17 August 2011

Science – feeding a hungry world

By Dr Moritz Müller

Two weeks ago, more than 30 students and lecturers from Swinburne University of Technology Sarawak Campus took part in a 30-hour long famine event in of support the less fortunate who have to face hunger every day. It is very saddening that although so many countries overproduce food, people still starve in many parts of the world. 

To alleviate hunger, science has come to the fore. However, the application of science in food production is not new but goes back many centuries. In the 1800s, wine and beer often turned bad and no one knew why. Louis Pasteur looked at bad beer through a microscope and observed that it contained small bacteria, instead of the expected yeast cells, which help to make beer through a process called fermentation. Although micro-organisms are essential in fermentation they must be the right ones. Pasteur made brewing a more scientific procedure and showed brewers how to culture the right organisms for good beer. He also demonstrated to the wine industry that if wine is gently heated to sixty degrees celsius for a short time, the growth of harmful bacteria is prevented and the wine does not go sour. This work was later extended to milk, which is why we have pasteurised milk today.

Since the days of Pasteur, food science and technology research worldwide have resulted in new and useful products, and brought improvements to food production.

Corn was the first plant to be genetically modified in a commercial scale. Since then many other plants have followed, with soybean being one of the most prominent. Genetically modified soybeans were first commercially grown in the US in 1996. Within less than 20 years, about 90% of the crop in the US was genetically modified. The modified beans are resistant to herbicide, which can then be sprayed on the field without damaging the soybeans. Today soybeans can be found in an array of products such as cooking oil, flour and also in nutritional supplements such as protein extracts and vitamin E.

Rice has also been modified to enhance its nutritional value. The genetically modified variety is called “golden rice” and is implanted with a gene from the daffodil flower which makes beta-carotene, the raw material for vitamin A. According to Greenpeace, an adult would have to eat only one third of golden rice compared to normal rice in order to meet the daily needs of vitamin A. Deficiency in the vitamin results in blindness and infant mortality.

Going one step further, plants can also express bacterial or human genes and have been used extensively as bioreactors for vaccines, antibodies and other proteins. Potatoes, for example, have been modified to become an edible vaccine against diarrhoea. So, you can now enjoy your potato salad without having to worry about running to the bathroom. Good news for those who love potatoes, bad news for those who don’t.

Aquaculture is another area in which science and biotechnology play a major role. Finfish and shellfish are genetically manipulated mostly for the same reasons as plants – to enhance disease resistance, accelerate growth as well as to increase their tolerance to cold and improve the flesh quality so that they taste better. Some aspects of cultivating fish are economically cheaper than animal farming or commercial fishing. It takes approximately seven pounds of grain to raise one pound of beef, but less than two pounds of fish meal are needed to raise approximately one pound of most fish. Fish species that are fed genetically engineered food cost around 50 sen/pound and the return is often seven to eight times higher. That is quite a good deal, although the return will take a few years to achieve.

One area of aquaculture where Asia dominates is commercial shrimp farming. It began in the 1970s and since then production has grown rapidly, mainly to match the market demands of the US, Japan and Western Europe. On the downside, Thailand lost more than 17% of its mangrove forests to shrimp ponds in just six years, from 1987 to 1993. Destruction of mangroves leaves coastal areas exposed to erosion and flooding, alters natural drainage patterns, increases salt intrusion and destroys critical habitats for many aquatic species.

For every kilogram of shrimp farmed in Thai shrimp ponds developed in mangroves, 400 grams of fish and shrimp were lost from wild captured fisheries. Cultivating shrimps also consumes a huge amount of water and produces a lot of waste water in return. One ton of shrimp in a farm requires 50 to 60 thousand litres of water. In Thailand alone, shrimp ponds discharge some 1.3 billion m³ of waste water into coastal waters each year, a massive problem that can only be solved if scientists and engineers come up with better solutions.

On the brighter side, researchers in China are developing a protein supplement based on yeast – a very popular organism with biotechnologists – that can be used as a substitute for more than half the fish-meal in aquaculture feed preparations. With this supplement, less needs to be fed to the fish, thereby reducing waste. That will mean fewer inputs and impacts, without eroding aquaculture’s profitability.

These are only a few examples how science has helped to improve food production. There are many more out there and there will be more to come in the future. Who knows, maybe someone will discover the “mega-yeast” that can help to feed the world so that no child has to go hungry.

Dr Moritz Müller is a lecturer with the School of Engineering, Computing and Science at Swinburne University of Technology Sarawak Campus. He can be contacted at mmueller@swinburne.edu.my