Waste not: The sustainable food chain

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The “buy local” mantra for food has become commonplace in sustainable food purchasing circles. Unfortunately, in our passion to support our local food economy and composting efforts, other important and potentially higher impact food policy decisions have been neglected or drowned out. Namely: reducing waste.

Few would disagree with buying local as an effective means by which we support our region’s economy, farmers and ranchers, and other food and beverage producers. And in fact, many food purchasing institutions — from food carts and restaurants to hospitals and schools — use these purchasing practices as an important part in their mission and marketing efforts.

Now, the Portland media is abuzz about the potential move to municipal pick-up and composting of food waste. Converting food waste to agricultural compost and then using it in our local food production? This might sound like the next step forward.

But first, let’s take a step back — or rather, a step up the food-production stream.

Recently I worked on a study, along with PSU Systems Science Professor Wayne Wakeland and Ph.D. student Robin Fenske, of food purchasing at large-scale institutions, such as hospitals and universities. We found that these institutions shared the same goals as consumers in terms of supporting local food purchases.

But, while the institutional food purchasers saw food waste reduction as an important goal — food thrown out is revenue lost — this issue evaded the consumer’s radar altogether. From the consumers’ perspective, food waste can now be framed as a positive by-product: compost rather than garbage.

As part of the study, we performed life-cycle greenhouse gas emission analysis on the three most common food products purchased by institutions (processed tomatoes, fresh potatoes, and chicken) comparing the implications of local versus national production, transportation, alternative packaging, along with raw and cooked waste disposal, including composting.

We found that, in every case, the lifecycle emission for wasted food overwhelmed any positive effects of buying local and reducing packaging. With cooked foods going to waste — particularly cooked animal products — those emissions were 50 percent to 100 percent higher per serving. By contrast, buying locally produced foods rather than national, centrally produced products, had a greenhouse gas emissions savings of 3 percent to 5 percent.

What are some of the things that can be done to reduce food waste in institutions? Well, certain schools have removed trays from the cafeteria so that eaters are prevented from overfilling their trays with food items when “their eyes are bigger than their stomachs.” This simple move reduced food waste dramatically while simultaneously eliminating the energy costs of washing trays.

Many institutions have moved to technology solutions such as Sous-vide (vacuum-sealed individual portioning) which allows for single-serving food production. Another approach is as basic as consumer education. Some institutions weigh all food waste and post the daily results above the dining room garbage cans. This too has been shown to reduce waste considerably.

Planning our food purchases and menus to support local foods without creating food waste is a good start. With any generated food waste, composting on site trumps hauling it to a centralized composting site.

From a business development perspective, Portland entrepreneurs and chefs have an opportunity to innovate around packaging, cooking and waste-reduction technologies. This opportunity seems like a great fit for the progressive food and sustainability culture in Oregon.

The research report, OTREC RR-08-154, was sponsored by the Oregon Transportation Research and Education Consortium.

Dr. Mellie Pullman is the Willamette Industries Professor of Supply Chain Management at Portland State University. She specializes in sustainable food supply chains and bridging the urban-rural divide through food. She can be reached at mpullman@pdx.edu.