DECISION SUPPORT IN RURAL TELECOMMUNICATION NETWORK PLANNING

In this work we present the relevant features and methodological approaches of a DSS (Decision Support System) for dynamic planning of rural telecommunication networks. We outline the complexities and difficulties of the formulation and of the planning process. A relevant feature of the model is the attempt to integrate AI techniques and specialized heuristics (using mathematical programming algorithms for particular sub-problems), aiming at obtaining solutions of better quality. The structure of the DSS is presented and justified as well as the main procedures of the model, regarded from the point of view of the decision environment.     

EFFECT OF WAX APPLICATION ON THE QUALITY,LYCOPENE CONTENT AND CHILLING INJURY OF TOMATO FRUIT

ABSTRACT

Waxed and nonwaxed mature green tomato fruits were stored at 12C (nonchilled) or 5C (chilled) for 5, 10, 15 and 20 days before being transferred to 22C for 3, 6, 9 and 12 days, were evaluated for weight loss, chemical composition, skin color, chilling injury (CI) index and pigment content. Waxed fruits showed a delay in weight loss, color development and ripening. The sensitivity of tomato fruit to CI was reduced in waxed fruits, which showed a delay in the appearance of symptoms. A delay in chlorophyll degradation and lycopene synthesis was observed as a result of the use of wax and low temperature. Waxing of tomato fruits allowed their storage at temperatures below critical reducing CI sensitivity and maintaining quality giving more time for marketing.

PRACTICAL APPLICATIONS

Nowadays, local tomato producers use wax on fruits as an everyday practice to carry postharvest fungicides and to improve brightness. They store tomato fruits at nonchilling temperature (12C) because lower temperatures would cause chilling injury and irregular ripening. In this way, it is interesting that waxing tomato fruits allow reducing their storage temperature, protecting them from chilling injury and maintaining their quality and correct color change and ripening; thereby producers and sellers have more days to position their fruits with no extra cost.     

EFFECT OF PACKAGING MATERIALS ON COLOR,VITAMIN C AND SENSORY QUALITY OF REFRIGERATED MANDARIN JUICE

ABSTRACT

Refrigerated mandarin juice was packed in four different containers, three cartons with different composition and one polyethylene terephthalate transparent bottle, and was stored at 4C for 90 days. During the storage of these juices, changes in the headspace gas composition, vitamin C, and CIE L*, a* and b* color coordinates were evaluated. In addition, a consumer panel evaluated the sensory color, fresh mandarin flavor and presence of off‐flavors in the juices. Experimental data indicated that the deterioration of mandarin juices (ascorbic acid degradation and darkening of color) was triggered by the rise in oxygen in the headspace of the storage containers. The type of container played a predominant role in determining the juice quality, with carton containers with an inner layer of aluminum foil providing the juices with the best quality throughout their storage.

PRACTICAL APPLICATIONS

Results from this study will provide manufacturers of mandarin juice with information dealing with the storage and quality of juices packed in different containers. In this way, if manufacturers want to use transparent polyethylene terephthalate (PET) bottles showing the color and appearance of the juice, they will be aware that the shelf life of the juice will be much shorter than in packed cartons; this reduction will be from more than 90 to 36 days (PET bottle). On the other hand, if manufacturers want to use carton for their packaging, they will be aware that using a container with a thick inner layer of aluminum foil will maintain the quality of the juice for a longer time (over 90 days) compared with a shelf life of about 54 days from cartons with an inner layer of ethylene vinyl alcohol copolymers.