Urban Food Chains

the links between diet and power

asparagus fruit plants strawberries vegetables
Asparagus and strawberries
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Money is a totally meaningless measure of value for many things. Take food production for instance.

From an accountant’s point of view, there is no monetary distinction to be made between a farm growing a thousand pound’s worth of wheat during a crop year and a market gardener’s business growing a thousand pound’s worth of asparagus and strawberries over the same period of time. It is only when you come to live on these harvests that the difference becomes apparent.

Luxury crops such as asparagus and strawberries, or Yorkshire rhubarb, became potentially more profitable when the Victorian railway network suddenly cut the cost of market access, moving delicate products quickly and efficiently. Market gardeners were by definition close to urban centres, but the railways extended the range over which they could sell.

The reason asparagus-and-strawberries is such a common combination is that both crops need a lot of skilled labour to harvest. Having assembled a gang of labourers to pick asparagus, it makes sense to have another crop to follow through and move the workforce from one to the next as the season progressed.

In the case of Yorkshire rhubarb, production is concentrated into an area surrounded by railway lines. Like the asparagus-and-strawberries growers, market access was the key to their profitability.

However, especially given the short seasons for these luxury crops, no-one is going to live on a diet of asparagus and strawberries. We use a different set of values to establish what a sustainable food system might look like and what it would need to produce.

Europe fruit Switzerland
Longer shelf life for fresh produce
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Swiss researchers have found a way of using fruit and vegetable peelings to make a coating that extends the shelf life of fresh produce. Staff at the Empa research body have been working with Lidl Switzerland since 2019 to develop what promises to be a game changer.

Bananas have been chosen to test Empa’s cellulose coating.

Testing the coating on bananas, a gain of up to a week was recorded in the product life. There is the added benefit that with a reduction in the use plastic materials, the risk of condensation or rot in transit is also lower. “The big goal is that such bio-coatings will be able to replace a lot of petroleum-based packaging in the future,” explains Gustav Nyström, head of the Empa lab.

Lidl Switzerland has 150 stores that will take part in testing the new coating as it continues its development over the next two years.

Further details from the Empa website.

cultivation olives
Dietary gold on trees
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pic Wikimedia Commons

Today (Friday November 26) is World Olive Tree Day, as growers in the northern hemisphere prepare to pick the next crop of olives. More than two thirds of the world’s olive trees grow in the Mediterranean basin and survive thanks to their deep roots. Younger trees planted in more recent groves will often be irrigated until their roots have reached cooler, damp rock formations.

Olive oil ranges in colour from green to gold.

Olives are a winter crop: starting in November unripe green olives are gathered and pressed for distinctively strong, green oil. As the winter progresses, the olives darken and ripen, the oil changing to gold as the flavour softens with the fruit. The harvest continues into February and March, depending on varieties and locations.

Traditional olive-picking techniques needed the olives to be hard enough not to break up as pickers beat the trees with heavy sticks. Today, large groves are harvested with a mechanical arm attached to the trunk of the tree. The tree is then shaken vigorously, emptying the fruit onto large sheets spread out to catch the crop. The process is stressful for the tree, but is quicker than the stick-wielding villagers. The remaining winter months are a time of recovery.

Once picked, olives are fragile. Away from the tree, the olives start to accumulate free oleic acid as they oxidise during the different stages of processing. Only when the oil is extracted and stored under nitrogen can the oxidation be halted. The largest pressing plants, typically in Spain, where batches are consolidated and have more time to oxidise, face the prospect of minimising the effects as best they can.

Olives picked for the table have an additional constraint: unlike olives bound for pressing, every table olive needs to be visually perfect. To remove the stones from olives, the flesh needs to be firm and the olive must be unripe. To produce black pitted olives, green olives are treated to make the flesh black and then the stones can be removed mechanically. By the time an olive has fully ripened and turned black naturally, it is no longer possible to remove the stones mechanically, since the soft flesh just falls apart. The taste, however, is exquisite.

olives
Olive oil grades
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Olive oil is a highly-prized commodity, for a very wide range of reasons. As a key ingredient of many elements in the Mediterranean diet, it is a pivotal component of Mediterranean cuisine. Across the region, household use of olive oil would be counted in dozens of litres a year.

Spain is the world’s biggest producer and user of olive oil: collectively, domestic consumers buy tens of thousands of tonnes every month. The country usually produces over a million tonnes of olive oil a year, much of it shipped to packers all around the world.

Greek olives are harvested in small quantities and pressed within hours of coming off the tree. Domestic Italian production is an even lower tonnage. Italian blenders are very skilled at procuring the right mix of flavours and colours of oil from all over the world to blend in bulk. The bottles were often marked “Prodotto in Italia” (“produced in Italy”) but this delightfully vague ambiguity was outlawed by the European Commission.

Pressing yields anything up to 20% by weight in oil. This ranges from the cheap and cheerful institutional canteen cooking oil, olive pomace oil, through to single estate, single variety specialist extra virgin olive oils containing less than 0.08% in free oleic acid. Like wine, the estate bottled oils are like an exclusive club: they are as distinctive as the groves they came from.

The next grade, virgin olive oil, will have less than 2% free oleic acid, which will be reflected in the taste. The different grades of virgin olive oil are too delicate to be suitable for deep frying, which is the main use for olive pomace oil. Pomace is the paste that is left over from the mechanical pressing process used to extract virgin oil grades. Due to its lower moisture content, olive pomace oil is better suited to high temperature applications.

customs clearance Europe fruit haulage lorry plane plants retail ship vegetables
Amber light for greens
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UK fresh produce wholesalers were among the first adopters of end-to-end database-driven stock management. In the early 90s, when multiple retailers were rolling out electronic Point Of Sale systems, overnight there was enough reliable data to drive ordering and procurement systems.

To maintain year-round availability of core inventory, wholesalers needed to be very granular in what constitutes an SKU. By the standards of the day, the databases they developed were ahead of their time. By around 1994, one wholesaler was tracking product grades by (16-bit) colour, calibration range, farmgate and dockside Brix, crop/season dates, with regional adjustments for weather bringing seasons forward or holding them back.

The SKUs were effectively large matrices, with a very long tail of incremental detail that went far beyond grower details and crop varieties. The database effectively became the business and was stored in triplicate on hard drives that were lodged in rotation with the bank: one active, two off-site, rotated daily.

With a global reach, shiploads of third country fresh produce were being sold while the goods were still on the water. Title remained with the consignee until after the ship had docked and unloaded.

For third country fresh produce, the transition from the Common European Tariff to the UK Global Tariff is a detail for which the variables are knowable in advance. For third country produce, the UK already has the PEACH system (Procedure for Electronic Application for Certificates) which is run by DEFRA. Visit https://www.gov.uk/guidance/automatic-licence-verification-between-defra-rpa-and-hmrc where you can download a spreadsheet that maps CN numbers on to plant varieties and gives handling details for importers. The back end of PEACH is currently plumbed into TARIC-3, so a UK-based replacement  is doubtless in hand.

Import duty on imported fresh produce can be agreed on the  basis of a Method 4 valuation, agreed by HMRC (https://www.gov.uk/government/publications/fresh-fruit-and-vegetables-under-method-4-valuation). EU-grown fresh produce should be transferable to this method when the time comes, as the need arises.