Food borne illness is major health concern of people in both developed and developing countries (Abunna, 2016). According to World Health Organization, the infectious diseases that occur by consuming contaminated water or food are called foodborne diseases. (Abebe et al., 2020). Micro-organisms are food borne pathogens i.e. bacteria, fungi, viruses. Particularly food borne bacteria i.e. Salmonella enterica, Staphylococcus aureus, Campylobacter jejuni, Escherichia coli, Listeria monocytogenes spread food borne ailments (Zhao, 2014). Food borne diseases affect 30% of population in the developed countries whereas up to 2 million fatalities are estimated per year in the developing countries (Abunna, 2016). Oxidation reactions during production, distribution and storage of food products lower the food quality (Mirian Pateiro, 2018). Synthetic preservatives are used as antimicrobial and antioxidants in food products that may lead to allergies, intoxication, and degenerative diseases (Laranjo, 2017). So, scientists are searching for antimicrobial agents and antioxidants of natural origin that may help attenuate oxidative damage. Essential oils (EOs) may be used as alternative to synthetic preservatives due to their resistance against pathogens (Myszka et al., 2019).
The compounds which neutralize free radicals and reactive oxygen species (ROS) in the cells are called antioxidants. The antioxidants protect organisms from free radicals that are responsible for chronic diseases such as cardiovascular disease, cancer, aging, and anemia etc. (Zehiroglu & Ozturk Sarikaya, 2019). Free radicals are produced by uncoupled flow of electrons during metabolic processes. They may be harmful to lipids, nucleic acids, proteins, carbohydrates (Gulcin, 2020). Antioxidants reduce the oxidative stress related diseases by counteracting the deleterious effects of free radicals (Neha et al., 2019). Using EOs as natural antioxidants help avoid degenerative diseases (Bhalla et al., 2013). In a study 1% (v/w) EO of T. Capitata to minced beef significantly reduced the population of L. monocytogenes (El Abed et al., 2014). Therefore, EOs can be used for the preservation of meat products to increase the shelf life against L. monocytogenes. EOs are volatile, secondary metabolites of medicinal plants. They are aromatic oily liquids obtained from different parts of plants e.g. roots, leaves, herbs, flowers, barks, and buds (Burt, 2004). Essential oils possess antimicrobial and anti-inflammatory properties so they are used as analgesics, sedatives, anesthetics, and spasmolytic materials (Bakkali et al., 2008).
There are various techniques used for extraction of EOs from plants. The most common methods of extraction are hydro distillation (HD), steam distillation (SD), supercritical fluid CO2 extraction (SCF-CO2), subcritical water extraction (Reyes-Jurado et al., 2015). The hydro distillation process (HD), devised by Avicenna; is the oldest method of essential oil extraction. HD is the simplest, oldest method for extraction of EOs from plant materials. However, this technique have some disadvantages like low extraction efficiency, high fuel and water consumption, hydrolysis of compounds, prolong extraction time and decomposition of heat sensitive compounds. SD is simple, comfortable, more reproducible, and has high energy efficiency (Akdağ & Öztürk, 2019). SD has disadvantages just like HD such as prolonged extraction time, degradation of ester or unsaturated compounds, and low extraction efficiency (Reyes-Jurado et al., 2015).
SCF-CO2 involves the use of recycling fluid in periodic steps of compression or decompression. carbon dioxide is mainly used to extract essential oils by SCFE (Fornari et al., 2012). This process provides several properties such as lower density, lower viscosity, and high diffusivity. These properties enable fast extraction of essential oil at low temperatures. It is an environment friendly, cost-effective, and simple process (El Asbahani et al., 2015). This method requires less time as compared to conventional techniques. The major demerit of this technique lies in the non-polar nature of CO2. Due to the non-polar nature of CO2, the total content of bioactive phenolic compounds in essential oils cannot be extracted (Tyskiewicz et al., 2018). (Xiong & Chen, 2020) used this technique for the extraction of tangerine peel EO. Similarly, (Wu et al., 2019) extracted Cymbopogon citronella leaves EO using SCF- CO2. (Ayub et al., 2018) used SCF- CO2 to extract EO from Oleogum resin of Boswellia serrata Roxb
Superheated steam extraction (SHSE) is an alternative extraction technique in which superheated steam is used for extraction of EO. Superheated steam has temperature higher than saturation temperature at normal pressure. In the form of latent heat of vaporization, it carries a lot of thermodynamic energy. It has a high thermal conductivity, extraction capacity, and low oxygen conditions, preventing oxidation of extracted components. (Ayub et al., 2022). (Rouatbi et al., 2007) employed SHSE for the extraction of thyme and black pepper EO. Similarly, (Ayub et al., 2022) used this technique for the extraction of EO from oleogum resin of Boswellia serrata
Pinus roxburghii, referred to as Chir Pine, belongs to the Pinaceae family of gymnosperms. It is located in the Himalayas range of Pakistan, China, Afghanistan, India, and Nepal (Shuaib, 2014). Five species of pines including Pinus Roxburghii cover an area of 1928 thousand hectares in Pakistan. These species are mainly found in rangelands of northwest Frontier, Punjab, and Baluchistan (Hassan & Amjid, 2009). The plant is bitter, pungent, sweet, heating, oleaginous, intestinal antiseptic, antidyslipidemic and is used in treatment of the ear, throat, eye, skin, blood, bronchitis, diaphoresis, ulcer, inflammations, and itching (Abbasi et al., 2010). Wood is stimulant, diaphoretic and used in cough, fainting, and ulceration (Chopra et al., 2002). Pinus roxburghii EO has been used for the treatment of bronchitis, typhoid. (Arshad & Ahmad, 2004). Pinus Roxburghii is the rich source of high-quality oleoresin. Oleoresin, on distillation, produces an essential oil generally known as turpentine oil and rosin is left behind as a non-volatile solid residue (Shuaib et al., 2018). Diterpene resin acids are major constituents of rosin. Oleoresin is also composed of terpenes which are complex mixtures of monoterpenes, diterpenes, sesquiterpenes, oxygenated monoterpenes, oxygenated diterpenes, and oxygenated sesquiterpenes (da Silva Rodrigues-Corrêa et al., 2013). Turpentine oil is a complex mixture of monoterpenes and sesquiterpenes. Pinus oleoresins have role in pharmaceuticals and cosmetics (da Silva Rodrigues-Corrêa et al., 2013). It is also used for scorpion and snakebite stings (Sinha & Tandon, 2019). Turpentine oil is used in disinfectants and denaturants (Sood, 2018).
A thorough evaluation of previously published research studies manifested that SHSE is still not practiced for extraction of EO from Pinus roxburghii oleoresin. Therefore, the research work was performed to extract EO from Pinus roxburghii oleoresin by SD, SCF-CO2 and SHSE at different temperatures. Moreover, the effect of extraction methods and extraction temperatures on the yield, antioxidant and antimicrobial activities, and chemical composition of EOs was evaluated.