ReviewProcessing- and product-related causes for food waste and implications for the food supply chain
Introduction
In 2011 the Food and Agriculture Organisation of the United Nations estimated that one third of the worldwide food production is wasted or gets lost on the way from farm to fork (FAO, 2011). Wasted food is associated with an unnecessary use of energy and water, and emissions of greenhouse gases generated by production and delivery operations (Papargyropoulou et al., 2014, Tiwari et al., 2014); it is also contradictory to the increased amount of food demanded by a growing population (Ehrlich and Harte, 2015, Godfray et al., 2010). Reducing food waste is therefore one of the goals the UN have set to achieve a more sustainable world by 2030 (United Nations, 2015).
In many cases it is processing that links agricultural materials to the consumer. It is therefore important to ensure processing efficiency, and to have sufficient information on factors which may induce or prevent food waste generation on the processing level. 39% of the food losses in the EU occur in food manufacturing, and 5% along the distribution chain (European Commission, 2011).
Suboptimal foods have recently been defined as edible foods perceived as undesirable by the consumer because of visual or sensory deviations, or uncertain safety (Aschemann-Witzel et al., 2015). Suboptimal foods frequently end up as food waste, i.e. “… any food, and inedible parts of food, removed from the food supply chain to be recovered or disposed” which is inaccessible for consumption (Fusions, 2014).
In line with this definition, food waste in the context of this review is considered as
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Any food-derived material lost during processing in the form of residues, faulty batches, retained or analysis samples, or by-products, and that is not recovered for human consumption. Such materials are frequently denoted as food or post-harvest losses because they are associated to food manufacturing and usually not wasted on purpose (Parfitt et al., 2010, Russ and Schnappinger, 2007); and
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Foods that are rejected and finally discarded at retail or household levels because they do not match consumer expectations or legal requirements regarding quality or safety. This type of food waste is mainly connected to the consumer who decides what to purchase and consume, but also involves other actors (farmers, processors, carriers) who are responsible for the quality in which the food is delivered to the consumer (Aschemann-Witzel et al., 2015, Salhofer et al., 2008), and includes food that undergoes microbiological spoilage or mechanical damages during delivery, forcing the retailer to eventually reject it.
After providing a general overview on food wasted in the supply chain with a specific focus on logistical issues (chapter 3), this work aims to discuss
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Processing techniques and requirements of quality assurance in the food industry that limit an efficient and sustainable resource exploitation (chapter 4), and
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Physical, chemical, and biological mechanisms by which impeccable food items are converted into suboptimal foods (chapter 5).
The paper provides a unique overview of processing- and product-related causes of food waste, and contributes to tackling the food waste issue by identifying potential actions of food supply chain actors.
Section snippets
Literature search
A literature search was carried out using scientific databases (Web of Science, Business Source Complete, EBSCO, SciFinder, Science Direct, PubMed, and Google Scholar) and the book catalogue of the Staats- und Universitätsbibliothek Dresden (Germany). A general overview on the topic was obtained by searching for pre-defined keywords, namely “food waste” and “food loss” in combination with “food industry”, “food manufacturing”, or “food processing”. “Consumer” and “household” level food waste,
Food overproduction and redistribution
To provide edible products for the human population, a food has to pass several stages along the supply chain. It starts with raw materials production, followed by processing and subsequent distribution to consumers through the retailing system (Fig. 1). Although food is wasted at all supply chain stages, the cause of food waste does not necessarily arise at the same stage as the waste itself (Adenso-Díaz and Mena, 2014, Göbel et al., 2015, Mena et al., 2014, Papargyropoulou et al., 2014,
Food industry waste and losses
Reliable data on exact quantities of industrial food waste is scarce because of poor definitions and insufficient documentation. Kranert et al. (2012) accumulated several studies and estimated that the German food industry is responsible for approx. 14 kg of the 82 kg food waste per head and year; technical problems during processing and quality assurance measures were identified as the main causes, each representing approx. 30% of this quantity. Data published by the European Commission (2009)
Typical quality changes of food items
Apart from foods where deviations from desired quality come from natural variability (e.g., oddly shaped fruits and vegetables), suboptimal foods can be the result of poor processing, and/or physical or chemical reactions that are frequently accelerated through incorrect handling (Fig. 3). Perception of and dealing with suboptimal foods is highly individual among consumers, but it was proposed that a better understanding and a higher valuing of food may be a key factor for food waste reduction (
Conclusions and implications for the food supply chain
This review identifies significant causes for food waste in the supply chain related to logistical handling, product processing, and consumption. From the available literature, potential actions to reduce food waste are identified for the following areas:
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Product deterioration and spoilage during transportation and storage. Devices such as RFID or GPS technologies, or strategic management processes may help to minimise losses along the supply chain by increased control of product shelf life and
Limitations of the study and further outlook
As research in investigating both consumer and producer causes of food waste generation is scarce, there is much left to explore in this domain. Further research may also use quantitative methods that help to generalise the findings from this qualitative study, especially with regard to the relative amounts of food waste arising from different issues within food processing. Expert interviews proved to be useful in identifying general causes of food waste in the processing sector, but further
Acknowledgements
The authors thank the co-workers at each partner organisation for their assistance in completing the manuscript, specifically Doris Jaros, Yvonne Schneider, and Susanne Struck. Furthermore, the interviewees are gratefully acknowledged for dedicating time to the project and sharing their information and thoughts on food waste.
The research has been funded by the SUSFOOD ERA-net ‘COSUS’ project (see https://cosus.nmbu.no/). The funding institutions for this review are the German Federal Ministry
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