Spice essential oils as natural preservatives in processed sausages: a systematic review of their physicochemical, antimicrobial, antioxidant, and sensory effects

Abstract

Objective

The increasing demand for natural, safe, and high-quality meat products has prompted interest in replacing synthetic preservatives with plant-based alternatives. This systematic review aimed to evaluate the effects of spice essential oils (SEOs) on the physicochemical, antimicrobial, antioxidant, and sensory properties of processed sausages.

Methods

Following PRISMA guidelines, a comprehensive literature search was conducted in English databases from November 2007 to September 2025 and 54 relevant articles were selected based on predefined inclusion criteria.

Results

The reviewed studies demonstrated that SEOs significantly improved the oxidative stability, microbial safety, and sensory quality of sausages. These essential oils can regulated pH and water activity during storage.

Conclusion

SEOs represent effective natural preservatives that can enhance the safety, stability, and sensory acceptability of processed sausages. Optimizing their concentration and application methods, alongside synergistic combinations with natural extracts or reduced nitrite levels, can provide a promising strategy for producing healthier meat products.

Highlights

• •Spice essential oils (SEOs) significantly improve microbial safety and oxidative stability in processed sausages.
• •Using appropriate concentrations of SEOs such as thyme, oregano, clove, and rosemary enhance shelf life while maintaining sensory quality.
• •Optimal SEO concentrations provide natural preservation without adverse flavor or texture changes.
• •Combined use of SEOs and reduced nitrite levels can replace synthetic preservatives effectively.
• •Encapsulation and bioactive film technologies improve stability and controlled release of SEOs in sausages.

1. Introduction

Meat and meat products are among the main and vital sources of protein in the human diet. However, these products are perishable, especially against lipid oxidation and the growth of spoilage microorganisms, has created serious challenges in maintaining their quality, safety and shelf life (Brannan, 2009; No et al., 2007). Producing healthier meat products, especially fresh and fermented sausages, has received more attention in recent years due to the connection between nutrition and health (Siró et al., 2008). While fermented sausages have a higher microbiological safety because of controlled fermentation and a lower pH, fresh sausages are more vulnerable to microbial spoiling because of their high pH and water activity and are typically made without the use of chemical preservatives (Carballo et al., 2019).

Growing consumer desire for natural and nutrient-dense products has led to a rise in the usage of n-3 polyunsaturated fatty acid molecules, such as DHA and EPA (found in foods like fish oil and flaxseed), in meat products. Despite their high nutritional value, these chemicals can oxidize, which can degrade the product's sensory quality during storage (Gonzalez-Esquerra & Leeson, 2001; Rahiminiat et al., 2017). On the other hand, microbial growth, especially lactic acid bacteria (LAB), plays a significant role in determining the shelf life of meat products (Borch et al., 1996). Among these, concerns arising from the use of chemical preservatives are limiting factors in the safe and high-quality production of meat products (Berni et al., 2017; Domínguez et al., 2016). Therefore, the development and use of new processing technologies, natural additives, and advanced packaging systems are top priorities in the meat products industry (Dave & Ghaly, 2011).

Nitrites and nitrates are commonly used in processed meat products to control microbes, stabilize color, enhance flavor, and prevent lipid oxidation. However, their consumption has been associated with the formation of N-nitrosamine compounds, which have known carcinogenic and toxic effects (Honikel, 2008). Increasing health concerns and consumer demand for “clean label” products have led to increased efforts to reduce or replace synthetic nitrites (Ukuku et al., 2016). Two main strategies have been investigated for this purpose: replacing nitrite with safer compounds and using nitrosamine inhibitors. Plant extracts rich in phenolic compounds, such as flavonoids, are considered as suitable natural alternatives; because they maintain the quality and safety of meat products and have antioxidant and antimicrobial properties, as well as other positive health effects (Oussalah et al., 2006; Ukuku et al., 2016). Additionally, the use of nitrate-rich plant extracts that are converted to nitrites during the curing process is consistent with the “clean label” trend and maintains product quality and safety (Ko et al., 2017).

Terpenes, terpenoids, phenylpropenes, and phenolic compounds are just a few of the many bioactive compounds found in essential oils (EOs), which are volatile, complex, and natural substances that are derived from different portions of aromatic plants (Ayala-Zavala et al., 2008; Bakkali et al., 2008). In addition to their use as natural flavorings, these compounds attracted the attention of researchers and the food industry because of their antibacterial, antifungal, antioxidant, anti-inflammatory, anticancer, and antimutagenic qualities (Khader et al., 2010; Liu et al., 2009; Madhuri & Pandey, 2009; Namsa et al., 2009). EOs have been shown in numerous laboratory and epidemiological investigations to suppress the growth of a variety of spoilage and pathogenic microorganisms, including as Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli O157:H7 (Burt, 2004; Murbach Teles Andrade et al., 2014; Silveira et al., 2012).

Despite their potential, the industrial application of EOs in food formulations faces challenges. These include decreased effectiveness in food matrices due to interactions with substances such as proteins and fats, the requirement for higher concentrations to achieve comparable effects in a laboratory setting, resulting in adverse sensory changes, and the sensitivity and volatility of these substances to oxidation and heat (Burt, 2004; Lis-Balchin et al., 1998). Strategies like the use of flavoring herbs and technology like encapsulation have been proposed to improve stability, release control, and sensory compatibility in order to get around these restrictions (Araújo et al., 2018).

EOs are a potential and dependable substitute for synthetic preservatives, particularly in perishable foods like meat and meat products, thanks to growing consumer awareness of the advantages of natural products and scientific data showing their beneficial effects on human health (Gutierrez et al., 2009). Given the growing consumption of meat products like sausages and the high demand for the use of natural compounds as new food preservatives to prevent spoilage and disease instead of chemical preservatives, the aim of the present study was to determine the effect of spice essential oils (SEOs) as natural and safe preservatives on the shelf life of processed sausages through a systematic review.

2. Methods

2.1. Search strategy

This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. To find published articles investigating the impact of SEOs on the physicochemical, antioxidant, microbial and sensory properties of processed sausages, a comprehensive search of English and Persian-language databases was conducted without language restrictions using relevant keywords. Three researchers (A.A., N.M. and S.E.) conducted the searches separately, and a fourth researcher (S·S.) was consulted in case of disagreement. This systematic search was conducted in Medline, Embase, Web of Science, Google Scholar, Pubmed, Science Direct, Scopus, Magiran, SID, ISC and Cochrane databases from November 2007 to September 2025 based on the following search strategy:

((“sausage” OR “processed sausage” OR “processed meat” OR “cured meat” OR “frankfurter” OR “salami” OR “bologna”) AND (“essential oil” OR “EO” OR “volatile oil” OR “plant extract” OR “spice” OR “spice essential oil” OR “herb” OR oregano OR thyme OR clove OR cinnamon OR rosemary OR sage OR coriander OR cumin OR garlic OR ginger) AND (“shelf life” OR preserv* OR spoilage OR rancidity OR “lipid oxidation” OR “oxidative stability” OR “antimicrobial” OR “microbial stability” OR “food quality”))

2.2. Screening and selection

The results were limited to animal studies with experimental designs aimed at determining the effect of SEOs on the shelf life of processed sausages. Exclusion criteria included: review articles, theses, case reports, letters to the editor, abstracts of congress articles, books, non-English language articles, studies that did not include sausage-type meat products, studies that used plant extracts without EOs, and those that included non-food applications of essential oils were excluded from this systematic review, and finally, studies were limited to purpose-based articles. Also, the references of all articles were reviewed and those that were relevant to the purpose of the present study were selected. Then, the titles and abstracts of the articles in the reviewed databases were entered into the Endnote software. The initial review of the articles was conducted by two researchers (A.A. and N.M.) independently, based on the aforementioned criteria, and in case of disagreement, a third person (S.S.) was consulted.

2.3. Data extraction

Data were extracted using a standardized form, including: author, year, country, type of sausage, essential oil type and concentration, processing/storage conditions, control treatments, shelf-life outcomes measured (microbiological, oxidative, sensory, physicochemical), and main findings.

2.4. Results

Based on the database search up to September 2025, 168 articles were retrieved and reviewed by the researchers. After reviewing the titles, 83 articles were identified and entered the qualitative evaluation stage of the abstracts. Finally, 54 articles were selected and included in this systematic review (Fig. 1).

Fig. 1.

Diagram illustrating the included studies, detailing the processes of identification, screening, eligibility assessment and final studies.

3. Result & discussion

A summary of the information extracted from the articles is given in Table 1. The findings of the selected articles are presented separately for physicochemical, antimicrobial, antioxidant, and sensory properties.

Table 1.

Summary of studies investigating the effects of SEOs on the shelf life of processed sausages.

Type of EO(s)	Conc.	Type of sausage	Effect(s)	Reference
Oregano oil	Not mentioned	Harbin red sausage	•Antioxidant activity •Antimicrobial activity •Decrease in pH •Desirable sensory properties	(Yin et al., 2025)
Thyme oil	3.5, 7.5 and 10% w/w	Fresh pork sausage	•Antioxidant activity •Antimicrobial activity •Thermal stability •Increase in the a* parameter (redness)	(Souza et al., 2025)
Thyme oil, Oregano oil and Clove oil	40–60 μg/kg	Chicken sausage	•Antimicrobial activity •Desirable sensory properties	(Proaño et al., 2025)
Cinnamon oil and Clove oil	Various encapsulated concentrations	Fresh sausage	•Antioxidant activity •Antimicrobial activity	(Sirena et al., 2024)
Origanum oil, Satureja hortensis oil, Satureja montana oil and their mixtures	0.05 and 0.15 μL/g	Fresh turkey sausages	•Antioxidant activity •Antimicrobial activity •Reduction in the formation and accumulation of BAs	(Šojić et al., 2023)
Rosemary oil, Thyme oil and Oregano oil and an Acorn extract	1, 5, 10, 15, 20, 25, 50, 100, 250, 500, 750 and 1000 μL/mL	Dry-cured sausage-based agar	•Antifungal activity •Controlling the production of Ochratoxin A	(Roncero et al., 2023)
Rosemary oil	120 ppm	Sausage from broilers fed different levels of thymus essential oil and rapeseed oil	•Increased water holding capacity and pH •Reducing lipid oxidation •Increasing pH	(Abbasi et al., 2023)
Caraway oil	0.01, 0.05 and 0.1 μL/g	Dry-fermented sausage	•Antioxidant activity •Antimicrobial activity •Desirable sensory properties	(Tomović et al., 2022)
Zanthoxylum bungeanum oil	0.08 g in microcapsules	Chinese-style sausage	•Antioxidant activity •Improving texture and color properties	(Meng et al., 2022)
Cinnamon oil and Clove oil	0.05% w/w	Low-salt sausages	•Antimicrobial activity •Accelerate the lipid and protein oxidation	(Xiao et al., 2021)
Sage oil	0, 0.05 and 0.1 μL/g	Dry fermented sausages	•Antioxidant activity •Antimicrobial activity •Desirable sensory properties •No negative impact on pH, color and texture	(Šojić et al., 2021)
Oregano oil	100 mg/kg	Fermented cooked sausage	•Physicochemical stability •Sensory acceptance	(Ozaki et al., 2021)
Thyme oil	0.05%, 0.0095% and 0.00095% w/w	Meat sausage	•Antimicrobial activity •Good sensory acceptance	(Lages et al., 2021)
Thyme oil	Not mentioned	Smoked horse meat sausage	•Antimicrobial activity •Prevent formation of BAs	(Huang et al., 2021)
Cinnamon oil	1% and 2% w/w	Oriental sausage	•Antimicrobial activity •Minimize chemical changes	(El Bayomi et al., 2021)
Ziziphora Clinopodioides oil	0, 0.1% and 0.3% w/w	Balkan-style fresh sausage	•Increasing shelf life •Antimicrobial activity •Desirable sensory properties	(Ajourloo et al., 2021)
Juniperus communis oil	0.01–0.1 μL/g	Dry fermented sausage	•Antioxidant activity •Antimicrobial activity •Desirable sensory properties	(Tomović et al., 2020)
Basil oil and Caraway oil	0.7, 1.5 and 4.5 μL/mL	Smoked fermented sausage	•Antifungal activity	(Kocić-Tanackov et al., 2020)
Garlic oil	2% v/v	Vacuum-packed sausage	•Antioxidant activity •Antimicrobial activity •Desirable sensory properties	(Esmaeili et al., 2020)
Oregano oil and Rosemary oil	0.05%, 0.1%, 0.2% and 0.4% w/w	Refrigerated vacuum packed Tuscan sausage	•Increasing shelf life •No color changes	(Badia et al., 2020)
Thymbra spicata oil	300 and 500 ppm	Turkish dry fermented sausage	•Antimicrobial activity •Inverse relationship between consumer acceptance and EO concentration	(Al & Yildirim, 2020)
Shirazi thyme oil	20% and 40% in nanocapsules	Sausage	•Antioxidant activity •Antimicrobial activity •No adverse impact on color and sensory properties	(Vafania et al., 2019)
Winter savory (Satureja montana L.) oil	0.075 and 0.15 μL/g	Fresh pork sausages	•Antioxidant activity •Antimicrobial activity •Strong sensory effects	(Šojić, Pavlić, Tomović, et al., 2019)
Coriander oil	0, 0.075, 0.1, 0.125 and 0.15 μL/g	Cooked pork sausages	•Antioxidant activity •Antimicrobial activity •Provide higher redness of sausage	(Šojić, Pavlić, Ikonić, et al., 2019)
Clove oil, Holybasil oil, Thyme oil and Cassia oil	0.25 and 0.125% w/w	Fresh chicken sausage	•Antioxidant activity •Antimicrobial activity •Decrease all sensory •Attributes after 5 days	(Sharma et al., 2019)
Tarragon oil	0.1% v/w	Frankfurter	•No change in the odor, color intensity, and hardness •Decrease the flavor and overall acceptability	(Kirkin et al., 2019)
Zataria multiflora Boiss oil	1 mL/kg	Balkan-style fresh sausage	•Not significant antimicrobial effect •Production of BAs during fermentation	(Carballo et al., 2019)
Cinnamon oil, Clove oil, and Anise oil	0.3 g/kg	Harbin dry sausage	•Antioxidant activity •Antimicrobial activity •inhibition effects on BAs •Improve the sensory quality	(Sun et al., 2018)
Thyme oil and Rosemary oil	0.2, 0.5, 0.8 and 1% w/w	Turkish fermented sausage (sucuk)	•Antimicrobial activity •Antifungal activity •Not negative effect on the physicochemical, color, and sensory properties	(Soncu et al., 2018)
Clove oil, Holybasil oil, Thyme oil, Cassia oil, Ajowan oil and Beetel oil	0.25 and 0.125% w/w	emulsion-based (ready-to-eat) chicken sausage	•Antioxidant activity •Antimicrobial activity •Decrease in pH	(Sharma et al., 2018)
Cinnamon oil, Caraway oil, Citron oil and Clove oil	0.5% v/v	Vacuum-Packed Cooked Cured Sausage	•Antimicrobial activity	(Khorsandi et al., 2018)
Garlic oil	0.00625 μL/mL	Fresh sausage	•Antimicrobial activity •Acceptable sensory parameters •Maintain the red color and pH	(Araújo et al., 2018)
Cinnamon oil	0.2 and 0.4% v/w	Cooked Lyoner-type sausage	•Antioxidant activity •Antimicrobial activity •Desirable sensory properties •Improve odor and color	(Aminzare et al., 2018)
Clove oil	1% w/w	Sausage	•Antioxidant activity •No significant variations in pH and aw •Not significant effect on the sensory quality	(Ugalde et al., 2017)
Clove oil, Holybasil oil, Thyme oil and Cassia oil	0.25%, 0.125%,0.25% and 0.125% w/w, respectively	Fresh chicken sausages	•Antioxidant activity •Antimicrobial activity •Decrease all sensory attributes after 5 days	(Sharma et al., 2017)
Basil oil, Bay oil, Black pepper oil, Cinnamon oil, Cumin oil, Garlic oil, Nutmeg oil, Oregano oil, Parsley oil, Rosemary oil, Tarragon oil and Thyme oil	0.005% and 0.05% w/w	Dry cured sausage	•Antimicrobial activity but with sensory limitations that does not allow its use in high concentrations	(García-Díez et al., 2016)
Oregano oil and Thyme oil	0.25% v/v	Tunisian dry fermented poultry meat sausage	•Antioxidant activity •Antimicrobial activity •Not significant effect on the sensory quality •Not significant effect on the proteolysis, water activity and textural parameters (hardness and elasticity)	(El Adab & Hassouna, 2016)
Nutmeg oil	10 and 20 ppm	Cooked sausage	•Antioxidant activity •Antimicrobial activity •improvement of aroma	(Šojić et al., 2015)
Basil oil	0.19, 0.38, 0.75, 1.87, 3.75 and 7.5 mg/g	Italian-type sausage	•Antimicrobial activity	(Gaio et al., 2015)
Cinnamon oil	0.02 and 0.04% v/w	Lyoner-type sausage	•Antioxidant activity •Not significant effect on the sensory quality	(Aminzare et al., 2015)
Bay leaf oil	0.05 and 0.1 g/100 g	Fresh Tuscan sausage	•Antioxidant activity •Antimicrobial activity •Desirable sensory properties	(Da Silveira et al., 2014)
Ocimum basilicum oil	0.025–5% v/v	Fresh chicken sausage	•Antioxidant activity •Antimicrobial activity •Not significant effect on color •Adverse sensory effects	(Barbosa et al., 2014)
Cinnamomum zeylanicum oil	20. 40 and 60 ppm	Cooked sausage	•Antioxidant activity •Antimicrobial activity •Not significant effect on sensory parameters	(Moarefian et al., 2013)
Oregano oil	0.2% v/v	Petrovac sausage	•slow down the moisture loss and retard lipid oxidation •Desirable sensory properties •No difference in the color	(Šuput et al., 2012)
Mentha piperita oil	20, 40 and 60 ppm	Cooked sausage	•Antioxidant activity •Antimicrobial activity •Acceptable sensory properties	(Moarefian et al., 2012)
Winter savory (Satureja montana L.) oil	7.8, 15.6 and 31.25 μL/g	Mortadella-type sausage	•Antioxidant activity •Reduce redness and increase yellowness •Undesirable sensory changes	(de Oliveira et al., 2012)
Oregano (Origanum vulgare) oil	1 mL/L	Spanish fermented sausages	•Antifungal activity •Not significant effect on pH, water activity, or color changes	(Chaves-López et al., 2012)
Zataria multiflora Boiss oil	5 and 10 g/kg	Ready-to-eat mortadella-type sausage	•Antioxidant activity •Antimicrobial activity	(Moradi et al., 2011)
Winter savory (Satureja montana L.) oil	7.8, 15.6 and 31.25 μL/g	Mortadella-type sausage	•Antimicrobial activity •Reduce organoleptic properties	(de Oliveira et al., 2011)
Oregano oil	0.02% w/w	Bologna sausage	•Antioxidant activity •Antimicrobial activity •Not significant effect on the sensory quality	(Viuda-Martos et al., 2010b)
Rosemary oil and Thyme oil	0.02% w/w	Mortadella-type sausage	•Antioxidant activity •Antimicrobial activity •Not negative effect on the sensory quality	(Viuda-Martos et al., 2010a)
Thyme oil and Oregano oil	0.02% w/w	Bologna sausage	•Antioxidant activity •No negative effect on the chemical or physical properties •Not negative effect on the sensory quality	(Viuda-Martos et al., 2009)
Marjoram (Origanum majorana L.) oil	0, 0.046, 0.069, 0.092, 0.23, 0.46, 0.598, 0.690, 0.782, 0.92, 2.3 and 4.6 mg/mL	Fresh sausage	•Antimicrobial activity •Inverse relationship between acceptance rate and EOs concentration	(Busatta et al., 2008)
Oregano (Origanum vulgare) oil	0, 0.046, 0.069, 0.092, 0.23, 0.46, 0.598, 0.690, 0.782, 0.92, 2.3 and 4.6 mg/mL	Fresh sausage	•Antimicrobial activity •Desired slight alteration of the sensory parameters	(Busatta et al., 2007)

Abbreviations: BAs = Biogenic amines, EOs: Essential oils.

3.1. Effect on physicochemical properties

The use of optimal concentrations of SEOs in sausage processing can improve sensory quality and significantly affect the physicochemical properties of the final product, including moisture, water activity (aw), and pH. These parameters play an important role in determining the shelf life, microbiological safety, and overall quality of sausages. Changes to these parameters due to the addition of SEOs indicate the protective and modifying effects of these natural compounds (Chaves-López et al., 2012; Ozaki et al., 2021). In various studies, the effect of thyme essential oil on muscle pH and storage characteristics of sausages has been investigated. For instance, a high concentration of 500 ppm of thyme EO caused a significant increase in the pH of thigh and breast muscles in broilers, which was accompanied by an improvement in water holding capacity (WHC) and a decrease in Malondialdehyde (MDA) concentration in the muscles. These results indicate the antioxidant and protective effects of thyme EO in improving product quality and shelf life. Also, chicken sausages containing thyme EO had a higher pH than samples without EO, which could improve texture and reduce microbial spoilage (Abbasi et al., 2023; Huang et al., 2021).

Another study has demonstrated how grape seed extract and cinnamon EO can lower the pH of sausages. The product's pH was considerably lowered during storage by both treatments, particularly the grape seed extract, which inhibited the growth of lactic acid bacteria and was more efficient against gram-positive bacteria. As a result of these findings, sausages' quality and shelf life both improved. Additionally, samples treated with these EOs showed no discernible change in water activity (aw) over storage, which is vital for preserving the quality and safety of the final product. Furthermore, samples treated with these EOs showed no discernible change in water activity (aw) over storage, which is vital for preserving the quality and safety of the final product (Aminzare et al., 2015; Aminzare et al., 2018). Another study examined how varying nitrite and coriander EO concentrations affected the pH values of cooked pork sausages as they were stored. The concentration of coriander EO and the duration of storage had a substantial impact on the pH readings. When this EO was added, the pH values increased; but, after 40 days of storage, the growth of lactic acid bacteria (LAB) caused the pH values in all analyzed sausages to significantly decline (Šojić, Pavlić, Ikonić, et al., 2019).

Studies on Tuscan sausages and other types of fermented sausages have also shown that the addition of SEOs such as rosemary and oregano generally slows down the process of pH reduction during storage and helps maintain pH within the appropriate range. This is due to the antimicrobial and growth-regulating effects of lactic acid bacteria, which play a key role in the fermentation and preservation of the product. In some cases, the water activity (aw) level in samples containing EOs did not change significantly. However, in fermented dry sausages, aw gradually decreased due to reduced moisture and microstructural changes (Badia et al., 2020; El Bayomi et al., 2021). Further studies on various EOs, including clove, holy basil, thyme, cassia, ajowan, betel (Sharma et al., 2018; Sharma et al., 2019), and bay leaf (Da Silveira et al., 2014), showed that these oils significantly decreased moisture and pH during storage. However, the pH drop in treated samples usually occurred later and with less intensity than in control samples. This indicates the preservative and microbial growth regulating effect of the EOs, which helps maintain quality and increase product shelf life (Badia et al., 2020).

Other studies have investigated the effects of EOs from Origanum majorana L., Satureja hortensis L., and Satureja montana L. on fresh turkey sausage. These studies have shown that the pH and water activity (aw) of the sausage fluctuated during storage in all treatments, but no significant changes were observed following the addition of the EOs. These results suggest that SEOs may have less effect on these parameters and their effects are more manifested in improving sensory and antimicrobial properties (Šojić et al., 2023). The effect of oregano and thyme EOs on the characteristics of Tunisian dry fermented chicken sausages was investigated in a study. The results of this study showed that, in addition to changes in aw, which indicates moisture loss, the type of treatment with oregano EO had no effect on aw and it decreased with increasing drying time and reached values  below 0.85 at the end of the ripening period (day 19). However, the decrease in aw is not only due to water loss; it is also the result of microstructural and compositional changes in the system during ripening. Specifically, the lytic activities of enzymes and the formation of low-molecular-weight molecules reduce the aw of the food system. The pH of the sausages changed significantly due to treatment with oregano essential oil (El Adab & Hassouna, 2016).

Finally, the combined effect of EOs and other factors, such as sodium nitrite and the fat content of sausages, demonstrated that these factors can affect the pH and other physicochemical properties of the product synergistically (Badia et al., 2020; El Adab & Hassouna, 2016; Sharma et al., 2018; Šojić et al., 2023; Sun et al., 2018). Increased fat can accelerate the lipolysis process and the production of free fatty acids, which leads to a decrease in pH, while EOs and nitrites usually increase pH and control microbial growth (Tomović et al., 2022). Overall, the results of these studies demonstrate that the addition of SEOs can significantly affect the physicochemical properties of sausages. These effects include controlled moisture maintenance or reduction, water activity reduction or stabilization, and pH changes. SEOs, through interaction with proteins and lipids of meat products, can cause changes in protein structure, water holding capacity, texture, and emulsion stability. These changes lead to improved shelf life, microbial safety, and the final quality of meat products. As can be seen, the sources and compositions of some of the SEOs used in the sausage industry are given in Table 2.

Table 2.

Sources and composition of some SEOs to be used in sausage products.

Common name of essential oil	Source	Major components	Reference
Oregano	Origanum vulgare	Carvacrol Thymol γ -Terpinene p-Cymene	(Burt, 2004, Busatta et al., 2007, Fasseas et al., 2008, Karabagias et al., 2011, Šuput et al., 2012)
Thyme	Thymus vulgaris	Thymol Carvacrol γ -Terpinene p-Cymene	(Daferera et al., 2000, El Adab & Hassouna, 2016, García-Díez et al., 2016, Marino et al., 1999, Proaño et al., 2025, Souza et al., 2025, Viuda-Martos et al., 2009)
Clove	Syzygium aromaticum	Eugenol Eugenyl acetate	(Burt, 2004, Khorsandi et al., 2018, Sharma et al., 2019, Sirena et al., 2024, Ugalde et al., 2017, Xiao et al., 2021)
Cinnamon	Cinnamomum zeylandicum	trans- Cinnamaldehyde	(Aminzare et al., 2015, Aminzare et al., 2018, Burt, 2004, El Bayomi et al., 2021, Sirena et al., 2024, Sun et al., 2018, Xiao et al., 2021)
Rosemary	Rosmarinus officinalis	α-Pinene Bornyl acetate Camphor 1,8-Cineole Limonene	(Abbasi et al., 2023, Badia et al., 2020, Bozin et al., 2007, Roncero et al., 2023, Soncu et al., 2018)
Sage	Salvia officinalis	Camphor α-Pinene β-Pinene 1,8-Cineole α-Thujone Viridiflorol Borneol Eucalyptol	(Marino et al., 2001, Šojić et al., 2021)
Coriander	Coriandrum sativum	Linalool Camphor Geranyl acetate p-Cymene	(Samojlik et al., 2010, Šojić, Pavlić, Ikonić, et al., 2019)
Cassia	Cinnamomum cassia	(E)- Cinnamaldehyde Benzoic acid Cinnamaldehyde Phenylacrylic acid Benzaldehyde	(Du & Li, 2008, Sharma et al., 2017, Sharma et al., 2019)
Caraway	Carum carvi	Carvone Limonene α-pinene β-pinene myrcene	(Khorsandi et al., 2018, Tomović et al., 2022)
Basil	Ocimum basilicum	Linalool Methyl chavicol (Estragole) 1,8-Cineole Eugenol Methyl cinnamate	(Gaio et al., 2015, García-Díez et al., 2016)
Winter savory	Satureja montana	Carvacrol Thymol p-Cymene γ-Terpinene	(de Oliveira et al., 2012, Šojić, Pavlić, Tomović, et al., 2019)
Tarragon	Artemisia dracunculus	Methyl eugenol β-Ocimene β-Caryophyllene α-Pinene	(García-Díez et al., 2016, Kirkin et al., 2019)
Anise	Pimpinella anisum	Anethole Estragole γ-Himachalene Anisaldehyde	(Sun et al., 2018)
Ajowan	Trachyspermum ammi	Thymol γ-Terpinene p-Cymene β-Pinene	(Sharma et al., 2018)
Beetel	Piper betle	Eugenol Caryophyllene Methyl eugenol	(Sharma et al., 2018)
Cumin	Cuminum cyminum	Cumin aldehyde β-Pinene γ-Terpinene p-Cymene	(Dragoev et al., 2016, García-Díez et al., 2016)
Nutmeg	Myristica fragrans	Myristicin Safrole Elemicin α-Pinene β-Pinene	(García-Díez et al., 2016, Šojić et al., 2015)
Parsley	Petroselinum crispum	Myristicin β-Phellandrene Apiol α-Pinene	(García-Díez et al., 2016)
Black pepper	Piper nigrum	β-Caryophyllene Limonene Pinene Sabinene Myrcene β-Bisabolene	(Dragoev et al., 2016)
Bay leaf	Laurus nobilis	Eugenol Methyleugenol Cineole (1,8-cineole) Linalool Safrole	(Da Silveira et al., 2014)
Marjoram	Origanum majorana	Terpinen-4-ol γ-Terpinene α-Terpinene Sabinene Linalool cis-Sabinene hydrate	(Busatta et al., 2008)

3.2. Effect on antimicrobial properties

Foodborne illness outbreaks affect thousands of consumers worldwide each year. The main pathogens contaminating meat products are Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, Salmonella enterica, Bacillus cereus, Yersinia enterocolitica, and Enterococcus faecalis (de Candia et al., 2017). Numerous studies demonstrate that because SEOs include active phenolic, terpenoid, and other bioactive compounds, they significantly reduce the growth of pathogenic and spoilage microorganisms in cooked sausages. The type of EO, concentration, storage conditions, interaction with other antibacterial agents, and product type all affect these effects (Aminzare et al., 2015; Aminzare et al., 2018; Esmaeili et al., 2020; Sharma et al., 2018).

Thyme and rosemary EOs have been found in numerous tests to lower the microbial load and lengthen the shelf life of sausages. With these oils, nitrite (at least 60 ppm) can even be partially substituted without sacrificing quality (Abbasi et al., 2023; El Adab & Hassouna, 2016; Huang et al., 2021; Roncero et al., 2023; Soncu et al., 2018). Ziziphora clinopodioides EO alone or in combination with lysozyme, dramatically decreased the number of Listeria monocytogenes and mesophilic bacteria. The main components of this EO, including geraniol, thymol, and carvacrol, were also identified as key antimicrobial agents (Ajourloo et al., 2021). Studies on cinnamon EO and grape seed extract showed that the combination of these two substances can inhibit the growth of lactic acid bacteria and psychrophilic bacteria. However, grape seed extract alone was more effective in inhibiting gram-positive bacteria, including LAB (Aminzare et al., 2018). E. coli O157:H7 and Lactobacillus plantarum populations were considerably decreased by garlic EO, whether it was applied alone, in conjunction with nisin Z, or in chitosan edible films (Araújo et al., 2018).

Oregano and marjoram EOs exhibited significant inhibitory effects against mesophilic lactic acid bacteria and fungi at different concentrations (Badia et al., 2020; Busatta et al., 2007; Busatta et al., 2008). Basil EO also had a broad inhibitory effect on a wide range of bacteria and was ineffective only on Pseudomonas aeruginosa (Gaio et al., 2015). On the other hand, Satureja montana L. EO in combination with nitrite was able to completely inhibit the growth of Clostridium perfringens (de Oliveira et al., 2011; de Oliveira et al., 2012). The use of tarragon, parsley, black pepper, lemon and nutmeg EOs has also been reported in some studies. Tarragon EO has limited use due to the presence of estragole, but at low concentrations it produces a suitable inhibitory effect (Kirkin et al., 2019). Nutmeg EO at concentrations of 10 and 20 ppm was able to reduce the microbial load of sausage during a 60-day storage period (Šojić et al., 2015). Parsley, black pepper, and lemon EOs were effective in controlling Listeria monocytogenes, Salmonella, and S. aureus when used in combination with other EOs (García-Díez et al., 2016).

Caraway and basil EOs exhibited the highest inhibitory activity against fungi and molds. Caraway (Carum carvi L.) EO was able to completely inhibit mold species even at low concentrations (1.5–4.5 μL/mL) (Kocić-Tanackov et al., 2020; Tomović et al., 2022). Coriander and bay leaf EOs had significant antifungal and antibacterial effects (Da Silveira et al., 2014; Šojić, Pavlić, Ikonić, et al., 2019). Juniperus communis L. EO and its compounds, such as pinenes and limonene, effectively inhibited the growth of food pathogens in dry fermented sausages (Tomović et al., 2020). On the other hand, another study showed that the fermentation process in fresh Balkan sausages was accompanied by the controlled growth of B. thermosphacta and Enterobacteriaceae species. The use of Zataria multiflora Boiss EO, hop extract, or a combination of both at different concentrations had no significant effect on microbial growth in sausages (Carballo et al., 2019).

Another study investigated the antibacterial properties of EOs of black cumin, cinnamon, turmeric, cardamom, and cloves against lactic acid bacteria isolated from cooked, vacuum-packed sausages. In this study, eight LAB strains were isolated from 18 spoiled vacuum-packed sausages. The results showed that these EOs were able to inhibit these spoilage microorganisms, depending on the sensitivity of the tested strains (Khorsandi et al., 2018). On the other hand, oregano, thyme and clove EOs showed good antimicrobial efficacy against S. aureus, E. coli, Salmonella and coliforms in chicken sausage. As a result, the findings of this study indicated the high potential of using these essential oils as natural alternatives to improve the taste of chicken sausages (Proaño et al., 2025). New technologies, such as nanoencapsulation and nanoemulsions, have been effective in improving the stability and effectiveness of EOs. Nanoemulsions of oregano and thyme EOs encapsulated with gelatin/chitosan showed that in addition to maintaining antimicrobial properties, they can be a suitable alternative to nitrite (Vafania et al., 2019; Yin et al., 2025).

The antimicrobial activity of EOs is strongly influenced by the complex matrix of products. The presence of significant amounts of fat, protein and other food components can reduce their accessibility to microbial cells through physicochemical interactions with the active compounds of EOs. The lipophilic nature of EOs causes these compounds to accumulate mainly in the lipid phase of the sausage, and as a result, their effect on microorganisms present in the aqueous phase is limited (Da Silveira et al., 2014). However, the main mechanism of antimicrobial activity of EOs is based on damage to the bacterial cell membrane, which leads to increased membrane permeability, leakage of ions and vital metabolites, disruption of the intracellular pH balance and ultimately inhibition of cell growth or death. Compounds such as monoterpenes and phenolic compounds, especially thymol and carvacrol, play a key role in this process and exert their antimicrobial effect by disrupting the integrity of the cytoplasmic membrane and inhibiting cellular respiration (Proaño et al., 2025).

Despite the remarkable effectiveness of EOs in vitro, their antimicrobial performance in processed sausages is not always predictable and depends on factors such as the type of EO, the concentration used, storage conditions, pH, water activity and especially the atmospheric conditions of the product. Studies show that the effect of EOs in aerobic environments is usually more pronounced than in anaerobic conditions, because the composition and dynamics of the microbiota are different in the presence of oxygen (Busatta et al., 2008). In addition, the interaction between the antimicrobial compounds of EOs and the components of the sausage matrix can lead to a reduction or loss of their inhibitory effect. Therefore, to optimize the antimicrobial performance of them in processed sausages, it is essential to pay attention to formulation design, select appropriate storage conditions, and adjust factors such as pH and essential oil concentration (Carballo et al., 2019).

Overall, the review of results shows that several EOs including thyme, rosemary, cassia, cinnamon, garlic, oregano, marjoram, basil, savory, tarragon, parsley, black pepper, lemon, nutmeg, coriander, cumin, clove, holy basil, cassia, ajwain, beetel, and Juniperus communis were all effective in controlling a wide range of spoilage and pathogenic bacteria and fungi in processed sausages, the common types of which are mentioned in Table 3. Although EOs have the greatest antimicrobial efficacy at high concentrations, sensory limitations prevent their widespread use in large quantities. Therefore, the combined use of EOs together or with other preservatives (such as nitrite in reduced amounts, biological agents such as nisin, and modified packaging conditions) can be used as a multi-step strategy to increase microbial safety and extend the shelf life of sausages.

Table 3.

Common spoilage and pathogenic microorganisms associated with processed sausages.

Microorganisms		Genera/Species
Spoilage Microorganisms	Bacteria	Lactobacillus spp. Leuconostoc mesenteroides Pediococcus acidilactici Brochothrix thermosphacta Hafnia alvei Enterobacter cloacae Pseudomonas spp. Klebsiella Acinetobacter
	Yeasts and Molds	Candida spp. Debaryomyces hansenii Penicillium spp. Aspergillus
Pathogenic Microorganisms		Listeria monocytogenes Salmonella spp. Staphylococcus aureus Escherichia coli O157:H7 Campylobacter spp.

3.3. Effects on antioxidant capacity

Lipid oxidation is one of the most important factors affecting the quality, nutritional value and sensory acceptability of meat products. During this process, the degradation of unsaturated fatty acids produces compounds such as malondialdehyde (MDA), which not only causes unwanted flavors and discoloration, but can also cause mutagenic and carcinogenic effects by forming prooxidant compounds (Moarefian et al., 2012). In addition, protein oxidation through free radical chain reactions leads to a decrease in the bioavailability of essential amino acids and a decrease in the digestibility of proteins. For this reason, many researchers have turned their attention to the use of natural antioxidant compounds, especially SEOs, as a safe and efficient alternative to synthetic antioxidants (Aminzare et al., 2015; Moarefian et al., 2013).

Several studies have examined the advantages of various EOs in lowering oxidation and increasing oxidative stability in various types of processed sausage. Eugenol and eugenol acetate, two phenolpropanoid compounds found in clove EO, are regarded as some of the most potent natural antioxidants found in meat products. The main mechanism of these compounds is through neutralization of free radicals, inhibition of chain reactions, and stabilization of α-tocopherol. The combination of clove and cinnamon EOs significantly increased the antioxidant capacity of fresh sausages and showed a strong synergistic impact. However, it has been reported that at very high concentrations, cinnamon EO may lose its inhibitory effect and even accelerate oxidation in the final stages of storage (Sirena et al., 2024).

The presence of phenolic compounds such as thymol and carvacrol in the EOs of thyme and oregano plays a decisive role in inhibiting lipid oxidation. By donating hydrogen atoms to free radicals, these compounds convert them into more stable forms and prevent the spread of chain reactions. The addition of thyme or oregano EOs along with citrus by-products increased the inhibition of radical formation and improved the oxidative stability of bologna sausage (Viuda-Martos et al., 2009). Zanthoxylum bungeanum EO is a common seasoning in Chinese-style sausages and also contains significant bioactive components. Microencapsulation of this EO results in the gradual release of active compounds, providing effective protection for sensitive components during storage. Compared to direct addition of the EO, the use of the microencapsulated form significantly reduced the peroxide and TBARS values, suggesting more effective inhibition of oxidation (Meng et al., 2022).

The use of chitosan films containing Shirazi thyme EO and grape seed extract in mortadella sausage has also been shown to significantly inhibit oxidation In terms of lowering TBARS, grape seed extract is more effective than thyme EO because of its antioxidant components, such as flavonoids and bioflavonoids. Meanwhile, the gradual release of phenolic compounds from the coating films during the initial storage period has been reported to delay the onset of oxidation (Moradi et al., 2011). Sage EO, which contains oxygenated monoterpene compounds such as alpha-thujone, beta-thujone, camphor, and eucalyptol, has also been able to significantly reduce TBARS levels. The partial replacement of nitrite with sage EO has maintained oxidative stability in dried fermented sausages and has made it possible to reduce nitrite consumption without loss of quality (Šojić et al., 2021). Similarly, the combination of cinnamon EO and grape seed extract has shown significant synergistic activity. Higher concentrations of these two compounds produced the lowest TBARS in Lyoner-type sausages during 40 days of storage. Grape seed extract was more effective than cinnamon EO, which is attributed to the higher concentration of polyphenols in this extract (Aminzare et al., 2018).

Rosemary EO has also been introduced as a natural alternative to nitrite in sausage formulations. When compared to control samples, the concentration of malondialdehyde was considerably lower in chicken sausages that were enriched with rosemary EO. Because it contains chemicals like carnosol, carnosic acid, and rosmarinic acid, rosemary has a strong capacity to suppress lipid peroxidation (Abbasi et al., 2023). imilarly, while the changes were not statistically significant (P < 0.05), the flavonoids and phenolic terpenoids in basil EO decreased the amounts of TBARS in chicken sausages while they were being stored (Barbosa et al., 2014). Similarly, Mentha piperita EO at low concentrations reduced peroxide during the first few days of storage, but lost its inhibitory effect at higher levels (Moarefian et al., 2012).

A study of EOs containing Clove oil, Holybasil oil, Thyme oil, Cassia oil, Ajowan oil and Beetel oil found that treatments containing EO mixtures exhibited the highest antioxidant activity. By raising the total phenolic content and slowing the rate of DPPH elimination during storage, these results confirm the presence of synergistic effects between phenolic and terpenoid components in the EO mixtures (Sharma et al., 2018). In the field of active films, oxidation in sliced sausages was considerably decreased by using garlic EO or its nanocapsule form in edible films based on whey protein. The sulfur compounds in garlic EO, including allicin and thiosulfinate derivatives, are considered to be primarily responsible for its antioxidant activity (Esmaeili et al., 2020). Caraway EO, which has a predominant carvone composition, has been identified as one of the most effective natural antioxidants for dry fermented sausages (Tomović et al., 2022).

Several studies have shown that the addition of winter savory (Satureja montana) EO significantly reduces TBARS. Thymol and carvacrol, which are included in this EO, have been linked to its stronger antioxidant action, particularly at lower doses. However, antagonistic reactions between phenolic chemicals and nitrite have been noted at larger concentrations of the EO, suggesting that its consumption level should be optimized (de Oliveira et al., 2012; Šojić, Pavlić, Tomović, et al., 2019). Coriander EO (Coriandrum sativum), with its major compounds such as linalool, camphor, and geraniol, has also been able to reduce TBARS values  and preserve oxidative stability in cooked sausages at different concentrations (Šojić, Pavlić, Ikonić, et al., 2019). A significant decrease in TBARS was also reported for nutmeg EO during 60 days of storage. In comparison to the control sample, the EO's active aromatic and phenolic components decreased lipid oxidation and enhanced product stability (Šojić et al., 2015).

The findings of this study show that processed sausages benefit from longer shelf life and greater oxidative stability when they contain high concentrations of phenolic and terpenoid compounds such as sulfur, eugenol, thymol, carvacrol, linalool, and carvone, as shown in Fig. 2. These compounds neutralize free radicals resulting from lipid and protein oxidation by donating hydrogen or electrons, stopping the chain of oxidation reactions (Šojić et al., 2015; Viuda-Martos et al., 2009). In addition, SEOs can slow down the initiation and progression of oxidation by chelating catalytic metal ions such as iron and copper, which are abundant in meat (Moarefian et al., 2013). Some of them also help maintain the sensory quality, color, and nutritional value of meat products during storage by reducing lipid peroxidation and inhibiting the formation of undesirable secondary compounds. Furthermore, contemporary technologies such as microencapsulation and bioactive films containing EOs can regulate the release of active substances, improve stability and reduce adverse sensory effects in meat products.

Fig. 2.

Chemical structures of some components of major essential oils (Bakkali et al., 2008; Burt, 2004; Hyldgaard et al., 2012; Suppakul et al., 2003).

3.4. Effect on sensory parameters

Several studies have investigated the effects of various SEOs on the sensory properties of processed sausages. These investigations have shown that the effect of them on characteristics such as odor, flavor, color, texture, and overall acceptability depends highly on the type of EO used, its concentration, and the presence or absence of common preservatives, such as nitrite (Barbosa et al., 2014). In general, the use of EOs as antimicrobial and antioxidant agents has limitations, because effective concentrations for inhibiting microbial growth may reduce the product's sensory acceptability. Therefore, it is essential to determine the optimal dose that provides a good balance between antimicrobial efficacy and sensory acceptability (Souza et al., 2025; Šuput et al., 2012).

One study found that adding rosemary EO to chicken sausage in place of nitrite did not significantly alter the sausage's color, flavor, odor, or texture when compared to the control group (p > 0.05) (Abbasi et al., 2023). In contrast, adding Ziziphora clinopodioides EO decreased flavor and odor scores in the early days of storage; however, this negative effect diminished as the storage period progressed. Further analysis revealed that sensory scores related to color, flavor, and odor decreased overall as microbial load and chemical changes increased; this was attributed to the inhibitory activity of the EO and lysozyme (Ajourloo et al., 2021).

Another study showed that the addition of cinnamon EO (0.04%) and grape seed extract, either individually or in combination, significantly improved the odor of the product compared to the control. There was no significant difference in flavor or texture between the treatments, but the scores of treatments containing EO were consistently higher than the control (Aminzare et al., 2018). Evaluation of oregano and rosemary EOs showed that there was no significant difference between the samples at lower concentrations (0.05% and 0.1% by weight). However, at higher one (0.2% and 0.4% by weight), samples containing oregano EO had higher L* values  than rosemary (Badia et al., 2020).

In a study, corn starch-based biopolymer films containing commercial clove (Syzygium aromaticum (L.)) EO were fabricated. According to the results of this study, there was no significant difference in color between the treatments (starch-wrapped sausages and those wrapped with starch and 1% clove EO) and the control group (unwrapped sausages) (Ugalde et al., 2017). Another study found that Mentha piperita EO significantly changed the color parameter at the highest concentration (60 ppm) in cooked sausages. However, no difference in sensory scores was reported compared to the control group (Moarefian et al., 2012). Also, the use of marjoram EO showed that sensory acceptance was inversely related to the concentration of the EO, with sensory quality decreasing at higher concentrations (Busatta et al., 2008). The addition of savory EO to nitrite-free mortadella sausages had no significant effect on brightness (p > 0.05). This was attributed to the SEO's inhibitory effect on the formation of nitrosomyoglobin pigments (de Oliveira et al., 2012).

In another study, the use of oregano and thyme EOs in dry-fermented sausages did not affect the natural color changes during the ripening period and the decrease in L* was attributed to moisture loss (El Adab & Hassouna, 2016). In this regard, basil EO did not cause any noticeable changes in odor and color at low concentrations, but at higher one (≥ 1.87 mg/g) a significant difference and a decrease in overall acceptance were observed (Gaio et al., 2015). The evaluation of tarragon EO showed no significant difference in color or texture compared to the control. However, the taste of the treatments containing tarragon was pungent, resulting in lower overall acceptance (Kirkin et al., 2019). Similarly, nutmeg EO did not cause any change in aroma during 30 days of storage, but after 60 days, the sample containing 20 ppm had a higher sensory quality than the others (Šojić et al., 2015).

Caraway EO caused significant changes in taste and odor in dry fermented sausages. At lower concentrations, these changes were limited; however, higher one (0.1 μL/g) can resulted in an unusual taste and reduced acceptance (Tomović et al., 2022). In the case of bay leaf EO, the results showed that both tested concentrations (0.05 and 0.1 g/100 g) significantly changed the sensory characteristics compared to the control sample, though consumers preferred the control (Da Silveira et al., 2014). The addition of Thymbra spicata EO at concentrations of 300 and 500 ppm to sucuk sausage showed that the higher concentration resulted in a significant decrease in overall acceptance and the sample without essential oil was more desirable (Al & Yildirim, 2020). Similarly, the use of a combination of EOs including clove, cinnamon, thyme, holy basil, ajowan, and beet, in chicken sausage improved its appearance and stability, although the control treatment had obtained higher scores in the early stages (Sharma et al., 2017; Sharma et al., 2018).

The addition of rosemary, thyme and orange fiber EOs to mortadella sausage showed no significant differences in most sensory characteristics compared to the air-packed control. The best results were obtained for the vacuum-packed sample with rosemary EO and orange fiber (Viuda-Martos et al., 2010a). A similar study found that using oregano EO with orange fiber in bologna sausage maintained color and overall acceptability during storage (Viuda-Martos et al., 2010b). Also, in the evaluation of the combination of high-pressure processing (HPP) and cinnamon and clove EOs in low-salt sausage, it was found that the samples containing the essential oil had lower L* and higher b* values than the control groups. These differences were attributed to the pigments present in the EOs (Xiao et al., 2021).

The addition of thyme EO and powdered beet juice to sausages also received good acceptance from sensory judges and was considered acceptable even without curing salts (Lages et al., 2021). Also, the use of winter savory EO showed a significant effect on the pleasant aroma and taste due to its high concentration of volatile terpenes (Šojić, Pavlić, Tomović, et al., 2019).

According to the reported results, the sensory properties of processed sausages are significantly affected by the concentration of SEOs, such that the type and amount of them can improve or impair indicators such as odor, taste, color, texture, and overall acceptance. In general, it can be concluded that low to moderate doses of SEOs can provide antimicrobial and antioxidant effects while maintaining a desirable sensory quality. On the other hand, excessive use of them, especially those with a strong aroma, may significantly reduce consumer acceptance. Therefore, determining the optimal concentration and investigating the interaction of EOs with other formulation components (especially nitrite) seems essential for producing healthier meat products that are also acceptable to consumers.

4. Conclusion

This systematic review clearly demonstrates the great potential of SEOs as natural and multifunctional preservatives in processed sausages. The bioactive compounds found in these oils, primarily phenolic and terpenoid constituents such as thymol, carvacrol, eugenol, linalool and cinnamaldehyde exhibit strong antioxidant and antimicrobial properties. This effectively inhibits lipid oxidation and the growth of spoilage and pathogenic microorganisms. The incorporation of SEOs in sausage formulations generally enhances physicochemical stability by maintaining favorable pH and water activity levels, improving color retention, and extending shelf life. Moreover, when used at optimal concentrations, these EOs can enhance sensory attributes such as flavor and aroma, resulting in higher consumer acceptance. However, excessive concentrations may negatively affect sensory quality due to their intense aromas and flavors, limiting their application in large quantities. Future studies should focus on optimizing the type, concentration, and application methods of SEOs in sausage formulations to achieve maximum preservative efficacy with minimal sensory impact. Moreover, future work should include pilot-scale and industrial trials to evaluate practical feasibility, economic aspects, and consumer acceptance, alongside molecular-level studies to elucidate the mechanisms of action of bioactive compounds. Regulatory considerations are also essential to support the broader commercial application of SEOs in meat processing.

CRediT authorship contribution statement

Aref Adeli mosabbeb: Writing – original draft, Validation, Methodology, Conceptualization. Negin Majdi: Methodology, Investigation, Data curation. Soheil Eskandari: Validation, Conceptualization. Saeedeh Shojaee-Aliabadi: Validation, Supervision.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability

No data was used for the research described in the article.