Special food is prepared for celebrations, festivals, and other social events. People can easily buy food at stores, but substantial leftover arise from such events. Therefore, food loss has become a social problem.

In September 2015, the United Nations General Assembly adopted the 2030 Agenda for Sustainable Development, which includes 17 Sustainable Development Goals (SDGs). An item on this agenda is “Ensure sustainable consumption and production patterns” (Figure 1) This item specifies a target for food loss as follows: “(12.3) By 2030, halve per capita global food waste at the retail and consumer levels and reduce food losses along production and supply chains, including post-harvest losses.” In 2011, the Food and Agriculture Organization of the United Nations (FAO) reported that “Roughly one-third of the edible parts of food produced for human consumption, gets lost or wasted globally, which is about 1.3 billion ton per year.” In this essay, the word “food loss” includes the meaning of food waste for convenience.

The Ministry of Agriculture, Forestry, and Fisheries (MAFF) provided a summary of information regarding Japan at their web site. (https://www.maff.go.jp/e/policies/env/frecycle.html) The agency calculated that the amount of food loss was 6.21 Mt according to data from the Food Recycling Law and Waste Management Law YF2014. The breakdown of business-related and household waste was 3.39 and 2.82 Mt. Business-related waste involves irregular vegetables, refunded foods, and leftover at restaurants. Household waste involves leftover and expired food at home. The Ministry compared the scale of food loss with food aid and reported “Food loss generated in Japan (6.21 Mt) is about twice the food assistance amount by World Food Programme (WFP) in the whole world” and the “weight of food loss per person per day in Japan is about a bowl of rice.”

A total of 800 million people worldwide (one-ninth of the world population) suffer from a lack of nutrients. Thus, the MAFF became involved in actual campaigns, such as the “No-Food Loss Project,” to promote the reduction of food loss with human’s wishes such as “Mottainai” which means “to shame wasting” and wishing to donate food to who need.

The calorie-based data from the Food Balance Sheet in FY2017 from MAFF revealed that Japan strongly relies on importing food. Moreover, the food self-sufficiency ratio is only 38%. Stable food supply from overseas cannot be ensured; thus, the food loss ratio must be reduced, and stable food supply in terms of food security must be obtained.

From the viewpoint of environmental/energy problems, energy is consumed from producing agricultural products through selling at stores. This practice increases the discharge of carbon dioxide (CO₂), which is one of greenhouse gases (Figure 2). Creating food loss means wasting the capacity of CO₂ discharging. Moreover, throwing food loss away entails costs.

Agriculture requires a considerable amount of water, while livestock needs cereal crops. According to the World Meteorological Organization, the annual usage of agricultural water in 2025 will be 3162 km³, which accounts for 64% in world annual water usage (4912 km³). This amount is also twice the total amount of industrial and domestic water, which is 1106 km³ (23%) and 645 km³ (13%), respectively. (The Global Diversity of Irrigation Pamphlet issued by the Planning Subcommittee of the Committee of Agricultural and Rural Development)

Water stress refers to a situation in which the water resources in a region or country are insufficient for its needs. According to the Organization for Economic Co-operation and Development, in 2050, “Freshwater availability will be further strained in many regions, with 2.3 billion more people than today (in total over 40% of the global population) projected to be living in river basins experiencing severe water stress, especially in North and South Africa, and South and Central Asia.”

Japan imports a substantial amount of food. That means Japan imports a considerable amount of water used for agriculture at production sites. The hidden water in the flow of trading is called virtual water. Based on the idea of virtual water, Japan, which has low food self-sufficient ratio, imports substantial amount of water. Therefore, increasing food loss also means wasting water.

According to the food sanitation law, food is categorized in to two groups. The first category is food with expiration dates, which easily deteriorate (for example, within five days, including production or process). The second category is food with best before dates, which requires displaying the time limit, except for food with expiration date (Figure 3). However, even if food has a best before date, deterioration will still commence once the packaging is opened.

Many kinds of plastic packaging are used to protect food. For example, the two food categories with expiration and best before dates require different functions.

The cleanliness and security of prepared food with expiration dates. For example, no contamination through transporting, protection of contents from dust and from being touched, protection of contents from bugs and viruses, and verification of contents without opening must be ensured.

In the summer and rainy seasons, food easily deteriorate due to hot temperature and high humidity. However, plastic packaging is unsuitable for food produced under the aforementioned conditions. Therefore, controlling temperature and humidity at the store and during transport is crucial. Moreover, eating food early before its deterioration is important.

Food with best before date such as snacks and instant noodles also requires maintenance of cleanliness and security in production. In addition, food packaging requires barrier functions with long storage time. Sterilization is usually conducted to prevent the procreation of viruses on the production process. Figure 4 shows the basic style of plastic packaging. Different from prepared food that is covered, the food is completely sealed. Pouch (a bag style packaging), tray, and cup styles are used.

Several types of plastic packaging have barrier functions. The functions include the following: to keep dry from humidity, to keep moist from dry, storing in vacuum to avoid oxygen not undergoing oxidation, and storing dried food in nitrogen gas as inactive gas to avoid oxygen and moisture. Moisture affects their texture of dried food and, making them breeding sites for bacteria. Food is an organic matter, and some food requires the barrier function to avoid light (ultraviolet). A common example is the packaging of chips. Observed the packaging around you and attempt to guess their type of packaging.

Disinfected retort pouch food can store food for over a year with functional plastic packaging (including curry, which usually spoils within a day). However, food usually starts to spoil once the pouch is opened. Best before dates show the period with unopened packaging.

Fermentation of food and ripening of fruits with time are also feasible, but determining their best time is difficult due to personal preference. Thus, the discussion of proper packaging is complicated.

The identifying mark of recycling can be found on the back side of plastic packaging products. This mark facilitates easy segregation for consumers and promotes separate collection and recycling for municipal governments.

In terms of material, several types of plastic packaging are also available. Materials, such as polyethylene and polypropylene, are used. Laminated multiple materials can also be utilized. Figure 5 shows the basic unit structures of plastic packaging. Plastic packaging is a combination of basic units. The structure is similar to mille-feuille and has a plastic packaging with high performance. The structure could also be more than five layers. Plastic packaging not only comprises plastic materials but also aluminum layer for retort pouch and paper for milk carton. Combining materials is good, but this combination requires more recycling processes than those of single material packaging. For an efficient recycling process, changing the packaging design to facilitate easy recycling is discussed.

The number of single and elderly people is growing in Japan. It helps the market expansion of prepared food consumption. Consequently, an increase food sold at stores, leftovers, and food returned the best before date is observed, and these phenomena result in food loss. Solutions for food loss reduction are currently emerging. For example, sufficient management of quality and logistics is studied using the Internet of Thing and artificial intelligence based on weather information and preference of regular customers.

Life style will be different in 5 to 10 years. The aforementioned topics must be linked with each other and observed from a high viewpoint to facilitate discussions on social systems and life styles. The requirement will also change with time. Therefore, eco-friendly plastic packaging with a flexible and wide perspective is suggested. The goal of SDGs will be realized through these actions.

February 24, 2020 – Hitoshi Sugiyama, translator

This is a translation from the Japanese original article written by Kazukiyo Nagai, which was published on April 4, 2019.