Advances in Spray-Drying and Freeze-Drying Technologies for the Microencapsulation of Instant Tea and Herbal Powders: The Role of Wall Materials

The microencapsulation of tea and herbal extracts is gaining considerable attention in the food industry, particularly in the production of instant powders. This review examines the application of spray-drying and freeze-drying technologies for the encapsulation of bioactive compounds, focusing on the role of wall materials. Over the past two decades, carbohydrate-based (e.g., maltodextrin), gum-based (e.g., gum Arabic), and protein-based (e.g., whey protein isolate) materials have been widely used due to their impact on sensory properties, stability, protection of bioactive compounds, and other critical attributes of encapsulated products. Despite their widespread use, these materials have distinct advantages and limitations, such as cost, availability, and compatibility with different extracts. This review provides a comprehensive analysis of their physical and chemical properties, examines alternative and emerging wall materials (e.g., beta-cyclodextrin, sodium alginate, and inulin), and highlights the potential of combining different materials to optimise encapsulation outcomes. It also identifies current research gaps and future directions to improve the efficacy and quality of encapsulated tea and herbal powders.

Ultrashort-chain perfluoroalkyl substance trifluoroacetate (TFA) in beer and tea - An unintended aqueous extraction

Trifluoroacetate (TFA) is an ultrashort-chain perfluoroalkyl substance, which is ubiquitously present in the aqueous environment. Due to its high mobility, it accumulates in plant material. The study presented here shows for the first time that TFA is a widely spread contaminant in beer and tea / herbal infusions. In 104beer samples from 23countries, TFA was detected up to 51 µg/L with a median concentration of 6.1 µg/L. An indicative brewing test and a correlation approach with potassium (K) indicate that the main source of TFA in beer is most likely the applied malt. It could be proven that the impact of the applied water is negligible in terms of TFA, which was supported by the analysis of numerous tap water samples from different countries. The unintended extraction of TFA was also demonstrated for tea / herbal infusions with a median concentration of 2.4 µg/L.