![]() These samples consisted of 5 batches of 8 combinations of two cheese ages, two mixing speeds, and two holding times. Essential properties, such as texture profile, rheological properties, and particle size were analyzed by textural profile analyzer (TPA), dynamic stress rheometer (DSR), and dynamic light scattering analyzer, respectively, on 40 process cheese samples produced at the K-State Dairy Products Lab. ![]() Fluorescence spectroscopy and near infrared, as rapid and noninvasive techniques, are suitable for on-line measurement of the key emulsion attributes. However, this is difficult for process cheese manufacturers as they are dealt with varying natural cheese depending on the availability. These properties vary from product to product, and are crucial to maintain in order to ensure consistent quality. ![]() Emulsion characteristics are the functional properties of process cheese in specific applications, and can be assessed through texture, fat droplet size, viscoelasticity, and other attributes related to its performance in final products. In another study, fluorescence spectroscopy was used to predict the emulsion characteristics of process cheese made by bench-top Thermomix™. The fluorescence-based classification models can provide a rapid tool for industry to quickly determine the quality of processed milk powders. The highest classification accuracy was observed for random forest at 87% success rate. Classification models were constructed using partial least square discriminant analysis (PLSDA), random forest (RF), and forward selection quadratic discriminant analysis (FS-QDA), and models were validated by bootstrapping techniques. To enhance the fluorescence signal, pre-treatment steps included autoclaving, acidification, and centrifugation to extract the available DPA from spores present in the reconstituted NDM at 10% concentration. The results ranged from 1.7 to 5.0 log CFU/g NDM. Traditional plating methods were performed to obtain the reference values of spore count. In this study, a total of 40 NDM samples were procured from commercial sources. ![]() Fluorescence spectroscopy, due to its high specificity and accuracy, can target dipicolinic acid (DPA), which is an intrinsic fluorescent compound in spores, to predict the spore level in contaminated powders. Current spore enumeration methods are either time-consuming, labor intensive, or expensive, and thus are often not practical in common production facilities. Powder manufacturers need to monitor the spore level throughout production and cease processing in the case of intolerable contamination caused by biofilm attachment and development on the equipment. Some thermophilic and mesophilic spores can survive severe heat treatment, leading to problems in food products that uses NDM as an ingredient. Spore contamination is one of the major quality concerns in nonfat dry milk (NDM). ![]()
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