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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #329717

Research Project: Sensing Technologies for the Detection and Characterization of Microbial, Chemical, and Biological Contaminants in Foods

Location: Environmental Microbial & Food Safety Laboratory

Title: Study on Raman spectral imaging method for simultaneous estimation of ingredients concentration in food powder

item DHAKAL, SAGAR - Us Forest Service (FS)
item Chao, Kuanglin - Kevin Chao
item Qin, Jianwei - Tony Qin
item Kim, Moon
item Schmidt, Walter

Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 6/20/2016
Publication Date: 8/18/2016
Citation: Dhakal, S., Chao, K., Qin, J., Kim, M.S., Schmidt, W.F. 2016. Study on Raman spectral imaging method for simultaneous estimation of ingredients concentration in food powder. ASABE Annual International Meeting, St. Joseph, MI, ASABE Paper No. 16248037.

Interpretive Summary: Increasingly globalized food supply chains and the economic motivation to provide inexpensive food products have contributed to the food safety problems of counterfeit food products and food adulteration. Incidents of food fraud have helped increase the interest in development of methods for screening food products for contaminants. In this study, a macro-scale Raman chemical imaging method was developed for identification and estimation of different ingredients mixed in food powder. Raman spectral images of non-dairy creamer mixed with vanillin, melamine and sugar at 5 different concentrations were acquired. Result shows that the method can identify and estimate the concentration of vanillin, melamine and sugar with correlation coefficient of 0.99, 0.99, and 0.97 respectively. This Raman chemical imaging method shows promise for use by food processors and regulatory agencies as a non-destructive method for rapid screening of food ingredients for adulterants that pose food safety risks.

Technical Abstract: This study investigated the potential of point scan Raman spectral imaging method for estimation of different ingredients and chemical contaminant concentration in food powder. Food powder sample was prepared by mixing sugar, vanillin, melamine and non-dairy cream at 5 different concentrations in a bench top acoustic mixer for 20 minutes. A 785 nm laser source was utilized to collect Raman spectral covering the surface area of 96 mm x 46 mm and sample depth of 3 mm for each concentration sample, with spatial resolution of 0.5 mm. Self modeling mixture analysis (SMA) was used by utilizing the reference spectra of each component to extract pure component spectra. This was used to identify each component in the sample based on their spectral information divergence (SID) values to the reference spectra at all the concentration levels. Raman spectral image of each concentration level was created using contribution images from SMA. The identified pixels of each component in Raman spectral image was used to develop a relationship with concentration of corresponding component in the sample. The method is useful for simultaneous estimation of ingredients concentration in food powder mixture.