Showing 2 results for Polyethylene
A. Kashi, S. Hosseinzadeh, M. Babalar, H. Lessani,
Volume 7, Issue 4 (1-2004)
Abstract
Watermelon (Citrullus Lanatus) cv. Charleston Gray is one of the most important cultivars grown in Iran. It has some good quantitative and qualitative characteristics but unfortunately is sensitive to Blossom End rot. To solve this problem, this experiment was conducted in a factorial manner in randomized complete block design with four replications in Research Station and Laboratories of Department of Horticulture, College of Agriculture, the University of Tehran, during 1997 & 1998. In this experiment, black polyethylene mulch was used and calcium nitrate was foliar sprayed at concentrations of 0, 4, and 6 g/L. Results indicated that mulch could increase yield by 85% over two years due to weed growth suppression and conserving soil moisture for a longer time. Foliage fresh weight, number and average weight of fruits per plant and precocity were also significantly affected by black polyethylene mulch. Furthermore, mulch reduced the number and weight of fruits affected by Blossom End rot by about 13% and 12.5% (average of two years), respectively. Calcium nitrate addition during both years had no significant effect on the measured fruit characteristics nor on Blossom End rot.
N. Meghdadian, M. Shahedi, G. H. Kabir,
Volume 8, Issue 1 (4-2004)
Abstract
Iranian flat breads generally have short shelf life. The result of this situation is usually enormous bread wastage. Among the most important factors involved are lack of proper packing and storage methods. In this study, the best temperature for bread packing was determined and the effects of three types of plastic wrapping on Taftoon bread baked of the typical flour were investigated after 72 hours of storage. These wrappings included a two-layer wrapping of oriented polypropylene and polyethylene (OPP/PE) with a thickness of 60 µ, a three-layer wrapping of PP/PE/PE with a thickness of 70 µ, and a two-layer polyethylene with a thickness of 70 µ together with cardboard and plastic. Bread packing was carried out at two different temperature ranges (20-25oC and 45-50oC). Results from moisture measurements and water activity test indicated that the characteristics of breads packed in different wrappings showed significant differences (p<0.01). Moisture percentage and water activity (aw) were lower in layers with higher permeability to moisture and water vapor and, consequently, algal growths reduced in these wrappings. Reduced moisture content, however, reduced the final bread quality score. It was also found that employing cardboard covered in polyethylene had no significant effect on bread shelf life during 72 hours of bread storage. Another finding from the present study was that packing a large number of 10×10 cm bread pieces within one single wrapping with cardboard and plastic was satisfactory and that the presence of the cardboard helped maintain bread shape during transportation and storage.
