Judging food by its cover

“Paper or plastic?” In the US, this is the three-word grunt of the teenager bagging groceries at the supermarket. If only it was that simple: these days, the question of food packaging surrounds everything we eat.

Is it better to eat canned, fresh or frozen food? There are several angles to mull over within this one question. One one side, consider the health implications surrounding nutritional content. On the other, contemplate the energy implications, such as food miles, local food, seasonal food, carbon emissions and recycling.

I’ll attempt to get to the bottom of these issues, though admittedly not quite as fast as I can get to the bottom of a bowl of crab linguine. But that’s another story.

Seasonal considerations

Fresh is generally regarded to be best when it comes to food – and the fresher, the better. In many consumer’s minds, fresh foods are healthy, natural foods, those unspoiled by the rigours of a freezer and kept free from the evils of sodium. To a point, this is true.


However, eating fresh, refrigerated foods all year long isn’t always possible – or practical – or the tastiest. For example, tomatoes on the vine in the summertime provide a rich, flavourful product. Six months later, in the cold dark month of February, tomatoes are watery, uninteresting and even tasteless. During the winter months, eating canned chopped tomatoes is the smartest choice: the tomatoes inside the tin were likely grown in the sunshine of June but just did not make it to the market.

Seasonal food often implies local food, but not always: and if it’s local, it may not need all the bells and whistles that come with the packaging. Local markets are often as plastic-free as you get.

Frozen facts

Frozen product manufacturer Bird’s Eye run regular commercials about how frozen food carries the highest nutritional content. For example, their peas and carrots are immediately placed in a deep freezer, preserving from the start the vitamins and minerals so valuable to the system. The carrot in the ice cube is convincing, but it is still a marketing campaign, so I remain cynical.

After all, how much energy does it take to keep those peas frozen? According to a study by the Scientific Certification Systems (SCS) of Oakland, California, the average amount of energy consumed from farm to table for a frozen product is about 23 MJ per kilogram of food (APEALnews 29, May 2007). The life cycle includes food production, food processing, packaging, transportation, storage and meal preparation. As a comparison, SCS estimates that refrigerated food uses about 14 MJ/kg and canned food slightly less at 13 MJ/kg.

The proof is in the packaging

The canned food industry wants to highlight the “from farm to table” aspect of food, however, because its product uses the most amount of energy in the packaging. The energy cost for the steel can is about 5 MJ/kg, more than one-third of the energy consumption. The cardboard and plastic packaging of frozen and refrigerated foods are 4 MJ/kg and 2 MJ/kg (APEALnews 29, as above).

When it comes to the question of recycling, though, the steel can comes out a winner. Steel and glass can be recycled endlessly, whereas paper and plastic can generally only be recycled a few times. The process of sorting and recycling is an easier one as well, which is perhaps why the recycling rate is so high: according to APEAL, the association of European producers of steel for packaging, in 2005, the metal packaging recycling rate was 92% in Belgium, and 12 European countries had recycling rates over 60%.

How far is too far? Green beans from Kenya, bananas from the Caribbean

The can has its merits, but how do we know how far it has come to sit on our pantry shelf? We as consumers have been conditioned to like variety in our food, which has led us to buying food from Africa or Australia, thousands of miles away. A backlash has been brewing, with many of us turning inwards, trying to source our produce as locally as possible. “Food miles” is another buzzward.

Here, a holistic approach is necessary too, in my opinion. Those green beans may have come from Kenya, but would it be better to grow them in a glasshouse, using kilowatt after kilowatt of electricity? And do we want the workers in the Caribbean dependant on bananas for their livelihood to go out of business? The question just keeps getting bigger and bigger.

The Guardian ran an excellent article on this topic. Here, academics from the University of Wales Institute at Cardiff argue for a system that “considers all environmental impacts from farm to dinner plate,” measuring food in “global hectares.” They offer the ‘eco-friendliest’ diet possible:

A typical day on the diet
Breakfast: Cereal and milk, tea/coffee (from weekly allowance half as large as normal diet)
or
Toast and jam (or marmalade)
Lunch: Avocado and poached egg with toast
or
Black-eye bean, rocket and pinenut salad
Dinner: Spinach, leek and pinenut risotto with yoghurt.
Fruit salad
or
Pork cassoulet with mustard, honey and cinnamon, served with green salad. Sweet pancakes with jam, honey, tahini, chocolate sauce or yoghurt
Drinks/Treats: Two glasses of beer, pack of fruit pastilles, two Jaffa Cakes
or
One can cola and nine boiled sweets
(The Guardian, 4 June 2007)

Overall, I am happy with this diet. But when it comes to the snacks section, I am not quite so pleased. I do not encourage any diet that calls for beer, cola, boiled sweets or gummi-bears. Where’s the nutritional content?

If I’m not mistaken, that brings us back to the “fresh is best” question. Well, is it?

My verdict: Eat seasonally all-year round. If you want a certain product out of season, source it in a canned or frozen variety. Eat locally as much as possible. (For example, grow your own herbs in a windowbox.)

Don’t eat garbage – whether it is frozen peas, canned tomatoes or fresh celery, make your own food.

(Oh, and I didn’t even get into organic food. We’ll talk about that another day.)