Heat treatment is applied to dairy products to ensure microbiological quality and increase the shelf life. However, a suitable control of this process is necessary to guarantee nutritional and sensory quality. The aim of this study is to adapt the high performance liquid chromatography (HPLC) method for determination of lactulose and lactose content in commercial samples of UHT and sweetened condensed milk. The HPLC method used showed a good resolution of the analytes evaluated. The analyzed UHT milk samples presented levels for lactulose in accordance with the limit recommended by the International Dairy Federation. There was no significant variation in lactulose concentration for sweetened condensed milk samples. However, one sweetened condensed milk sample showed lactose level lower than the established values (10–12%).

This study aimed to create a unique WPI film formulation that would help maintain strawberry quality. Therefore, an edible coating from WPI was developed, and its physical, mechanical, and rheological characteristics were analysed. WPI is a biopolymer residue with attractive barrier characteristics, biodegradability, and neutral taste that can be used as an edible coating on fragile fruits such as strawberries. Key innovations from this research include a comprehensive evaluation of whey as the sole polymeric component in edible coatings for strawberries, assessing its standalone protective potential; improvement of film formulation based on whey proportion; and an inferred shelf-life extension of whey-coated strawberries aligned with commercial acceptability standards, bridging the gap between research and practical application. This study showed that increasing protein proportion reduced the film’s solubility from 47.6% to 22.4%, thus enhancing its water resistance by up to 2-fold. Still, the film became tensile stiffer and more elastic modulus at 50% RH than at 70% RH. The filmogenic solution’s viscosity enhanced from 2.25 at 25 °C to 4.19 Pa.sn at 4 °C, indicating homogeneous coating of the fruit surface at room temperature and its adhesion at storage temperature. During cold storage, WPI coating reduced the mass loss of strawberries from a range of 5.83–16.71% in the control to a range of 2.56–13.22%, thus decreasing the mass loss by up to 2-fold compared to uncoated fruit from the control treatment, which resulted in better visual quality and a 33% extension of the shelf life of commercial strawberries. Overall, WPI films and coatings have the potential to offer a sustainable and effective protective layer for highly perishable and delicate fruits, extending shelf life and, consequently, reducing waste. Together, these properties can revolutionise the fresh produce industry to enhance global supply chain efficiency.

Food packaging generally consists of low-cost and non-degradable plastic materials that contribute to environmental pollution. For this reason, new food-packaging systems with good mechanical and barrier properties have been developed as an alternative to replace synthetic polymers used in food packaging. In this sense, this article briefly reviews the active packaging concept and the development of biodegradable films, edible coatings, and sachets used in food preservation. These technological innovations gained increasing importance in the food industry over the years, constituting a new paradigm in the industry, as they interact desirably with food, promoting various solutions such as: extending or maintaining the shelf life, monitoring or improving the quality and safety of food products. In addition, these innovative systems have aroused the interest of researchers for their ability to prevent deterioration and maintain the fresh aspect, firmness, and brightness of foods, making them more attractive to consumers. Several studies have shown that active packaging is an efficient system for preserving fruits and vegetables. The application of biodegradable films, edible coatings, and sachets was discussed in this work, showing the benefits of their use in various food products.