Consumers may soon be able to go for longer between milk-buying trips. That's because Brazilian company Agrindus hopes to start marketing plastic milk bottles that use embedded silver nanoparticles to kill bacteria. Grade A pasteurized fresh whole milk packaged in those bottles can reportedly last for up to 15 days, as opposed to the usual seven.
The technology was developed by partner company Nanox, and involves first coating silica ceramic particles with silver nanoparticles. This reportedly has a synergistic effect, with the silica boosting the antimicrobial properties of the silver.
Those coated particles take the form of a powder that is subsequently mixed into liquid polyethylene. Using blow- or injection-molding, that plastic is then made into bottles which Agrindus plans to sell to dairy goods companies. The particles can also be used to make milk bags, which should extend shelf life from four to 10 days.
While there are definitely concerns about the effects that silver nanoparticles can have on peoples' health and the environment, Agrindus claims that the particles in its bottles remain in the plastic, and don't detach to mix with the milk.
The material is currently being tested in Brazil, and the company hopes to start marketing it to American and European dairies within the near future.
This isn't the first time that we've seen silver nanoparticles used in antibacterial food packaging. Previous examples have included meat-wrapping paper and plastic film.
Source: FAPESP
I assume this anti-biotic property was also one reason that silver or silver plated containers were poplar in the past as well, at least amongst those who could afford them.
Temperature has a profound impact on the recovery and growth of the bacteria in the milk. Leaving the milk in a hot car or putting it out on the counter or table and letting it come up to room temperature can reduce the safe consumption period by 75% or more.