Salvatore D’Aquino

Combined effects of potassium sorbate, hot water and thiabendazole against green mould of citrus fruit and residue levels

Postharvest treatments of potassium sorbate only controlled recently established infections of Penicillium digitatum on Femminello siracusano lemons but did not confer any persistent protection. The loss of efficacy of potassium sorbate to control green mould decay was related to its irregular deposition on the fruit surface, as revealed by environmental scanning electron microscopy of oranges, and to the brief persistence of potassium sorbate residues. When treatment was done at 53°C, the co-application of potassium sorbate with thiabendazole reduced thiabendazole residues in Moro and Sanguinello oranges, compared to thiabendazole treatment alone. However, treatment efficacy against two isolates of P. digitatum (thiabendazole-sensitive and thiabendazole-resistant) notably improved, indicating that potassium sorbate and hot water potentiated thiabendazole activity. Potassium sorbate residues remarkably decreased during fruit storage and were not affected by the co-application of thiabendazole.

Kumquat—Fortunella japonica

Abstract Kumquats ( Fortunella spp.), the smallest of the citrus fruits, are characterized by a fleshy, sweet and edible exocarp, a reduced mesocarp and an acidic endocarp. Kumquats are an excellent source of nutrients and phytochemicals including flavonoids, vitamins, carotenoids, and terpenoids, with a marked antioxidant activity. The rich content of essential oils, besides contributing to the nutraceutical properties of the fruit, confer a distinctive and pleasant flavor. The postharvest life of kumquats is greatly offset by their high perishability under ambient conditions, due to the high transpiration rate which leads to a rapid decline of firmness and increase of weight loss and shriveling. The postharvest life of kumquats is further limited by the high susceptibility to postharvest decay, particularly incited by Penicillium digitatum and Penicillium italicum , the causal agents of green and blue molds, respectively. Cold storage is an effective means to prolong fruit shelf-life, especially when combined with postharvest treatments other than synthetic fungicides, which delay pathogen growth without leaving chemical residues on fruit. This aspect is very important for consumer safety, as kumquat fruits eaten as a whole. Besides fresh consumption, fruit are largely used to prepare jams, candies, fruit in spirits, syrups, and liqueurs as well as decorations.

Postharvest applications of clove essential oils on dry seeds stored under simulated warehouse conditions

Abstract Clove essential oil was applied in postharvest trials on peanuts, beans, apricot kernels, and lentils stored in jute bags, and on wheat, maize, rice, and rape kept in silos, at ambient temperature (20°C). Eugenol, accounting for 85.6% of clove essential oil, has been used to assess clove essential oil residues after treatments in dry seeds. Two trials at different concentration and storage time were carried out. Immediately after treatment eugenol residues were under the instrumental limit of detection (LOD, 0.5 μg/Kg), except for wheat, peanuts, and rice (0.03, 0.10, 0.24, 0.23 mg/kg, respectively), and increased till a maximum after 2 weeks, except peanuts and apricot kernel which peaked after 30 days (12.69, and 0.47 mg/Kg, respectively). Sensory analysis showed that ventilation of the seeds allowed to decrease eugenol residue values under the flavor perception capacity of the in house panel (0.10 mg/kg), thus not affecting the organoleptic characteristics of the seeds.