On June 20, the US Environmental Protection Agency presented a 2005 Presidential Green Chemistry Challenge Award to the joint Archer Daniels Midland Company (ADM) and Novozymes team for their use of enzymes to develop healthier oils and fats for use in applications such as margarine, baking and confectionery. The ADM/Novozymes enzymatic interesterification team was present to receive the award during a ceremony held at the National Academy of Sciences in Washington.

Established in 1995, the Presidential Green Chemistry Challenge recognises businesses and individuals that have made outstanding achievements by discovering novel ways to significantly reduce pollution at its source and use green chemistry to improve the environment.

The award was won jointly by ADM and Novozymes. Both companies were well-represented at the award ceremony in Washington.

This is the second Presidential Green Chemistry Award presented directly to Novozymes in the past four years. Novozymes has also been a partner on one additional award during that time period. This year's award-winning innovation uses an enzyme called Lipozyme® TL IM as an alternative to the conventional chemical interesterification process. The ADM/Novozymes team won the award in the category "use of alternative synthetic pathways for green chemistry", one of five award categories.

Novozymes and ADM have cooperated closely to develop an enzymatic interesterification process for the commercial production of oils and fats that are free of trans fats. Since the first commercial production in the USA in July 2002, more than 6 million kg of interesterified oil have been produced at ADM's Quincy plant in Illinois. In anticipation of increasing demand, ADM will be opening a new enzymatic interesterification facility later in 2005 at Mankato in Minnesota.

Labelling change
Up to now, trans fat content has not been stated on the nutritional fact panels of US food labels. But as from January 1, 2006, this will change due to new legislation responding to increasing concern in America about the detrimental effects of trans fats on health, particularly heart conditions. The change is intended to reduce the consumption of trans fats in the American diet. Health-conscious consumers will become better informed and able to choose low trans fat foods.

Faced with the new mandatory labelling, the food and ingredient industry has been investigating how to reduce trans fats in foods. Trans fats (also known as trans fatty acids) are a component of animal fats. However, the most common source of trans fats in the American diet is partially hydrogenated vegetable oil. In its natural state, vegetable oil contains no trans fats, but to solidify the oil into shortenings and margarine, hydrogen is used. Traditionally, food processors have partially hydrogenated vegetable oil, and this generates trans fats.

One of the alternatives that is available for avoiding the formation of trans fats is to interesterify fully hydrogenated oil together with non-hydrogenated oil. The interesterification of liquid oil mixed with hard fats can be used to produce sem i-solid fats. Fully hydrogenated vegetable oil contains no trans fats and can be used for the hard component.

The resulting fats have roughly the same functionality as partially hydrogenated oils, but they contain zero or virtually zero trans fats (see table).

Advantages of enzymes

Headquartered in Decatur, Illinois, ADM has over 26,000 employees and more than 250 processing plants around the world. ADM is one of the world's largest processors ofsoybeans,corn, wheat and cocoa. The company has experience of chemical interesterification at plants in Europe and has discovered that the enzymatic interesterification process has many advantages over the chemical process. For one, it does not require the use of sodium methoxide, a highly flammable and reactive substance that can create a number of undesirable side reactions. On the contrary, the enzymatic interesterification process uses no harsh chemicals. Furthermore, the process generates no wastewater or solid waste, and reduces losses of edible oils. Oils are processed under milder conditions so that certain nutrients are better preserved.

Despite all the advantages, the high cost of the enzymatic process has prevented adoption of the technology in the bulk fats industry until recent years.

Now cost-officient                                                                                                               
To bring costs down, Novozymes improved lipase production and developed an inexpensive method that can be used to immobilise the enzyme, leading to the current commercial enzyme Lipozyme TL IM. These two improvements reduced the cost of the immobilised enzyme by more than half, making it possible to consider enzymatic interesterification for bulk fats production.

But there was still a long way to go, and that's where ADM came in. Enzymatic interesterification has been tested in ADM's r esearch labs since 2000 and in commercial-scale production since 2002 in the USA. In July 2002, ADM implemented the process for the commercial production of cocoa butter substitute (CBS) at its facility in Quincy.

In January 2003, the ADM Quincy facility extended the enzymatic process to the manufacture of shortenings and margarine products containing no trans fatty acids. Then, in July 2003, ADM announced the launch of NovaLipid® zero and reduced trans fat oils and fats, including naturally stable oils, tropical oils, blended oils and enzyme-interesterified shortenings and margarines. This gives companies a broad range of options for zero and reduced trans fat food products.

"We provide our customer base with trans-free solutions, and some of our customers have already made the change," says Mike Rath, ADM's senior marketing manager for the NovaLipid line. "The market potential for interesterified oils and fats lies in two main categories. Margarines and baking applications are segments where enzyme-interesterified oils and fats meet the desired functionality and melt profiles."

The table shows a comparison between shortening made with enzyme-interesterified fats and current commercial all-purpose shortening produced by hydrogenation. These two fats produced by ADM have similar melting properties, but there is a big difference in trans fat content. Al­­­­most a third of the conventional shortening by weight consists of trans fats.

Two challenges
This enzymatic technology addresses two major challenges for the food and ingredient industry: firstly, providing healthier products to the public; and, secondly, developing environmentally responsible production technology.

The commercialisation of enzymatic interesterification can have a tremendous impact on public health by replacing partially hydrogenated oils with interester­ified oils that do not contain trans fats. It remains to be seen how successful this new process will be at replacing partial hydrogenation on a wide scale, but the impact of this enzymatic technology is potentially huge. For example, margarines and shortenings currently consume 4.5 billion kg of hydrogenat ed soybean oil each year in the USA. Compared to partial hydrogenation, the ADM/Novozymes process has the potential to save 180 million kg of soybean oil, eliminate 9 million kg of sodium methoxide, 53 million kg of soaps, 23 million kg of bleaching clay and 228 million litres of water each year.

In comparison with the chemical interesterification process, environmental benefits include eliminating the use of several harsh chemicals, and thus eliminating by-products and waste streams. There are also reduced losses of edible oil.

Here is an example of utilising green chemistry to reduce the impact of an industrial process on the environment while at the same time creating healthier products for the consumer. The 2005 Presidential Green Chemistry Challenge Award is recognition of this achievement.