The affinity of aflatoxin M1 toward the main milk protein fractions in ewe and goat milk was investigated by using an ELISA. This study took into account the possible effects of common dairy processes such as ultrafiltration, acidic or rennet curding, and production of ricotta from acidic or rennet whey. Treatments that allowed the separation of casein from whey proteins under conditions that do not alter the physical or chemical status of the proteins (such as ultracentrifugation) were used as a reference. None of the treatments used in typical dairy processes caused significant release of the toxin, in spite of the relevant changes they induced in the interactions among proteins. Only the combined heat and acidic treatment used for production of ricotta cheese altered the structure of whey proteins to the point where they lost their ability to bind the toxin. This study also showed that, regardless of the physical state of the sample, a commercial electronic nose device, in combination with appropriate statistical tools, was able to discriminate among different levels of sample contamination.

The last 10 years of knowledge on near infrared (NIR) applications in the horticultural field are summarized. NIR spectroscopy is considered one of the most suitable technologies of investigation worldwide used as a nondestructive approach to monitoring raw materials and products in several fields. There are different types of approaches that can be employed for the study of key issues for horticultural products. In this paper, an update of the information collected from the main specific International Journals and Symposia was reported. Many papers showed the use of NIR spectroscopy in the horticultural field, and the literature data were grouped per year, per product, and per application, such as studies of direct (chemical composition) and indirect (physical and sensorial) properties (P), process control (PC), and authenticity and classification studies (AC). A mention was made of a recent innovative approach that considers the contribution of water absorption in the study of biological systems.

This review aims to update information on the use of near infrared (NIR) spectroscopy in identifying and quantifying the presence of adulterants and contaminants in milk and milk powder. Milk and milk products are recognised excellent sources of nutrition globally and are of great economic importance. In recent years, there have been a number of documented incidences of both deliberate adulteration and accidental contamination of foodstuffs. There is a clear need to detect these by a fast, accurate and non-destructive methodology. This has stimulated researchers to explore the possibility of applying NIR technology for their detection. NIR spectroscopy is a logical technique for use as it offers a rapid, low-cost and convenient analysis of key constituents. Fast responses are particularly important to industry, where an answer is needed within minutes. Most important, apart from its powerful prediction capability, the non-destructive nature of this technique is very useful for fast analysis in on-line and at-line inspections and authentication of food. NIR has the potential for detecting milk and milk powder adulteration by both economically motivated adulterants such as melamine as well as contaminants that may have been introduced unintentionally such as microorganisms. In comparison with mid-infrared and Raman, NIR spectroscopy allows the detection of contaminants and their quantification faster and with the same, or better, performances. Furthermore, NIR instrumentation is, in general, less sensitive to environmental conditions and is highly flexible. In particular, for the detection of a very low level of contamination, further investigations are warranted to identify the basis of the calibrations and test their performance when put into routine use. Consumers must have confidence in the analyses which ensure safe and genuine dairy products.

This work aimed to prove the feasibility of using near infrared (NIR) spectroscopy to detect vegetable proteins (soy, pea and wheat isolates) in milk powder. One hundred and fifty-five samples of genuine and adulterated milk powder (NIZO, Ede, The Netherlands) were analysed by NIR spectroscopy using an InfraAlyzer 500 (Bran+Luebbe). NIR spectra were collected at room temperature, and data were processed by Sesame Software (Bran+Luebbe) to select the most significant wavelengths. Calibrations were made on all samples in the range 0–5% of added vegetable proteins. Separate prediction and validation sets were prepared using samples not included in the calibration set. The best results were obtained by applying multiple linear regression (MLR) to the first derivative of absorbance values at five wavelengths. NIR spectroscopy proved a very effective tool for detecting the presence of vegetable proteins in milk powder on the basis of standard error of calibration ( SEC), standard error of prediction ( SEP) and standard error of validation ( SEV) values found in this study. The calibration carve was characterised by a regression coefficient ( R²) equal to 0.993 with a SEC of 0.20, a SEP of 0.23 and a SEV of 0.21.