Keio University

[Feature: The Future of Japanese "Food"] Shinnosuke Ishikawa: Eliminating Vegetable Waste with Grinding Technology

Published: February 04, 2022

Writer Profile

  • Shinnosuke Ishikawa

    President and CEO, Green Ace Inc.Graduate School of Media and Governance Project Assistant Professor

    Shinnosuke Ishikawa

    President and CEO, Green Ace Inc.Graduate School of Media and Governance Project Assistant Professor

Vegetable Waste in Japan

It is a well-known fact that food waste is a problem in Japan. Annual food waste is estimated at 5.7 million tons due to various reasons such as leftovers, unsold items, and products nearing their expiration dates.*1 However, it is hardly known that waste at the "production site," which is difficult for consumers to see, is also serious. In 2020, 13.04 million tons of vegetables were harvested in Japan, of which 11.25 million tons were shipped.*2 In other words, about 2 million tons of vegetables were harvested but not shipped. While some of this is for farmers' own consumption, it is not hard to imagine that nearly 2 million tons are being discarded.

One reason for this is the existence of items that are difficult to ship due to their shape or size, known as "non-standard" products. For example, in Yamagata Prefecture, the shipping standard for spinach is "20 cm or more and less than 30 cm, with no damage or pest-infested leaves."*3 Producers aim for this standard through fertilizers, pesticides, and daily care, but not all vegetables can achieve this. In addition, some vegetables are discarded to adjust shipping prices. Are you familiar with the term "poverty amidst a bumper crop"? A farmer's income is the product of vegetable prices and production volume. If the effect of a significant drop in vegetable prices lowering income outweighs the effect of increased production increasing income, the farmer's income will drop despite the increase in production. This is poverty amidst a bumper crop. In other words, even vegetables that farmers have carefully grown to fit within standards are discarded if they exceed consumer consumption. Such vegetables are crushed in the fields without being harvested. No one can see this sight without their heart aching. It is said that if unharvested vegetable waste is included, the annual amount of vegetable waste reaches 4 to 5 million tons.

Consumer Vegetable Intake

While vegetable waste is a very serious problem, are there no issues on the consumer side? In fact, Japanese people are not consuming enough vegetables. According to the Ministry of Health, Labour and Welfare's "Health Japan 21 (2nd Term)," the target vegetable intake is 350g per day, whereas the actual intake is only 291g.*4 In particular, while those aged 60 and over consume about 300g of vegetables, those aged 20 to 40 consume only about 250g. Considering that younger generations eat fewer vegetables, it is easy to imagine that vegetable intake will decrease further in the future.

I would like to consider the future of Japan from the perspective of agricultural waste and consumer vegetable intake. There is a view that agriculture with high waste will be streamlined or downsized to match consumer intake, balancing supply and demand and increasing economic rationality. But is this vision of the future truly correct? If consumers stop eating vegetables and Japanese agriculture continues to shrink, our nation's prosperity cannot be maintained. I want to strongly advocate for a society where consumer vegetable intake increases and vegetable waste decreases, as this is a prosperous society for both consumers and producers.

Powderization as a Method for Effective Use of Agricultural Products

How can we break through this current situation? There are various methods for processing vegetables, but among them, I focused on "powder," which has high preservability and potential for secondary processing. Generally, powders with low water activity (less than 0.5) tend to have a long shelf life because microorganisms cannot multiply. In addition, since food in powder form has no specific shape, it is easy to add to other foods.

Generally, vegetables are dried and then turned into powder. However, this method had the problem of losing the original color, aroma, and nutritional components of the vegetables because they are exposed to high temperatures for a long time during drying. To create high-quality powder, the effects of heat and the oxidation of components must be suppressed during drying. Therefore, we began research on technology to dry and grind vegetables in a short time with almost no heat applied. This technology has the characteristic of drying the surface of the vegetable while simultaneously expanding the surface area by grinding it, turning it into powder instantaneously. As a result, the vegetables are only exposed to heat for a short time, and the components are preserved. To quantitatively demonstrate this effect, a comparison of nutritional components with other companies' vegetable powders produced using conventional technology revealed that components were preserved several to several hundred times higher (Figure 2).

Figure 1: Vegetable Powder
Figure 2: Comparison of Nutritional Components (Created based on component analysis data) Analysis Agency: Japan Food Research Laboratories

Diverse Uses of Vegetable Powder

Vegetable powder made with this process retains nutritional components, pigments, and dietary fiber essential for the body as close as possible to raw vegetables, so it can be used for various purposes. Vegemin, which we operate, is a brand that utilizes the characteristic of vegetable powder concentrating nutrients. By powdering, the nutrients of vegetables are concentrated about tenfold, and just 3g of powder allows one to consume the nutritional equivalent of one plate of salad. Currently, Vegemin is used by households with children who dislike vegetables, single-person households worried about lack of vegetables, and elderly households with small appetites. In addition, it is attracting attention as a raw material that can add nutrition in the manufacturing of processed foods.

Furthermore, if we focus on pigment components, it can also be used as a dye. Toyoshima & Co., Ltd.'s FOOD TEXTILE develops an apparel brand dyed with vegetables. Powdering could also increase the efficiency of pigment extraction.

In addition, by utilizing dietary fiber, it is possible to create things like plant-based plastics. HEMIX by Business Innovation Partners Co., Ltd. is a 100% plant-derived biodegradable plastic that utilizes hemicellulose, a type of dietary fiber. Powder can also be used in the utilization of such fibers.

Figure 3: Diverse Uses of Powder

The Future of Waste Vegetables through Increased Utilization

As described, there are many initiatives even within Japan to effectively utilize waste vegetables. Of particular note is the initiative called "upcycling," which aims to create products with higher dimensions and value than the original product, rather than simply turning materials into raw materials for reuse. Consumers do not make purchasing decisions based solely on sustainability; they purchase because they feel the value of the product itself. This is perfectly natural, but there are not a few cases where products are created that are far removed from consumer needs due to an over-focus on sustainability.

In the future, we must involve not only venture companies like ours but also small, medium, and large enterprises to provide new value to society. As these initiatives increase, consumers will become more prosperous, and producers will be able to secure profits to the extent that waste is reduced. I intend to take on many more challenges to transform society as a whole into a sustainable one through upcycling initiatives.

*1 Ministry of the Environment, "Estimated Amount of Food Waste and Food Loss in Japan" (FY2019)

*2 Ministry of Agriculture, Forestry and Fisheries, "Planted Area, Harvest, and Shipment of Designated Vegetables and Vegetables Equivalent to Designated Vegetables for 2020"

*3 Yamagata Prefecture Certified Local Wholesale Market, Marukan Yamagata Seika Market Co., Ltd., Spinach Standards Table

*4 Ministry of Agriculture, Forestry and Fisheries, "Food Balance Sheet" (FY2019)

*Affiliations and titles are as of the time of publication.