The effect of oleum myrtle on the fruit quality of strawberries during MAP storage

Evaluation of Essential Oils as Sprout Suppressants for Potato (Solanum tuberosum) at Room Temperature Storage

Chlorpropham (CIPC) has been the dominant method of chemical sprout suppression for the last half-century. However, stricter regulations including outright bans on its use in several countries has prompted investigation into alternative products to replace it. Growing interest in organic foods has increased focus on the use of biopesticides, including essential oils (EOs), as potential sprout suppressants in stored potato. We evaluated the potential of ten EOs for sprout suppression in potato cultivar Ranger Russet at room temperature. Treatment with Cymbopogon citratus EO was found to be the most effective sprout suppressant, completely suppressing sprouting over the 90-day storage period. The EOs of Myrtus communis and Melaleuca quinquenervia significantly reduced sprout length relative to the control but did not have any effect on sprout number. These findings demonstrate the potential of select EOs as effective potato sprout suppressants that could replace CIPC use in this industry while also giving more power to organic potato producers and processors to control sprouting in their operations.

Exposure to Volatile Essential Oils of Myrtle (Myrtus communis L.) Leaves for Improving the Postharvest Storability of Fresh Loquat Fruits

Fresh loquat (Eriobotrya japonica Lindl.) fruits easily lose their marketability because of fungal spoilage, browning, and weight loss after harvest. The use of essential oils as postharvest treatment is a talented alternative to fungicides mainly because of their ability to reduce respiration and transpiration of the fresh fruits during storage. However, the postharvest studies with the volatiles of essential oils are limited. The present study was conducted to determine the effectiveness of volatile essential oils of myrtle (Myrtus communis L.) leaves for preserving the postharvest storability of loquat fruits. Test fruits of the present study were exposed to 5 different treatments, which are (i) water vapor (2 min), (ii) myrtle leaves (3% w/w), (iii) myrtle leaf vapor (2 min), (iv) myrtle leaf vapor (10 min), and (v) untreated control. A total of 30 compounds were isolated from the essential oil, and the three highest amounts of compounds were determined as eucalyptol (39.38%), α-pinene (24.98%), and linalool (8.18%). Exposure to myrtle leaves (3% w/w) and myrtle leaf vapor (2 min) was also noted to provide higher efficacy for reducing the weight loss, decay incidence, and browning index.

In vitro and in vivo antifungal activity of Cuminum cyminum essential oil against Aspergillus aculeatus causing bunch rot of postharvest grapes

Bunch rot in grapes is an aggressive disease and needs to be controlled during the postharvest period. We investigate the antifungal potential of Zanthoxylum bungeanum Maxim., Zanthoxylum rhetsa, Cuminum cyminum, Coriandrum sativum, and Zingiber montanum (J. Koenig) Link ex A. Dietr. essential oils against Aspergillus aculeatus that cause bunch rot disease on postharvest grapes. C. cyminum essential oil exhibited stronger significantly inhibition percentage of 95.08% than other treatments in in vitro assay. Cumin aldehyde (33.94%) and α-terpinen-7-al (32.20%) were identified as major volatile compounds in C. cyminum oil. Antifungal potential of C. cyminum oil was then tested in conidia germination and in vitro tests compared to cumin aldehyde and α-terpinen-7-al. Their EC₅₀ values against the conidial germination were also estimated. Significant reduction of conidia germination was also detected in C. cyminum essential oil and cumin aldehyde at a concentration of 1,000 and 100 μg/mL, respectively. EC₅₀ values of the C. cyminum essential oil, cumin aldehyde, and α-terpinen-7-al were 67.28 μg/mL, 9.31 μg/mL, and 13.23 μg/mL, respectively. In vivo assay, the decrease of the disease severity (0.69%) and incidence (1.48%) percentage of A. aculeatus on grape berries treated at 1,000 μg/mL of C. cyminum essential oil was significantly greater than that obtained from other treatments after 10 days incubation. In addition, grape berries treated with C. cyminum essential oil decreased weight loss and retained fruit firmness. The changing of total soluble solids, total phenolic content, and antioxidant activity are also delayed in treated fruits. Therefore, essential oil of C. cyminum may be applied as a biological antifungal agent to control A. aculeatus in postharvest grapes without any negative effects on its quality.

Antiviral Activity of Essential Oils Against Hepatitis A Virus in Soft Fruits

Berries have repeatedly been associated with outbreaks of hepatitis A virus (HAV) infection. The fruits are usually minimally processed in the food industry due to their delicate nature. While washing treatments partially remove enteric viruses, the commonly used chemical additives produce toxic by-products. A valid alternative to preserve the food safety of these products could be the use of essential oils (EOs). EOs exert antimicrobial activity and do not interfere with the nutritional characteristics of food products. We investigated the efficacy of four essential oils, lemon (Citrus limon), sweet orange (Citrus sinensis), grapefruit (Citrus paradisi), and rosemary cineole (Rosmarinus officinalis chemotype 1.8 cineole) in reducing viral loads of HAV in soft fruits. Mixed fruit berries were inoculated with 10^6.74 TCID₅₀/ml of HAV, and treated with four different EOs (0.5% lemon, 0.1% sweet orange and grapefruit, and 0.05% rosemary) for 1 h at room temperature. Virus infectivity was then assessed by titration assays for its ability to grow on cell cultures. A statistically significant reduction in HAV titer on the fruit surface was observed after treating the berries with EOs of lemon (2.84 log TCID₅₀/ml), grapefruit (2.89 log TCID₅₀/ml), and rosemary cineole (2.94 log TCID₅₀/ml). Rosemary cineole was the most effective EO in reducing viral titer on berries, followed by grapefruit EO. These results improve our knowledge about the antiviral activity of these EOs and highlight their potential use in fresh produce sanitation.