Low cost Frequency Based Sensor for the Detection of Paneer Spoilage Rajni Kanta*, Subhradeep Samaddera , P. K. Prabhakarc, P. P. Srivastava, S. S. Pathakb and A. K. Dattaa aAgricultural
and Food Engineering Department, bDepartment of Electronics and Electrical Communication Engineering, Indian Institute of Technology Kharagpur-721302 cDepartment
of Food Science and Technology, National Institute of Food Technology Entrepreneurship and Management, Kundli, Haryana, India *Corresponding author Email:
[email protected] Tel: +919472242903
Introduction • •
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Food Freshness is a key factor for public safety. Food spoilage is a direct indication of its quality. Food spoilage occurs due to the microbial and enzymatic activities which change the composition of the medium with their metabolites, thereby changing the dielectric properties of food. Paneer spoilage can be detected either by sensory evaluation or by microbial analysis, both of which involve destructive sampling. A non-destructive method of detecting paneer spoilage is proposed here using a Radio-Frequency (RF) based sensor. The frequency of RF systems can vary from the lower ranges of the spectrum around 135 kHz to the range of 5.875 GHz.
Experimental setup for generating RF: • Setup has been made using a 555 timer IC to generate a low frequency of 100 kHz and detect it via an oscilloscope. • Paneer was wrapped in foil and put into the sample holder. • Low frequency is passed through the sample. Change in the frequency is being detected, which is due to the change in the dielectric constant of the sample.
Fig. 3. 555 timer IC
Fig. 3. Oscilloscope
Results and Discussion • •
Results showed that there was decrease in the frequency when passed through the samples. For the paneer kept at 25oC the frequency changed from 67 ± 0.2 kHz on day 0 to 57 ± 0.2 kHz on day 21. Table 1. Frequency measurement for paneer samples at different periods
Fig 1. Electromagnetic spectrum •
The development of sensors for detecting food spoilage has been motivated by need to produce safe foods and to provide better healthcare .
Objectives • •
Development of a low-cost radio frequency based sensor for spoilage detection of food. Evaluation of spoilage of paneer samples at different days storage periods.
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Materials and Method Paneer making: • Paneer was made from combination of both Cow milk and buffalo milk types of milk. • Both types of milk were acquired from local supplier. ➢ Cow milk fat 3.4 ± 0.2 %, TS 9.1 ± 0.4 %. ➢ Buffalo milk fat 5.8 ± 0.1 % ,TS 8.6 ± 0.3 %. • Among all, the paneer made by coagulation of mixed milk (85:15) gave good scores in terms of flavour, body & texture and colour & appearance.
Days 00C (kHz) 100C (kHz) 250C (kHz) 0 67±0.2 67±0.1 67±0.2 3 62.5±0.3 62±0.2 61±0.2 6 62±0.1 61.5±0.2 59±0.2 9 61.5±0.1 60±0.3 58±0.2 12 61±0.2 60.5±0.1 57±0.3 15 60.5±0.2 60±0.3 57±0.1 18 60±0.3 59.5±0.1 57±0.2 21 59.5±0.1 59±0.3 57±0.2 But, an inconsistent decrease in temperature was being seen with the 555 timer setup. Also, when the setup is used for long time it gets heated up which causes a change in the supplied frequency of 100 KHz.
Summary and Conclusion •
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From, the data analysis it can be seen that there is a difference in the frequency when spoiled paneer sample is used. It can be concluded that RF based sensors can be used for nondestructive evaluation of food spoilage. Radio Frequency Identification (RFID) systems have found favour over other identification and inventory techniques chiefly due to their nonline-of-sight operation and capability to function in adverse environments.
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There have been no conflicts of interest in the study.
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Declaration of conflict of interests
References
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Fig 2. Paneer sample The paneer samples were deliberately spoilt keeping at temperatures of 0, 10 and 25oC up to 21 days, measuring frequencies every 3 days.
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Buzby, J. C., & Roberts, T. (1997). Economic costs and trade impacts of microbial foodborne illness, World Health Statistics Quarterly, vol. 50, pp. 57–66, 1997.
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Guo, W., Zhu, X., Liu, H., Yue, R., & Wang, S. (2010). Effects of milk concentration and freshness on microwave dielectric properties. Journal of Food Engineering, vol. 99, 344-350.
