Nanotechnology in Food & Agriculture

ingredients delivers greater bioavailability,improved solubility and increasedpotency compared to these substancesin larger or micro-encapsulated form(Mozafari et al. 2006). This is touted asdelivering consumer benefits. The greaterpotency of nanoparticle additives maywell reduce the quantities of additivesrequired, and so benefit food processors.However the greater potential for cellularuptake of nanomaterials, coupled withtheir greater chemical reactivity, couldalso introduce new health risks.Modern food processing methodsproduce nanoparticlesThe emerging discussion of potentialhealth risks associated with nanomaterialsin foods has largely focused onmanufactured nanomaterial food or foodpackaging additives and has ignorednanoparticles created during processing.However nanoparticles are also present inmany foods because of the technologyused to process the foods, rather thanbecause they are food additives oringredients. Although food processingtechnologies that produce nanoparticlesare not new, the rapidly expandingconsumption of highly processed foods ismost certainly increasing our exposure tonanoparticles in foods.Processing techniques which producenanoparticles, particles up to a fewhundred nanometres in size, andnano-scale emulsions are used inthe manufacture of salad dressings,chocolate syrups, sweeteners, flavouredoils, and many other processed foods(Sanguansri and Augustin 2006). Theformation of nanoparticles and nanoscaleemulsions can result from food processingtechniques such as high pressure valvehomogenisation, dry ball milling, dry jetmilling and ultrasound emulsification.Although many food manufacturers mayremain entirely unaware that their foodscontain nanoparticles, it is likely that theseprocessing techniques are used preciselybecause the textural changes and flowproperties they produce are attractive tomanufacturers.Recent research has also foundin food nanoparticles which canbest be described as contaminants.Nanopathology researcher Dr AntoniettaGatti has found that many foodproducts contain insoluble, inorganicnanoparticles and microparticles thathave no nutritional value, and whichappear to have contaminated foodsunintentionally, for example as a result ofthe wear of food processing machinesor through environmental pollution (Gattiundated; Personal communication withDr A.Gatti 19 September 2007). Gatti andcolleagues tested breads and biscuitsand found that about 40% containedinorganic nanoparticle and microparticlecontamination (Gatti et al. submitted forpublication).While this report focuses on the issuesassociated with the intentional addition ofnanomaterials to foods, food packagingand agricultural products, we recognisethat the health implications of foodprocessing techniques that producenanoparticles and nanoscale emulsionsalso warrant the attention of foodregulators. The potential for such foods topose new health risks must be investigatedin order to determine whether or notrelated new food safety standards arerequired. Just as a better understanding ofthe health risks of incidental nanoparticlesin air pollution have resulted in effortsto reduce air pollution, improvedunderstanding of the health risksassociated with incidental nanoparticlecontaminants in foods may also warrantefforts to reduce incidental nanoparticles’contamination of processed foods.14| NANOTECHNOLOGY IN FOOD & AGRICULTURE