Monitoring Moisture, Fat, and Protein in Cheese Products

In the cheese-making process, a subtle balance between protein levels, fat, and moisture plays a vital role in the mouth-feel, flavor, and quality of the end product. Apart from ensuring end product with the best quality, accurate monitoring of protein, fat, and moisture throughout the production process also has a direct effect on realizing optimum yields, and thereby profitability.

The SMART 6™–ORACLE™ is a combination system that enables quick fat and moisture determination with results within 5 minutes. Dual-frequency energy is utilized by the SMART 6 moisture and solids analyzer to quickly analyze any product, dry or wet, within 3 minutes. ORACLE completely isolates the signal from fat molecules, even in complex sample matrices, thereby avoiding the need for method development. Then Sprint^® direct protein measurement system employs dye-binding technology to guarantee that only true protein is detected, instead of total nitrogen, which could lead to erroneous measurements due to the presence of non-protein nitrogen. Sprint eliminates the need for regular calibrations, and methods can be easily formulated by any lab user. Competitive, faster technologies (TD-NMR, FT-IR, and NIR) mandate progressive, high-cost calibrations and method development for every distinctive sample due to differences in consistency, texture, and color.

This article shows that results for protein, fat, and moisture analysis performed using CEM’s rapid testing technology are on par with the reference chemistry, where the average difference is less than 0.10% for all the tests. CEM requires only a very few preprogrammed methods to provide highly precise and accurate results within a few minutes when compared to competitive rapid technologies and reference chemistry.

Key System Benefits

• Rapid — Provides results within 5 minutes
• No calibration — CEM offers preprogrammed cheese methods, leading to considerable savings in calibration development and maintenance (for example, FT-NIR and NIR)
• Accurate — Not sensitive to variations in consistency, texture, or color. Protein results are not skewed by nitrogen-containing additives in the end product.
• AOAC Approved Methodology^1–3
• Precise — CEM technology eliminates repeatability problems related to reference chemistry, such as operator technique, solvent composition, temperature, and extraction time.

Experiment

Four different samples of natural and processed cheese were commercially acquired and assessed for protein, fat, and moisture to exhibit the performance of CEM’s rapid testing technology. For the analysis of fat and moisture, a 2 g sample of each type of cheese was pre-dried in the SMART 6 and then transferred to the ORACLE for fat determination. The natural cheese method was used for measuring the natural feta, mascarpone, and mozzarella cheese types. A single processed cheese method was employed for evaluating the processed American cheese.

For the analysis of protein, a 0.5 g sample was placed in the Sprint system to be automatically homogenized, mixed with iTag^® binding solution, and evaluated through absorption at 480 nm. Three representative samples (low, medium, and high protein content) of known concentration were measured in triplicate to form a response curve for creating Sprint methods. Once these methods are developed, they do not need recalibration. In order to determine a basis of comparison, reference testing for protein (Kjeldahl), fat (Mojonnier), and moisture (air oven) were carried out in duplicate.

Results and Discussion

Table 1 and 2 illustrate the precision and accuracy of CEM’s rapid testing technology for the quantification of protein, fat, and moisture in cheese samples. The difference between the CEM technology and the reference methods — which was in the range of 0.01% – 0.08% for protein, 0.02% – 0.18% for fat, and 0.1% – 0.24% for moisture — is shown in Table 1. Due to the direct measurement of protein, a correction factor is not required to account for non-protein nitrogen.

Table 1. Accuracy of CEM technology compared to reference methods

Table 2 illustrates that standard deviations were in the range of 0.02%–0.18% for protein, 0.04%–0.13% for fat, and 0.11%–0.13% for moisture. These results indicate that CEM’s rapid testing technology reliably matches reference chemistry results for a broad range of cheese types with exceptional precision.

Table 2. Precision of CEM technology

Conclusion

Accurate fat and moisture values were evaluated within 5 minutes with the help of the SMART 6–ORACLE system. The combination system ensures better precision when compared to reference chemistry within a fraction of the time required to perform oven and extraction analyses. The Sprint system has the ability to accurately quantify protein in all the samples within 4 minutes without the need for high temperatures or using hazardous chemicals. On the whole, CEM’s rapid testing technology offers highly precise and accurate results within a few minutes, thereby enabling better process control and, eventually, more savings than reference methods.

References

1. AOAC PVM 1:2004 – Rapid Determination of Moisture/ Solids and Fat in Dairy Products by Microwave and Nuclear Magnetic Resonance Analysis
2. AOAC 967.12 – Protein in Milk
3. AOAC 930.29 – Protein in Dried Milk

This information has been sourced, reviewed and adapted from materials provided by CEM Corporation.

For more information on this source, please visit CEM Corporation.