Determining effect of phosphine (eco2fume®) fumigation under atmospheric and vacuum conditions on dried fig quality

Dried fruit are foods with a long shelf life although several factors, including storage pests, may limit their marketability. Prior to the decision to phase it out under the Montreal Protocol, Methyl Bromide (MB) was the most extensively used fumigant to control storage pests, due to its efficacy and relatively low cost. The objective of the study was to test the effectiveness of two phosphine (PH3) concentrations (1000 and 1500ppm) under conditions of normal atmospheric pressure (760mmHg) and vacuum (50 and lOOmmHg), in order to develop suitable alternatives to MB. For inclusion in the dried fig industry, MB alternatives should, of necessity, be able to prevent storage pest problems via brief exposure periods, as well as preserve the fruit quality. In the experiment, the major quality parameters were analyzed after two months of storage under ambient conditions and compared with the untreated (0% PH3/ 760mmHg) control. The results revealed that the phosphine treatments revealed no negative effects on the sugaring index, total soluble solids, titratable acidity, total phenolic content and antioxidant activity of the dried figs; however, they exerted a limited effect on the water content, water activity and firmness of the treated fruit. Both the phosphine treatments, under vacuum at 50 mmHg, and 1500ppm PH3 at lOOmmHg resulted in lower L* and C* values causing darker fruit color. Therefore, ECOFUME® treatment for 24 hours is recommended due to its low investment, operational costs and short exposure period. © by PSP

Effects of the post-harvest application of methyl bromide alternatives on storage pests and quality of dried fig [Hasat sonrasi{dotless} metil bromür alternatifi uygulamalari{dotless}n kuru incirde depo zararli{dotless}lari{dotless} ve kalitesine etkileri]

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 (PH3) 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, CO2 in pressurized tanks is recommended due to its short exposure period, and CO2 under atmospheric pressure in gas-tight cubes is recommended due to its low cost and suitability for organic production. © TÜBİTAK