Essential oils of aromatic and medicinal plants play a role in food safety

Antioxidant, Antimicrobial, and Insecticidal Properties of Chemically Characterized Essential Oils Extracted from Mentha longifolia: In Vitro and In Silico Analysis

The present study aimed to explore the phytochemical profile, and evaluate the antioxidant, antimicrobial, and insecticidal properties, of Moroccan Mentha longifolia L. essential oil (ML-EO) using in vitro and in silico assays. Noteworthily, as chromatography (GC-MS/MS) revealed that ML-EO is majorly composed of piperitenone oxide (53.43%), caryophyllene (20.02%), and (-) germacrene D (16.53%). It possesses excellent antioxidant activity with an IC50 of 1.49 ± 0.00 for DPPH and 0.051 ± 0.06 μg/mL for ABTS. Moreover, the RP and TAC activities were 0.80 ± 0.01 μg/mL and 315.532 ± 0.00 mg EAA/g, respectively. ML-EO exhibited a potent antimicrobial effect, specifically against Pseudomonas aeruginosa. It also exhibited strong antifungal ability, especially against Candida albicans. Regarding insecticidal activity, for ML-EO, a dose of 20 µL/mL produced a complete reduction in fecundity, fertility, and emergence of adult C. maculatus with mortality rates reaching 100%. In silico results showed that the antioxidant activity is mostly attributed to α-Cadinol, the antibacterial efficiency is attributed to piperitenone oxide, and antifungal capacity is related to cis-Muurola-4(15),5-diene and piperitenone oxide. Accordingly, ML-EO has high potential to be used as an alternative for preserving food and stored grain and protecting them against microbes and insect pests in the food and pharmaceutical sectors.

Plant extracts and essential oils in the dairy industry: A review

Plants have been used as food additives worldwide to enhance the sensory qualities of foods and extend their shelf life by reducing or eliminating foodborne pathogens. They also serve as therapeutic agents due to their beneficial effects on human health through their anti-cancerous, anti-inflammatory, antioxidant, and immune-modulatory properties. Plants can be added to food as a dry powder, grated material, paste, juice, or as an extract that can be produced by a variety of methods. Plant extracts and essential oils are concentrated sources of bioactive phytochemicals that can be added to food in small amounts in a variety of forms. These forms include liquid, semi-solid, or dry powder for easy and uniform diffusion. Encapsulation can protect bioactive compounds from temperature, moisture, oxidation, and light, as well as allow for controlling the release of the encapsulated ingredients. Nanoemulsions can enhance the bioactivity of active components. This review explains how plant extracts and essential oils are used in the dairy industry as antimicrobial materials, analyzing their impact on starter bacteria; as natural antioxidants to prevent the development of off-flavors and increase shelf life; and as technological auxiliaries, like milk-clotting enzymes, stabilizers, and flavoring agents. Therefore, plant extracts and essential oils are a better choice for the dairy industry than plants or their parts due to a wide range of applications, homogeneous dispersion, and ability to control the concentration of the bioactive ingredients and enhance their efficiency.

Effect of Galangal Essential Oil Emulsion on Quality Attributes of Cloudy Pineapple Juice

Galangal essential oil is obtained from the rhizomes of galangal with proven anti-inflammatory, antioxidant, antiviral, and antimicrobial properties, which are valuable in the food industry. To explore the effect of galangal essential oil on the quality of pineapple juice, 0.05, 0.1, 0.2, and 0.4% galangal essential emulsion were added, and their influence on the physical stability, physicochemical properties, microbial quantity, and aroma profiles of cloudy pineapple juice were evaluated. The essential oil emulsion of galangal is a milky white liquid with a strong aroma of galangal. The pH values of emulsion increased from 4.35 to 5.05 with the increase in essential oil concentration, and there was no significant difference in the particle size of the pineapple juice. The results showed that the galangal essential oil emulsion was stable and the stability of the cloudy pineapple juice was significantly enhanced by the essential oil emulsion determined using LUMiSizer. The cloudy pineapple juice with a 0.2% essential oil emulsion showed the most stability during storage. The lightness of the cloudy pineapple juice increased instantly with the essential oil emulsion addition. In addition, the microbial quantity of the cloudy pineapple juice was decreased by the individual essential oil emulsion or combined with thermal treatment to hold a longer shelf life. The microbial counts in pineapple juice treated by 0.4% essential oil emulsion and thermal treatment only increased from 1.06 to 1.59 log CFU/ml after 4 days of storage at 25°C. Additionally, the pH and total soluble solids showed a slightly increasing trend; however, the value of titratable acidity, free radical scavenging capacity, and ascorbic acid content of the cloudy pineapple juice showed no significant change. Finally, the results of the electronic nose showed that the aroma components of the pineapple juice were changed by the essential oil emulsion and thermal treatment, and the difference was especially evident in the content of the sulfur, sulfur organic, and aromatics compounds. Consequently, the results indicated that galangal essential oil emulsion can be used as juice additives to improve the quality attributes and extend the shelf-life of cloudy pineapple juice.

Antifungal and Antitoxigenic Effects of Selected Essential Oils in Vapors on Green Coffee Beans with Impact on Consumer Acceptability

The main objective of this study is to evaluate the effect of selected essential oils thyme chemotype linalool (Thymus zygis L.), thyme chemotype tymol (Thymus vulgaris L.), eucalyptus (Eucalyptus globulus Labill.), lavender (Lavandula angustifolia Mill.), mint (Mentha piperita L.), almond (Prunbus dulcis Mill.), cinnamon bark (Cinnamomum zeylanicum Nees), litsea (Litsea cubeba Lour. Pers), lemongrass (Cympogon citrati L. Stapf), and ginger (Zingiber officinalis Rosc.) in the vapor phase on growth, sporulation, and mycotoxins production of two Aspergillus strains (Aspergillus parasiticus CGC34 and Aspergillus ochraceus CGC87), important postharvest pathogens of green and roasted coffee beans. Moreover, the effect of the essential oils (EOs) on the sensory profile of the coffee samples treated with EOs was evaluated. The major components of tested EOs were determined by gas chromatography and mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). The results showed that almond, cinnamon bark, lemongrass, and litsea EOs are able to significantly inhibit the growth, sporulation, and mycotoxins production by toxigenic fungi. Sensory evaluation of coffee beans treated with EOs before and after roasting showed that some EOs (except lemongrass and litsea) do not adversely affect the taste and aroma of coffee beverages. Thus, application of the vapors of almond and cinnamon EOs appears to be an effective way that could serve to protect coffee during its transport and storage from toxigenic fungi.

Encapsulation of Natural Bioactive Compounds by Electrospinning-Applications in Food Storage and Safety

Packaging is used to protect foods from environmental influences and microbial contamination to maintain the quality and safety of commercial food products, to avoid their spoilage and to extend their shelf life. In this respect, bioactive packaging is developing to additionally provides antibacterial and antioxidant activity with the same goals i.e., extending the shelf life while ensuring safety of the food products. New solutions are designed using natural antimicrobial and antioxidant agents such as essential oils, some polysaccharides, natural inorganic nanoparticles (nanoclays, oxides, metals as silver) incorporated/encapsulated into appropriate carriers in order to be used in food packaging. Electrospinning/electrospraying are receiving attention as encapsulation methods due to their cost-effectiveness, versatility and scalability. The electrospun nanofibers and electro-sprayed nanoparticles can preserve the functionality and protect the encapsulated bioactive compounds (BC). In this review are summarized recent results regarding applications of nanostructured suitable materials containing essential oils for food safety.

Effects of Horseradish Oil and Eight Isothiocyanates Vapour Treatment on Postharvest Disease Control and Their Efficacy as Preservatives of Mature Green Tomato

This study evaluated the potential of horseradish (Armoracia rusticana) oil (ARO) and eight isothiocyanates (propyl ITC [ProITC], isopropyl ITC [IsoproITC], n-butyl ITC [n-BuITC], 3-butenyl ITC [3-BeITC], phenyl ITC [PhITC], benzyl ITC [BzITC], 2-phenylethyl ITC [PhEITC], and allyl ITC [AITC]) as preservatives and antifungal agents for postharvest tomato disease control. Results showed that ARO and eight ITCs demonstrated antifungal activities against Botrytis cinerea, Alternaria alternata, Rhizopus stolonifer, and Geotrichum candidum, which can cause the decay of mature green tomato during storage. Allyl-ITC (AITC) had the lowest EC₅₀ values of mycelia growth suppression, with 0.18, 0.44, 0.29, and 0.43 μg/ml air for B. cinerea, A. alternata, R. stolonifer, and G. candidum, respectively. ARO, 2-PhEITC, BzITC, and AITC exhibited better efficacy as preservatives of mature green tomato than other ITCs on the basis of some parameters, such as low decay rate, slow reduction in weight loss, slight change in hardness, slow decrease in acidity, and total soluble solid content of treated tomatoes. GC-MS revealed that 2-PhEITC (77.78%) and AITC (15.87%) were the major components of ARO. These results can be used as a basis to develop preservative products composed of ITCs.

Natural Preservatives from Plant in Cheese Making

Today, consumers are increasingly demanding safety alternatives concerning the use of synthetic additives in the food industry, as well as healthy food. As a result, a major number of plant-derived preservatives have been tested in the food industry. These natural ingredients have antioxidant properties and have shown to increase the bioactive molecules levels and the microbiological stability of the food items. The effect of the plant-based preservatives on the sensorial properties of the new products has also to be considered, because natural preservatives could result in sensorial characteristics that may not be accepted by the consumers. Cheese is a dairy product widely appreciated all over the world, but it is also susceptible to contamination by pathogenic and spoilage microorganisms; therefore, the use of preservatives in cheese making represents an important step. This review deals with one of the innovation in the cheese sector, which is the addition of natural preservatives. Several aspects are discussed, such as the effect of natural ingredients on the microbial stability of cheese, and their influence on the chemical, nutritional and sensorial characteristics of the cheeses. Although the promising results, further studies are needed to confirm the use of natural preservatives from plants in cheese making.