Integration of Independent Component Analysis with Near Infrared Spectroscopy for Rapid Quantification of Sugar Content in Wax Jambu (Syzygium samarangense Merrill & Perry)
YUNG-KUN CHUANG1,3, SUMING CHEN1,2*, Y. MARTIN LO3, CHAO-YIN TSAI2,
I-CHANG YANG3, YU-LIANG CHEN1, PEI-JU PAN1 AND CHIEN-CHIH CHEN1
1. Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei, Taiwan, R.O.C.
2. BioenergyResearchCenter, NationalTaiwanUniversity, Taipei, Taiwan, R.O.C.
3. Department of Nutrition and Food Science, University of Maryland, College Park, MD, U.S.A.
(Received: December 13, 2011; Accepted: July 25, 2012)
ABSTRACT
Independent component analysis (ICA) was integrated with near infrared (NIR) spectroscopy for rapid quantification of sugar content in wax jambu (Syzygium samarangense Merrill & Perry). The JADE algorithm (Joint Approximate Diagonalization of Eigenmatrices) and linear regression with spectral pretreatments were incorporated to analyze the NIR spectra of wax jambu against sucrose solutions. Unlike other multivariate approaches, ICA enabled comprehensive quantification of sugar content in wax jambu. In the present study, ICA was applied as the sole tool to build the NIR calibration model of internal quality of intact wax jambu without any other multivariate analysis methods. The best spectral calibration model of wax jambu (600 to 700 nm and 900 to 1,098 nm) yielded rc = 0.988, SEC = 0.243 °Brix, rv = 0.971, SEV = 0.381 °Brix, and RPD = 4.15 using the normalized first derivative spectra and 9 independent components (ICs). All ICA results were better than those of partial least squares regression (PLSR). Thus, ICA can quickly identify and effectively quantify the sugar contents in wax jambu with calibration models achieving high predictability.
Key words: near infrared (NIR) spectroscopy, calibration model, wax jambu, sugar content, independent component analysis (ICA)