Alternatives to Starch for Bioplastics Manufacturers

Kathrin Schilling

The huge demand for plastics is a major driver in fossil fuel production worldwide. This is because traditional plastics are made from crude oil and its derivatives.

Plastic production has increased exponentially since 1950, with a projected 33 billion metric tons to be produced each year by 2050 (Source: UN GRID-Arendal). It makes a lot of commercial sense to use as a material: resilient yet malleable enough to be applied across industries and uses. Non-degradable plastics are everywhere, present in products as diverse as:

  • food containers

  • personal care products

  • structural materials (car dashboards; PVC pipes)

  • fibres and finishes

  • single-use products such as plastic bags and straws

Advancements in technology and increased awareness of the damage caused by traditional plastics have resulted in plastic manufacturers claiming to produce eco-friendly, biodegradable products. There are three main types:

  1. Bioplastics are primarily produced from corn starch and do not result in carbon dioxide emissions when they break down but have other issues.

  2. Biodegradable plastics contain additives that cause them to decay more rapidly in the presence of light and oxygen but might leave toxic substances in their wake.

  3. Eco/recycled plastics is simply the reuse of previously used plastic in a new plastic product, which is not ideal.  

Bioplastics are a promising technological advancement but have so far been tied to the food industry.  Just because a material is technically “renewable”, it is not automatically the most environmentally friendly option in the long term. Therefore, the search is still on for a truly sustainable replacement of fossil fuels in the plastics industry.

Bioplastics manufacturers and researchers are becoming increasingly aware of this problematic issue 

Renewable vs. sustainable

A lot of bioplastics manufacturers and companies using polymers, resin fillers or any sort of base materials are branding their products as sustainable.

However, since they use plant-based products like starch, corn, wheat or conventional flour, their process is not entirely respecting the principles of sustainability. Even if these bio-ingredients are indeed technically biodegradable and compostable, they are foodstuffs which have been alienated from their original purpose.

The unseen damage of using crops for bioplastics

Since crop farming requires massive amounts of resources and as their non-food use competes with food production cycles, there is lots of room for ecological improvement.

Starch is obtained from crops like corn or potatoes. It is a natural raw material that has been misleadingly or erroneously marketed as a sustainable alternative. For starch to be produced, massive amounts of land, resources and water are needed.

These requirements alone have destroyed huge areas of land in developing countries, causing disruptions in local economies, soil depletion and people displacement. In short, It is often unsustainable to use food products for non-food applications.

Alternative ingredients for Bioplastics

Bioplastics manufacturers and researchers are realising that it is possible to leave corn starch behind and that it might even be a good opportunity to take action and switch to using agricultural byproducts such as fruit stone powders rather than rely on fossil fuels.

First and foremost, refined biomasses such as fruit stone powders can be used. Ground fruit stones and shells, e.g. olive stone powder, have similar benefits and their properties have been tested in diverse bioplastics applications.

The advantages of fruit stone powders are:

  • Chemical composition, stability and texture are similar

  • Fruit stone powders are not only renewable but also fully sustainable

  • They are durable and versatile, i.e. suitable for diverse biopolymer formulations

  • They do not require fresh water or fertilisers to grow.

The perspectives for 2019 and beyond are quite promising: it looks like fruit stone powders will gain place alongside and gradually replace starch in bioplastics, presenting additional options for going petroleum-free.