Influence of Glycerol and Tween on Yeast Films Functionalized with Cinnamon and Lavender Essential Oils  
1 Faculty of Food Science and Engineering, Bioaliment-TehnIA Research Platform, Dunarea de Jose University of Galati, 800201 Galati, Romania, [EMAIL_ADDRESS] (M.T. ); [EMAIL_ADDRESS] (I.A. ); [EMAIL_ADDRESS] (D.B. )2 Faculty of Engineering, Center of Excellence Polymer Processing, Dunarea de Jose University of Galati, 800201 Galati, Romania; [EMAIL_ADDRESS] (F.S. ); [EMAIL_ADDRESS] (C.F. )2  
2 Faculty of Engineering, Center of Excellence Polymer Processing, Dunarea de Jose University of Galati, 800201 Galati, Romania; [EMAIL_ADDRESS] (F.S. ); [EMAIL_ADDRESS] (C.F. )2  
2 Faculty of Engineering, Center of Excellence Polymer Processing, Dunarea de Jose University of Galati, 800201 Galati, Romania; [EMAIL_ADDRESS] (F.  
example essential oils (EOs), organic acids, and bacterioxins, which can provide antimicrobial and/or antioxidant effects by delivering high concentrations of active substances on food surface. Once the EF is applied to food, it remains on the food during the entire storage and disintegrates either before food consumption or during food mastication [1]. Different mechanisms have been identified for the film formation capacity of biopolymers, depending on the major component of the film-forming solution. For example, polysaccharides-based EFs (e.g., cellulose, chitosan, starch, alginate, or pectin) are mostly formed firstly by polymer breaking into segments, followed by their reformation into a film matrix or gel, while hydrogen bonding and ionic crosslinking are created through solvent evaporation [2]. For animal- or plant-sourced proteins (e.g., casein, whey proteins, collagen, myofibrillar proteins, egg white proteins, soy proteins, wheat gluten, and zein), other mechanisms are used for obtaining film-forming solutions, such as crosslinking through either enzymatic treatment (transglutaminase), chemical (e.g., glutaraldehyde and glyceraldehyde), or phisical treatments (heating, sonication, or irradiation). Protein EFs have good barrier properties to oxygen, carbon dioxide, and lipids, especially at reduced relative humidities, although they exhibit poor water barrier [3]. Compared to petrol-based or vegetable-based polymers, microbial biopolymers used for edible packaging are biodegradable, cost-effective, abundant, fully renewable, available throughout the year, and independent of the climatic conditions [4]. Moreover, most of them are recognised as food-grade in human nutrition. Examples of film packaging materials from microbial polymers [5; 6; 7] are yeast and fungal biomass, exopolymers like kefiran from kefir culture, bacterial cellulose, gellan, and levan, which are able to form films by themselves or used in combination (gellan and levan [8]; water kefir grains with yeast biomass [9]). _Saccharomyces_ yeast, widely used in the baking, brewery, and wine industries for their fermentative capacity, has other less traditional applications, including involvement in bioremediation, removal of heavy metals from waste waters, biocontrol in agriculture, and production of biofuel or pharmaceutical formulations. Studies have shown that incorporation of yeast into packaging materials contributes to the total antimicrobial activity of the packaging, enhance the total nutritional value and may serve as probiotics [10]. Very recently, yeast has gained attention as an innovative, promising edible packaging material due to the ability of yeast cytoplasmic proteins and cell walls' \(\beta\) (1-3)-glucans to connect directly through alkali-sensitive bonds, forming gels which can be casted into EFs and coatings [5]. The yeast EFs benefit from their low cost and abundancy as secondary products from biotechnological process like brewing processes or precision fermentation to obtain non-bovine casein [11; 12]. A supplyimentary advantage of using baker's yeast is its reduced volatiles compared to brewery yeast.