Background: The modern Western lifestyle is characterized by the consumption of high-heat-treated foods because of their characteristic taste and flavor. However, it has been shown that treating food at high temperatures can generate potentially harmful compounds that promote inflammation and cardiovascular disease in subjects with diabetes.

The cheese industry faces many challenges to optimize cheese yield and quality. A very precise standardization of the cheese milk is needed, which is achieved by a fine control of the process and milk composition. Thorough analysis of protein composition is important to determine the amount of protein that will be retained in the curd or lost in the whey. The fluorescence-based Amaltheys analyzer (Spectralys Innovation, Romainville, France) was developed to assess pH 4.6-soluble heat-sensitive whey proteins (sWP*) in 5 min. These proteins are those that can be denatured upon heat-treatment and further retained in the curd after coagulation. Monitoring of sWP* in milk and subsequent adaptation of the process is a reliable solution to achieve stable cheese yield and quality. Performance of the method was evaluated by an accredited laboratory on a 0 to 7 g/L range. Accuracy compared with the reference Kjeldahl method is also provided with a standard error of 0.25 g/L. Finally, a 4-mo industrial trial in a cheese plant is described, where Amaltheys was used as a process analytical technology to monitor sWP* content in ingredients and final cheese milk. Calibration models over quality parameters of final cheese were also built from near-infrared and fluorescence spectroscopic data. The Amaltheys analyzer was found to be a rapid, compact, and accurate device to help implementation of standardization procedures in the dairy industry.

Infant formulas are designed to reach a high standard quality and meet infant physiological needs when breastfeeding is not possible. Whereas nutritional composition is strictly regulated, no specification on manufacturing process is provided, nor quality indicators to control final quality. However, due to the highly reactive ingredients composing the recipe, heat treatment operations may impact the final nutritional and functional quality of the product, namely through heat protein denaturation and Maillard reaction. Non-casein nitrogen content, furosine and carboxymethyllysine concentrations are the most common indicators measured to control these reactions, but they are too time consuming and expensive to allow routine control at production level. The FAST method is a rapid and simple way to monitor at-line both the % of whey protein denaturation and the intensity of advanced Maillard reaction. In this paper, we present the technique as well as its validation procedure by comparison with other reference or recognized techniques. On one hand, fluorescence of pH 4.6 soluble whey proteins (excitation/ emission 280/340 nm) is indicative of the protein fraction that becomes denatured in proportion to the time-temperature applied, and well correlated to the reference Kjeldahl method. On the other hand, fluorescence of advanced Maillard products (excitation/emission 340/430 nm) increases during heat treatment and is correlated with carboxymethyllysine in model infant formulas. In addition, light scattering of the solubilized powder at 280 nm is measured as an indicator of particle aggregates (PAD). Analyses are achieved within 5 min thanks to the specific analyzer Amaltheys® and sample preparation kit. Study of 24 commercial infant formulas allowed characterization of infant formulas groups with different grades of quality, including dispersibility and Maillard reaction. Amaltheys indicator strongly contributed to products discrimination.