Ali Motevali; Ebrahim Shahbazi; S. Jafar Hashemi; Reza Tabatabaei
Abstract
Maintaining the quality of fruits and increasing their shelf-life are the main concerns during post-harvest processes. One of the important methods for increasing the shelf-life of fruits is the use of modified atmosphere packaging (MAP). In this study, changes in some qualitative characteristics (color, ...
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Maintaining the quality of fruits and increasing their shelf-life are the main concerns during post-harvest processes. One of the important methods for increasing the shelf-life of fruits is the use of modified atmosphere packaging (MAP). In this study, changes in some qualitative characteristics (color, pH, TSS, texture stiffness) of apricot fruits were reviewed using MAP method at three levels of storage temperatures (ambient 22, 4 and 8 °C), three different gas mixes (first combination: 8% CO2, 4% O2 and 88% N2; second combination: 10% CO2, 15% O2 and 75% N2; third combination15% CO2, 10% O2 and 75% N2) and two thicknesses of polyethylene packages (30 and 50 µm). The data were extracted and analyzed within one week intervals by relevant tests. The results showed that the slop of color, TSS and pH changes were ascending and the slope of the texture stiffness was declining in all treatments. The highest total changes in color, TSS, pH and texture stiffness were 26.27, 7.6 (%), 3.17 and 18.04 (N), respectively, attributed to ambient storage temperature (22 °C), third gas composition (10% CO2, 15 % O2 and 75% N2) and 30 µm thickness of the package . Also, the lowest total changes of the parameters were 14.16, 2.0 (%), 1.11 and 13.49 (N) attributed to 4 °C temperature, first gas composition (8% CO2, 4 % O2, and 88% N2) and 50 µm package thickness of package. The later considered as the best treatment.
Roozbeh Abdi; S. J. Hashemi; Reza Tabatabaei Kolour
Abstract
In this study, a U-shaped reactor with aeration, heating and stirring systems was designed for composting process. The length, width and height of reactor were 110, 66 and 70 cm respectively. The experiment was carried out at different aeration rate (0.2, 0.4 and 0.6 Lit/min.Kg DM) and time (0, 19, 38, ...
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In this study, a U-shaped reactor with aeration, heating and stirring systems was designed for composting process. The length, width and height of reactor were 110, 66 and 70 cm respectively. The experiment was carried out at different aeration rate (0.2, 0.4 and 0.6 Lit/min.Kg DM) and time (0, 19, 38, 57, 76, 96 hour). The agitation speed and temperature for the purpose of this experiment was; 55 and 1 rpm respectively. In order to adjust the C/N ratio and humidity of compost, two additives namely: zeolites and rice bran was used. The initial moisture content of waste material was between 60 to 65 percent in all operations. Results showed that the changes in the EC, germination index, and C/N ratio were significant. The EC of compost declined and the pH value increased at the end of process for all operations. The average C/N ratio of compost materials changed from 28 to 20.9 after 96 hours in the reactor. In traditional method, the C/N ratio reached to 19.8 after 21 days. Composting process time has a significant effect on germination index. The maximum germination index occurred at the aeration rate of 0.4 Lit/min. Kg DM which was 85 percent. Also the results indicated that the designed reactor with continuous rotating agitator, heating and air pressure was able to convert the food waste to compost within 96 hours. Results indicate that the proposed composting system can create a suitable environment for the growth and performance of micro-organisms in order to accelerate the decomposition of food waste.
