How Can We Recycle the World’s Food Supply? It Might Involve Leftovers.
The environmental impact of food waste is staggering.
1.4 billion hectares of land, or 34% of the world’s total agricultural land, is used
How Can We Recycle the World’s Food Supply? It Might Involve Leftovers.
The environmental impact of food waste is staggering.
1.4 billion hectares of land, or 34% of the world’s total agricultural land, is used to grow food that’ll eventually end up in a landfill. Most of the food waste disposed in a landfill decomposes anaerobically and generates the powerful greenhouse gas methane, increasing our carbon footprint. Agriculture accounts for 69% of the world’s water usage, and yet one third of that water is wasted as uneaten food.
Unfortunately, the United States is the largest producer of food waste, with food waste as the leading occupant in American landfills.
In 2017, a study was conducted by the Natural Resources Defense Council (NRDC) to evaluate the amounts and types of food waste produced by consumers in the United States. Researchers collected food waste from Nashville, Denver, and New York City and categorized the waste across several categories. According to the study, 23% of consumer-level food waste in the United States comes from leftovers and makes up the highest fraction of edible food waste.
Using the 2010 food waste data provided by the USDA as a conservative estimate, that leads to a whopping 30.6 billion pounds and $37 billion worth of edible food.
That’s a lot of economic value going down the drain.
While composting or re-purposing edible food for animals can take food out of the landfill system, most of the capital, energy, and resources spent growing, harvesting, fertilizing, storing, and transporting food is still lost.
The highest possible net energy return and lowest environmental impact is to reuse human food for human consumption.
“1.4 billion hectares of land, or 34% of the world’s total agricultural land, is used to grow food that’ll eventually end up in a landfill.”
Many environmentally conscious startup companies are working to curb food waste by upcycling edible waste products into new food. ReGrained rescues the leftover grains of brewing beer and produces a high-nutrient flour for making energy bars. Toast Ale brews a pale ale using surplus bread as a source of fermentable carbohydrates. Treasure8 is a food technology company dehydrates excess fruits and vegetables to make snacks. These are just a few examples of a larger ecosystem of food recycling companies.
However, food waste in the kitchen and restaurant remains a large fraction of food waste that is difficult to capture at scale.
There could be another strategy to reduce food waste at the consumer level.
And the answer might lie in a mold.
Aspergillus oryzae, also known colloquially as koji in Japanese and qu in Chinese, is an edible mold that’s been used for thousands of years to prepare fermented soybeans, miso, soy sauce, sweet drinks, desserts, and rice wine. The term koji has been adopted by most Western chefs and cooks, and so I’ll continue to use koji to refer to this species of mold. Koji molds are grown on a solid nutrient source like steamed rice, wheat, or soybeans. In contrast, most food-based fermentations require the microorganisms to be submerged in a liquid, like how yeast brew beer or bacteria ferment milk into yogurt.
These microorganisms are distinct in that they secrete enzymes into their surrounding environment that break down and digest complex food molecules into simpler molecules that they can absorb. The power of koji fermentation truly lies in their enzymes, which humans have exploited to transform bland food ingredients into remarkably tasty foods for generations.
Koji molds contain the genetics and biochemical machinery to produce hundreds of different enzymes, but the most important ones for food are their proteases and amylases. Proteases digest proteins into amino acids while amylases digest starches into sugars, both of which impart flavor and taste and become the precursors to even more complex flavor formed from secondary fermentation by other microorganisms.
Any food rich in starch and protein that touches these enzymes slowly decays into a rich soup of these two basic building blocks of flavor. Koji enzymes are quite powerful and continue to be useful for many industrial processes involved in the food and chemical industries. In their purified form, these enzymes are used to produce sugar syrups, cheese powders, bread doughs, clarified fruit juices, alcoholic beverages, seasonings, and sauces.
In more recent times, koji has experienced a revival in the home and restaura