Conventional versus microwave-assisted hydrodistillation of sage herbal dust: Kinetics modeling and physico-chemical properties of essential oil

Kinetics of Microwave-Assisted Extraction Process Applied on Recovery of Peppermint Polyphenols: Experiments and Modeling

The aim of this work was to investigate the microwave-assisted extraction (MAE) kinetics of polyphenolic compounds from organic peppermint leaves. The phytochemicals of peppermint (Mentha piperita L.) are increasingly used in food technology due to their numerous biological activities. The processing of various plant materials by MAE and the production of high-quality extracts is becoming increasingly important. Therefore, the influence of microwave irradiation power (90, 180, 360, 600, and 800 W) on total extraction yield (Y), total polyphenols yield (TP), and flavonoid yield (TF) were investigated. Common empirical models (first-order, Peleg's hyperbolic, Elovich's logarithmic, and power-law model) were applied to the extraction process. The first-order kinetics model provided the best agreement with the experimental results in terms of statistical parameters (SS_er, R², and AARD). Therefore, the influences of irradiation power on the adjustable model parameters (k and C_eq) were investigated. It was found that irradiation power exerted a significant influence on k, while its influence on the asymptotic value of the response was negligible. The highest experimentally determined k (2.28 min^-1) was obtained at an irradiation power of 600 W, while the optimal irradiation power determined by the maximum fitting curve determination predicted the highest k (2.36 min^-1) at 665 W.

Isolation, Bioactive Potential, and Application of Essential Oils and Terpenoid-Rich Extracts as Effective Antioxidant and Antimicrobial Agents in Meat and Meat Products

Using food additives (e.g., preservatives, antioxidants) is one of the main methods for preserving meat and meat product quality (edible, sensory, and technological) during processing and storage. Conversely, they show negative health implications, so meat technology scientists are focusing on finding alternatives for these compounds. Terpenoid-rich extracts, including essential oils (EOs), are remarkable since they are generally marked as GRAS (generally recognized as safe) and have a wide ranging acceptance from consumers. EOs obtained by conventional or non-conventional methods possess different preservative potentials. Hence, the first goal of this review is to summarize the technical-technology characteristics of different procedures for terpenoid-rich extract recovery and their effects on the environment in order to obtain safe, highly valuable extracts for further application in the meat industry. Isolation and purification of terpenoids, as the main constituents of EOs, are essential due to their wide range of bioactivity and potential for utilization as natural food additives. Therefore, the second goal of this review is to summarize the antioxidant and antimicrobial potential of EOs and terpenoid-rich extracts obtained from different plant materials in meat and various meat products. The results of these investigations suggest that terpenoid-rich extracts, including EOs obtained from several spices and medicinal herbs (black pepper, caraway, Coreopsis tinctoria Nutt., coriander, garlic, oregano, sage, sweet basil, thyme, and winter savory) can be successfully used as natural antioxidants and antimicrobials in order to prolong the shelf-life of meat and processed meat products. These results could be encouraged for higher exploitation of EOs and terpenoid-rich extracts in the meat industry.

Essential Oils from Apiaceae, Asteraceae, Cupressaceae and Lamiaceae Families Grown in Serbia: Comparative Chemical Profiling with In Vitro Antioxidant Activity

The aim of the present study was to investigate the chemical profile and antioxidant activity of essential oils obtained from the most commonly grown plant species in Serbia. Aromatic and medicinal plants from Lamiaceae (Mentha x Piperita, Ocimum basilicum, Origanum majorana, Origanum vulgare, Salvia officinalis, Satureja hortensis, Satureja montana and Thymus vulgaris), Asteraceae (Ehinacea purpurea and Matricaria chamomilla), Apiaceae (Anethum graveolens, Carum carvi, Foeniculum vulgare, Petroselinum crispum and Pimpinella anisum) and Cupressaceae (Juniperus comunis) were selected as raw material for essential oils (EOs)' isolation. Hydrodistillation (HD) was used for the isolation of EOs while they were evaluated in terms of yield and terpenoid profiles by GC-MS. In vitro radical scavenging DPPH and ABTS⁺ radical activities were carried out for all EOs. Finally, a principal component analysis (PCA) was performed with the experimental results of the composition and antioxidant activity of the EOs, which showed a clear distinction between the selected plant species for the aforementioned responses. This work represents a screening tool for the selection of other EO candidates for further processing by emerging extraction techniques and the use of EOs as natural additives for meat products.

The effect of various extraction techniques on the quality of sage (Salvia officinalis L.) essential oil, expressed by chemical composition, thermal properties and biological activity

In this study, influence of the extraction techniques on the quality of the sage essential oil was investigated. Obtained samples were analyzed for chemical composition by GC/MS, thermal properties by thermogravimetric analysis (TGA), and for biological activity: antioxidant (DPPH, CUPRAC, FRAP, ABTS, HRSA and TBARS), microbiological (Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger), and cytotoxic (HeLa, LS-174, A549 and MRC-5) activities. Chemical composition showed that viridiflorol was principal compound in all samples followed by camphor, thujones, and verticiol. MWD 400 W was the most potent antioxidant agent, D 200 W and MWD 400 W antimicrobial agents, while hydrodistallates (D 200 W and D 400 W) were the most potent cytotoxic agents. An artificial neural network model was developed for the antioxidant activity anticipation of analyzed samples. These models showed good prediction properties (the r² value during training cycle for output variables was 0.998).

Extraction of Peppermint Essential Oils and Lipophilic Compounds: Assessment of Process Kinetics and Environmental Impacts with Multiple Techniques

Consumers are becoming more mindful of their well-being. Increasing awareness of the many beneficial properties of peppermint essential oil (EO) has significantly increased product sales in recent years. Hydrodistillation (HD), a proven conventional method, and a possible alternative in the form of microwave-assisted hydrodistillation (MWHD) have been used to isolate peppermint EO. Standard Soxhlet and alternatively supercritical fluid (SFE), microwave-assisted, and ultrasound-assisted extraction separated the lipid extracts. The distillations employed various power settings, and the EO yield varied from 0.15 to 0.80%. The estimated environmental impact in terms of electricity consumption and CO₂ emissions suggested that MWHD is an energy efficient way to reduce CO₂ emissions. Different extraction methods and solvent properties affected the lipid extract yield, which ranged from 2.55 to 5.36%. According to the corresponding values of statistical parameters, empiric mathematical models were successfully applied to model the kinetics of MWHD and SFE processes.

Microwave applications in the food industry: an overview of recent developments

Microwave radiation has the ability to heat a material with dielectric properties. Material absorbs microwave energy and then converts it into heat, which gives the possibility of a wide use of microwaves in many industry sectors or agricultural sciences. Microwaves are especially widely used in food industry. The main objective of this paper is to present an overview of recent development regarding microwave applications in food industry. Many techniques in food processing (pasteurization, sterilization, drying, thawing, blanching and stunning) are assisted by microwave energy. It should be mentioned also the use of microwaves in nutrients and nutraceuticals production. Waste generation is an integral part of food production. Microwaves have also application in wastes management. The results of experiments, factors affecting heating and their practical application have been discussed. Many cases have been compared with conventional process methods. The use of microwaves shows many advantages. The most important aspect is shortening the time of the thermal process (even by 50%) and reducing the costs of the operation. In addition, it allows to increase the efficiency of processes while maintaining high quality. The examples of microwave applications given in the article are environmentally- friendly because the conditions of thermal processing allow for reducing the use of solvents and the amount of sewage by decreasing the demand for water. It is anticipated that microwaves will become increasingly popular, with the development of new microwave technologies solving many problems in the future.

Sage (Salvia officinalis L.) Essential Oil as a Potential Replacement for Sodium Nitrite in Dry Fermented Sausages

This study investigates the effects of sodium nitrite replacement by the sage essential oil (SEO), on the physico-chemical, microbiological and sensory quality of dry fermented sausages (DFS) during 225 days of storage. The SEO (0.00, 0.05 and 0.10 µL/g) was added in DFS batters formulated with different levels of pork back fat (15% and 25%) and sodium nitrite (0, 75 and 150 mg/kg). The inclusion of SEO had no negative impact on pH, color (instrumental and sensory) and texture parameters. Total plate counts were lower than 6 log CFU (colony forming units)/g in all samples throughout the storage. Furthermore, the addition of SEO at concentration of 0.05 µL/g provided acceptable TBARS (2-Thiobarbituric acid reactive substances) values (<0.3 mg MDA (malondialdehyde)/kg) in the samples produced with reduced levels of sodium nitrite (0 and 75 mg/kg) without negative alternations on sensory attributes of odor and flavor. Generally, our findings confirmed that the usage of SEO could be a good solution to produce healthier DFS with reduced levels of sodium nitrite.