Harvest methods, fruit

For harvesters, there are only a few field experiments described in the literature. The harvesting method and crop have been studied and some reports exist which can be compared. What seems apparent from these reports Is that the exposure process is the same for the harvesting of such tree fruits as citrus and apples. At least, the proportion of harvester exposure to pesticide on the leaf surface Is the same. For other types of crops this proportion may be different. 

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. 

A method has been reported for the quantification of five fungicides (shown in Figure 5.39) used to control post-harvest decay in citrus fruits to ensure that unacceptable levels of these are not present in fruit entering the food chain [26]. A survey of the literature showed that previously [27] APCl and electrospray ionization (ESI) had been compared for the analysis of ten pesticides, including two of the five of interest, i.e. carbendazim and thiabendazole, and since it was found that APCl was more sensitive for some of these and had direct flow rate compatibility with the HPLC system being used, APCl was chosen as the basis for method development. 

Leafy vegetables and some fruits in particular are rich sources of chlorophylls. However, they are ranked among the most perishable post-harvest products and must be consumed within a few days after harvest or subjected to preservation methods to extend their freshness. Their typical green color is, if not the most important sensory attribute, an extremely important parameter of quality. Any discoloration can lead to rejection by consumers as the bright green color is intuitively linked with freshness. 

Picking fruit at an optimal harvest date is also an important factor affecting the nutritional and sensory quality and storability of fruit. Regardless of the production method, a fruit grower needs precise information on the seasonal (e.g. climate) and site-specific parameters that determine the optimal harvest... 

The details of the juice extraction process will depend on the fruit, but this section outlines a typical method. Some processors size the extraction plant to handle all the juice they will require for the year within the harvesting period others will freeze or otherwise store the fruit and extract juice as it is required on a much smaller plant. 

Mycotoxins are toxic secondary metabolites produced by fungi growing within or on foods. They can be a serious threat to human and animal health (Nagler el al., 2001). Table 11.4 details mycotoxins associated with soft drinks and fruit juice manufacture and raw materials. Patulin is the most common mycotoxin associated with fruit juice, particular ly apple juice (Pitt Hocking, 1997). It commonly occurs if juice is produced from stored apples. Mould growth in infected apples increases with time, raising levels of patulin. The use of windfall apples for juice is also a factor. Avoidance of windfall apples, filtration of juice and pressing quickly after harvest are all methods to reduce the incidence of patulin in juice. Patulin can be destroyed by fermentation to cider or by the addition of ascorbic acid (Marth, 1992). Within Europe, the European Union has set a limit of 50 ig/kg for patulin in both apple juice and cider. A recent survey of apple products in Chile found that 28% of samples of juice and concentrate exceeded this limit (Canas Aranda, 1996). 

These primitive peoples had one major concern howto preserve the crops and wild fruits and vegetables, as well as the meat from the animals they slaughtered. Over time, they developed methods for storing excess food in such a way that it could be eaten even when there was little fresh food available. Especially in northern climates where winters could be harsh, food preservation became vitally important if people were to live from harvest to spring, when the first wild fruits and vegetables became available. 

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