A few years ago I became aware of how the produce we eat this century is so very, VERY different from the previous. Due to modern agriculture, important nutrients are depleted – even missing completely – from the soils we now grow our grains, fruit and vegetables in. Add to that artificial ripening and the time it takes to get from harvest and into our bellies; it’s even more important to eat fruit and veges that are fresh (eaten within a few days of harvest) these days.
Fruit and vegetables have their optimal nutrition when they are picked ripe. But nowadays often fruit is picked earlier and artificially ripened. Tomatoes and bananas are prime examples. The fruit may attain full color after picking, but it will not attain the highest nutrient levels.
After picking, fruits and vegetables continue to breathe. This process – called respiration – breaks down stored organic materials and leads to loss of flavour and nutrients. The longer produce has to breathe before it is consumed, the less likely it is to retain nutrients. But different produce has different respiration rates. Asparagus, broccoli, mushrooms, peas and sweet corn all have a very high respiration rate and will lose nutrition and flavor more quickly than apples, garlic or onions, all of which have low respiration rates.
On this note, if you buy your fruit and vegetables from the supermarket you might be surprised to know that the typical storage time for apples is 6-12 months! And carrots up to 9 months!
Here’s what I do to ensure my family gets the highest nutrition from the fruit and vegetables we consume.
Grow Your Own
I am certainly no expert when it comes to growing my own vegetables, but it really isn’t that hard to develop a vege patch and sow some seeds. The difference in taste is very noticeable, especially with fresh carrots, cherry tomatoes and sugarsnap peas. Pick when ready and eat within a couple of hours – you can’t get much better than that!
There is some learning and planning involved; when it’s the best time to sow different vegetables and managing successive crops. It’s always nice to give some produce away when you have a glut tho.
Of course many of us are time poor (I totally get that) or for some there’s an issue of space so…
I buy very little vegetables from the supermarket. Our household’s main supply of vegetables gets delivered (for $2!) once a week from a local grower. It is grown spray-free, picked that morning and delivered mid-afternoon.
Buying locally also decreases the amount of handling, since local produce is commonly picked by hand rather than machine. Minimal handling means less chance of contamination, which can increase the rate of decay (and loss of nutrients).
EAT IN SEASON
When you buy locally this happens naturally, but in the supermarket it sometime seems like fruit and vegetables are harvested all year round! Adjust what you eat according to the seasons: right now (May and the end of autumn in New Zealand) that means feijoas, green kiwifruit, mandarins and pears. Vegetables have a longer growing season but at the moment pumpkins and yams can be added to your grocery list.
Storing bought FRUIT and veges
How you store your bought produce can effect their nutrient content. The key is to provide them with an environment which reduces moisture loss and decreases respiratory activity. This means keeping most vegetables cold and sealing some in airtight containers.
The technology behind crisper drawers in refrigerators has developed over time. These days most new fridges have multiple vegetable drawers with a different level of humidity from the rest of the refrigerator, and the humidity can be adjusted according to the the type of produce to both prevent loss of moisture, and also allow ethylene gas produced by certain fruits to escape, thus preventing them from rotting quickly. Crisper drawers which do not have a humidity control are, by default, high humidity crispers.
If you aren’t in the market for a new fridge, I love Tupperware FridgeSmart containers which have venting system controls to adjust airflow and moisture, similar to the latest fridge models. The best thing is the pictures on the side showing you what airflow is best for which fruit and vege!
Note however that refrigerating certain foods can reduce their nutritional quality, or accelerate the spoiling process. Herbs, potatoes and fruit such as apples, bananas, citrus fruits, berries, peaches, apricots, and nectarines are all best stored out of the fridge. That’s what your fruit bowl is for.
Buy CANNED ANd Frozen
People often think that fresh is better but that depends on your definition of fresh! (As you’ll now be aware)
The nutrient content of canned and frozen fruits and vegetables is actually comparable to fresh and, in some cases, it may be higher than fresh! Produce to be canned or frozen is picked when ripe and processed immediately after harvesting, so nutrient losses after picking are minimal.
Before a food is canned or frozen, it is usually heated very quickly with steam or water. The water-soluble vitamins, including vitamin C and B-complex, are sensitive and easily destroyed by blanching. But fresh food often deteriorates more rapidly than canned and frozen foods so we can’t say one is better than the other.
Overall, the nutrients in canned fruits and vegetables tend to be relatively stable because they are protected from the deteriorating effects of oxygen. Just look out for added salt and sugars.
Generally speaking, freezing helps retain the nutrient content of fruits and vegetables. However, some nutrients begin to break down when frozen produce is stored for more than a year. Those Best Before dates matter.
One Last point – How you Prepare
Most vegetables are peeled or trimmed before cooking to remove the tough skin or outer leaves. But most nutrients, such as vitamins, tend to lie close to the skin surface, so excessive trimming can mean a huge reduction in a vegetable’s nutrient value. Try washing or scrubbing vegetables rather than peeling them. And use the outer leaves of vegetables like cabbage or lettuce unless they are wilted or unpalatable.
Some vitamins dissolve in water, so you lose your vitamins to the cooking water if you prefer to boil your vegetables. Alternative cooking methods such as grilling, roasting, steaming, stir-frying or microwaving generally preserve a greater amount of vitamins and other nutrients.
It is inaccurate to say that cooking food always lessens the nutrient value tho. Cooking can be advantageous in many ways, including making phytochemicals more available, for instance, phytochemicals are more available in cooked tomatoes than in raw tomatoes.