Extending the use of fiber optic equipped visible/near infrared reflectance spectrometer to measure peel color of various fruits and vegetables




Bachelor of Science in Agricultural and Biosystems Engineering

Major Course

Major in Agricultural and Bio-Process Engineering


College of Engineering and Agro-Industrial Technology (CEAT)

Adviser/Committee Chair

Kevin F. Yaptenco


A visible/near infrared reflectance (VNIR) spectrometer was used to measure L*a*b* and HSV color values for 60 fruit and vegetable samples. The L*a*b* values were calculated from the visible spectral data as defined by the Commission on Illumination (CIE). Color values from the VNIR instrument were compared with reference values collected from a colorimeter, designed specifically to measure color. Calibrated color equations were then generated through linear regression analyses. In general, there was a good agreement between the spectrometer and colorimeter readings. Result from the independent samples t-test with a 5% level of significance also showed that there is no statistically significant difference between the two methods of color measurement. A validation experiment was also conducted to determine the daily peel color changes of tomatoes stored under ambient and refrigerated conditions, and starting from the mature green stage until it reaches the full red stage of ripeness. Linear regression analysis showed an excellent agreement between hue angles computed using the calibrated equation and using the colorimeter, with R2 equal to 0.966. This finding indicates that the spectrometer is able to generate color readings that agree well with colorimeter data.




UPLB College of Engineering and Agro-Industrial Technology (CEAT)

Call Number

LG 993.5 2015 A2 /P33

Document Type


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