 131, 128, 121 and 114 days after anthesis. NIRFlex N-500 (Büchi Labortechnik AG, Flawil, Switzerland)with spectra range of 1000–2400 nm was used as spectra acquisition of papaya in reflection mode. After randomly dividing 120 spectra into calibration set and 60 spectra independent prediction set, spectra in the calibration set were subjected to a partial least square (PLS) method with preprocessing of first derivative Savitzky-Golay 9 points (dg1) and multiplicative scatter correction (msc) to establish calibration model. Validation of calibration models on the independent prediction set indicates the prediction accuracy with coefficient of correlation (R), SEC (standard error of calibration), SEP (standard error of validation set) and coefficient of variance (CV)of 0.90, 0.17%, 0.04% and 10.95 for starch content; 0.90, 0.12% and 0.12%and 4.85% for soluble solid content, respectively.The results indicated that NIR spectroscopy could be used to predict the starch and soluble solid content of papaya rapidly and nondestructively. Keywords: NIR spectroscopy, starch, soluble solid content, papaya, nondestructive _____________________________________________________________________________________________ INTRODUCTION As considering to market destination, papaya fruits are generally harvested at condition of hard green mature. Classification of maturity level of papaya is important in order to classifymore reliable for those papaya fruits send to local market or long distance market.Operator determines maturity level of papaya based on the visual assessment such as skin colour and shape of the fruit. This method is sometimes not reliable and depend on the experience of the operator. Classification method based on the internal qualities parameter such as starch and soluble solid content of each single fruit is expected more accurately. Maturity level of picking date of fruits is usually chosen on the basis of the climacteric trend, germination, the operator’s experience, and fruit is monitored close to the presumed date, using ripening parameters, e.g. starch content, soluble solids content, fruit flesh firmness, acidity and skin color[1]. When destructive analysis techniques are adopted, it is not possible to monitor the physiological changes on the same samples over the entire ripening period. Hence, it is important to obtain a rapid, reliable and non-destructive analytical tool as an indicator of quality