**5. Plant essential oils based nano formulations against deteriorating fungal postharvest rots**

Postharvest fruit decay is controlled with essential oils and is observed as an innovative drift in natural conservation [24]. Clove essential oil (CEO), as a natural antimicrobial agent, is generally recognized as a safe substance, shows strong in vitro activity against fungal rots [26]. Various studies revealed importance of essential oils *viz.* Eucalyptus [27], Thyme, Savory, Cinnamomum, Peppermint [28] and their antifungal efficacy against postharvest fungal rots of fruits *viz.* peaches, pears, apples, banana [29], citrus [30], strawberry, grapes, avocado, mango, and papaya. Another study revealed that organic extracts of various parts of *Lawsonia inermis* L. against *Aspergillus niger*, *Penicillium notatum*, *Fusarium oxysporum*, *Colletotrichum gloeosporioides* and *Rhizopus stolonifera* were highly effective in different environments [31, 32].

Furthermore, it was also reported that plant EO treatments have the prospective to control black, green and blue mold disease on fruits. It was narrated that the mycelial growth and conidial sprouting were distinctly affected by essential oils in a dose dependent manner [33]. Ultimately plant pathologists and scientists found excellent substitutes against postharvest fungal rots of perishable fruits and vegetables in the form of biocides [34].

Plant essential oils were applied against peaches with soft watery lesions and fluffy mycelium of fungus on outer surface, collected during fruit market survey at Cairo Egypt with soft watery lesions and fluffy mycelium of fungus on outer surface during fruit market and essential oils resulted insignificant reduction in growth of fungal mycelia [35].

However, the efficacy of plant essential oils holds significant importance in restraining pathogens mode of dispersal, by minimizing the spore load on fruit surfaces in the storage atmosphere [36]. Usually, plant essential oils are harmless together for the ecosystem and anthropological wellbeing, hence attention in their use as antifungal agents of postharvest fungal rots is increasing rapidly. Plant essential oils are non-hazardous to the treated fruits, vegetables and environment followed by human consumption. Plant EO's are elementary active natural pesticides and beneficial agents against various fungal phytopathogenic rots [37].

Plant EO's extracted from anise (*Pimpinella anisum* L.), thyme (*Thymus capitatus* L.), lemon (*Backhousia citriodora* F. Muell.) spearmint (*Menta spicata* L.) hold excellent antimicrobial nature and revealed inhibitory results against postharvest fungal peach rots. The fundamental component, citral, in citrus essential oil showed

### *Essential Oils Based Nano Formulations against Postharvest Fungal Rots DOI: http://dx.doi.org/10.5772/intechopen.113834*

fungitoxic effect against various threatening postharvest phytopathogenic rots. Clove (*Syzgium aromaticum*) essential oil has been used since ages for its excellent properties including antifungal applications. In the previous dual eras, growing concern has been determined on clove EO to reduce postharvest fungal rots and progress storage quality of agricultural products [24, 26].

Moreover, eucalyptus (*Eucalyptus globulus*) essential oil possesses broad biotic activity, including anti-fungal, anti-microbial, acaricidal and nematicide features. The central components present in Eucalyptus EO, including eucalyptol, γ-terpinene, limonene, *p*-cymene, 1,8-cineole, α-pinene, ocimene α-terpineol, camphene and linalool play major fundamental role in disrupting cell wall of phytopathogenic rot fungi. Plant EO's are of utmost importance in holding fungistatic properties. Destruction of fungal spore germination by plant essential oils show fundamental role in limiting the spread of phytopathogenic rot pathogens [36]. Many essential oils can enhance shelf life and preserve quality harvested fruit while having no detrimental impact on the fruit itself [37].

Essential oils provide an alternative and more ecologically friendly strategy against fungal postharvest rots [20]. The fungicidal nature of plant essential oils might be owed to synergism amongst their mechanisms, subsequently, maximum activity has been reported to be improved mutually. The fungicidal action of plant EO's might be boosted by the technique of application. The possible potentially applicable strategies of with plant essential oils by immersion or spurting against postharvest phytopathogenic rot fungi has already been observed in fruit and vegetables. The pattern of several postharvest handlings may advance the efficacy of controlling postharvest fungal rots [38].
