Abstract—Quality of sweet tamarind (‘Prakaytong’variety) must be acceptable as customer needs. Total soluble solids (TSS) and titratable acidity (TA) are important indexes for consideration of quality. Short wavelength near infrared spectroscopy (SW-NIRS) in transmittance mode ranged 665- 955 nm was investigated to use for detection of total soluble solids and titratable acidity in sweet tamarind. A set of 209 samples (137 samples for a calibration set and 72 samples for a prediction set) was used for total soluble solids determination. A set of 163 samples (104 samples for a calibration set and 59 samples for a prediction set) was used for titratable acidity determination. Partial least squares regression (PLSR) was used to develop the calibration models. Smoothing (Savitsky– Golay) spectral pretreatment obtained good results of a calibration model for total soluble solids (R=0.90, RMSEC=1.71) and obtained accuracy for screening in the prediction set (R=0.86, RMSEP=1.91). Smoothing (Savitsky– Golay) combined with first derivative spectral pretreatment obtained accepted results for the calibration model for titratable acidity (R=0.87, RMSEC=0.29) and obtained accuracy for screening in the prediction set (R=0.83, RMSEP=0.33). All results indicated that it is possible to use SW-NIRS for nondestructive prediction of total soluble solids and titratable acidity in sweet tamarind.

Index Terms—Sweet tamarind, total soluble solids, titratable acidity, near infrared spectroscopy.

S. Suktanarak and S. Teerachaichayut are with Faculty of Agro-Industry, King Mongkut‟s Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520, Thailand (e-mail: sineenart4@gmail.com, ktsontis@ kmitl.ac.th).

 

Cite:S. Suktanarak and S. Teerachaichayut, "Quantitative Analysis of Total Soluble Solids and Titratable Acidity of Sweet Tamarind by SW-NIRS," International Journal of Bioscience, Biochemistry and Bioinformatics vol. 3, no. 4, pp. 328-331, 2013.