Thursday, November 12, 2015

Splat Goes the Theory

The tomato is one of our lovelier foods; juicy icon of the good life. There’s almost nothing better than buying fresh tomatoes on a Saturday morning, bringing them home to your kitchen, washing them carefully, slicing them, admiring their shiny interiors with the miraculous seeds inside, adding a few drops of green, virgin olive oil, and perhaps a leaf or two from the basil plant on the windowsill. Just paradise.

Few people are indifferent to the sun-drenched cherry tomatoes served up in every picturesque Italian village trattoria; or a well-tended vegetable garden where the branches of each tomato plant are carefully tied by hand with a green ribbon – these fruits are harvested with loving care. Most likely you feel that such tomatoes should be organically grown, on small fields, reflecting tradition and history. You might think that, this way, they accrue authenticity, honesty and truth, that their production will be small-scale, and preferably local.

But how ‘good’ are they really? And what does ‘good’ mean in this context? Are the organic hand-picked tomatoes sold at farmers’ markets really better, in a technical sense, or do they just make us feel like better consumers – perhaps even better human beings? If the organic tomato is just a vehicle for romantic fallacy, then we have to look dispassionately at how they are grown from the perspective of sustainability.

The logic of farmers’ markets begins with this: that the route from harvest to plate ought to be as direct as possible. That’s fine if farmers live round the corner from consumers. But urban land is in short supply, expensive, often polluted, and unsuitable for horticulture. And there is more. Even in a short chain from farm to table, produce can get spoiled. A fresh tomato is not dead; like all fresh products, it’s a living organism with an active metabolism, post-harvesting, that provides a fertile substrate for microorganisms and causes tomatoes to deteriorate very fast. Freshness does not in itself translate into sustainability: unless the supply chain is well‑organised, losses can be considerable. And food losses come down to a waste of land, water, energy and chemicals used to produce what is ultimately discarded. This ought to be a good argument for local markets, but it is not. Everything depends on transportation, storage and speed. Poorly packed products go to waste in a matter of hours.

Thanks to decades of research, we now understand the interacting metabolisms of vegetables and microorganisms. We can design high-tech transport and storage techniques that slow down, even halt, deterioration through the use of harmless mixtures of gases. Chips fitted to containers give off signals when the gas composition and temperature need adjusting to plan ripening at the exact moment of delivery. Likewise, to minimise food losses in supermarkets, packaging techniques and materials have been developed to prolong shelf life. Surprising but true: modern treatments with biodegradable plastic bags and sealing create an optimal environment inside the package and reduce loss. So does the industrial washing of packed and cut vegetables, which also saves water, compared with household‑level processing.

What then of labour? While ‘handpicked’ sounds attractive to the urban consumer or occasional gardener, this type of manual labour is backbreaking if done all day long. Remuneration is poor, job security close to zero, and only few are willing to do this kind of work. To top it all, the yield from organic farming is low. So think about the alternative: harvesting vegetables such as tomatoes with smart robots that carefully grab each fruit, after assessing its ripeness with a special camera; using smart technology to fine-tune the dosing of fertiliser to every stage of plant development. This enhances flavour and texture, and reduces the overall amount of fertiliser needed. The result is that, in greenhouses, one square metre of tomato plants produces more than 70 kilos of high‑quality tomatoes, all of which make it to consumers’ kitchens.

Since we’re on the subject of freshness, consider this: ketchup might actually be better for us than fresh tomatoes – and not just because of economics (the tomatoes used in ketchup are subgrade ones that would otherwise be destroyed). While fresh tomatoes contribute to a healthy diet, human digestive systems are not tuned to extracting most nutrients from fresh tomatoes. Tomatoes are far more nutritious when cooked or processed into ketchup or paste. So, ketchup is no bad thing – unless overloaded with sugar and salt. Indeed, a growing body of evidence suggests that the discovery of fire and cooking – that is, heating food – has been essential in the evolution of the human brain because it allowed for a better absorption of nutrients. Moreover, drying and smoking promoted the preservation of perishable foodstuffs, and perhaps facilitated the emergence of a more complex diet and division of labour.

But surely, you’ll object, tomatoes grown in small-scale gardens taste better. Not so! Double-blind tasting panels have been unable to pick out the greenhouse tomatoes as lacking in flavour, or tomatoes grown without fertiliser as more tasteful. According to Dutch reports on such testing, taste is more dependent on the variety of tomato than on the way it is grown. More importantly, the context of eating determines everything. The on-the-vine tomatoes you consume with mozzarella and olive oil on a village square in Italy will never taste the same at home. It’s a matter of psychology and gastronomy, not chemistry and biology.

by Louise O Fresco, Aeon | Read more:
Image: Yuki Murata/Getty