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assembled, the components with which they are constructed, and the resulting system properties such as morphology, size, composition, and interfacial characteristics. The selection of a suitable nanoencapsulation system for antimicrobials can thus be a daunting task. However, there are a number of criteria that food manufacturers may consider when selecting a nanoencapsulation system: Maximum additive concentration (MAC) or loading capacity (LC). The maximum additive concentration or loading capacity is a measure of the amount of material that can be encapsulated (me) per unit mass of carrier material (mc), i.e. MAC or LC Âź me/mc. As we have previously seen, depending on the nature of the system, the actual calculation of the MAC may differ somewhat. The MAC or LC may be given as a mass percentage or as a molar ratio, but only if pure compounds with known molecular weights are used as carriers and encapsulated materials. Nanocapsules vary greatly in their loading capacities in systems with LC well below 1 (e.g. most microemulsions) to ratios that exceed 1 (e.g. liposomes if watersoluble compounds are encapsulated). In general, the LC should be as high as possible to minimize the costs of the encapsulation system. Alternatively, the encapsulated compounds need to be increasingly active to offset reduced loading ratios. Minimum inhibitory concentration (MIC). The MIC is a measure of the efficacy of an antimicrobial and from an application point of view is a key property that needs to be determined. Unfortunately, there is still considerable discussion going on in the scientific community as to which microbial protocol is best suited to determine the efficacy. Protocols range from in vitro tests such as agar diffusion, agar/broth dilution, gradient, and spiral plating to actual application tests that involve recovery and enumeration of microorganisms from the food system. During the development stage, food manufacturers may use in vitro tests for screening of suitable candidate systems, but validation of candidate system in their actual food product is an essential prerequisite to ensure that their encapsulated antimicrobial has the required activity. In terms of activity, it is important to note that not only the efficacy but also the specificity of the antimicrobial, i.e. the spectrum of activity, may be altered upon nanoencapsulation. For example, unencapsulated antimicrobials may not have any strain specificity, but the encapsulated system may show increased (or decreased) activity against specific strains due to the altered interaction with microbial surfaces. Mechanism of delivery and action. An antimicrobial delivery system must be designed so that it carries the functional component to a particular site-of-action (microbial surface or microbial cell interior) and then