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Vegetable losses: How can more food be saved?

By Jonathan Sehl, Osnabrück University of Applied Sciences

While the global population is expected to grow to 10 billion people by 2050, many people will not have a secure food supply. Experts estimate that between 702 and 828 million people will suffer from hunger in 2021. In addition to external factors such as climate change, food systems are also important drivers of the deteriorating global food situation. At the same time, around a third of all food produced is wasted along the value chain. The role played by primary production and the options for alleviating the problem were analysed as part of a bachelor's thesis.

What exactly are food losses?

This question is not easy to answer, as there are different definitions. According to the EU Waste Framework Directive, for example, pre-harvest losses are not defined as waste, as they are only categorised as food once they have been harvested. This is criticised by the non-governmental organisation WWF, for example. The argument is that the sorting of produce in the field results from the high demands of the trade and consumers, which means that this loss is also caused by the market. Accordingly, all rejects from pre-harvest, harvest and downstream processes should be taken into account. However, the exact reasons for rejects are often difficult to define, as plant technology measures can also lead to pre-harvest losses.

How high are the losses?

Globally, food waste in primary production is estimated at 1.2 billion tonnes per year. This in turn accounts for 15.3% of the total volume of food production. This figure includes post-harvest waste from all primary production. It does not include food that does not meet commercial standards or market requirements and is therefore discarded before or during harvesting. Taking these quantities into account, the FAO estimates food waste in primary production at 20 to 25 %. There are major differences between different types of vegetables.

Thünen Report 71 covers food waste according to the EU Waste Framework Directive in Germany from 2015, according to which households generate the most waste (52%), followed by processing (18%), out-of-home catering (14%) and retail (4%). Agriculture only causes 12% of all food waste, totalling over 1 million tonnes.

So is everything not so bad?

Where is food waste generated?

52 % - private households

18 % - processing

14 % - out-of-home meals

12 % - Agriculture

4 % - trade

(Source: Thünen Report 71)

Own surveys on food losses

The primary data presented here on cucumbers, tomatoes, sweet potatoes and carrots originate from repeated surveys of reject quantities on two organic farms in the Osnabrück area. The reject quantity is merely the quantity of produce that is not marketed as so-called A produce. However, this quantity is not automatically a loss or waste. This is because further processing or marketing options are conceivable.

In the case of the outdoor crops (carrots and sweet potatoes) recorded, the amount of waste is significantly higher than for the two types of vegetables (cucumbers and tomatoes) from protected cultivation. In the case of sweet potatoes, for example, there were over 1.2 kg of B produce for every 1 kg of A produce. One reason for this is the more careful and controlled production of greenhouse crops. While crops grown in the open are harvested mechanically from the soil, the fruit is harvested by hand in the greenhouse, whereby the stage of growth can be taken into account. In the case of cucumbers, for example, a distinction can be made between ‘without pre-harvest loss’ and ‘with pre-harvest loss’, as crooked cucumbers, for example, were removed before harvesting by plant cultivation measures. In the case of tomatoes, there were virtually no pre-harvest losses.

Lack of data on food losses

As with most data on food waste in primary production, the data does not come from primary data, but from mass balances or coefficients and statistics determined on the basis of the literature. The frequent use of secondary data and the lack of direct counts and measurements is also evident from other studies. This harbours great uncertainty regarding the accuracy of the data. Consequently, in addition to a standardised definition, primary data collection is urgently needed in order to work on the problem in a more targeted manner.

Why are goods discarded?

In addition to collecting primary data through measurements and weighing, qualitative interviews were conducted with representatives from production and processing. This made it possible to shed light on the reasons for rejects in production on the one hand and to evaluate measures to reduce waste on the other. The interviews revealed that some players in the food industry already market B-goods or use them in processing. A distinction can be made between organisations that focus on the procurement of B-goods and surplus produce (e.g. Querfeld and Dörrwerk from Berlin) and organisations that only use discarded vegetables on occasion.

Many stakeholders criticise the difficult and costly procurement of B-goods, which is associated with additional work. A lower purchase price for B-goods is thus levelled out by the additional costs incurred. At the same time, however, producers often have large quantities of B-goods that do not find a buyer. Interviews with producers have shown that a lot of vegetables are often produced spontaneously and concentrated in a short period of time. There are usually no short-term sales channels for the produce. At best, the produce can be donated to charitable organisations or it ends up in the biogas plant. A solution that is also economically viable only exists in exceptional cases.


Marketing of B-goods must be improved

Through marketing, processing, food donations or feeding, a wide range of measures are already being implemented by the people surveyed. Nevertheless, a great deal still needs to be done to ensure that producers have the opportunity to market B-goods and that buyers who would like to use B-goods have access to them. Simpler marketing channels and access to B-goods could ultimately also have a positive effect on the final price of A-goods.

It should be noted that farmers are often already working at the limit of their capacity and have little time to take care of an additional marketing channel. Of course, it is also important to increase the acceptance of B-goods among retailers and consumers. In addition, data and experience would have to be collected in order to reliably guarantee reject quantities on the part of producers and supply them to customers.

While there is already a great deal of voluntary commitment to the use of discarded food, there are already a few companies that have specialised in the marketing and processing of B-goods. The aim must be to ensure that this does not remain an exception. The utilisation and marketing of B-goods should become the norm.

Better classification of "waste"

According to the definition of the World Resources Institute (WRI), carrot waste and a large proportion of sweet potato waste are not categorised as food waste, as they are either used as animal feed or are further processed industrially. Therefore, the food waste quantities of the four crops differ in relation to the total harvest quantity, the total amount of waste and the utilised amount of waste. While the relatively small amount of cucumber and tomato waste ended up completely in the biogas plant, the carrots were used as animal feed. And most of the rejected sweet potatoes went to industrial producers. Even though the energy efficiency of tomatoes and cucumbers in a biogas plant is rather modest, this utilisation option is considered the simplest solution for the farm.