(THE STAR/ANN) - I habitually read the ingredients information and nutrition panels on packaged foods. Thanks to mandatory regulations in developed countries, many food producers are forced to routinely provide data about the contents of their food products, even for less-developed countries.

As a food mensch, it simply makes good sense to know what can end up on our dinner plates - hence I am innately curious about what really makes up the comestibles inside the packaging rather than rely on the external pretty packaging.

The good news is that such information is often concise and detailed - there often is not really that much to read. And generally the less there is to read, the better the product.

The bad news is that some of the information can be a little technical; in some cases even obfuscated and confusing (eg. by the use of E-numbers, duplicative ingredients, chemical names, et cetera) - also the print font sizes tend to be (very) small, presumably to allow for more room for glitzy pictures or logos on the packaging.

What is there and what is really there

Let us start with the ingredients list. The stuff you look for in a packaged food item should reflect roughly your expectations - so if you bought a tub of tuna salad, most of the tub should contain tuna meat.

In fact, the order in which the ingredients are listed should reflect the content percentage in descending order - and reading the list of constituents can throw up some surprises.

That was how I noticed that sausages can legally contain less than 28 per cent meat, even in Britain - with some packs listing the main ingredient as wheat rusk (processed wheat flour, water and salt).

It is a bit better with sausages labelled as "pork sausages" - in which case they have to contain a minimum of 42 per cent pork meat. But as with all British sausages, this "meat" can consist of up to 30 per cent fat and 25 per cent connective tissue (muscle sinew, tendons, rind, cartilage, et cetera) so real meat as you and I know it would only make up 45 per cent of the so-called "meat" in economy sausages - and that is one good reason why my family is not allowed to eat them.

Things are even worse with items like sausage rolls - where one would expect a hefty proportion of sausage meat. But in reality, even allowing for meat cheapened with fat and connective tissue, the "meat" in sausage rolls can actually be only the third item in the ingredients list (in some cases 8 per cent or less), overtaken comprehensively by processed wheat flour and plain water.

But even I have to admit that regardless of the content, a lot of processed foods can still taste plausible, and often not vastly different from proper, expensive versions of the same foods - at least, economy processed foods are good enough to convince a significant proportion of consumers that it is not worth paying more for proper food. How this happens is where the ingredients lists get really interesting.

Psychology and physiology in processed foods

Why and what humans enjoy eating has been extensively (and expensively) researched for many decades, even centuries - and special technical and chemical solutions have been developed which cover both psychological and physiological aspects of eating.

The psychological facets cover not only the pretty packaging formats, but also how processed food itself can be made visually desirable and safe to eat, while the physiological aspects involve texture, taste, smell and chemesthesis (chemical stimulation of various receptors in the mouth) - with nutrition often an afterthought.
All this must, of course, be achieved without killing consumers immediately, though longer-term health effects often appear to be ignored.

While the actual food production processes and flavour solutions used to enhance basic ingredients to yield the finished food products are often very tightly-kept secrets, the ingredient list does shine some light on the technology involved in manufacturing packaged foods.

Some of the ingredients are likely to be additives, either listed by their customary or chemical names but often summarised by the use of E-numbers, possibly for brevity but also possibly to obscure the actual compounds.
Please note that not all additives have E-numbers (eg. caffeine) - but as E-numbers are usually the most obscure items on a list of ingredients, some of the more interesting or common ones are highlighted in this series.

Heavy psychology

It might surprise you that psychology plays a heavy part in modern food processing - and that is simply because us humans have (reasonable) expectations about what we put into our mouths.

We are conditioned to link, for example, colour with taste - so if we see an orange-coloured drink, we expect it to taste of orange. We also link shapes with taste - so if we see sausage or burger shapes, we expect them to taste of meat, even though animals do not look like sausages or burgers.

Actually, processed meat is normally grey, not reddish-pink - the pink hue is introduced artificially because we associate grey meat with rancidity and putrefaction.

With processed meats, the nice colour we see is often a fortuitous byproduct of certain preservation additives, often enhanced by some additional colourants.

In summary, humans very much prefer food that is visually appealing, tastes like it is supposed to taste and actually safe to eat - that is why presentation and food safety are linked to psychological considerations for processed food.

Pretty colours

The need for good presentation brings us to the first group of E-numbered additives. E-numbers are always prefixed with "E" followed by a 3 or 4 digit number and sometimes further suffixed by a letter - but the numbering system is not always consistent as additives are sometimes seemingly assigned random numbers in various groups.

Regardless, the first group of E-1xx numbers is generally to do with the colour compounds allowed in processed foods. Some of these colours are extracted naturally, such as E100 (curcumin) and some are wholly artificial such as E133 (brilliant blue FCF), which is derived from coal tar.

The E1xx colours can be mixed; eg. E133 is sometimes combined with another artificial yellow compound E102 (tartrazine) to produce a green dye for colouring food (eg. processed peas, vegetables and cakes).
Colours can also be lightened by adding E171 (titanium dioxide), a strong white colour used in chewing gums, toothpaste and paints.

The use of E1xx numbers is very versatile - as an example, for cooked meats and meat pastes, the colourings permitted can involve E127 (erythrosine), E150a (caramel), E160c (paprika extract, or capsanthin and capsorubin) or E172 (iron oxides and hydroxides).

In the past, other food dyes such as E154 (brown FK) and E128 (red 2G) were also permitted but have since been banned by the EU due to various health issues.

This is not to say that the currently permitted colours are free from any side-effects, especially if consumed excessively - as an example, E110 (sunset yellow FCF, orange yellow S) is used in cereals, baked goods, sweets, ice cream, et cetera, and has been linked with hyperactivity, allergies, kidney problems, tumours in test mammals, and so on.

Preservatives - Part 1

Meat also leads us to the next section of E numbers - those in the E2xx category, which are mostly food preservatives and acidity regulators.

The most commonly used E2xx numbers for meat are probably E250 (sodium nitrite) and E251 (sodium nitrate) - for not only do these compounds cure and conserve meat, they also add a nice pink hue to meat products (due to the nitrites combining with pig haemoglobin to form pink nitrosohemoglobin).

Other similar compounds used in processed meats are E249 (potassium nitrite) and E252 (potassium nitrate), though not as extensively.

Without nitrites or nitrates, hams would be dull grey, bacon would be brown and salamis would be black and brown - the reason is that these nitrogen-based compounds inhibit the actions of bacteria and fungi which cause putrefaction.

Unfortunately, nitrites and nitrates are also converted by the digestive system into nitrosamines - and most nitrosamines are known carcinogens.

The story of how processed meats are now listed as Group 1 carcinogens by the WHO and why nitrites and nitrates are still being used has been documented in an earlier article.

The other E2xx compounds may or may not be as parlous as nitrites and nitrates - it seems not all of them have been extensively tested for carcinogenicity in humans.

However, there are quite a few other items already known to have side effects in humans. Hyperactivity in children has been linked to E210 (benzoic acid), a chemical used in sweets, chewing gum, cheeses, baked goods, cordials, et cetera.

Sulphur-based compounds in the range E220 (sulphur dioxide) through to E228 (potassium hydrogen sulphite) are commonly used to preserve fruits, juices, cordials, wines, et cetera, and have implications for people with asthma and kidney conditions.

If you tend to get headaches, then watch out for propionates in the range between E280 (propionic acid) and E283 (potassium propionate) which are often used as preservatives for baked goods, dairy products and meat - these propionates have been linked with migraines.

Preservatives - Part 2

Meat and in particular, bacon, also brings us around to the following group of E3xx additives, which relate mostly to another class of preservatives known as antioxidants - although this section also include food acidity regulators (as food decompose slower in an acidic environment).

You might think that antioxidants are good compounds to ingest and to some degree, the natural antioxidants may be of some benefit - however, there are also artificial antioxidants which are rather curious.

For example, E319 (tertiary-butyl hydroquinone (TBHQ)), E320 (butylated hydroxyanisole (BHA)) and E321 (butylated hydroxytoluene (BHT)) are used to inhibit the spoilage of fats, oils, fish and other foods - but the toxicity of TBHQ in humans is unclear, BHA can either promote or restrict cancer growths, high doses of BHT are known to kill test mammals; and additionally they may also interact with nitrosamines with indeterminate results.

BHA and BHT are even banned in parts of the EU but remain commonly used in other countries, including the United States. Note that antioxidant additives are added to prevent the oxidisation of food which happens when processed food comes in contact with air - not necessarily to tackle free radicals in human bodies.

Where bacon gets involved is that the US Department of Food & Drug Administration (FDA) now requires that commercially-produced bacon include either the antioxidant additive E301 (sodium ascorbate) or E318 (sodium erythorbate).

The reason is that cooking bacon can produce a nasty nitrosamine called nitrosopyrrolidine but treatment with E301 or E318 has been found to significantly reduce its production.

The most common antioxidant additive is probably E300 (ascorbic acid), which is simply vitamin C - this versatile compound has no known side effects and is commonly used in meats, cereals, wine, fish, flour, drinks, et cetera.

As with all additives, over-ingestion of some compounds beyond the normal expected levels can lead to issues; excessive doses of E222 (lecithins) can cause stomach problems, E330 (citric acid) can lead to eye or skin problems, E375 (niacin) can provoke liver dysfunction and headaches, et cetera.

Generally safe

Please note that despite the synopses of fluctuant side-effects mentioned (it is simply not possible to cover all potential reactions due to the numbers and combinations of additives), most food additives are limited in their use and therefore should not be problematic when processed foods are consumed in reasonable amounts by healthy humans.