Effects of the post-harvest application of methyl bromide alternatives on storage pests and quality of dried fig

Authors: FATİH ŞEN, KAMER BETÜL MEYVACI, UYGUN AKSOY, MEVLÜT EMEKÇİ, AHMET GÜRAY FERİZLİ

Abstract: Storage insect pests, microbial deterioration, and mycotoxins are major threats to dried fruit. Methyl bromide (MeBr) was the fumigant used to control pests until it was banned. The present study compared the use of MeBr (60 g m^{-3} for 24 h) and alternatives-magnesium phosphide (1 and 2 g of phosphine (PH_3) per ton of dried fig for 5 days), and carbon dioxide (CO2) at atmospheric pressure (in gas tight cubes for 5 days) and high pressure (2 h in pressurized tanks at 25 bars)-in controlling major pests (Ephestia cautella (Zell.) and Carpoglyphus lactis) of dried fig and in respect to dried fig quality. Fruit quality was investigated before exposure and after 2 months of storage at ambient conditions by analyzing moisture content, water activity, surface color, firmness, total soluble solids, titratable acidity, pH, and sugaring index. The effect on fruit surface was examined under a scanning electron microscope. The results show that the tested methods effectively controlled storage pests without any major adverse effects on quality, and each had an advantage for the implementation stage. Magnesium phosphide treatment of 1 g t^{-1} for 5 days is recommended due to its low investment and operational costs, CO_2 in pressurized tanks is recommended due to its short exposure period, and CO_2 under atmospheric pressure in gas-tight cubes is recommended due to its low cost and suitability for organic production.

Keywords: Dried fig, magnesium phosphide, CO_2, storage pests, quality

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