The antimicrobial activity of essential oils components (EOCs) is well-known. However, their high volatility and powerful aroma limit their application in the formulation of a wide range of food products. In this context, the antimicrobial activity of carvacrol, eugenol, thymol and vanillin grafted onto the surface of three silica supports with different morphologies, textural properties and chemical reactivities (fumed silica, amorphous silica and MCM-41) was evaluated herein. Materials characterization revealed a good immobilization yield and all the devices showed a micro-scale particle size. Sensory evaluation revealed that sensory perception of EOCs decreases after covalent immobilization. Moreover, immobilization greatly enhanced the antimicrobial activity of the essential oil components against Listeria innocua and Escherichia coli compared to free components. The incorporation of EOCs immobilized on silica particles into pasteurized milk inoculated with L. innocua demonstrated their effectiveness not only for in vitro conditions, but also in a real food system.

Alkalization, also known as “Dutching,” is an optional, but very useful, step taken in the production chain of cocoa to darken its color, modify its taste, and increase natural cocoa solubility. Over the years, various attempts have been made to design new and more effective alkalization methods. Moreover, different authors have attempted to elucidate the impact of alkalization on the physicochemical, nutritional, functional, microbiological, and sensory characteristics of alkalized cocoa. The aim of this review is to provide a clear guide about not only the conditions that can be applied to alkalize cocoa, but also the reported effects of alkalization on the nutritional, functional, microbiological, and sensory characteristics of cocoa. The first part of this review describes different cocoa alkalization systems and how they can be tuned to induce specific changes in cocoa properties. The second part is a holistic analysis of the effects of the alkalization process on different cocoa features, performed by emphasizing the biochemistry behind all these transformations.