Impact of postharvest treatments on storage life and quality of "Mexican" lima

Plant Production Dep., College of Food and Agric. Sciences, King Saud UniversityThe present work was carried out on "Mexican" lime (Citrus aurantifolia Swing.) during 2004 and 2005 seasons. The purpose of the present study was to investigate the effect of hot water, calcium chloride and sodium chloride on storage life and quality of "Mexican" lime. Fruits were subjected to the following treatments: T1) water dipping at ambient temperature (≈ 20°C); T2) hot water dipping at 55°C; T3) hot water dipping containing sodium chloride, 1% (W/V) at 55°C; T4) hot water dipping containing sodium chloride, 2 % (W/V) at 55°C; T5) hot water dipping containing calcium chloride, 1% (W/V) at 55°C; T6) hot water dipping containing calcium chloride, 2% (W/V) at 55°C. Fruits were subjected to water dipping for 5 min. Treated fruits were stored in cold room at 12°C, relative humidity (RH) was maintained at 90 %. The obtained results revealed that dipping fruits in hot water with sodium chloride 1% & 2% was effective in prolonging the shelf- life two weeks more than the other treatments in both seasons. The weight loss increased with increasing storage period in both seasons. The fruits dipping in hot water at 55°C significantly had a measurable influence in reducing the percentages of loss in fruit weight at ambient temperature (≈ 20°C). The lowest values of weight loss were detected with fruits dipped in hot water containing calcium chloride 2 %, while the highest values were detected with fruits dipped in water at ambient temperature in both seasons. Fruits dipped in water at ambient temperature and hot water at 55°C degreened after four weeks, while fruits dipped in hot water with sodium chloride (1% & 2%) or calcium chloride (1%&2%) reached yellow color after eight weeks. Fruits dipped in hot water with calcium chloride 1% or 2% have significant high values of juice %, TSS and technological index at ten weeks of storage period compared with other treatments in both seasons. All treatments had no effect on the values of fruit acidity and vitamin C. However, vitamin C significantly decreased with increasing the storage duration

A Comparison of Three Boundary Layer Schemes for Numerical Weather Prediction

Air pollution is a global issue that affects humans’ health and economic growth. In the field of meteorology, numerical models play an essential role in weather and air quality forecast. For more accurate prediction of pollutants concentrations in the atmosphere, an efficient parameterization of the planetary boundary layer is required. In this paper, performances of three different planetary boundary layer schemes were investigated through estimating PM10 pollutant mass concentration during a sand storm using the regional climate model. Wind speed and planetary boundary layer height were also evaluated to examine the consistency of the model. The simulated results were validated by comparing the estimated values to the observed and reanalysis data. The results showed that the model provided good forecast for the dust event. However, one scheme had been recommended for predicting the PM10 concentration