Identifying Quality Parameters In Milk
Introduction
Efficient production of high quality dairy products requires full control of incoming milk. Milk at intake may be of a different composition than that of the milk to be marketed, therefore, processors must adjust the composition as per requirements. This compositional modification is also necessary if the milk is to be converted into a different product. Often the product must conform to the legally prescribed standards, or the quality standards set by the manufacturer. Adjusting the composition as close to targets as possible can result in great savings.
The FT-IR technology is highly suitable for these purposes. Instead of the time consuming and labor intensive traditional wet chemistry methods, with FT-IR the multi component analysis is done in seconds. Sample preparation is not necessary, so that the products can be analyzed without the change of physical or chemical properties.
LactoScope 500
The LactoScope 500 Dairy Analyzer is AOAC and IDF compliant for the analysis of fat, protein, lactose, and total solids in milk.
With FT-IR optics, this analyzer is easy-to-use and comes with our robust Results Plus software. It is ideal for checking incoming milk and end products with low cost of ownership, modular design, low reagent expense, and 30-second response time. The LactoScope can test other products such as cream, yogurt and whey thereby increasing its value and versatility. It’s the ideal component analysis tool for dairy laboratories. The LactoScope is chosen for its excellent accuracy and versatility for dairy products such as yogurt and ice cream mixes and concentrates.
The LactoScope 500 can also give results for Freezing Point Depression (FPD). Normal Freezing Point is constant in milk around -0.519° C. It represents the temperature at milk will freeze when it is cooled and for this reason it can be used to detect added water.
The Intuitive Results Plus software provides rapid implementation with minimal training and is designed to make analysis as rapid and secure as possible and is compatible with LIMS systems.
Method
Measurements were carried out using a LactoScope FTA according to standard protocol. Several hundreds of raw and processed milk samples were analyzed and spectral data collected. The FPD is predicted from the sample conductivity and infrared measurements for the concentrations of fat, protein and lactose.
The cell and electronics required for the conductivity measurement are integrated in the LactoScope. Reference analysis for protein, fat, SNF, lactose and FPD were carried out using techniques approved by ISO standards.
Calibration models were developed to model the relationships between the collected FT-IR spectra and reference chemistry results using PerkinElmer Hongis Regression (HR), Artificial Neural Network Regression (ANN) and Partial Least squares regression (PLS).
Results and Discussion
Table below summarizes statistics of developed calibrations.
The large product variability built into the calibrations allow them to be robust and accurate for all kinds of raw and processed milks.
Sofia Karlberg – PerkinElmer, Inc., Stockholm, Sweden
Nadja Eremina – PerkinElmer, Inc., Stockholm, Sweden
26/11/2024