Contaminants plant-conditioning agents

Over the last few decades, safety has become one of the most important topics related to food. From this view, quality control of vegetable raw materials has at first to cover the following issues natural and anthropogenic contaminants (e.g. heavy metals, pollution from industrial and private combustions, not professionally deposited waste products, radionuclides), residues of fertilisers (e.g. nitrate), plant-conditioning and plant-protective agents, filth, pests, the microbial status and the occurrence of microbial toxins. It is not possible to discuss all these aspects in detail however, with a focus on herbs and spices, two of them should be stressed more thoroughly. For further information, see [8]. 

Pilot studies in 1982 have led to the installation of cross-flow MF in some industrial laundries. Both chemical conditioning and the addition of adsorbing and/or absorbing agents are necessary to render the contaminants filterable. The permeate may be recycled into the plant. Table 2.927 shows the nature of the raw wastewater and the effluent from the membrane system. 

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