Despite its potential in improving shelf life, boosting crop growth and indicating the condition of food, INMs are controversial from a health perspective.
For example, the use of heavy metals in the food industry as an antibacterial can have adverse effects on mankind and the environment.
“The contribution of inorganic nanomaterials (INMs) is of great significance considering its potential for development of the food industry,” the authors said.
“Implementation of most INMs is still in the research and development stage, and applications in the food industry are yet to find approval owing to health concerns.”
Despite these concerns, the research team of Drs Isuru Ariyarathnaa, R.M.P.I. Rajakaruna, and D. Nedra Karunaratne from the Universities of Auburn in the United States and Peradeniya in Sri Lanka, outline a number of breakthroughs in the field.
INM’s emerging role in improving food’s shelf life is a response to the escalation in consumer interest in healthy, fresh food.
Food package quality in particular has improved to minimise food waste by blending active substances that slow down the growth of microorganisms.
Studies have shown the antibacterial property of inorganic substances in food packages can optimise the shelf life of food.
Commercially, firms such as Nanocor and its nanomaterial Imperm, an ultra-high barrier nylon which provides protection for oxygen sensitive carbonated soft drinks and waters, have made gains.
Furthermore nanocomposites such as Lanxess’ Durethan KU 2-2903 is used as an additive in polyamide flexible film packaging of perishable foods providing protection against heat and oxygen degradation.
Crop growth role
Nanomaterial’s role in crop growth has largely been in a preventative or filtering capacity.
The review highlights a study that uses magnetic solid phase extraction to separate out the herbicide linuron from fruit and vegetable samples.
“Food crops can accumulate residues of linuron,” the review explained. “This is a health hazard since linuron is a carcinogen.”
Where INMs come into direct contact with crop development, results have been promising.
A study found weight, root length, shoot length, and antioxidant status significantly increasing when silver nanoparticles were used in treating mustard green seedlings.
Another study has shown that silver nanoparticles are capable of enhancing the chlorophyll, carbohydrate, and protein contents, shoot and root lengths and the leaf area on corn and common beans.
Whilst silver is an effective antibacterial, it is also a non-biocompatible substance.
Its role in crop development is of ongoing concern as the element in nanoparticle form is capable of reaching internal organs in the human body via oral consumption, dermal exposure, or by inhalation.
The authors believed it necessary to take precautions when applying some INMs into the food industry.
The review also detailed the use of INMs in sensors and detectors of microorganisms, moisture and gases in food products.
Current microbial detection techniques rely mostly on isolation and culturing of the various microbial samples.
However, these techniques are often costly, labour intensive, require significant training and skills by the operator and can require the use of a laboratory.
One study mentioned uses a time-temperature indicator exploiting silver nanorods. This technology can be used to detect spoiled milk.
Furthermore, magnetic iron-derived nanoparticles and DNA molecules have been used to establish a biosensor that detects the food poisoning bacteria, Salmonella typhimurium.
Regulatory opinion that detail nanotechnology use in food has been ongoing and subject to much change.
In March 2009, the European Food Safety Agency (EFSA) published guidelines, which were updated in May 2011, to include additional assessment of potential risks.
The updated guide also provided practical advice to regulators on how to evaluate applications from industry in using nanomaterials in food additives, enzymes, flavorings, food contact materials, novel foods and food supplements.
Source: Food Control
Published online ahead of print: doi.org/10.1016/j.foodcont.2017.02.016
“The rise of inorganic nanomaterial implementation in food applications.”
Authors: Isuru Ariyarathnaa, R.M.P.I. Rajakaruna, D. Nedra Karunaratne