Authors: Joanna Blythman
The driving force behind this distinctive gas packaging trend is the combination of a strong consumer appeal (fresh products) and a number of benefits to the retailers in connection with logistics, product presentation, value added products, extended food shelf life etc. The purpose of gas flushed packaging is to give the product a long shelf life.
More often than not, MAP is used to disguise signs of what the food industry calls ‘light processing’: cleaning, washing, paring, coring and dicing. Whether you’re talking pineapple chunks, or microwave-ready broccoli florets, these interventions behind the scenes inevitably make fruits and vegetables more perishable because they disrupt cell tissues and break down cell membranes. In fact, these ‘fresh-cut products’ as they are known in the business, are what scientists refer to as ‘wounded’ tissues, so they deteriorate more rapidly than intact fruits and vegetables. MAP is used to delay the obvious signs of trauma – browning and off-flavours – but not always that effectively. Nutritional value is also reduced, but that loss is invisible to the eye.
Of course shelf life is not to be confused with freshness, as many of us discover when we open a puffy, modified atmosphere ‘pillow pack’ of salad leaves, only to watch them wilt soon after. Using MAP, prepared vegetable suppliers can add up to 8 days to the use-by date of salad leaves. Allowing for the fact that some time will have elapsed between the leaves being picked and then despatched to the processors for cleaning and packing – let’s add on another 1–2 days here – it’s no surprise that our bagged salads swoon like a Victorian heroine when exposed to natural air. Poor things, they might be as much as 10 days old, and consequently, their vitality and nutrient profile will be more weakened and degraded than we might like to think.
Then again, collapsed salad leaves could be the worse for wear for other reasons. As a prelude to packing, they will have been put through a vigorous washing machine, or a Jacuzzi-style wash tank, designed to ensure lots of agitation. The best scenario here is that they are washed in spring water, a selling point on a minority of products sold by up-market retailers. Most, however, are sloshed around in tap water dosed with chlorine. Fruit acids – citric, tartaric, and more – in either powder or liquid form, are often also included in the mix. The chlorine passes for ‘cleaning’ and the acids act as a preservative by inhibiting the growth of bacteria. Some companies that consider themselves progressive and go-ahead are dumping the chlorine for fruit acid washes. Not only do they allow a ‘no chlorine’ claim to impress consumers, they also have another practical advantage, as the maker of one such product explains:
NatureSeal FS is not adversely affected by the build-up of organic matter (soil, leaves, and other plant matter). This means that there is no need for frequent changes of wash tank water; some processors operate their wash tanks for at least 8 hours before discharging to drain. Chlorine, which is affected by organic matter, requires more frequent re-dosing and hence the danger of imparting taste taints. This requires wash tanks to be discharged and the water to be changed more often.
In other words, in the cloudy world of fruit and vegetable preparation, it’s a choice between fresher water dosed frequently with chlorine, or less frequently changed water blended with acids. Either way, it’s a far cry from fruit and vegetables washed in the kitchen sink in tap water. But then, we’ve been trained by the public health establishment to view our own kitchen sinks with suspicion and to see the tired old gassed, chemical-dipped, bought fruits and vegetables as a safer bet.
With their ‘before and after’ images, the brochures of companies that promote products to extend shelf life to processors are reminiscent of those adverts that illustrate life-changing claims for the transforming effects of hair transplants, or the wrinkle-diminishing capacity of face cream. Grow Green Industries introduces eatFresh-FC, somewhat enigmatically, as an ‘antimicrobial mix of synergistic blend of organic components, citrates and antioxidants [sic]’, which, it says, ‘preserves colour, texture and freshness, and is proven to extend the shelf life of cut and whole fruits, such as strawberries, apples, pears, mango, avocado and various vegetables’. It goes on to illustrate the point visually. It shows two strawberries after 7 days; the one on the left, the control, has not been dipped in eatFresh-FC; the one on the right has. The control looks rotten, the dipped berry looks immaculately luscious. There are kindred images of cut bananas, apples, pears and avocados, with the undipped fruits inevitably looking brown and old compared to their picture-perfect, dipped equivalents. Grow Green Industries recommends this miraculous, age-defying preparation for use in food service – that’s ready prepared food for bars, restaurants, takeaways, schools, hospitals and food retailers. Those oddly tasteless cut apple slices that turn up in airline meals and in sandwich bar ‘fresh’ fruit salads almost certainly owe their considerable keeping properties to such dips.
‘Edible coating technologies’ don’t stop there. Whole ‘fresh’ fruits and vegetables can be dipped, drenched or sprayed in products such as Semperfresh, described by its makers as a ‘combination of sugar esters and other edible ingredients: vegetable oils and plant cellulose’. It coats each fruit in a very thin, invisible, odourless and tasteless film, which ‘slows down the ripening process – effectively putting the produce “to sleep”.’ Semperfresh is recommended for use both pre- and post-harvest, and can help fruit stay fresh ‘for up to twice as long’. It is coatings such as this that make our cherries, apples and pears gleam, and give our peppers, cucumbers and aubergines their lustre.
Moving on from coatings, a number of edible films, known in the food preservation business as ‘smart’ or ‘intelligent’ films, are now used by food processors and manufacturers in products as diverse as cheesecake, deli meats and pizza. Imperceptible to consumers, they are made up of gummy, sticky substances that inhibit the growth of bacteria, such as starch, cellulose derivatives, chitosan (an indigestible sugar obtained from the carapace of shellfish), alginates (gel-like seaweed substances), fruit puree, milk and soy proteins, egg white and wheat gluten. According to one advocate of this technology, when used on cut fruits, edible films ‘can provide a food with a safe product lifetime of as long as two weeks’. A new edible and cook-able meat coating that promises to extend the shelf life for fresh meat by up to 3 days is being tested. The coating is made from ‘a reliable source of naturally occurring peptide compounds’, and will be transparent, inodorous and unflavoured. One litre of this MeatCoat solution costs €1.53 and is sufficient to coat 13 square metres of meat.
Edible films are frequently used as carriers for a wide range of artificial additives, such as flavourings and colourings, as well as synthetic preservatives, such as benzoic acid, sorbic acid, propionic acid, lactic acid and nisin. Their presence also slows down the build-up of warmed-over flavour (WOF). Wrapped in edible film, the WOF in a 9-day-old treated pork patty is reduced ‘down to the levels more typically found in a 3-day-old untreated’ one.
Enzymes, often made using genetic modification techniques, are also creeping into our food chain to extend what the industry refers to as the ‘perceived freshness’ of baked goods. When we see muffins, cupcakes and soft pound cake at a coffee bar or in-store bakery, how fresh do we think they are? I’d guess that most of us would assume a couple of days old, no more. But for all we know, they have been made with an enzyme product, such as XFresh, described by its makers as follows:
XFresh makes use of enzyme technology to prolong the sensory shelf life and perceived freshness of both pound cakes and smaller cake products like muffins, magdalenas and cupcakes. The technology has proven to be highly effective, extending the sensory shelf life by up to 50%. Consumer tests and professional panels show that applications based on XFresh technology improve the perceived freshness of cakes by up to 50%. In one instance, a four-week-old cake made with XFresh technology was judged to be as fresh as a one-week-old conventional cake.
So what if your muffin or cupcake isn’t fresh from the oven? Many consumers will be only too delighted if their food keeps for longer, even if they don’t know why. Few of us realise that the cosmetic perfection in chilled food we have come to expect is stage-managed. Under the coy banner of ‘food protection’, manufacturers now have access to various bacteria-slaying, or delaying, shelf-life extenders that are marketed as being more natural than synthetic preservatives. For instance Verdad F41, a white distilled vinegar made from sugar, corn or tapioca, was developed specifically for vacuum packed pork and poultry to help it ‘maintain colour, uniformity, and reduce[s] grey discolouration during shelf life’. ‘Enhanced’ with this preparation, chicken thighs won’t turn that off-putting yellowish-grey colour as they age. Verdad F41 is ‘label friendly’ – it can be described as cultured corn sugar and/or vinegar – which doesn’t raise consumer hackles. But what domestic cook would ‘wash’ chicken in vinegar and then consider it fresh?
At the cutting edge of shelf life extension lies a new generation of preservative ‘systems’ or ‘solutions’ that combine a number of chemicals refined and isolated from food sources. Food industry chemists are busily exploring the preservative potential of oregano, rosemary, thyme, clove, cinnamon, green tea, mustard, garlic, lactic acid bacteria, lysozyme from egg white, pleurocidin from the skin of a fish, grape seeds, blueberries and cranberries. Natural preservatives already on the market include NaturFORT, promoted as ‘a versatile combination of rosemary and green tea extract that complement each other by providing superior protection of flavour, colour and odour profiles’ in products such as salad dressing and mayonnaise. Fortium, recommended as a shelf-life extender for crisps, is listed as a ‘plant-derived product line based on mixed tocopherols and [unspecified] formulated blends’ that provides ‘extra protection for high stress processing conditions’. (Spuds take a bit of a pounding in the crisp factory.) BioVia™ YM 10, made from cultured dextrose and plant extracts, is marketed as a natural antifungal blend, ‘specially designed to enhance the quality of a wide variety of refrigerated and shelf-stable culinary products’, such as ‘fresh’ salsas and dips. While these preservatives can be presented as natural, what’s natural about putting them in foods that would not otherwise contain them?
Arguably, these newer, ‘natural’ preservatives are preferable to the old synthetic ones. Do you know anyone who would like to think that their ‘fresh’ fish had been treated with Ecoprol 2002, a clear, light brown, slightly pungent liquid blend of propyl gallate, citric acid, potassium sorbate, orthophosphoric acid, acetic acid, and propylene glycol? The purpose of this six E number cocktail of artificial preservatives is given as follows:
Mixture of food grade additives aimed to reduce the speed of alteration of natural marine species, allowing longer life. The antimicrobial antioxidant components act as highly effective preservative that extends the shelf life of seafood, especially in the commercialisation [sales] stage, without altering the taste, colour, odour, or texture. The additive components act to provide a protective coating against deterioration of fresh produce by microbial action, oxidation of fats and oils, and body dehydration.
In comparison to old, unreconstructed synthetic chemical concoctions such as this, any life-extending substance that bears some faint claim to naturalness represents progress. Or does it? The old arsenal of preservatives, whatever its collective impact on human health, at least did the job of preserving food, albeit in a thuggish way. Milder-mannered ‘natural’ alternatives are much less effective, possibly even ‘a disaster waiting to happen’, as one food industry chemist has warned:
Because we have safe and reliable [synthetic] preservatives we have managed to keep products safe throughout their shelf-life. But with the demand for all-natural, minimally processed products with an extended shelf-life, the potential for low-level contamination is raised.
In other words, if you reduce the use of artificial preservatives without also shortening use-by dates, you have the recipe for a major food poisoning incident caused by chilled, supposedly fresh food.
In the past, it was blindingly obvious when food was not fresh. It stank, grew whiskers, oozed ominous liquids, discoloured, and developed warning moulds. Before the era of domestic refrigeration, we used chilly pantries to postpone for a few days this inevitable decay, and had a solid, empirical grasp of the keeping properties of foods. We relied on venerable preservation techniques – drying, curing, pickling, fermentation, brining, freezing, preservation in salt, sugar, alcohol, bottling – to extend the edible life of our food further. In time, the emerging food industry developed techniques, such as canning and ultra-heat treatment, which allowed us to eat food years after its natural ‘start date’. Nevertheless, we understood that a can of peas, or dried milk powder, although still fit for consumption, wasn’t exactly fresh in the fullest sense of that word. Those peas weren’t from a freshly picked pod, that milk had come more recently from a factory than a cow. We knew that something had been done to these foods to make them last longer than they otherwise would. Nowadays, many of us have only the haziest idea of how long foods will keep in the natural course of events. Refrigeration has become a surrogate for genuine freshness. Anything that is cool to the touch gives us an unwarranted sense of security.
Whose fault is that? Hazy consumer awareness of the keeping potential of foods is a state of (un)consciousness that has been encouraged by food processors and retailers. Back in 1987, the food scientist Dr Robert L. Shewfelt coined the term ‘fresh-like’ to describe that booming category of products that seem fresh, but aren’t, and this adjective has since slipped seamlessly into the lexicon of modern food processing. In the food industry, ‘fresh’ now means ‘fresh-like’, a word play that suits food manufacturers and retailers. Fresh-like foods are a money-spinner – we pay a premium for them, thinking that they are truly fresh.