Effects of Essential Oils on Post Harvest Quality and Shelf Life of Mango (Mangifera Indica L.)

Effects of essential oils, namely Cinnamon, Citronella, Peppermint, Eucalyptus, Lavender, Thyme, Rosemary, Basil oil enriched coconut oil emulsion on shelf life and quality of ambient stored mango cv. Rangkuai were evaluated. Citronella oil (Cymbopogon nardus) @ 0.5% (v/v) was found to maintain low weight loss (5.14%), high fruit firmness (52.85 N/cm2), ascorbic acid (33.62 mg/100 g), total phenol (89.67 mg/100 g) and least fruit decay (8.33%) at 12 days after storage (DAS) and had delayed accumulation of pulp colour (L: 91.06, a: -2.61, b : 24.03), β-carotene (3.85 mg/100 g) and total sugar (4.46%) for delayed ripening, thus found to extend the shelf life by 7 days compared with control (12.85 days). Bangladesh J. Bot. 50(4): 1143-1149, 2021 (December)

Use of Essential Oils for the Control of Anthracnose Disease Caused by Colletotrichum acutatum on Post-Harvest Mangoes of Cat Hoa Loc Variety

Anthracnose disease caused by Colletotrichum spp. makes heavy losses for post-harvest mangoes of Cat Hoa Loc variety during storage, packaging, and transportation. The synthetic fungicides are commonly used to control the disease, but they are not safe for consumers’ health and environment. This study was aimed to investigate the use of essential oils (EOs) as the safe alternative control. Pathogen was isolated from the infected Cat Hoa Loc mangoes and identified by morphology and DNA sequencing of the ITS region. Six EOs (cinnamon, basil, lemongrass, peppermint, coriander, and orange) were chemically analyzed by GC–MS. The antifungal activity of EOs was studied in vitro and in vivo. The results showed that the isolated pathogen was Colletotrichum acutatum. Cinnamon, basil, and lemongrass EOs effectively inhibited the growth of C. acutatum in descending order of cinnamon, basil, and lemongrass. However, they (except basil oil) severely damaged fruit peels. The antifungal activity was closely related to the main compounds of EOs. Basil EOs effectively controlled anthracnose development on Cat Hoa Loc mangoes artificially infected with C. acutatum, and its effectiveness was comparable to that of fungicide treatment. Consequently, basil EOs can be used as a biocide to control anthracnose on post-harvest Cat Hoa Loc mangoes.

Toxicity and Biochemical Effects of Cumin and Basil Essential Oils on Tribolium Castaneum

The essential oils (EOs) of cumin (Cuminum cyminum L.) seeds and basil (Ocimum basilicum L.) herb were extracted by hydrodistillation and tested against the red flour beetle, Tribolium castaneum (Herbst) for insecticidal and biochemical effects on certain enzymes of this insect. Major components of C. cyminum EO determined by gass chromatography-mass spectrometry (GC/MS) analysis were γ-terpinene (15.78 %) and benzenemethanol (11.32 %), while those of O. basilicum EO were linalool (56.7 %) and epi-α-cadinol (11.4 %). The lethal concentration values for 50% mortality after three days of T. castaneum whole body exposure were 678 mg kg–1 for cumin oil and 755 mg kg–1 for basil oil. The enzymatic activity of treated insects showed a reduction in total protein, alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase compared to untreated ones. However, α-amylase activity increased with both tested EOs. Hence, for T. castaneum control, these EOs may represent alternatives to conventional insecticides.

In vitro Trypanocidal Activity of Essential Oils of Some Plants against Trypanosoma evansi

In this study, the antitrypanosomal action of Lavandula angustifolia Mill. (Lavender), Matricaria chamomilla L. (chamomile) and Ocimum basilicum L. (Basil) essential oils was investigated against Trypanosoma evansi. The Gas Chromatography/Mass Spectrometry (GC/MS) was used to analyze these essential oils and identifying their chemical components. The main components present in lavender oil were 1,8-cineole (88.02%) and camphor (8.09%). In chamomile oil, bisabolol oxide (43.81%), cis-α-farnesene (17.79%) and bisabolone oxide (7.71%) were found to be the most predominant components. Basil oil is principally composed of benzene, 1-methoxy-4-(2-propenyl) (52.68%), L-linalool (29.46%) and 1, 8-cineole (9.46%). In vitro results revealed that all the tested oils exhibited notable trypanocidal action and inhibited the growth of T. evansi. The minimum antitrypanosomal activity was determined by chamomile oil and the strongest was determined by lavender oil. These findings suggest that the tested essential oils could be investigated in future studies for the treatment of T. evansi.

Encapsulation of Basil Essential Oil by Paste Method and Combined Application with Mechanical Trap for Oriental Fruit Fly Control

In this work, the chemical compositions of basils oils, including those of lemon basil, white holy basil, Thai basil, tree basil and red holy basil, were analysed. Methyl eugenol was detected in all types of basils. The essential oils of red and white holy basils possessed a comparable ability (~25%) to attract male Oriental fruit fly to the synthesised fruit fly attractant in the laboratory experiment. To control the release of the active ingredients, the white holly basil oil (WBO) was encapsulated with maltodextrin (MD) and gum arabic (GA) by paste method. The essential oil is retained in the wall complex much longer with the addition of MD. The results also revealed that the combination of the MD:GA (25:75) had the highest loading efficiency of the oil (9.40%) as observed by the numerous porous structures by scanning electron microscopy. Fourier-transform infrared spectra of the encapsulated polymer confirmed traces of essential oil functional groups. The field test study advised that WBO-encapsulated products improved fruit fly attractive efficiency by maintaining the release rate of basil essential oil.