How is NIRS Used in the Quality Control of Chocolate Bars?

High-quality control measures are required across the food production industry to guarantee food quality and protect the consumer. Confectionary products, such as chocolate, must follow regulatory standards as product control is mandatory to meet compliance and to ensure consistent quality. The latter is of particular importance for indulgent food products.

Near-infrared spectroscopy (NIRS) is a rapid, chemical-free analysis method that can be used for determining several important quality control parameters of chocolate bars without the need to conduct any special sample preparation.

The NIRS solution is user-friendly and can be implemented in the quality control laboratory or at-line during the production cycle.

DS2500 Analyzer

With powerful near-infrared spectroscopy on offer, The DS2500 Liquid Analyzer functions on the production line as well as in the laboratory. The analyzer demonstrates its capacity for being able to run the routine analysis of liquids across the entire production line, making a dynamic machine.

Moreover, it is well-suited for harsh production environments as the sturdy design makes the DS2500 Liquid Analyzer resistant to dust, moisture, and vibrations.

The DS2500 delivers precise, reproducible results in under a minute while covering the full spectral range from 400 to 2500 nm. Thanks to its intuitive functionality, the analyzer addresses the needs of the pharmaceutical industry while ensuring users are always supported during their daily tasks.

Irrespective of the sample type and challenges, a range of custom accessories optimize the instrument’s functionality which helps deliver high-grade results, from coarse-grained solids such as granulates to semi-solid samples such as creams. Users can expect a productivity boost when using the MultiSample Cup for measuring solids, as it can hold up to nine samples while enabling sequential automated measurements.

Experimental Equipment

The Metrohm DS2500 Solid Analyzer analyzed 18 chocolate bars from various suppliers. Figure 1 shows chocolate bars were placed directly onto the sample window and measured in diffuse reflection mode.

To vary the samples, three different locations were measured across each chocolate bar, and the averaged spectra were used for subsequent prediction model development. The software package Vision Air Complete was used to capture data and develop the prediction model, as shown in Table 1.

Table 1. Hardware and software equipment overview. Source: Metrohm Middle East FZC

Figure 1. Metrohm NIRS DS2500 Solid Analyzer with a chocolate bar covering the sample window. Image Credit: Metrohm Middle East FZC

Result

The Vis-NIR spectra obtained were used to create prediction models for the various reference parameters as shown in Figure 2.

An omission validation procedure was used and the correlation diagrams display the relation between the Vis-NIR prediction and the reference values as shown in Figures 3–8 alongside the respective figures of merit (FOM).

Figure 2. Selection of Vis-NIR spectra of chocolate bar samples. Data was obtained with a DS2500 Solid Analyzer. A spectra offset was applied for visualization purposes. Image Credit: Metrohm Middle East FZC

Result Calories In Chocolate Bars

Figure 3. Correlation diagram and the respective FOMs for the prediction of calories in chocolate bars using a DS2500 Solid Analyzer. Image Credit: Metrohm Middle East FZC

Result Fat In Chocolate Bars

Figure 4. Correlation diagram and the respective FOMs for the prediction of fat in chocolate bars using a DS2500 Solid Analyzer. Image Credit: Metrohm Middle East FZC

Result Saturated Fat In Chocolate Bars

Figure 5. Correlation diagram and the respective FOMs for the prediction of saturated fat in chocolate bars using a DS2500 Solid Analyzer. Image Credit: Metrohm Middle East FZC

Result Carbohydrates In Chocolate Bars

Figure 6. Correlation diagram and the respective FOMs for the prediction of carbohydrates in chocolate bars using a DS2500 Solid Analyzer. Image Credit: Metrohm Middle East FZC

Result Sugar In Chocolate Bars

Figure 7. Correlation diagram and the respective FOMs for the prediction of sugar in chocolate bars using a DS2500 Solid Analyzer. Image Credit: Metrohm Middle East FZC

Result Protein In Chocolate Bars

Figure 8. Correlation diagram and the respective FOMs for the prediction of protein in chocolate bars using a DS2500 Solid Analyzer. Image Credit: Metrohm Middle East FZC

Conclusion

This article demonstrates how near-infrared spectroscopy (NIRS) can effectively analyze the calories, fat, saturated fat, carbohydrate, sugar, and protein levels in chocolate bars. When compared to traditional methods of assessing these nutritional parameters, NIRS offers significant savings in both time and cost. NIRS enables these measurements to be performed without the need for chemical reagents, providing accurate results in a matter of seconds.

This information has been sourced, reviewed and adapted from materials provided by Metrohm Middle East FZC.

For more information on this source, please visit Metrohm Middle East FZC.