Optical Properties of Tigernut (Cyperus Esculentus) as Influenced by Moisture Content and Wavelength

Abstract

Tigernut (cyperusesculentus) is one among the underutilized crops in Nigeria despite its high economic value. This study investigated the absorbance, transmittance and colour of yellow tigernut as influenced by moisture content at 8%, 16%, 24%, 32% and 42% (db) respectively. The tigernut samples were collected directly from a farm in Minna, Niger state and cleaned to remove all foreign materials, initial moisture content was determined using ASAE standard after which sampleswere conditioned to the desired moisture levels following standard method. Using a spectrophotometer, the absorbance ranged from 3.04 to 6.35 and transmittance ranged from 0.00 to 0.19 within a wavelength range of 320nm to 720nm while the colour using a Chroma meter ranged from 3.73 to 4.14, 5.19 to 8.18 and 13.1 to 19.0 for L (brightness), a (red) and b (yellow) respectively. ANOVA also revealed that moisture has significant effect at p<0.05 on absorbance, transmittance and colour of the tigernut. Correlation and regression analysis revealed a positive linear relationship between all moisture contents with absorbance, transmittance and colour

Keywords: Moisture content, optical properties, absorbance, transmittance, colour and tigernut