Rapid Analysis of Milk Using Low-Cost Pocket-Size NIR Spectrometers and Multivariate Analysis

Abstract

The miniaturisation of analytical devices, reduction of analytical data acquisition time, or the reduction of waste generation throughout the analytical process are important requirements of modern analytical chemistry, and in particular of green analytical chemistry. Green analytical chemistry has fostered the development of a new generation of miniaturized near-infrared spectroscopy (NIR) spectrometric systems. However, one of the drawbacks of these systems is the need for a compromise between the performance parameters (accuracy and sensitivity) and the aforementioned requirements of green analytical chemistry. In this paper, we evaluated the capabilities of two recently developed portable NIR instruments (SCiO and NeoSpectra) to achieve a rapid, simple and low-cost quantitative determination of commercial milk macronutrients. Commercial milk samples from Italy, Switzerland and Spain were chosen, covering the maximum range of variability in protein, carbohydrate and fat content, and multivariate calibration was used to correlate the recorded spectra with the macronutrient content of milk. Both SCiO and NeoSpectra can provide a fast and reliable analysis of fats in commercial milk, and they are able to correctly classify milk according to fat level. SCiO can also provide predictions of protein content and classification according to presence or absence of lactose.

Miniaturized near-infrared instruments in dairy products or dairy industry: First steps in a long-distance race?

“…Not surprisingly, milk has been the most studied dairy product. Several compounds such as protein, fat and solids-non-fat, 10 lactose, protein, fat and solids-non-fat, 11 fat, 12 lactose 13 and fatty acids 14 in milk have been predicted using NIR portable instrumentation and multivariate regression models. In most of the cases, the authors claim that good and reliable results are obtained, comparable to those obtained from lab-based instruments.…”

“…So far, the lowest reported concentrations using NIR miniaturized instrumentation in dairy products involve ranges with lower values of the order of 0.02 g/100 g for fatty acids in milk 14 using MicroPhazir but without a rigorous evaluation of the limit of detection. A rigorous evaluation of the limit of detection has only been reported in one article, 12 being the limit of detection of 0.245 g/100 mL for the detection of fat in commercial milks.…”

QCM Sensor Arrays, Electroanalytical Techniques and NIR Spectroscopy Coupled to Multivariate Analysis for Quality Assessment of Food Products, Raw Materials, Ingredients and Foodborne Pathogen Detection: Challenges and Breakthroughs

“…Near infrared spectroscopy (NIR) is a rapid, non-invasive, and non-destructive technique that allows investigators to collect powerful analytical information from a sample. For these reasons, this analytical technique has been widely employed for food quality assessment at different production stages of several products, such as dairy products, juices, edible oils, fruits, seeds, and others [190][191][192][193][194]. However, this technique presents certain challenges, such as an incredible amount of molecular information, spectrum variations between samples, and overlapping spectral bands due to the presence of several components in the samples, as well as other problems [38].…”

Laser Fluorescence and Extinction Methods for Measuring the Flow and Composition of Milk in a Milking Machine

“…Most modern farms have only a flow meter installed in the milking machine, while the milk quality analyzer is a separate sample analyzer or samples are sent to specialized laboratories for quality analysis. Methods using NIR analyzers with more advanced data processing algorithms are being developed and improved [20][21][22]. So far, only one system is known that provides a simultaneous analysis of the quality and measurement of milk yield, including a combination of rather complicated devices in operation [23,24].…”