Measurement of soy contents in ground beef using near-infrared spectroscopy

Authors: JIANG, HONGZHE - China Agricultural University; Zhuang, Hong; SOHN, MIRYEONG - US Department Of Agriculture (USDA); WANG, WEI - China Agricultural University

Submitted to: Applied Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2017
Publication Date: 1/19/2017
Citation: Jiang, H., Zhuang, H., Sohn, M., Wang, W. 2017. Measurement of soy contents in ground beef using near-infrared spectroscopy. Applied Sciences. 7(1):97. doi:10.3390/app7010097.

Interpretive Summary: Soy protein products, such as flour, grits, concentrates, isolates, and textures, are widely used in processed meat products. Soy proteins provide functional properties in meat products such as texture-forming, fat and water emulsification, and gelation, and in the same time, they also reduce the total cost of processed meat products. However, soybean allergy is a very common food allergy, especially among babies and children. Thereby, the addition of soy products to meat products, in some cases, is not allowed. The regulatory department in the United States has been requested to examine soy contents in further-processed meat products, such as ground meat, meat patties, frankfurters and chili with meat and beans. Currently, soy proteins in meat products are analyzed by microscopic methods, electrophoretic methods, or chromatographic methods. But these methods are either time-consuming or invasive. Near-infrared (NIR) spectroscopy is a sensitive, fast and non-destructive analytical technique with simplicity in sample preparation and has widely been evaluated for use in the quantitative and qualitative analysis of quality and adulteration in meat and meat products, such as beef, pork, poultry and seafood. The objective of this study was to investigate if the NIR spectroscopic method could be used in the qualitative and quantitative analysis of soy contents in ground beef. Our results show that the data collected with NIR spectroscopy can be used both quantitatively and qualitatively to predict soy protein contents in ground beef with great accuracy, suggesting that NIR technology could be an alternative way for determining soy products/proteins in further processed meat products.

Technical Abstract: Models for determining contents of soy products in ground beef were developed using near-infrared (NIR) spectroscopy. Samples were prepared by mixing four kinds of soybean protein products (Arconet, toasted soy grits, Profam and textured vegetable protein (TVP)) with ground beef (content from 0%–100%). NIR spectra of meat mixtures were measured with dispersive (400–2500 nm) and Fourier transform NIR (FT-NIR) spectrometers (1000–2500 nm). Partial least squares (PLS) regression with full leave-one-out cross-validation was used to build prediction models. The results based on dispersive NIR spectra revealed that the coefficient of determination for cross-validation (Rcv 2) ranged from 0.91 for toasted soy grits to 0.99 for Arconet. The results based on FT-NIR spectra exhibited the best prediction for toasted soy grits (Rcv 2 = 0.99) and Rcv 2 > 0.98 for the other three soy types. For identification of different types of soy products, support vector machine (SVM) classification was used and the total accuracy for dispersive NIR and FT-NIR was 95% and 83.33%, respectively. These results suggest that either dispersive NIR or FT-NIR spectroscopy could be used to predict the content and the discrimination of different soy products added in ground beef products. In application, FT-NIR spectroscopy methods would be recommended if time is a consideration in practice.