The detection of sugar in honey by transmission fiber optic displacement sensor

Abstract

A fiber optic displacement sensor (FODS) using a transmission technique was developed to determine the purity of honey. This was achieved by detecting the output signal of pure honey and adulterated honey with different addition percentage volume of sugar (fructose and glucose). Five types of honey from several retail shops were selected as specimens and labeled as A, B, C, D and E. Each honey sample was adulterated with different percentage of fructose and glucose ranging from 0-10%. Prior to sensor development, an absorption band for honey was determined by using the UV-Vis spectrophotometer. Blue diode laser at 435 nm was found to be an appropriate light source to be used in this FODS. The performance of sensor was calibrated by sensing the output signal without any honey sample. The displacement was verified within the range of 0 mm to 5.0 mm and 0 mm displacement was found to be the optimized distance for this beam through technique. The output voltage was found to be inversely proportional to displacement. The sensitivity was found to be 32.65 mV/mm with a correlation coefficient of 99%. The result from performance of sensor towards pure and adulterated honey showed that the highest sensitivity of all samples was achieved at 10% concentration of adulteration and the lowest sensitivity was obtained at 0% adulteration (pure honey). The highest sensitivity with adulteration was found in honey E with a sensitivity of 3.17 mV/% for fructose and 4.94 mV/% for glucose. Thus, FODS based on transmission technique has a potential to detect sugar content in adulterated honey for a particular honey type.