Sunday 24 October 2010

The apple from the edge of the world

Eating an apple by Sean
Dreilinger
under BY-NC-SA

On 1 October a warning was posted on the site of the Food Standards Agency (UK) advising food operators that shipments of apples imported from Chile have been found containing morpholine (at about 2 ppm) and that those apples should not be sold in the UK market. Similar advice was given by the food safety authorities across the EU and - where necessary - recalls where initiated.

In various places around Europe, the news piece got attention, as would happen with any news item related to food safety. In this particular case, however, the warning/recall/etc. drill from the food safety authorities is due to a legal reason rather than the appearance of a major threat for consumer safety: Morpholine (1-oxa-4-azacyclohexane) is a chemical used in a variety of applications. The major one is corrosion protection in water tanks and steam production systems. The morpholine molecule is amphiphilic making it also a good emulsifier. As such, morpholine can added in wax mixtures used by the produce industry in the coating of fruits like apples, citrus fruits, etc., making those easier to spread on the fruits.

Using various coating mixtures onto fruits, post-harvest, is a common practice. Such coatings hinder water evaporation and protect the fruit from various environmental factors, thus prolonging their shelf life. Fruits do have a natural water-repelling coating. Often, though, this gets damaged or remove by post-harvest handling. It's good to keep in mind that such coatings cannot make a fruit fresh; they just protect the freshness of the fruit.

The use of morpholine in wax coatings is not allowed in the EU, but it is permitted in other places in the world (e.g., USA, Canada, Chile, etc.). The EU has chosen the safe route here. The concern is not so much for morpholine itself, for which studies (examples here and here) do not indicate significant toxicity, mutagenic or teratogenic action, but rather for its nitrosated derivative that has been shown to be mutagenic and carcinogenic in lab animals. The conversion of morpholine to its nistosated derivative can be done in the body in the presence of nitrites. Even in the latter case, current risk analysis scenarios, as hinted in the FSA statement, suggest a very (very) small risk for the consumer. Peeling the apples would remove the risk factor altogether but - to be fair - plenty of consumers prefer eating them unpeeled; a normal rinse, would not affect the coating and would not remove its content.

As in every food safety discussion, voices calling for reviewing the handling of morpholine-containing wax-coated fruits have surfaced. After all, the food law is not necessarily a reflection of scientific findings. It's politics, too. It's very much a balancing game, where risk is on the one side and benefit on the other (and I'm talking about all kinds or risks and benefits, not just the ones about human health). Often, law makers take sides based on (their) common sense.

IMHO, not using a chemical that when ingested may pose a risk - no matter how inconceivably small - makes sense, especially when there is a list of down-to-earth, food grade compounds that could be used to achieve the same technological purpose (e.g., lecithin, fatty acid esters). Edible coatings may still be a rather active scientific niche but there are already proven formulations that could be used. Normal packaging materials could also be sufficient.

Going beyond the scientific/ technological discussion, I believe that for the food operator things are rather easy. Knowing what the law dictates is the way that their business will not be disrupted. Simply, that's the way to compete at the local level. I'm not saying that monitoring the food law across the globe is an easy task, although things have been slowly improving on that field: the EU and several other countries offer online access to legal documentation. Beyond that, there are officers that can be asked and professionals that they can help. In any case, such challenges are part of the global commerce game.

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