Softening of Canned Apricots: A Chelation Hypothesis

Infiltration of apricot (Prunus armeniaca L.), Patterson cultivar fruits, which are susceptible to rapid softening, with calcium chloride before processing resulted in definite firming of the canned apricots. Non-susceptible fruits treated with citrate buffers (pH 3.7) showed dramatic post-process softening. In individual, untreated, early, green fruit, firmness after processing was directly correlated with the bound calcium:citrate ratio. Based on a chelation hypothesis, it was proposed that softening was accelerated when chelators such as organic acid anions removed structural calcium from the cell wall once cell membranes were lysed by heating.     

OXIDATIVE STABILITY OF SESAME PASTE (TEHINA)

Tehina samples were prepared from raw, roasted and steamed, or microwaved dehulled sesame seeds from Egypt. Samples contained 54, 96 α 0.36% lipid, 20.68 β 0.19% protein, 3.28 ± 0.05% ash and 1.76 ± 0.06% moisture. The peroxide values (PV) of tehina, stored under Schaal oven conditions at 65C after 35 days, reached 72.2, 86.2 and 97.2 meq/kg for samples prepared from raw, roasted and steamed, and microwaved seeds, respectively. The p-anisidine values (p-AnV) of samples stored under the same conditions and over the same period were 9.3, 10.1 and 10.2, respectively. Meanwhile, both PV and p-AnV of tehina samples stored at room temperature were considerably lower than those kept at 65 C and did not exceed 2.9 and 2.6 meq/kg, respectively. Both PV and p-AnV of tehina samples were lower than those obtained for oils extracted from dehulled sesame seeds which were subjected to similar pretreatment conditions.     

Canning-Induced Fruit Softening and Cell Wall Pectin Solubilization in the 'Patterson' Apricot

The canning of slightly immature ‘Patterson’ apricot fruits leads to an immediate softening of the halves to the extent that many are of unacceptable texture. This softening occurs in conjunction with a substantial solubilization of uronic acid-, arabinose-, and galactose-rich (presumably pectic) polysaccharide material into the canning liquid. The solubilization is not accompanied by pectin depolymerization suggesting that some process other than acid-catalyzed polymer hydrolysis is responsible for fruit softening during processing.     

Desertification impact assessment in Egypt using low resolution satellite data and GIS

In this study, desertification processes and their impact on land cover changes in Egypt from 1992 to 2000 were analyzed using low‐resolution satellite data. Two images of NOAA‐AVHRR and SPOT vegetation data acquired in November 1992 and 2000 were used to assess desertification and changes of agricultural lands in Egypt. A supervised classification of the two images was carried out using the Maximum Likelihood technique. Change image was produced using classified images, through a cross‐tabulation Geographic Information Systems (GIS) module, to assess the trend and form of land cover changes.

It was found that agricultural land increased by about 14.3% during the study period, in particular, around the Nile River Delta and around the Northern Lakes of Egypt. The newly cultivated lands were extracted mainly from desert and salt marshes. At the same time, parts of the agricultural lands were turned into degraded land due to desertification and urban expansion.     

Near-minimum time control of flexible manipulators with a payload

In this paper near-minimum time controllers for coordinating flexible two-link robots carrying an object in a workspace are developed. Bang-bang control theory in conjunction with synchronization of execution time for each joint is used to derive the near-minimum lime controller. The near-minimum time control law is implemented for two distinct cases. One is for a single flexible robot grasping a payload white the other is for a master/slave configuration for the motion of two flexible robots and their load. Simulation results indicate the feasibility of the proposed schemes.     

NOAA AVHRR image referencing

Abstract

A simple and fast algorithm for image referencing of the NOAA (National Oceanic and Atmospheric Administration) AVHRR (Advanced Very High Resolution Radiometer) data has been derived to facilitate the identification of geographic co-ordinates corresponding to any pixel on an NOAA image and vice versa. The procedure assumes a spherical Earth and circular orbit and takes into account the effects due to the Earth's rotation and oblateness and the scan skew. Inputs to the procedure are the ascending nodal longitude and lime, the time of the first scan line and one ground control point (GCP). The effects of an ellipsoid Earth and an elliptical orbit are corrected by using the GCP to adjust the spacecraft altitude and inclination angle. No detailed emphemeris data arc required. The average r.m.s. errors obtained by comparing with independent sets of well-distributed GCPs for each image are about 2 pixels and 2 lines or 3 km displacement. Results from the procedure are illustrated by the rectification of NOAA images over France.     

Effects of Short-term Exposure to Low O2 and High CO2 Atmospheres on Quality Attributes of Strawberries

Strawberries (Fragaria ananassa Duch., cv. ‘Selva') were stored 10 days in 1.0%, 0.5%, or 0.25% 0₂ or air + 20% CO₂; or 6 days in air + 50% or 80% CO₂ at 0 or 5°C without detrimental effects on quality. Decay and softening were reduced by treatments. An untrained taste panel, under ordinary eating conditions, did not consistently differentiate ‘Pajaro’ strawberries kept in 0.25% 0₂ from those stored in air. A trained taste panel, under controlled conditions, perceived slight off-flavor in ‘G3’ strawberries kept in 0.25% or 0% 0₂. This correlated with ethanol, ethyl acetate, and acetaldehyde in juice. The 50% or 80% CO₂ treatments caused injury after 8 to 10 days, while 20% CO₂ treatments did not. All high CO₂ treatments caused increase in pH of juice.     

A discrete-time coordinated adaptive stabilizer for multimachine power systems

A digital PSS design technique for a multimachine power system suitable for easy integration into the power system control hierarchy at the generating plant level is presented in the paper. The adaptive inputs are obtained at each unit as feedback from local measurements, and the reference models in the proposed PSS scheme are designed to reflect the dynamic interaction between each generating unit (GU) and the multimachine system. The effectiveness of the proposed technique is demonstrated on a multimachine power system using computer simulation studies.     

SOLAR INDUSTRIAL PROCESS HEAT POTENTIAL IN ALEXANDRIA,EGYPT

The present paper investigates the economic viability of the solar domestic hot water systems for industrial processes in Alexandria, Egypt. Also, the optimum parameters of such systems in Alexandria, Egypt have been determined.

The industries covered in the present study are soft drinks, and vegetable oil. The weather data for Alexandria, Egypt (latitude 31.2°) was used. The data file of Alexandria contains monthly average values of daily radiation on a horizontal surface, clearness index, ambient temperature, wind speed, and relative humidity.

The economic calculations for this study are based on life-cycle savings calculations. The f-chart design method is used to estimate the long-term annual thermal performance of solar domestic hot water systems.

The main results obtained can be summarized in the following: 1) solar domestic hot water systems are preferable alternatives to the conventional heating systems currently used in food industries in Egypt. 2) significant life-cycle savings can be achieved with solar heating systems.     

CHEMOMETRIC CHARACTERIZATION OF FIVE TUNISIAN VARIETALS OF OLEA EUROPAEA L. OLIVE FRUIT ACCORDING TO DIFFERENT MATURATION INDICES

The usefulness of some chemical parameters as a tool to discriminate five varietals of olives was evaluated. Fruits were collected from the same orchard in order to eliminate geographical and climatic effects. Biochemical and quality characteristics in the fruits at complete ripeness were also investigated. Results showed that pomological characteristics and fatty acid composition may differ, depending on the variety and ripeness state, which is confirmed by an analysis of variance. A linear trend between mannitol and oil content was observed ( r =  0.665; P <  0.001). Jeddaria Chaal olive oil had both the highest triolein (39.33%) and oleic acid value (74.43%). However, Chemlali Chouamekh olive oil showed the highest pigment (59.29 and 26.37 mg/kg of chlorophylls and carotenes, respectively) and α-tocopherol content (201.40 mg/kg). Thus, the cultivars were clearly differentiated in their metabolic behavior and the biochemical characteristics of their oils. Ripening state is used mainly as a guideline to establish the olive harvest time. The present data provide information about the maturation patterns of different cultivars and how it can influence the quality of the final product.

PRACTICAL APPLICATIONS

This research is strongly oriented to the agronomic application. The obtained results can orient an agronomist to the optimum ripening date of olive fruits with a good amount of oil and a balanced fatty acid composition.