Material Pulse: Food Waste

Tackling the Carbon Footprint of a Wasteful Culture

Producing a larger carbon footprint than the airline industry and accounting for 8% of all greenhouse gases, food waste is a huge drain on the world’s economy, and more importantly, compounds the current challenges we have with getting food to all humans on the planet. The waste itself happens at all points along the journey, from spoiled crops due to inefficient harvesting, damage and spoilage during transport, products past their sell-by date at the supermarket, and as a consequence of our own poorly planned efforts that result in good food going directly from fridge to garbage can. There are many efforts to combat these problems, but as we are unlikely to solve every issue, there remains a massive amount of food waste that could potentially be repurposed into something more useful. 

FROM ORANGE PEELS TO SNAIL POOP

Take orange peel, for instance. Extract the natural substance limonene, oxidize it and connect it with carbon dioxide, and what is produced is a bio-based plastic, the basis for various industrial applications without high costs. PLimC [for poly(limonene carbonate)] is the name of this general-purpose plastic that scientists from the University of Bayreuth, Germany, have come up with. Though still in the research phase, it offers a glimpse of what is possible by treating food as a resource for materials as well.

Rinds, pits, shells, and bones all have potential as material sources thanks to their fibrous or structural nature, and any waste food that has calorific value can be used as building blocks for starch-based plastics or as food itself for plastic-creating bacteria. Products have even been made from food that has already passed through the bodies of animals. Examples are Ecor which uses “bovine processed fiber” (cow pats) and Museo della Merda’s

dinnerware line called Merdacotta®, essentially made from dried cow dung mixed with Tuscan clay. Elsewhere, snails have been co-opted to help, discharging a colored pulped product when fed a diet of paper of that same color, as demonstrated by designer Manuel Jouvin. 

Bio-Plastic from Household Trash by UBQ Materials

The Israeli company UBQ Materials uses a patented process that converts household trash into reusable bio-based plastic. During this process, recyclable items such as glass, metals, and minerals are extracted and sent for further recycling. The remaining garbage such as food scraps (i.e. banana peels, chicken bones) and dirty plastics, cartons, and papers are then dried and milled into a powder. The steely grey powder then enters a reaction chamber, where it is broken down and reconstituted as a bio-based plastic-like composite material. It uses no greenhouse gas emissions or residual waste byproducts and requires little energy and no water during production. For every ton of material produced, the process prevents anywhere from between 6,000 lbs to 60,000 lbs (3t to 30t) of CO2 from being created by keeping waste out of landfills and from decomposing. UBQ material is billed as the most climate-positive thermoplastic on the market. Algae farmers grow algae all over the world for high-value products such as specialty oils and colorants for food products. These producers then harvest the biomass and extract their product of interest (i.e. oils). The company takes the leftover waste material from algae growers in Texas and California that currently has no use, and burns it to create a black pigment that can be used as a carbon black substitute, while providing the same color density.

Plastic & Fibers from Waste Milk by Mi Terro & QMilk

Mi Terro has created a range of products that are made from spoiled milk from dairy farms. Its soft-yarn milk t-shirt, for instance, contains five glasses of excess milk that would have otherwise gone down the drain. Having already collaborated with Nike and Danone, the company now intends to focus more on agricultural waste since it is easier to transport than liquid milk. Mi Terro is currently working with Budweiser to develop the world’s first beer bottle made from spent grain. Its 100% plant-based packaging films are already home-compostable, ocean-friendly, and 3-5 times cheaper than other bio-based materials. The next step will be to produce packaging films and other moldable plastics from locally sourced food waste.  

Elsewhere, the German company QMilk has been producing plastics and fibers from casein, a derivative of waste milk, for some time, through a slightly more involved process. The company’s fibers are billed as the only natural fiber with thermo-bonding properties, which means that other natural fibers can be added without conventional plastics or phenolic resins, allowing the product to be composted at the end of its life.

Its biopolymer, meanwhile, is a 100% natural plastic – it biodegrades without residue within a few months, is naturally antibacterial, dermatologically tested, and flame-retardant.  

A Biopolymer from Waste Cooking Oil by Nafigate

Also developing plastics from waste food, Nafigate has produced the world’s first fully biodegradable and biocompatible biopolymer (P3HB) manufactured from waste cooking oil. Unlike bioplastics made from 1st generation feedstock (corn, sugarcane, potatoes), it is produced by microbial fermentation from 100% waste cooking oil (WCO) without using crops or other feedstock, which requires the use of agricultural land. In addition, the WCO can be used as a source of energy during its production, making this biopolymer significantly more affordable than bioplastics made from corn or sugarcane. The technology is based on a “closed-loop” production system within which the resource input and waste produced are minimized, resulting in about 50% less energy consumption than conventional polyethylene (PE) production. The material is biodegradable in freshwater and seawater and is used for packaging, cosmetics, and smart fertilizers. 

The sludge that is freshly activated from wastewater treatment in a food processing industry can also be used to make biodegradable plastic. Active sludge contains various types of microorganisms that can be used to produce PHB (Poly-b-hydroxybutyrate), made by various bacteria as microbial polyester and stored in cells in the form of granules. PHB production costs are very high, so the use of activated sludge is expected to be more efficient than processed sugars. Banana, cassava, pineapple peel all have great potential to be used as sources for PHA plastics, since the high sugar content works wonders with the hungry bacteria.

Upcycled Avocado & Olive Waste by Biofase

Mexican Biofase proposes cutlery, straws, plates, and food containers all produced from waste avocado pits. The resin, 60% from waste seeds and 40% from “synthetic organic compounds,” can be injection-molded, extruded or used as laminated or thermoformed film. Backyard compostable (though over the best part of a year, so it cannot be certified as such), the materials are food-safe and have good heat resistance.  

Similar initiatives are using waste olive pits. Cue BioPura from Biolive in Turkey and a project in Spain dubbed Go Oliva that have created a plastic alternative for use in olive oil packaging. Note, each of these solutions, whether olive or avocado pit still requires some level of additional binder, whether bio- or petroleum-based. 

In an ideal world, there would be no food waste, and efforts to get closer to this goal are to be encouraged, but until the day comes when none of us forgets about last week’s dinner in the back of the fridge, there will be opportunities for companies who can repurpose this viable resource. 

The Material Pulse reports are part of an exclusive, ongoing collaboration between BEAUTYSTREAMS and Material ConneXion.