Nanobubble (NB) technologies have received considerable attention for various applications due to their low cost, eco-friendliness, scale-up potential, process control, and unique physical characteristics. NB stands for nanoscopic gaseous cavities, typically <1 μm in diameter. NBs can exist on surfaces (surface or interfacial NBs) and be dispersed in a bulk liquid phase (bulk NBs). Compared to the microbubbles, NBs exhibit high specific surface area, negative surface charge, and better adsorption. Bulk NBs can be generated by hydrodynamic/acoustic cavitation, electrolysis, water-solvent mixing, nano-membrane filtration, and so on. NBs exhibit extraordinary longevity compared to microbubbles, prompting the interest of the scientific community aiming for potential applications including medicine, agriculture, food, wastewater treatment, surface cleaning, and so on. Based on the limited amount of research work available regarding the influence of NBs on food matrices, further research, however, needs to be done to provide more insights into its applications in food industries. This review provides an overview of the generation methods for NBs, techniques to evaluate them, and a discussion of their stability and several applications in various fields of science were discussed. However, recent studies have revealed that, despite the many benefits of NB technologies, several NB generating approaches are still limited in their application in specific agro-food industries. Further study should focus on process optimization, integrating various NB generation techniques/combining with other emerging technologies in order to achieve rapid technical progress and industrialization of NB-based technologies.

Because of their high protein and low lactose content, milk protein concentrates (MPC) are typically used in the formulation of ready-to-drink beverages. Calcium-mediated aggregation of proteins during storage is one of the main reasons for loss of storage stability of these beverages. Control and calcium-reduced MPC [20% calcium-reduced (MPC-20) and 30% calcium-reduced (MPC-30)] were used to evaluate the physicochemical properties in this study. This study was conducted in 2 phases. In phase I, 8% protein solutions were prepared by reconstituting the 3 MPC and adjusting the pH to 7. These solutions were divided into 3 equal parts, 0, 0.15, or 0.25% sodium hexametaphosphate (SHMP) was added, and the solutions were homogenized. In phase II, enteral dairy beverage formulations containing MPC and a mixture of gums, maltodextrin, and sugar were evaluated following the same procedure used in phase I. In both phases, heat stability, apparent viscosity, and particle size were compared before and after heat treatment at 140°C for 15 s. In the absence of SHMP, MPC-20 and MPC-30 exhibited the highest heat coagulation time at 30.9 and 32.8 min, respectively, compared with the control (20.9 min). In phase II, without any addition of SHMP, MPC-20 exhibited the highest heat coagulation time of 9.3 min compared with 7.1 min for control and 6.2 min for MPC-30. An increase in apparent viscosity and a decrease in particle size of reconstituted MPC solutions in phases I and II with an increase in SHMP concentration was attributed to casein micelle dissociation caused by calcium chelation. This study highlights the potential for application of calcium-reduced MPC in dairy-based ready-to-drink and enteral nutrition beverage formulations to improve their heat stability.

Current methods for lactose measurement in dairy products are time consuming and tedious and may require expensive equipment and skilled technicians. The aim of this research was to develop a novel and rapid method for the routine measurement of lactose in dairy products. The proposed method is based on the rapid hydrolysis of lactose using β-galactosidase and subsequently measuring glucose using a blood glucose meter. Blood glucose meters were developed after decades of research and clinical trials and are used extensively worldwide by individuals with diabetes to monitor their blood glucose levels. The method was developed and validated in a series of experiments. In the first experiment, temperature and time required for the near-complete hydrolysis of lactose were determined. Subsequently, the influence of glucose meters and their test strip lots were evaluated. We found that meters were not significantly different. However, the test strip lots were significantly different from each other. In the second experiment, the proposed method was validated using different concentrations of lactose solutions (1.9-6.5%) and compared with a HPLC-based reference method. In the third experiment, the proposed method was used to determine the lactose content of raw milk. The proposed method shows potential for rapid, routine, and low-cost measurement of lactose in milk and other dairy products.

Consumer focus on health and wellness is driving the growth in high-protein dairy beverages. The review discusses shelf-stable ready-to-drink beverages that are primarily dominated by sports nutrition and the "better for you" beverage categories. Both of these categories tend to have a "high in protein" claim. Because of their functionality, sensorial attributes, and protein quality, dairy protein ingredients are the ingredients of choice to meet protein claims. Due to the higher protein content of the beverages, the functionality of dairy protein ingredients plays a critical role in final product quality and stability. In the United States, Food and Drug Administration regulations classify shelf-stable foods into acid/acidified and low-acid foods. The differentiation is based on pH and water activity (a_w). In the context of shelf-stable high-protein dairy beverages, any beverage with a_w of >0.85 and with a finished equilibrium pH of >4.6 is classified as low acid. Beverages to which acids or acid foods are added and have a finished equilibrium pH of ≤4.6 and a_w >0.85 are classified as acidified food. Acid foods have a natural pH of ≤4.6. The final pH requirement of these shelf-stable products will affect the type of dairy protein used in these applications. In acidified dairy protein beverages, the go-to ingredient is whey protein. In low-acid beverages, the protein ingredients of choice are milk protein ingredients (with a casein-to-whey protein ratio of 80:20, as found in typical bovine milk) and casein-enriched ingredients. Rendering the product shelf-stable depends on whether the product is classified as acidified or low acid. Low-acid, shelf-stable beverages, in general, have 2 manufacturing options: retort and UHT processing, followed by hermetic sealing. Pasteurization is the standard processing choice for shelf-stable acidified beverages, followed by hot fill. Because of differences in pH and heat loads during the manufacture of high-protein dairy beverages, the functionality of protein ingredients will play an essential role in determining the final beverage quality. Two of the most important functional properties of dairy protein ingredients that have a role in producing these beverages are solubility and heat stability. This review elucidates the physicochemical properties of dairy protein ingredients for low- and high-acid shelf-stable dairy protein applications, analytical techniques to characterize protein ingredients, beverage processing conditions, and quality defects observed.