International Journal of Computer Engineering and Applications, Volume XII, Special Issue, March 18, ISSN

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1 International Journal of Computer Engineering and Applications, Volume XII, Special Issue, March 18, ISSN OPTICAL METHOD FOR MEASUREMENT OF SUCROSE CONCENTRATION IN SUGARCANE JUICE P. B. Patel Dr. D. Y. Patil Institute of Technology, Pimpri, Pune-18, Maharashtra, India S. T. Hamde S.G.G.S. Institute of Engineering and Technology, Nanded, Maharashtra, India. Abstract-The impurities content in sugarcane juice affects the qualities of sugar and panela, which is solid form of sucrose. The final analysis of sugar cane juice color from a chemical point of view is based on measure of the amount of impurity and sucrose percentage that causes the visual appearance. Color is used both to monitor the sugar manufacturing or refining process, and to rate the final product at the consumer level. In most of the sugar manufacturing industries the offline method is used for determining sugar color by using turbidity principle and ph measurement which are not online measurement methods. In this work, color of clear sugarcane juice is determined by the color sensor (PD 153), which can be directly correlated with the sugar as a final product. In this work, Light Emitting Diode (LED) is used as light source. Optical method of color measurement is online process, by placing the setup in the area where the purified juice is passed for the further process. Since, it is online process it saves one personnel which is required to continuously take sample for measuring the color. Here we need to observe or get feedback only if there are certain changes in color. For getting feedback, single conditioning of detector is done using microcontroller and display is used for indication purpose. Key Words: Sugar Cane Juice, Turbidity, Color Sensor, Visual Appearance. 1. Introduction The color of juice is the most important parameter for defining the quality of sugar. In sugar industries (sugar from sugar cane juice and sugar from sugar beet), the main challenge is to maintain the quality of final granulated sugar [1]. In order to achieve this, industry has to follow some standard process. There are various factors which need to monitor continuously in order to maintain the desired standard. International Commission for Uniform Method of Sugar Analysis (ICUMSA) plays a vital role for deciding the standards for the color value of clear sugarcane juice. One of the factors is the color of clear sugarcane juice. Nowadays in industry the color is identified by taking sample of the juice and performs an experiment in laboratory to identify the color of sugarcane 1

2 OPTICAL METHOD FOR MEASUREMENT OF SUCROSE CONCENTRATION IN SUGARCANE JUICE juice [2]. Though it is good and accurate process it is time consuming and is not a repeatable process. So there is need of some automated mechanism which detects the color of clear sugarcane juice online. This work concentrates on the design of the instrument which measures the color of clear sugarcane juice online and reduces the laboratory work. By observing the reading available on the display, it is possible to comment on the quality of sugar cane juice i.e. sucrose concentration in sugarcane juice, which directly affects the final sugar quality. The distinction between visual appearance and the amount of impurity that causes the appearance is important because it influences the optical measurement and the method of expressing the results [3]. The visual color is a three-dimensional entity that involves the entire visible spectrum and the response of the human eye. This measurement has had very limited acceptance by the sugar industry. Generally brix measurement in sugar cane juice is done by using refractometer. Brix is nothing but degree of amount of dissolved solids in liquid. If measured value of brix is higher, sucrose percentage is also high in the juice [4, 5]. The sugar impurities which influence the optical measurement are of two classes: one is dissolved and the other one is suspended. They contain both high molecular weight organic and inorganic components, the latter being probably highly siliceous [6]. Also, relatively little is known about the molecular composition and structure of the dissolved impurities. A large number of different colored compounds have been isolated in cane juice and raw sugar, but this account for only a small fraction of the total color [7]. Two fundamental optical measurements can be made in sugar solution: absorption and scattering. 2. Methodology The objective of this work is to analyse the factor which is a measure of the amount of solids that can be gained from optical measurements of juice. The amount of impurity, on the other hand, can be related to the transmittance at one wave length and is a much less complex entity. 2 Input Light Source Fig 1. Block diagram of measurment setup However, since the word "color" will undoubtedly continue to be used to comment on either visual appearance or amount of impurity in a very ambiguous manner. If a scale is chosen that would be a good measure of amount of impurity then at least a fair indication of the visual appearance can be commented. Figure 1 shows the block diagram of the measurement setup. It shows the simple process of color measurement of clear sugarcane juice. A cylindrical glass chamber is used as sample holder, in which the interaction of light with the juice takes place. The purity of sugar cane juice is given by the equation: P = Su DSb (1) S u=sucrose Sample out DS b=dry Substances Sample in Output Colour Detector Signal Conditioning Circuit Monitor In sugar cane juice, 85 % is water, 15% is dry substances. A dry substance contains 13 % sucrose (S u) and 2 % Non sucrose components. Problems in interpretation arise when attempts are made to correlate these optical measurements with the non-sucrose constituents that are dissolved and suspended. The presence of strong chromospheres groups in certain dissolved materials can strongly influence the absorption and large suspended or colloidal dispersed particles contribute predominately to light scattering. Between these extremes are

3 International Journal of Computer Engineering and Applications, Volume XII, Special Issue, March 18, ISSN many materials for which this interpretation is not so distinct. Nevertheless, it is useful to divide the sugar impurities into two groups: a colorant fraction that contains the summation of all constituents that contribute to absorption and a scattering' material that has the corresponding light scattering behaviour [8]. Optical measurements obtained under a specified set of conditions were used for the measurement of the colorant and scattering material. The conditions was chosen to provide the best measure of impurities and also for convenience, speed, ease, precision, or for any other good reason that arises, such as minimization of undesirable side effects [9]. Human eye is insensitive to wavelength over 700 nm. So there is need to use sensor which is more sensitive to the wavelength more than visual wavelength range. PD153 is a color sensor and is more sensitive to wavelength between 400 to 1100 nm which is useful to detect the color above the visual wavelength. It is an element of two PN junctions (photodiodes) vertically incorporated into a substrate with its thickness of silicon action as optical filter. Figure 2 shows the structure of the sensor. When light source is illuminated, it passes through the sample which is clear sugarcane juice. Depending upon color of the juice sample the light is detected by the detector PD153. The detector, PD153 is a type color sensor. 1 juice [10]. Readings are obtained from the output of the detector. Lights of short wavelength absorbed near the surface of silicon and those of long wavelength going deeper to be absorbed. The PD1 is having less deep PN junction which will have greater sensitivity to the short wavelength light while the photodiode PD2 of the deeper PN junction which will have greater sensitivity to long wavelength lights. Figure 3 shows the typical correlation between the output voltage (V o) and the wavelength (λ) of the incident light. The light source used in this work is LED. The output voltage obtained at detector is converted into ICUMSA number by using microcontroller according to standard decided by the ICUMSA. Fig 3 Correlation between the output voltage and wavelength of the incident light for color sensor START PD1 Sample in (Pass clear sugar cane juice) 3 PD 2 Fig 2. Structure of color sensor The output of the detector is in terms of voltage and it is proportional to the wavelength. By using wavelength we can easily determine the color changes in the solution of clear sugarcane 2 1=Anode 2=Cathode 3=Anode 3 Yes ADC Set point (above 3 Volt). Display 100 IU Fig 4. Flow chart No Display 8000 IU

4 OPTICAL METHOD FOR MEASUREMENT OF SUCROSE CONCENTRATION IN SUGARCANE JUICE The sugar cane juice is passed through the sample holder. Light from light source passes through the juice sample. Output of color sensor is converted into digital signal by using the formula, ADC output = Vin 1024 V ref....(2) ADC output = Vin Figure 4 shows the flow chart of the steps considered for the measurement of the color of the juice. In first step juice is allow to pass through the measurement cell. Light from light source after passing through this juice is detected by output color sensor. Depending upon the sucrose concentration in juice the light will be collected by the detector. We have adjusted the set point as above 3 volt for allowable sucrose concentration in juice. This output is displayed on the display board. If output of the detector is above 3 volt, i. e. 3< V O <5 then display 100 IU and If it is below 3 volt, i.e. 0<V O<3 then display 8000 IU [11] Figure 5 (a,b,c) shows the graph of output response given by the signal conditioning circuit for all three juice compartments with in 1 min time duration interval. The setup along with the signal conditioning is tested for three different compartments of sugar cane juice in sugar industry (compartment number 1, 2 and 3). a) Reading at compartment no.1 3. Result and Discussions The results are obtained for this setup under given environmental conditions. Test has been carried out at Sant Tukaram Cooperative Sugar Factory, Pune. Table 1. Measurement at three juice compartments. Time (min) Measurement output voltage (volt) Compartment 1 Compartment 2 Compartment Reading at Compartment no. 2 b) c) Reading at Compartment no. 3 Fig 5. Graph of Output response given by Signal Conditioning Circuit for a) Compartment no. 1, B) Compartment no. 2, C) Compartment no. 3. 4

5 International Journal of Computer Engineering and Applications, Volume XII, Special Issue, March 18, ISSN We have taken the readings of juice sample for total 10 min time duration with 1 min time interval. Table no 1 shows the data recorded for all three juice compartments. Total 10 trials have been recorded. This data is compared with the variation in refractive index due to change in sucrose percentage. This is shown in Fig 6. The spectral radiant distribution is directly proportional to wavelength (λ) and temperature (T). above 3 volts so the sucrose contents is maximum. Fig 6. Graph of Refractive Index and output variation. Fig 7. Graph of Sucrose concentration and Refractive Index variation at 20 C. As the refractive index changes, the output at the detector also changes. Refractive index is always a function of wavelength (λ) and temperature (T). The output measurement are with wavelength (590nm) and at temperature (20 C ), this is shown in Fig Acknowledgement We express sincere thanks to Management of Sant Tukaram Cooperative Sugar Factory, Pune for allowing us testing of the sugarcane juice using designed setup. 5. Conclusion We have used a simple optical technique to measure the sucrose concentration in sugarcane juice. It is observed that the color is the function of sucrose contained in the sugar cane juice. If the output is 5 The comparison between the results obtained in laboratory and by the equipment setup was matching satisfactorily. The time required for analysis reduced to great extent as the online measurement is possible with this optical sensor prototype. References 1. N. M. Nawi, G. Chen and T. Jensen, Prediction of Sugarcane Quality from Juice Samples using Portable Spectroscopy, Journal of Mechanical Engineering and Science, Vol.7, , Dec Malacava, Daniel, Color Vision and Colorimetry Theory and Application, SPIE press, Bellingham WA, Donovan, M., Williams, J., Process for Production of Extra Low Color Cane Sugar, United State Patent, 6,174,378, Handbook of Cane Sugar Engineering by Hugot Beulah Jackson and T. Jayanthy, Determination of Sucrose in Raw Sugarcane Juice by Microwave Method, Indian Journal of Science and Technology, Vol 7(5), , May P. Laksameethanasana, N. Somla, S. Janprem, N. Phochuen, Clarification of Sugarcane Juice for Syrup Production Procedia Engineering 32, ,(2012). 7. Rao, P.V.K.J., Das, M., Das, S.K., Changes in Physical and Thermo-physical Properties of Sugarcane, Palmyra-Palm and Date-Palm juices at Different Concentration Sugar, Journal of Food Engineering 90, , Mao, L.C., Xu, Y.Q., Que, F., Maintaining the Quality of Sugarcane Juice with Blanching and Ascorbic Acid, Food Chemistry 104, , 2007.

6 OPTICAL METHOD FOR MEASUREMENT OF SUCROSE CONCENTRATION IN SUGARCANE JUICE 9. M. Saska, B.S. Zossi and H. Liu, Removal of Color in Sugar Cane Juice Clarification by Defecation, Sulfitation and Carbonation, International Sugar Journal Jagdish T et al., Direct Near Infrared Analysis of Sugar Cane Clear Juice Using a Fiber-Optic Transmittance Probe, J. Near Infrared Spectros. 2003; 11: Data sheet of International Commission for Uniform Method of Sugar Analysis (ICUMSA). 6