Role of Oregano (Origanum vulgare) Essential Oil as a Surface Fungus Inhibitor on Fermented Sausages: Evaluation of Its Effect on Microbial and Physicochemical Characteristics

Abstract

Oregano essential oil (OEO) was evaluated to determine its effect on the growth of natural contaminating molds on the surface of Spanish fermented sausage, the development of the internal microbial population of the sausage, and the physicochemical properties of the sausage. Results indicated a dramatic reduction in the contaminant molds. At the end of ripening, the main endogenous fungal species in control samples were Mucor racemosus (55%), Aspergillus fumigatus (20.6%), Cladosporium sphaerospermum (11.1%), Acremonium strictum (7.9%), and Aspergillus niger (4.7%). In samples treated with OEO, M. racemosus and A. fumigatus were the only species isolated; the treatment was more effective against A. fumigatus than against M. racemosus. The use of OEO to inhibit surface fungi did not affect the sausage drying process, pH, water activity, or color changes during ripening. These parameters change in a typical pattern for fermented dry-cured sausages during ripening. At the end of ripening, OEO-treated sausages had lower hardness and greater chewiness than the control but showed similar textural properties to sausages treated with potassium sorbate.

Antifungal Activity of Propolis, Thyme Essential Oil and Hydrosol on Natural Mycobiota of Sucuk, a Turkish Fermented Sausage: Monitoring of Their Effects on Microbiological, Color and Aroma Properties

“…The microbiota of sucuk is influenced by meat, spices and other additives used in production, as well as fermentation conditions including chamber properties, temperature and humidity (Chaves‐López et al . ). Therefore, the production of standard sucuk is challenging in general.…”

Effect of chitosan–essential oil, a surface mold inhibitor, on microbiological and physicochemical characteristics of semidried fermented sausages

“…The effect of the antifungal treatment on LAB count was not significant ( P > 0.01). Similarly, several researchers reported that treating sausages with EOs had no negative effect on LAB counts (Chaves‐López et al., 2012; El Adab & Hassouna, 2016; Ozturk, 2015). Survival of LAB in the presence of EOs with antimicrobial properties is related to their ability to produce Adenosine triphosphate (ATP) and to deal with osmotic stress conditions (Holley & Patel, 2005).…”

“…In addition to surface applications, it has been shown that direct addition of 0.75 mg/g Ocimum basilicum into Italian‐type sausages did not cause any variation in Micrococcaceae counts (Gaio et al., 2015). Many studies verified that both the superficial applications of EOs such as oregano (Chaves‐López et al., 2012) and direct addition of oregano and thyme EOs (El Adab & Hassouna, 2016) had no effect on the natural microbiota of the fermented sausages.…”

“…Chaves‐López et al. (2012) showed that dipping sausages into oregano EO resulted in slight but not significant decreases of mold‐yeast counts on the casing.…”

“…Development of natural antifungals is crucial for the meat industry. Several studies have investigated the beneficial effects of chitosan and EOs, either individually (Arslan & Soyer 2018, Chaves‐López et al., 2012) or in combination (Krkić et al., 2012; 2013), on microbial growth inhibition and lipid oxidation in fermented sausages. Recently, researchers have investigated the use of chitosan in different types of sausages (cooked, fermented, or raw) with distinct purposes.…”