Materials

Silver-laced bottles prolong shelf life of milk

Milk stored in the new bottles should last over twice as long as normal
Milk stored in the new bottles should last over twice as long as normal
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Milk stored in the new bottles should last over twice as long as normal
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Milk stored in the new bottles should last over twice as long as normal

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

8 comments
Steve Smith
Whole milk lasts longer than 7 days in the fridge where I come from.
Anne Ominous
I don't know where this information came from but I bought some milk in a plastic jug from the store 2 days ago and its "sell by" date was 17 days in the future.
Timelord
Seems like a complex, wasteful solution to the problem. I'll stick with UHT milk, which is good for 14 days after opening, not to mention doesn't require refrigeration before opening.
Synchro
Much of the fresh milk sold in France is not pasteurised at all, but microfiltered, and has a shelf life of about 3 weeks. Despite this, for some reason the French don't like fresh milk - nearly all the milk sold here (I'd guess around 90%) is UHT or sterilised, with an unrefrigerated shelf-life of 1-3 months. This is almost the complete inverse of the UK.
Straw_Cat
In the past, notably when wagon trains moved westward in the US in the 19th C, migrants often brought a milk cow with them. The milk was stored in barrels and a silver dollar was added to extend the 'shelf life' of the milk as the wagons moved through the heat of the day. 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.
Calson
Pasteurized milk does not have a safe consumption period of 7 days but rather 12-14 days depending on the temperature at which it is stored. The sell by date on a container of milk allows for the consumer to buy the milk and have a couple of days still to drink it. The milk is not unsafe to drink on the sell by date. 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.
esar
There's a milk brand in the UK called Cravendale that is micro-filtered as timelord stated earlier. It lasts 3 weeks, sometimes more if your fridge is set to 2°c It'll all be down to cost in the end
warren52nz
I've been making and using colloidal silver for over 10 years and I use it in a hot tub to keep it bacteria free. it really works, no two ways about it and it costs almost nothing.