This study (purchase required) used, high-performance liquid chromatography, combined with chemometric analysis, to classify buffalo vs cows ricotta based on the profile of water soluble peptides. The authors then identified specific peptides that could be used as species markers . Both mid-infrared spectroscopy and electrophoresis were also investigated as peptide measurement methods by were found to give insufficient discrimination, with IR overly affected by storage time of the extracts.
The authors created 11 experimental cheese formulations by increasing the proportions of cow whey mixed with buffalo whey. Water-soluble peptides were analysed using mid-infrared spectroscopy, high-performance liquid chromatography and electrophoresis. The data obtained from mid-infrared spectroscopy and high-performance liquid chromatography were statistically processed using principal component analysis, analysis of covariance and multiple linear regression..
High-performance liquid chromatography identified 14 peptide peaks, with three recognized as specific markers for cow whey in adulterated samples. PCA explained 77% of the variance, distinguishing pure and adulterated ricotta. Multiple linear regression modelling of high-performance liquid chromatography data predicted cow whey concentration with a correlation of R = 0.87. High-performance liquid chromatography with chemometrics was effective for detecting buffalo ricotta adulteration.
When applied to 14 commercial samples, the model suggested that nine contained adulteration ranging from 10% to 100% cow whey.
Photo by Conor Brown on Unsplash
Comments