Utilization of Fourier Transform Infrared Spectroscopy for Measurement of Organic Phosphorus and Bound Calcium in Cheddar Cheese

Abstract

The methods available for measuring organic P and bound Ca in cheese are either cumbersome or involve dilution of the cheese. Dilution of the cheese can lead to erroneous results, particularly in the case of bound Ca. Hence, the objective of this study was to evaluate the feasibility of Fourier transform infrared (FTIR) spectroscopy for direct measurement of organic P and bound Ca in Cheddar cheese. Two hundred sixteen samples of cheese were analyzed for protein-bound organic P, bound Ca using a water-extraction based method, and buffering curves. Additionally, the infrared spectra of the cheeses were collected between 4,000 and 650 cm(-1), at a resolution of 4 cm(-1), and 256 scans per sample. The spectral shifts in the infrared region from 1,050 to 900 cm(-1), in addition to the measured concentrations of organic P, bound Ca, and buffering peak area at pH 5.1, were used to develop calibration models using partial least squares (PLS) regression analysis. The spectral region of 956 to 946 cm(-1) correlated with the measured concentrations of organic P and the overall PLS model had a correlation (R2) of 0.76 between the predicted and measured concentrations. The spectral region at approximately 980 cm(-1) was correlated with the measured concentrations of bound Ca, and the overall PLS model had a correlation (R2) of 0.70 between the predicted and measured concentrations. A similar spectral region at approximately 980 cm(-1) was also correlated with the measured buffering peak areas and the overall PLS model had a correlation (R2) of 0.64 between the predicted and measured peak areas. A linear regression analysis between the bound Ca and buffering peak area demonstrated that bound Ca was correlated (R2 = 0.73) with buffering peak area. This study demonstrates that FTIR can be used to measure organic P in cheeses. It also has the potential to be used for measuring bound Ca in undiluted cheeses, and for prediction of the buffering capacity of cheese.

Potential estimation of major mineral contents in cow milk using mid-infrared spectrometry

“…In this region, Upreti and Metzger (2006) observed a region from 956 to 946 cm −1 related to the concentration of organic P. The region located around 980 cm −1 observed by those authors seemed to be related to bound Ca. In our study, these regions were not the most interesting for the measurement of Ca and P by MIR spectrometry.…”

“…The spectral zones known between Ca and the carboxylate group of casein at 1,410 cm −1 and 1,575 cm −1 (Byler and Farrell, 1989) did not show high correlation (R = 0.46 and R = 0.41, respectively). Upreti and Metzger (2006) studied the feasibility of developing calibration equations to measure organic P and bound Ca in Cheddar cheese. These authors based on the previous work of Fernandez et al (2003) limited the development of calibration equations to spectral data between 1,050 and 900 cm −1 .…”

Middle infrared spectroscopy characterization of ripening stages of Camembert-type cheeses

“…The associated bands of proteins, fats, lactose and lactic acid are well known and have been described in milk and cheese. In recent years, infrared (IR) spectroscopy has been applied to measure cheese composition (Rodriguez-Soana, Koca, Harper, & Alvarez, 2006;Upreti & Metzger, 2006), sensory and instrumental texture parameters (Blasquez et al, 2006;Karoui et al, 2006) and to determine the geographic origin of the cheese . These studies were carried out on ripened cheeses, but, it seems to be possible to use IR spectroscopy to follow compositional and molecular changes during cheese ripening.…”

Technical note: Fourier transform infrared spectral analysis in tandem with 31P nuclear magnetic resonance spectroscopy elaborates detailed insights into phosphate partitioning during skimmed milk microfiltration and diafiltration

“…Considering the constraints surrounding sample preparation for the investigation of the milk mineral behavior, attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FTIR) was considered an accessible spectroscopy technique that does not require sample modification. It has been already used to examine some features of milk and dairy products; for example, the secondary structure of casein (Byler and Farrell, 1989;Curley et al, 1998), the influence of UHT processing on different milk components (Grewal et al, 2017), and the calcium phosphate binding ability of cheese (Upreti and Metzger, 2006). Fourier transform infrared spectroscopy was also used to investigate inorganic calcium phosphate material (Trpkovska et al, 1999;Berzina-Cimdina and Borodajenko, 2012;Hirsch et al, 2014) alone or in combination with casein phosphopeptides (Lenton et al, 2016).…”