Antimicrobial, antioxidant, and sensorial impacts of oregano and rosemary essential oils over broccoli florets

Abstract

Combination of oregano and rosemary essential oils (EOs) was proposed to obtain a better antimicrobial and antioxidant effect on fresh‐cut broccoli compared to the use of individual oils. In in vitro assays, EOs combinations (oregano + rosemary) were more effective to inhibit the growth of Escherichia coli O157:H7, Salmonella Choleraesuis, Listeria monocytogenes, and Staphylococcus aureus compared to individual EOs doses. Oregano EO showed a higher antioxidant power compared to rosemary tested by DPPH and TEAC methods. Moreover, oregano + rosemary EOs (concentrations of 0.24 + 0.91 mg/ml) added within pectin coatings reduced coliform counts by 1 log unit and yeasts and molds by 1.8 log of coated broccoli; meanwhile, individual application of EOs (oregano at 0.48 and rosemary at 1.82 mg/ml) was not as effective. It was demonstrated that a mixture of EOs offered antimicrobial protection to fresh‐cut broccoli without negatively affecting its sensorial acceptability, even when no significant increment in its antioxidant capacity was observed. Practical applications Combination of essentials oils with different composition reduces the amount and costs of agents needed to inhibit bacterial growth and survival. The use of essential oils as oregano (Lippia graveolens) and rosemary (Rosmarinus officinalis) combined a diverse mixture of antibacterial compounds that could be a solution to avoid bacterial resistance developed for the treatment with single compounds. Additionally, the negative sensorial impact of higher single oils doses could be reduced when combined, creating a new range of flavors and odors.

Antibacterial, Antifungal, Antimycotoxigenic, and Antioxidant Activities of Essential Oils: An Updated Review

“…Additionally, it has been reported that the combination of EOs showed a synergistic effect on the antioxidant activities of EOs [ 34 , 198 ]. Misharina and Samusenko [ 199 ] determined the antioxidant properties of several EOs either as single or in combination ( Citrus limon L. (lemon), Citrus paradisi L. (pink grapefruit), Coriandrum sativum L. (coriander), and Caryophyllus aromaticus L. (clove buds)).…”

Identification and Classification of Libyan Rosmarinus Officinalis Essential Oil Components by GC-MS and Predication of Its Antioxidant Activity

“…On the other hand, extrinsic factors and described by ecological and environmental aspects such as attitude, soil composition, climate and light, all these factors can drastically affect the chemical composition of essential oils (Stahl-Biskup, 2002). Thus, these variations are of distinct important when studying the biological activity, such as, anti-oxidant capacity of essential oils as the degree of activity has to be related to its chemical composition (Panizzi et al, 1993;Lahlou and Berrada, 2003;Alvarez et al, 2019).…”

Effect of an edible coating composed of whey protein concentrate and rosemary essential oil on the shelf life of fresh spinach

“…A study by Alvarez et al. (2019) demonstrated the inhibition of the coliforms’ growth on fresh‐cut broccoli by a combination of oregano and rosemary essential oil (Alvarez et al, 2019). Another study on the refrigerated chicken meat covered with cellulose acetate film and REO reported that the coliform growth in the film containing 50% REO was significantly controlled and reduced compared to the control sample during the storage period, while the films that contained 20% essential oil did not demonstrate significant antimicrobial effect (Melo et al., 2012).…”