**1. Introduction**

Food packaging is designed to protect food from external factors, such as temperature, light or humidity that can lead to degradation [1]. Moreover, packages also protect its content from other environmental influences, namely, odors, microorganisms, shocks, dust, vibrations and compressive forces [1].

The production and application of synthetic materials in food packaging has grown quickly over the past few decades, resulting in serious environmental concerns due to the resistance to degradation of these synthetic materials [2,3]. In recent years, the replacement of synthetic plastics by natural polymers in packaging materials has been an intense research field [3,4]. Particularly, bio-based natural polymers (mainly polysaccharides and proteins) have been given increasing attention to be used in food packaging films because of their abundance, biodegradability, biocompatibility, and non-toxicity [3,4]. However, natural polysaccharides have their weak points in making hydrophobic films because most of them are hydrophilic and water absorbing, resulting in rapid solubilization in aqueous environments [5].

Protein-based films have several advantages over other types of edible materials. Proteins are constructed of nearly 20 different amino acids, and usually have good film forming capability [6]. Moreover, protein-based films are generally good gas barriers, possess good mechanical properties, and can also be regarded as nutrients [6].

Zein, a by-product obtained from corn starch processing, is prepared from corn protein flour. Zein is particularly rich in hydrophobic and neutral amino acids as well as some sulfur-containing amino acids, but lacks polar or ionizable amino acids [7]. Due to its large number of hydrophobic groups, zein is soluble in aqueous ethanol, yet insoluble in pure water. Since it possesses well-known film-forming ability caused by its unique amino acid composition, it is widely used in food packaging materials [7]. Pure zein films have good water barrier properties, but their mechanical properties are relatively poor. In order to overcome these deficiencies, blend zein films with other biodegradable biopolymers has been widely studied, and the zein provided good potential to produce blend films [7].

Superhydrophobic surfaces are used by several living organisms, both animals and plants. The most famous case from the plant kingdom (*Plantae*) is the lotus leaf (*Nelumbo nucifera*) [8]. The extreme water repellency of lotus leaves stems from the combination of low surface energy with the hierarchical topology present on the leaf surface [9]. Water droplets roll freely on these surfaces and remove dirt, keeping the leaves clean, even in the muddy waters where these plants tend to grow [9]. This extreme water repellency and self-cleaning performance of the lotus leaf is usually known as the "lotus effect" [10]. Recently, researchers have focused on recreating these surfaces, structured at the micro and nanometric scale, with new functionalities, replicating or mimicking the hierarchical surface morphology of the lotus leaf [11].

Licorice (*Glycyrrhiza glabra* L.) is a plant belonging to the *Fabaceae* family. Its sweet flavor makes it a popular ingredient in the production of candies and sweets in Europe [12]. The antioxidant and antibacterial properties of the licorice essential oil (EO) have already been demonstrated, together with its incorporation on carboxymethyl xylan films with potential to be used as novel food packaging materials [13].

Therefore, the aim of this work was to develop hydrophobic zein-based films incorporating licorice EO while biomimicking the lotus leaf surface, which is the innovation of this work. The films obtained were then characterized, and their bioactive properties evaluated.
