Essential Oils as Post-Harvest Crop Protectants against the Fruit Fly Drosophila suzukii: Bioactivity and Organoleptic Profile

Abstract

The essential oils extracted from mandarin (Citrus reticulata Blanco) fruits, and from tea tree (Maleleuca alternifolia (Maiden and Betche) Cheel) leaves have been chemically analyzed and tested for their bioactivity against D. suzukii. Besides, to estimate consumers’ acceptability of the essential oil (EO) treatments, we evaluated their impact on the organoleptic characteristics of the EO-treated fruits. The main chemical constituents of the two EOs were 1,8-cineole and 4-terpineol for M. alternifolia (22.4% and 17.6% of the total components, respectively), and limonene (83.6% of the total components) for C. reticulata. The behavioral tests indicate that the two EOs are able to deter D. suzukii oviposition and that D. suzukii shows positive chemotaxis to low concentrations of the EOs and negative chemotaxis when the EO concentration increases. While no negative effects on the organoleptic profiles were detected for fruits treated with C. reticulata EO, the olfactory profile of fruits treated with M. alternifolia EO was so negative that they were defined as “not suitable for consumption” by panellists. Overall, our findings indicate that the use of EOs for the post-harvest protection of small fruits is feasible, provided that the essential oils are selected not only for their bioactivity against the insect pest but also for their affinity with the consumers’ sensorial system.

Bioactivity of Different Chemotypes of Oregano Essential Oil against the Blowfly Calliphora vomitoria Vector of Foodborne Pathogens

“…To confirm the Probit results (and in the meantime to provide a more synthetic output of the results), bioassays data were also processed by one-way between-groups univariate analysis of covariance (ANCOVA), with the EOs as a fixed factor and the dose/concentration as a covariate to control its effects in the model. The mean response for each factor (EOs), adjusted for the dose/concentration, was reported as estimated marginal (EM) means, and significant differences among them were determined by post hoc comparisons using Bonferroni corrections for multiple comparisons [ 20 , 21 , 53 , 54 ]. The EOs protective effect data were processed by the Kruskal–Wallis test with the OAI as a factor.…”

“…On the contrary, the essential oils (EOs) of aromatic plants are characterized by low toxicity toward mammalians and high biodegradability [ 18 ]. Moreover, EOs of aromatic plant species, commonly used as food spices, have the advantage of being legally allowed in food and to have a smell profile already accepted by consumers [ 19 , 20 , 21 , 22 , 23 ].…”

Assessment of Lippia origanoides Essential Oils in a Salmonella typhimurium, Eimeria maxima, and Clostridium perfringens Challenge Model to Induce Necrotic Enteritis in Broiler Chickens

“…Similarly, in the present study, feed inclusion of 37 ppm LEO significantly reduced the proliferation of C. perfringens in the digested supernatant of an in vitro digestive model compared to the positive control diet by 1.94 logs. While EO have shown enhanced antimicrobial activity, the encapsulation of EO has shown higher antimicrobial activity compared to the use of EO alone by slowing down the degradation and reducing the organoleptic effects of EO [ 47 , 48 ]. In the present study, LEO was microencapsulated with maltodextrin through the spray dry process [ 27 , 28 ].…”

Search for Alternative Control Strategies of Drosophila suzukii (Diptera: Drosophilidae): Laboratory Assays Using Volatile Natural Plant Compounds

“…Six other compounds (benzaldehyde, cinnamaldehyde, cinnamon oil, ethyl cinnamate, geraniol, and star anise oil) did not repel females from ovipositing, but reduced egg hatch compared to the control, might have been ovicidal after diffusion through the oviposition medium. Fruits treated with these substances, however, will only be marketable if the compounds chosen are harmless for human consumption and cannot be detected through taste or odor [ 86 ].…”