Mould breaker

"The big issue in bakery has been either reducing sugar or salt content or increasing the moisture in the product to make it more palatable. Coupled with taking preservatives out, mould growth is on the increase,"​ says Peter Wareing, principal food safety adviser at Leatherhead Food Research. "Small changes (in recipe formulation) can make a big change to the integrity of the product and spoilage."​

Against the backdrop of sat fat, salt and sugar reduction, can packaging play a role in maintaining mould-free shelf-life?

Getting the industry to shout about its worries over spoilage is never going to be easy. "We are concerned that salt's role as a preservative (if lowered too much) would reduce shelf-life and increase waste, but would not wish to be more specific at this stage,"​ says a spokeswoman for the Federation of Bakers.

One man who should know is Stan Cauvain of bakery consultancy BakeTran, who works with major manufacturers across the UK. "Reductions in salt and sugar levels will undoubtedly reduce mould-free shelf-life as they are the two ingredients that have the most powerful effect on water activity. It will increase the risk of problems with mould-free shelf-life unless other steps are taken to compensate for their decreased effect."​

What's clear is that there is no single answer to maintaining mould-free shelf-life, especially with preservatives out of vogue. But packaging is one element alongside plant hygiene that should be closely considered. Shelf-life can vary from two weeks to three months, depending on a product's packaging film and atmosphere. For example, some ciabatta products would have a short existence without gas impermeable packaging and modified atmosphere packaging (MAP).

Mould growth with MAP​

MAP is not new and brings its own set of headaches. Because it's thicker or made from a multi-laminate, it costs more. And packaging that uses multiple films can often not be recycled. Moreover, temperature fluctuations in the distribution chain can cause problems with MAP. For example, there are currently worries over moulds being found in MAP bakery products transported chilled and then displayed ambient.

"I've dealt with one firm producing an ambient baked product (packed in MAP) that was being distributed chilled by its customer,"​ says Alan Campbell, head of packaging and manufacturing at food research centre Campden BRI. "A small amount of moisture was coming out of the product and settling on the inside of the pack. When it came into ambient conditions, that moisture settled on the surface of the product. Because of changes in the surface characteristics, the mould spores inherent got a chance to grow."​ That same product distributed at ambient temperature caused no problems at all.

"The issue of pack integrity, especially with gas flushing, is so very true,"​ concurs Cauvain. "While products may be transported by more costly chilled transport, the potential for condensation in poorly controlled subsequent storage environments is significant. It is this which leads to mould growth on such products."​

What's more, poor quality seals on MAP can release the gases, slashing shelf-life. And when problems occur, it's not always easy to pinpoint whether the machine or the materials were to blame, says Campbell.

So what else can be done? The truth is, innovation is scarce in the UK when it comes to solutions for emerging shelf-life issues in bakery and confectionery. "You might use an oxygen scavenger in some cases to really suck the last vestiges of moisture out of a pack,"​ says Wareing. "They can increase the shelf-life of relatively high water activity products such as moist, sticky cakes. But they're not used much in the UK because they're expensive. They tend to be used a lot in Japan which is ahead of the game in terms of packaging innovation and sometimes in the US.​

"Even more significant for reducing growth of moulds would be using ethanol emitters in the packaging film, which release ethanol over the life of the product moulds really don't like that. Again, it's used in Japan but we're slow over here to catch on. But it's certainly being looked at by some companies."​

Smart packaging​

Linpac Packaging is one packaging supplier that is stoking interest in so-called 'smart' packaging. "We're looking at 'active' packaging to extend product shelf-life through the use of food-safe anti-fungal coatings,"​ reveals Megan Ashcroft, European bakery marketing manager.

"We've also developed a range of airtight cake containers that extend the shelf-life of the food contained within, keeping bakery items fresher for longer. These two technologies are being developed even further to enable us to use them across our bakery range."​

While smart technologies are in development, there's little take-up yet, says Campbell.

"There are still people looking at and developing smart packaging anti-microbials are coming along but we're not seeing much in the marketplace. That will be the next area of interest,"​ he predicts.