Is it time to kill the salad bag?

The US Ambassador to the UK doesn’t understand why we have a problem with chlorinated chicken as we already wash our salads/greens in chlorine. Are we the only ones thinking that rather than adding more chlorine to our diets, we should probably be talking about how to ditch the chlorine-soaked, environmentally damaging, potentially unsafe and not particularly nutritious salad bags? (Although, I guess there is something to be said for consistency of that taste.)

In the UK, it’s estimated that a massive 480m salad bags are sold each year and for retailers it represents the largest volume and value sales area of the salad category. Once considered the ultimate consumer-focussed convenience item, it is estimated that consumers throw away 40% of bagged leaves. It’s time to talk about the plethora of issues with the salad bag.

Waste and food miles

Waste is an issue in every stage of the salad bag supply chain. The quality of produce from both outdoor and partially-protected crops relies on dependable sunlight levels, temperatures and soil consistency. Predicting the weather and its impact on crop availability makes it incredibly difficult to manage the supply process. Suppliers and retailers tend to find themselves searching for additional volume when the sun is shining and consumer demand is high and are then left with excess product from a crop flush, a week to 10-days after the clouds have rolled in. To ensure full availability in stores during the summer months, retailers can be forced to take non-UK produce in times of high demand. Conversely, retailers will often have to promote heavily following a crop flush to save it from being wasted.

Food miles also present an issue — although during the summer months (May-October), many of the salad items we see in stores will have been grown in the UK, outside of this season what we see in stores tends to come from Spain, Italy, Portugal and the Netherlands.

The production of high-quality, ready-to-eat items such as salad bags requires enormous amounts of water. Before packing, salad leaves undergo a multi-stage washing and rinsing process, where leaves are washed in sanitised (usually chlorine-based) water.

Plastic

Once washed and spin-dried, salad leaves are packed into modified atmosphere packaging (MAP) — plastic bags which are flushed with gas, altering the atmospheric concentrations of oxygen, nitrogen and carbon dioxide with the aim of slowing down respiration, deterioration of the leaves and preventing wilting. While MAP is incredibly effective and in some cases doubles the shelf life of products, it requires a fully sealed plastic pack. In addition to the single-use plastic waste concerns, MAP is effective only to a point for consumers — an unopened salad bag can sit in your fridge looking pristine for days, yet the moment it is opened, even if it’s stored chilled, leaves can quickly turn to a green slime.

Potentially unsafe

Producers must go to extreme lengths to limit the exposure of consumers to harmful diseases caused by the likes of E.coli and Salmonella and routinely wash leaves in chlorine as a mechanism for helping to maintain the food safety standards of these products. Despite this, our existing production methods cannot guarantee against contamination in the form of foodborne diseases or foreign bodies.

Nutritional value

Despite the advantages on shelf-life, MAP gas-flushing has a seriously detrimental effect on the nutritional content of pre-washed salad. The process has been shown to destroy vitamins and protective antioxidants, particularly vitamin C present in the leaves.

Start looking for your nearest vertical farm

The avoidable waste, the excessive use of plastic and water, the chemical additions in the form of pesticides in the growing process and the water and chemicals used in washing are all areas for consumer concern and it is time for us to consider a new solution. Vertical farming aims to provide protection and maintain optimal growing conditions in an environment that controls light, CO2, temperature, humidity, water, pH levels, and nutrients.

Crops growing at the Future Farming Hub facility based at the James Hutton Institute in Dundee.

There are a range of benefits to producing crops, particularly salad greens from vertical farms.

Sustainability:

• The growing environment in a vertical farm is not affected by the external climate;
• Facilities can be built in almost any location, as neither solar light or soil is needed, only electricity, nutrients, water and seeds;
• The units can be directly linked to local renewable energy sources (e.g. solar panels in a desert location);
• Production yields can be maintained year-round with no external restrictions (i.e. weather);
• Vertical farming systems are significantly more productive per square metre of growing area than traditional growing methods;
• The closed system of a vertical farm allows us to utilise our resources more efficiently (including water, energy, space, capital and labour) to reduce our impact on the environment (our facility recycles its own water and has the potential to generate its own water);
• Vertical farming enables us to grow produce close to where it is being consumed; drastically reducing the time from field to fork and the food miles for this easily damaged, perishable product.

Safe to eat:

• Vertical farming removes the need for the use of pesticides (usually applied to target specific pests but with the potential to be toxic to humans and non-target species such as bees, birds and mammals too);
• Closed system vertical farms allow for better control of pathogen risks, which could remove/reduce the need for the current system of washing (which is currently unavoidable for the control of pathogens) in traditionally grown crops.

Plastic

• Local production and shorter supply chains mean greater supply chain transparency and the potential removal/reduction of the necessity for extending the natural shelf life of products through MAP. Increased shelf life, improved quality and local production will all reduce food waste.

The implications of shifting our food supply chain in this manner are enormous. Year-round production of UK-grown crops would provide stability to our supply chain in terms of availability and price. Crops would be grown locally on demand in conditions that optimise their quality, flavour and nutrition without the fluctuations caused by environmental factors such as climate, soil type and irrigation etc.. It also has huge implications for questions of traceability as our global supply chain becomes more intricate and complex.

Vertical farming is not yet sustainable and the cost of vertically farmed produce remains higher than traditionally farmed produce. However, a number of companies and organisations (including the Future Farming Hub) are already building the tech and sharing the knowledge with consumers and industry to make vertical farming a real and sustainable alternative. It is time to revolutionise how we eat in a way that will fundamentally reduce waste and harm to the planet.