Bruker® MPA II FT-NIR Analyzer For Liquid Samples

Milk, the starting point of any dairy product, is one of the best controlled food products in the world. The composition of raw milk changes by season and region, which makes the standardization step necessary to maintain consistent milk quality during the processing steps. The optimal analytical solution for raw milk and liquid milk products is the combination of MPA II with the Liquid Sampling Module (LSM). This is a dual system that can switch software controlled between a powerful homogenizer and a peristaltic pump for sample treatment and transport, depending on the product and its viscosity. The dual concept allows the analysis of any liquid milk and dairy product in an optimal way either homogenized or not. In contrast to standard FTIR milk analyzers, all kinds of even viscous liquid dairy products can be analyzed due to the comparably large path length of 1 mm (1000 µm) of the flow cell. Raw milk is generally preheated and homogenized before measurement to assure highest precision and repeatability. In terms of accuracy and repeatability, this FT-NIR approach is equivalent to the traditional FTIR systems, but is offering more options. Typical accuracies are in the range of 0.03% or better for fat, and protein and repeatabilities are in the magnitude of 0.001%. The MPA II and LSM come with dedicated calibration packages that can be utilized for any milk type ranging from raw milk, skim milk, standardized milk, to UHT milk. Not only milk, but liquid milk derivatives and milk products can be easily measured using the same setup, regardless of the composition of the product. Due to the uniquely large path length of the measurement cell (1 mm), even highly viscous samples such as condensed milk and concentrates can be readily analyzed. These types of samples do not require homogenization or even should not be homogenized before the analysis. Is also ideal for sugar-containing products such as yogurt drinks, flavored milk, and even products containing fiber, like cat's milk. The LSM is designed to be flexible so that for these sample types, an operating mode using the peristaltic pump can be selected via software control. This enables users to switch back and forth between any sample type without making adjustments to the hardware. In addition to the different milk types, the following samples can be analyzed without any pre-processing. Typical dairy calibrations include but are not limited to:

• Whey and whey concentrate
• Whey protein and lactose concentrate
• Cream and whey cream
• Permeates and retentates
• Condensed milk, sweetened condensed milk
• Milk drinks, e.g. based on yogurt
• Melted ice cream.
Solid and semi-solid dairy products include a large variety of product types from various milk powders to cheese varieties, yogurts, and other semi-solid products like intermediates in the dessert production. Almost any product can be analyzed by FT-NIR utilizing a reflection measurement. In the lab or near productionthe MPA II, with an integrating sphere, provides a simple way of sample presentation and analysis. The sample is filled in a cup, quartz petri dish, or disposable polystyrene petri dish, and put on the instrument. The reflection analysis is done from the bottom and the sample is rotated acentrically during the measurement in order to collect more sample information and to level out in-homogeneities. For process analysis a wide range of probes and accessories enable on-line and in-line FT-NIR analysis of any solid or semi-solid product.