Apples mealiness

Mealiness in apples results from a breakdown in adhesion between cells so that chewing the apple tissue results in cell separation rather than cell rupture. Eating a mealy apple is therefore associated with the unpleasant sensory perception of a lack of juiciness, loss of crispness and hardness. A number of studies have succeeded in correlating the degree of mealiness with destructive reference tests such as the Magness-Taylor firmness and confined compression juiciness, but clearly there is a need for non-destructive, on-line detection of mealiness in apples. 

Fig. 5. Discriminant PLS analysis of NMR time domain CPMG data acquired at 100 MHz versus mealiness in Cox s apples having three degrees of mealiness and labelled (Coxa, Coxb and Coxc), acquired in the data for Ref. 34.

The Ti q) behave as wavevector-dependent relaxation times and the form of the wavevector dependence can provide a useful check on the consistency of models. Table 5 shows a comparison of the experimental coefficients for fresh apple tissue with those calculated with the numerical cell model. The agreement is quite reasonable and supports the general theoretical framework. It would be interesting to apply this approach to mealy apple and to other types of fruit and vegetable. 

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. 

Braconid wasps parasitize leafroller caterpillars, codling moth caterpillars, leafminer caterpillars, mealy apple aphid, green apple aphid. 

The development of modern analytical methods has permitted the examination of volatiles from fresh fruit to determine when to pick the fruit. It is the usual concept that fruits are at their best when picked "tree-ripe". However, in extreme cases, as with bananas and pears, these fruits must be picked when hard and green and be permitted to soften and ripen off the tree. If these fruits are permitted to ripen on the tree, they become mealy and unacceptable. Some fruit, like strawberries and peaches, are of best quality when left to ripen on the plants. Apples have been shown to have the best aroma if picked almost ripe and develop the most aroma about a week or two after picking. 

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