Tricks of the trade – fruit and vegies
Most fruit and vegies can be stored for at least a few weeks if the conditions are right. About four per cent of our supposedly “fresh” fruit and vegetables comes from overseas. Grapes may be imported from the US (packed with sulphur dioxide to prevent mould growth), while asparagus can come from Peru.
Quality is further compromised when fruit is picked before it’s fully ripe to make it easier to store and transport over long distances. And varieties are often chosen more for ease of storage and transport than for flavour. A huge amount of research has been done on making food last the distance:
- Produce is chilled as soon as possible after harvest, so that it deteriorates much more slowly.
Controlled-atmosphere storage and packaging (with lower levels of oxygen and higher levels of carbon dioxide than normal air) can further slow down deterioration.
1-methylcyclopropene (1-MCP) is increasingly being used to extend the storage life of some fruits and vegetables even more. This chemical blocks some of the biochemical changes that occur as fruit ripens and matures. Unfortunately, tests show the fruit remains hard and 1-MCP also prevents production of chemical compounds that contribute to flavour. Nonetheless, it’s already used extensively for apples, and increasingly for other fruit, such as avocados and melons.
- Fruit is often sprayed with fungicides to prevent mould; imported fruit and vegetables may be fumigated with methyl bromide to comply with quarantine regulations.
Tricks of the trade – meat
Chilled beef mince can now be stored for up to 44 days and cuts of lamb for up to 112. Some supermarkets still have their own butchery, but there’s a trend (following the US and UK) to distribute pre-butchered meat from a central location. Our story on steak looks at some of these issues. It’s then either vacuum-packed or placed in special modified atmosphere packs for display. The gases used for these packs are carbon dioxide and nitrogen – carbon dioxide inhibits growth of micro-organisms and nitrogen is an inert filler.
The gas mixture may also contain a small amount of carbon monoxide, which reacts with the myoglobin in the meat, producing a healthy-looking red colour, even when the meat is far from fresh. Carbon monoxide is permitted as a food additive in Australia, but it’s technically a “processing aid”, which means it does not have to be declared on the label. Neither of the big supermarket chains would tell us if they use carbon monoxide in packaging meat.
The extended storage time for meat made possible by new technology also poses health risks. Harmful bacteria can grow to dangerous levels while the food remains attractive to the eye. Clostridium botulinum is of most concern because of the severe illness it causes. Thorough cooking should kill most bacteria, but extra care is needed to make sure that the meat is cooked right through and to avoid cross-contaminating other foods with bacteria via knives or cutting boards, etc.
The effects of storage
They may still look perfect, but fruit and vegetables lose some vitamins from extended storage.
English spinach, for example, retains only 53% of its folate and 54% of its carotene after just eight days stored at fridge temperatures.
Apples held in cold storage for three months contain lower levels of antioxidants. With extended storage, they also lose flavour and aroma; they can go floury quickly unless kept in the fridge.
As vegetables age, they can develop unpleasant smells and bitter flavours, and droop or get tough and woody.
What you can do
Be wary of supermarkets You may find better quality and fresher produce at specialist butchers and fruit and vegetable shops than at your local supermarket; farmers’ markets can also be a source of good quality fresh produce. Organic meat, fruit and veggies are more likely to be locally produced and organic farmers often choose tastier cultivars, especially for fruit.
Follow the seasons Now that so much produce is available for most of the year, it’s easy to lose track of its seasonality. Fruit and vegetables that are in season are likely to be fresher, tastier and more nutritious. What’s in season at any one time obviously varies across the country – see What’s In Season?, opposite, for where to get current information for your area.
Choose ripe fruit that’s well coloured and with a bright appearance. Feel for a tender texture and smell the stem end for stone fruit and the blossom end for apples, tomatoes and melons. Only buy fruit with a full, fruity aroma.
Scrutinise your vegetables Green vegetables should be crisp and not shrivelled or yellow. With broccoli and lettuce, check there’s no rot at the end of the stem. If you don’t like the look of what’s on offer, you’re probably better off buying frozen or canned vegetables. While they may not be as crisp and crunchy, frozen vegetables retain most of their nutrients and can be more nutritious than “fresh” vegetables that have been transported over long distances. Canned vegetables (and fruit) also retain most of their original nutrients. They have less vitamin C, but the levels of dietary fibre, carotene and folate aren’t much affected by the canning process.