In search of the Holy Grail

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Related tags: Ready meals, Food, Spice

In search of the Holy Grail
Salt replacement and anti-microbial properties are being studied, says John Dunn

Nearly 100,000t of industrial seasonings, herbs and spices are used by UK food manufacturers each year, according to market research company RTS Resource. In a new report on the global market for seasonings, herbs and spices, RTS estimates that the total world market is growing at 2.1% a year, with meat and savoury products the largest sector.

The UK is the biggest user of industrial seasoning, herbs and spices in western Europe. And according to Jamie Rice, RTS director, the UK market is set to grow at 1.7% a year until 2014.

One reason for the growth, he says, is that we are eating more spicy food, more exotic, ethnic foods. However, another reason is the growing demand for more healthy foods and the use of herbs and spices to replace artificial preservatives, as consumers demand more natural ingredients and cleaner labelling of food products, says Rice.

"Herbs and spices as preservatives is a growing area as we get to know the science and understand what works. And you are going to see them used more and more in future food products." There is also growth in the use of herbs and spices as flavour enhancers in salt-reduced recipes, he says. "This is the Holy Grail for food manufacturers to be able to reduce the salt content of products but still retain the flavour and the functionality."

But, unlike the Monty Python team and their search for the Holy Grail in the 1975 comedy film, some serious research and serious money is going in to finding the right combination of herbs and spices as an alternative to salt. Equally, the food industry is working hard to find how to use herbs and spices as effective anti-microbial agents and preservatives and thus allow firms to remove artificial additives.

The world's biggest spice company, McCormick of the US, for example, is pouring money into researching the potential health benefits of herbs and spices and how they can affect blood pressure, blood sugar levels and muscle pain. It has identified what it calls the seven 'super' spices because of their high anti-oxidant properties. These are oregano, cinnamon, ginger, curry, red pepper, thyme and rosemary. The company hopes soon to commercialise products it has developed based on its research.

Salt replacers

Salt, or rather the sodium in it, is essential for life and something we cannot live without, says Dr Nigel Brunton, research officer at the Teagasc Ashtown Food Research Centre in Dublin. But too much dietary sodium can cause high blood pressure, leading to strokes and heart attacks. So Brunton is looking at using herbs and spices as a replacement for salt.

"We want to find ways of reformulating ready meals to compensate for the loss of flavour as a result of taking out the salt. Also, herbs and spices have anti-microbial properties so we want to see if we can use herbs and spices to enhance the shelf-life of ready meals. And since herbs and spices have very strong anti-oxidant properties, we want to see if we can improve the health profile of the ready meals as well."

Brunton is looking at three chilled ready meals: cottage pie, vegetable soup and a chicken supreme. Initially, he looked at the sensory profiles of the meals with salt in them and without salt in them. He found that there were flavour differences between a low salt meal and a meal with full salt.

"However, one of the most surprising things we found was that in many cases taste panels were not always expressing a preference for a meal with higher levels of salt. They were able to detect a difference. But they were not always expressing a preference for a high salt meal versus a low salt meal." Consumers are used to high salt levels, but don't necessarily prefer them, suggests Brunton.

The idea then was to find particular herbs and spices that could compensate for loss of flavour. The first stage was to look at the formulation of the meals and make a best guess at what type of herb to use. Then Brunton wanted to see if he could use those flavourings with high anti-oxidant properties and high anti-microbial properties in the ready meals.

As a result, Brunton and his team chose six herbs for inclusion in the reformulated ready meals: cloves, sage, pimento (peppers), oregano, garlic and rosemary. They were dried, provided by AllinAll Ingredients, a partner in the research.

"We wanted to see what was the sensory acceptable level of each of these herbs and spices in the ready meals. Then, what level did we need to reduce microbial activity and so increase the shelf-life? We have been able to eliminate some of the spices we used on the basis that they just weren't acceptable from a sensory point of view. Clove in particular has got very strong anti-microbial properties. It has got very strong anti-oxidant properties. But whatever level we included it in a ready meal, the panellists were picking it up, and they didn't like it.

"So far we have determined the sensory acceptable level for each of those different spices. But the problem now is that the sensory acceptable level is much lower than the level needed to deliver anti-microbial properties. For example, we need a level of about 4% for most of the spices to extend the shelf-life of the ready meals. However, sensory acceptable levels are below 1% in most cases."

What Brunton is doing now is looking at combinations of spices. "Research has indicated that there is a synergistic effect between different spices that will allow us to have low levels but deliver an anti-microbial effect."

Recent work at NIZO Food Research in The Netherlands, for example, has explored the synergistic interactions between anti-microbial peptides and herb and spice extracts. According to project leader Dr Tim Lambers, lactoferrin (a peptide obtained from milk), and thymol (the active ingredient in thyme oil) both show an anti-microbial activity against E.coli, for example. But used in combination they have an enormous synergistic effect, showing an almost complete inhibition of the growth of E.coli, he says. "This interaction between different types of natural anti-microbial compounds increases their efficiency and reduces their cost in use," he says. The aim of Brunton's work at Teagasc Ashtown Food Research is to come up with a best practice flow diagram that recommends the steps you should take to reduce salt in ready meals. Companies could use it to start to look at trying to reduce salt in their ready meals, he says. Brunton hopes to have it ready some time after his project ends in September.

Anti-microbial research

In recent years Campden BRI has also done a lot of work looking at the anti-microbial effects of various herbs and spices and their essential oils. "Some of the compounds have been known to be naturally anti-microbial for a long time," says Dr Gail Betts, manager of microbiological safety and spoilage. "Things like garlic and horseradish are well known to be able to inhibit micro-organisms. And herbs like basil, oregano, sage and thyme have been known to be anti-microbial. Eucalyptus oil and the citrus oils orange, lemon, lime are anti-microbial too."

What Campden BRI's work has shown is that the amount of herbs and spices you need to add to get an anti-microbial effect is often too high for the sensory quality to be acceptable. The levels at which you get an anti-microbial effect can be around 0.1%, which is very high indeed from a sensory point of view. Even a 10-fold lower percentage, say 0.01%, would still be detectable from a sensory point of view, says Betts. And if you have to go down to that level then you start to lose some of the anti-microbial effects, she adds.

You also need to match the herb or spice to the food type. "In some of the studies we did we baked lemon cakes and added orange oil to them. You can add almost 0.1% orange oil to a sponge cake and it will still be acceptable. Similarly, if you add basil to tomato and basil soup, then again it is OK. So you have to carefully match the product to the oil you use."

Food types are very important, too, she says. "If you have a food with a high fat content then you have to increase the amount of anti-microbial that you add because it absorbs to the fat layer and has less of an effect on the micro-organisms. A full-fat milk product, for example, has got almost 4% fat. Skimmed milk has 0.1% fat. So there is a 10-fold difference in the amount of the essential oils you need to add to the high fat milk to have the same effect as in skimmed milk.

"Similarly, if you have a food that is neutral in terms of its pH ie a dairy based product where there isn't much acidity then the microbes will grow happily. But on the other hand, a tomato-based product which has got high acidity, ie a low pH, will stress the micro-organisms anyway."

There are no hard and fast rules, says Betts. Each manufacturer will have to develop its own formulations. Her comments are echoed by Cindy Beeren, head of sensory and consumer science at Leatherhead Food Research. "It is trial and error. Herbs and spices are an opportunity to make a product more interesting and less bland. But they will need to be tried out in the product development labs to see which ones work and which ones don't."

But think just how much more healthy King Arthur and the Monty Python team might have been on their quest for the Holy Grail if they had eaten less salt in their ready meals:

"We dine well here in Camelot

We eat ham and jam and Spam a lot."

KEY CONTACTS

Campden BRI - 01386 842000

Leatherhead Food Research - 01372 822327

NIZO Food Research - 01475 670 358

RTS Resource - 01902 422282

Teagasc Ashtown Food Research - 00353 18059 500

Related topics: Ambient foods

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