Citation: Ðor ¯ devi´ c, N.; Karabegovi´ c, I.; Cvetkovi´ c, D.; Šoji´ c, B.; Savi´ c, D.; Danilovi´ c, B. Assessment of Chitosan Coating Enriched with Free and Nanoencapsulated Satureja montana L. Essential Oil as a Novel Tool for Beef Preservation. Foods 2022, 11, 2733. https://doi.org/10.3390/foods11182733 Academic Editor: Mi-Jung Choi Received: 10 August 2022 Accepted: 31 August 2022 Published: 6 September 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). foods Article Assessment of Chitosan Coating Enriched with Free and Nanoencapsulated Satureja montana L. Essential Oil as a Novel Tool for Beef Preservation Natalija Ðor ¯ devi´ c 1 , Ivana Karabegovi´ c 1 , Dragoljub Cvetkovi´ c 2 , Branislav Šoji´ c 2 , Dragiša Savi´ c 1 and Bojana Danilovi´ c 1, * 1 Faculty of Technology, University of Niš, Bulevar Oslobo ¯ denja 124, 16000 Leskovac, Serbia 2 Faculty of Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia * Correspondence: bojana.danilovic@junis.ni.ac.rs Abstract: The effect of chitosan coating enriched with free and nanoencapsulated Satureja montana L. essential oil (EO) on microbial, antioxidant and sensory characteristics of beef was analyzed. Different concentrations of free Satureja montana L. EO (SMEO) and nanoparticles (CNPs) were added to chitosan coatings, namely 0.25%, 0.5% and 1%. The beef samples were immersed in the chitosan coatings and stored at +4 ◦ C for 20 days. In this period, the changes in pH value, total viable count (TVC), lactic acid bacteria, psychrophilic bacteria and Pseudomonas spp. were analyzed. The lipid oxidation of beef was determined by the TBAR assay, while sensory analysis was performed by means of the descriptive evaluation method. Generally, the influence of chitosan coating with CNPs on the growth of the tested microorganisms was more pronounced compared to SMEO. Treatment with coating enriched with 1% CNPs resulted in the reduction in TVC and Pseudomonas spp. by 2.4 and 3 log CFU/g, compared to the control, respectively. Additionally, all applied coatings with SMEO and CNPs resulted in the prolonged oxidative stability of the meat The addition of free SMEO created an unnatural aroma for the evaluators, while this odor was neutralized by nanoencapsulation. The durability of color, smell and general acceptability of beef was significantly increased by application of chitosane coatings with the addition of SMEO or SMEO-CNPs, compared to the control. This research indicates the potential application of enriched chitosan coatings in beef preservation in order to improve meat safety and prolong shelf-life. Keywords: nanoparticles; meat storage; meat safety; lipid oxidation; microbial stability 1. Introduction The preservation of highly perishable foods, including meat and meat products, is a persistent challenge for the industry [1]. In addition to the application of low temperatures, the most common preservation method in the meat industry is the use of synthetic preser- vatives, such as nitrite, benzoate, sulfite, sorbate, as well as synthetic phenolic compounds, which are known for their long-term and dangerous effects on consumers’ health [2]. On the other hand, many microorganisms have developed resistance to the action of the per- missible concentrations of synthetic preservatives [3]. For these reasons, there is a justified demand from consumers, as well as science and the meat industry, for screening and application of natural, safe and effective preservatives [4]. Chitosan has attracted special attention from researchers as a natural preservative due to its great potential for the maintenance of meat quality and safety [5–7]. Due to its natural origin and good antimicrobial and antioxidant potential, chitosan can be used in food biopreservation in the form of films and coatings [8]. Chitosan films and coatings can incorporate active components, such as plant essential oils (EOs), which can improve their biological activity. The EOs of most plants (oregano, cinnamon, clove, thyme) are categorized as Generally Recognized as Safe (GRAS) and effective in low concentrations [9]. Foods 2022, 11, 2733. https://doi.org/10.3390/foods11182733 https://www.mdpi.com/journal/foods