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What’s in your canned food?
Date Published：9/18/2018 03:09:52 AM
CANNED food has its merits, from being a convenient source of ready-to-eat meals to having a long shelf life. However, this food category suffers from a bad reputation, and it’s mostly due to exaggerated science. It has managed to survive and plod on due to consumers’ reliance on its existence. Increasing awareness and better understanding of canning in the Internet era is helping to turn this around, though this will definitely take time and a good deal more research.
Preservatives in canned food – what level of concern do they warrant?
A major point to note is that from the very invention of canning, to its modern-day process – preservatives do not seem to be a necessary component with regards to canning’s core function, which is the preservation of food for a long period of time. Some big brands like Ayam Brand™ have publicly stated that their canned food is processed purely via sterilisation, and does not contain artificial preservatives[i],[ii]. However, a lot of canning today still does in fact make use of some form of preservative ingredient, especially salt and sugar, in order to maximise the shelf life and quality of its products, and all commercially canned food brands are legally required to list all ingredients in the can (including preservatives and other trace ingredients) on the label, making this clear to consumers.
Salt is the most common preservative in canned food, as it is both economical and easily available. However, especially with meat products, many brands tend to take an extra precautionary step and employ not only salt (chemically termed as sodium), but also phosphate, which forms salt – this means that on the label, sodium phosphate will be listed as an ingredient. It can help to cure the meats, balance pH levels, and stabilise food textures[iii]. The amount of sodium phosphate that is added to canned food is, by right, of a low amount, as the FDA has classified this as GRAS or generally recognised as safe. As such, the only ways that sodium phosphate would be of harm to the human body is 1) if the manufacturer adds large amounts of it to the product, above legal guidelines, or 2) the consumer chooses to eat large amounts of the sodium phosphate-containing product, thereby increasing its concentration in the body.
Of these, the latter is a real concern, as consumers that are more concerned with taste and flavour over ingredients and label-reading could accidentally ingest more than is safe, which could negatively impact the kidneys[iv]. The same concern has arisen for traditional canned foods that tend to solely contain salt as a preservative, as overconsumption would direly affect those with high blood pressure, or sugar, which carries with it other risks like diabetes and cardiovascular disease. As such, manufacturers have come up with a solution to tackle this issue and still maintain consumer interest and address health-conscious concerns, by adjusting the product content instead, and coming up with low-sodium/sugar or sodium/sugar-free products.
Low-sodium, light syrup, and similar healthier formulations attract consumers back to eating canned food.
Evolving canned food to address health concerns
For a canned food item to be considered low-sodium, it needs to contain no more than 140 milligrams of sodium per serving[v]. It is more common to find these in terms of fruit and vegetable items, given that meat products which are canned without salt is likely to suffer much more heavily in terms of flavour and shelf life. Many of these products, whether low-sodium or sodium-free, tend to be produced and marketed hand-in-hand with the ‘organic’ label, for example Green Valley® Organics Whole Kernel Corn[vi], or Walnut Acres™ Organic Whole Black Beans[vii], further enhancing the healthy image that these new, evolved versions of canned food seem keen to project.
However, not that many mainstream companies appear to be heavily touting this aspect, especially in Asia. Not many examples actually employ the term ‘low-sodium’ in the product names, e.g. Ayam Brand’s™ Tuna Chunks in Water[viii], which only contains 107 milligrams of sodium per serving, although there are definitely exceptions, e.g. Campbell’s® Low Sodium Classic Chicken Noodle[ix] and others in its Low Sodium soup range. Many canned products that may actually contain less than 140 milligrams of sodium per serving may go by unnoticed by consumers who are seeking a low-sodium option unless these are keen label-readers, which is not always the case.
As for sugar amounts, the products that are most heavily affected are fruits. This is especially so because canned fruits tend to be packaged in heavy syrup, in which a large amount of the dreaded sugar usually lies. Although this can be easily remedied by draining and washing the fruits before consumption, again, consumer awareness of this is a major concern. One of the most popular options for manufacturers is to can the fruits in their own natural fruit juices, preserving taste and preventing the addition of sugars, e.g. Del Monte’s Pineapple Chunks in 100% Juice[x].
In cans, BPA is used as an internal coating to prevent direct contact between the foodstuff and the metal portion of the can. But this turns off some consumers.
Metals in cans
The canned food industry faces other challenges aside from preservatives, and a large part of this can be attributed to new findings or perhaps exaggerated science. One of the main culprits here is the chemical Bisphenol-A, or BPA, which is commonly found in the cans used for canning food as well as other food packaging products. In cans, BPA is primarily used as a coating to prevent the actual product from coming into contact with the metal portion of the can[xi]. The main concern surrounding this is that BPA would leach from the can into food, and its consumption is toxic to the body, a concern amplified many times over by research claiming that canned food consumption is a prime source of BPA exposure[xii], as well as linking it to cardiovascular disease and diabetes[xiii]. However, research surfacing from the FDA’s National Centre for Toxicological Research as recent as 2014 claim that BPA is very rapidly metabolised and excreted in the human body, and also that orally consuming BPA only exposes the body to 1% or less of the total amount consumed[xiv]. Studies are still ongoing, but if these findings are added to the increasing number of manufacturers that are looking to use BPA-free lining in their products, there is hope that this shadow cast over canned food will eventually be lifted in time to come.
In April this year, The Economic Times reported findings from the Binghamton University in New York, that zinc oxide (ZnO) nanoparticles present in the lining of certain canned goods could damage the digestive system. Binghamton researchers found the canned food contained 100 times the daily dietary allowance of zinc.[xv]
Whichever way consumers look at, canned foods will be part of their diets, and manufacturers have the responsibility to produce nutritious and safe canned products every time.