How to count on food
Now we come to one of the most common additives on labels – E621 or MSG, to add a savoury taste. And the good news is, it’s not all bad news.
YOU are probably aware that humans have five main taste sensitivities in the mouth; namely bitter, salt, sweet, sour and umami. There are claims of other taste sensations such as kokumi (an extension of umami expressed as heartiness or “richness”, such as in mature cheeses and slow-cooked foods), fats, and perhaps also starches (particularly the shorter-chain carbohydrates) – and on the surface, the claims seem quite plausible though due to genetic differences in humans, it is possible that these additional tastes may not be experienced as commonly as the main five tastes.
Regardless of whether humans experience five, seven or eight tastes, food scientists know a lot about the chemicals that trigger taste cells in human taste buds (a taste bud is normally a collection of different taste cells) – and hence there is an assortment of compounds which can be introduced to processed foods to render them much more attractive to eat.
The bitter problem
At this point, the bitter taste sense warrants a little further discourse – it is the most sensitive taste in most humans and probably evolved to protect us from ingesting poisonous foods.
As a result, humans generally do not like food which is significantly bitter, apart from coffee, tea, beers, certain vegetables and some alcoholic cocktails. Children also have up to three times as many taste cells as adults and this explains why many kids are particularly averse to bitter foods such as broccoli, sprouts, mushrooms, cabbages, et cetera – they tend to slowly lose this antipathy as they grow up.
The sense of bitter is actually pretty interesting as humans can sense bitter in many, many thousands of separate compounds, and if you are curious about how this works, a little summary can be found on: http://www.thestar.com.my/lifestyle/ food/features/2014/08/24/curious-cook-ourincredible-sense-of-taste/
The problem is that some common food additives are particularly bitter chemicals and mass-produced food needs to address the general taste preferences of large populations – hence bitterness in processed foods is a problem which needs to be eliminated, or at least masked.
A classic example is drinks containing caffeine, which is a very bitter compound in its natural state – as a result practically all commercially packaged caffeine drinks are severely overloaded with sugars or sweeteners to mask the bitterness of caffeine.
There are around a dozen synthetic compounds which can block some of the bitter sensation – however, they are not very efficient as they cannot block all the bitter taste cells, so these compounds are not so commonly used.
Therefore, bitterness in processed foods usually need some form of masking, usually with sugars and salt. If there exists an effective way to reduce the taste of bitterness in foods, it is feasible that the sugar or salt content in many processed foods can be reduced by very significant amounts.
As a little digression, when looking into bitter-tasting food chemicals like E202 (potassium sorbate), E326 (potassium lactate), et cetera, I came across E211 (sodium benzoate) which is commonly used as a preservative agent in dairy, meat and other products due to its antiseptic properties – E211 is a curious compound as it can taste either salty, sweet, bitter or have no taste at all. How this happens, I have no idea but it appears to be linked to genetics.
Returning back to the main subject, apart from some exceptions, the E6xx numbers deal mostly with additives which enhance the umami aspects of food – basically, the savoury taste that we enjoy when eating good meats, fine cheeses and delicious stocks.
The most common additive in this range by far is E621 (monosodium glutamate or MSG), the umami-inducing chemical often vilified by self-righteous health websites and various uninformed people – and this gauche prejudice warrants some comment.
Reality and MSG
Much research have confirmed very low levels of MSG toxicity in humans – poor research results in the past obtained using test rodents ignored the facts that (i) infant rodents are susceptible to MSG due to differences in their Blood-Brain Barrier (BBB), and (ii) they were injected with doses of MSG impossible to achieve when scaled up to human dietary consumption levels – in any case, humans do not inject themselves with strong solutions of MSG.
However, some asthmatics may react to pure MSG ingested without food and there may be a very small sub-set of humans who may experience a minor allergy to MSG (possibly due to genetics), though no such gene has currently been identified.
Importantly, to date, there are no known human deaths which can be directly linked to the consumption of MSG. There is also no conclusive evidence of any link between MSG and obesity, though it is likely humans might prefer to eat more food enhanced with MSG.
Once digested, the sodium and glutamate molecules in MSG get unlinked and the freed glutamate is chemically equivalent to glutamic acid which is an amino acid found in practically all proteins – the residual sodium is used by the body as an electrolyte or removed via the kidneys.
The body also produces glutamate itself as part of its metabolic processes.
Some confusion may have arisen from the fact that excess MSG in the brain can be an excitotoxin (a compound which kills brain cells) – however, there is no proof that dietary MSG can cross the human BBB and kill cells in the brain (though this is not true of test baby rodents).
As such, all the evidence suggests that MSG is a safe compound when ingested normally with food – therefore the Chinese restaurant syndrome that some people complain about is more likely linked to foods with possibly excessive salt, sugar or other ingredients rather than MSG.
Objections to MSG
By the way, please do not think that I am