Time on their side

3 min read

Nestlé is to begin trials of UK-developed food labels that use membrane technology to give a clear warning of when a product is no longer fit for consumption.

The food giant will begin full-scale trials of Timestrip labels this autumn. They will be placed on a branded product, as yet unidentified, that is used by restaurants and caterers supplied by its Nestlé Foodservices UK division.

From next year, EU rules state that records must be kept of the opening of all perishables used in food establishments so that they can be destroyed once their consume-by period has passed.

According to Hertfordshire-based Timestrip, the system should also help reduce food waste, as staff will be able to see at a glance which of several identical products has been opened first and so must be used up.

The company later hopes to apply the technology to a wide range of time-sensitive products, including industrial components with a limited lifespan.

The Timestrip labels contain a tinted liquid dye that migrates across the label via a micro-porous material at a consistent rate, allowing lapsed time to be precisely monitored and indicating how long a package has been open.

The indicator can either be applied as an external label or can be incorporated into the design of the packaging itself.

‘We are working to design a cap for a squeezy bottle that will be activated as soon as the bottle’s top is opened,’ said Reuben Isbitsky, joint chief executive of Timestrip. ‘The customer doesn’t have to do much and the device is tamper-evident.’

When a packet is opened, the user must squeeze a button on the label to activate it.

The Timestrip indicators can be tailored so that the dye migrates at a varied pace, depending on the period of time that needs to be measured. The strip can also be designed so that the dye migrates faster in raised temperatures, meaning that it can provide a more accurate indication of the freshness of food designed to be refrigerated but left out in warm conditions.

The strips can be used on any product that must be consumed or replaced within a certain period of opening or first use, including food, pharmaceuticals and even devices such as filters on vehicles that need regular replacement.

‘EU regulations are demanding that the cosmetics industry features a period after opening date on packaging, showing users how long a substance will last,’ said Isbitsky. ‘This is good for the consumer from a hygiene point of view, but is also good for the manufacturer, as it gets people to repurchase once they know a substance has gone off.’

According to Timestrip, Nestlé has indicated that it will consider using the label on a wider range of products if this year’s trial is successful.


Packaging gets smart

Designing packaging that acts as more than just a protective barrier has long been a goal for the food industry.

So-called ‘active packaging’ aims to provide consumers with information about the state of its contents and whether they are fit to eat. This could ultimately prevent food such as soft fruits being spoilt by customers overhandling them in shops while checking for ripeness, and could encourage consumers to buy more by reminding them that products have been open for too long and therefore need discarding and replacing.

For some time, French supermarket Monoprix has been using a time/temperature indicator on a number of fresh foods. The device, made by Temptime of New Jersey, consists of a dark ring around a lighter circle, containing a chemical whose colour darkens at a rate depending on the temperature a package has been kept at. As bacteria on food respond to temperature in the same way, consumers can see whether it is safe to eat.

Similar indicators that work by measuring the amount of gas given off by a food are also being developed.

Smart packaging could also help to preserve food by altering conditions within the wrapper to prolong its life. Scientists are working to develop a wrapper that scavenges oxygen from sealed food to slow down deterioration.

Meanwhile, membrane wrapper Intelimer, made by Californian firm Landec, changes its permeability with the temperature to keep different products at their optimal O2/CO2 concentrations. Wrapping that changes colour in the presence of food poisoning bugs is also being developed in Canada.