Storage pears

Diphenylamine inhibits the development of scald disease during prolonged cold storage of apples and pears (42—45). It prolongs the fresh appearance of cut snapdragons (46), controls weather fleck in tobacco, inhibits algae formation, and shows growth inhibitory activity in potatoes (47). 

Fruits are seasonal in temperate climates, and a good harvest may be followed by a shortage if there is no method of preservation. The hard fruits, apples and pears, have traditionally been stored in cool places and may then last for several months, depending on the variety Refrigeration has extended the storage life, and made this more reliable. 

The fruits are loaded and the store sealed. Within a few days they consume a proportion of the available oxygen and respire carbon dioxide. Considerable research over the past 60 years, mainlyin the UK [47], has determined the correct balance of gases to prolong the storage life of the different varieties of apples and pears, both home grown and imported. 

Mosshammer, M.R., et al.. Impact of thermal treatment and storage on color of yellow-orange cactns pear (Opuntiaficus-indica [L.] MiU. cv. GiaUa )jnices, J. Food ScL, 71, C400, 2006. 

Pears. Triplicate samples of 20 Bartlett pears each were used and a fourth sample was placed in cold storage for subsequent examination, as with the apples. Washing trials were performed in a standard type washer (an Ideal fruit washer with an unheated main tank unit and a water rinse tank unit, Model WKA, manufactured by the Ideal Grader and Nursery Company, Hood River, Ore.). 

The fact that so many old pear cultivars bear French names shows how valued the pear was in France the long season and warm conditions of the Continent suit them well. Pears are more difficult to store than apples, but cultivars are available to span a season from midsummer through to winter without special storage conditions. Flardy in Zones 4-9, pears are quite long-lived trees, but the quality and size of fruit starts to decline after 30 or 40 years. 

Gurrieri, S. Miceli, L. Lanza, C. M. Tomaselli, E Bonomo, R. R Rizzarelli, E. Chemical Characterization of Sicilian Prickly Pear (Opuntia ficus indicd) and Perspectives for the Storage of Its Juice. J. Agric. Food Chem. 2000, 48, 5424-5431. 

Amiot, M.J. et al., Influence of cultivar, maturity stage and storage conditions on phenolic composition and enzymatic browning of pear fruits, J. Agric. Food Chem., 43, 1132, 1995. 

Spanos, G.A. and Wrolstad, R.E., Influence of variety, maturity, processing and storage on the phenolic composition of pear juice, J. Agric. Food Chem., 38, 817, 1990. 

The flavour of distillates from apple and pear is characterised by typical aroma compounds from these fruits formed by enzymatic degradation of fatty acids to C6-fragments like hexanol, trans-2-hexenol, as well as ethyl esters and acetates of hexanoic acid. In distillates of pears, especially of the variety Bartlett pear, the characteristic pear flavour is mainly dominated by the ethyl and methyl esters of frans-2-czs-4-decadienoic acid and trans-2-trans-A-decadienoic acid [27-29], The biogenesis of these monounsaturated, diunsaturated, and triunsaturated esters may be explained by -oxidation of unsaturated linoleic and linolenic acid in the fruits. The sesquiterpene compound a-farnesene, which is formed during postharvest ripening and storage of Bartlett pears [28], shows that quality and intensity of distilled pear spirits is mainly influenced by the quality and degree of ripeness of the fruits. 

GA Spanos, RE Wrolstad. Phenolics of apple, pear, and white grape juices and their changes with processing and storage. A review. J Agric Food Chem 40 1478—1487, 1992. 

Drake, S.R., and Nelson, J.W. (1991). Quality attributes of d Anjou pears after different drying temperatures and refrigerated storage. J. Food Quality. 14, 455 65. 

Kevers, C Pincemail, J.I. Tabart, J. Defraigne, J. Dommes, J. 2011. Influence of cultivar, harvest time, storage conditions, and peeling on the antioxidant capacity and phenolic and ascorbic acid contents of apples and pears. J. Agric. Food Chem. 59 6165 6171. 

All varieties of pears, even storage varieties, can only be kept for a few weeks without cold storage. They become mealy or their flesh turns brown after a short period of optimum ripeness. This period is particularly short in summer and autumn cultivars. This is why pears are often preserved as tinned fruit, in addition to being eaten as fresh fruit. A few special varieties are used for juice production and for manufacture of fruit brandies. Although they have a lower vitamin content than apples, fully mature, well developed pears are delicious. 

Fig. 3.2. Ripening time and storage life of important pear cultivars.

Ethoxyquin Ethoxyquin, 6-ethoxy-l,2-dihydro-2,2,4-trimethylqumoline (Figure 4), is used as an antioxidant in animal feeds primarily to protect carotenoid oxidation. It may also be used in fish products, fish oU, poultry fats, potatoes, apples, and pears during storage and especially to protect pigment oxidation in ground chili and paprika (93). Ethoxyquin may act as a free radical terminater. Dimerization of the radical may inactivate the antioxidant (94). 

To demonstrate the performance of the proposed approach a FISC that comprehends one item of each instance in Fig. 1 is considered. Model data (plant and storage capacities, costs, distances, production averages and deviations, harvesting periods, etc.) can be found in [1]. Although several varieties of pears and apples exist, for the sake of simplicity, in the present model all varieties of each fruit are lumped into apples and pears . As well, although many different types of packed fruit are produced for the different markets, only regional and overseas packed fruit is considered in this model. 

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