Soybean Oil

Soybeans are grown predominantly in North and South America (Brazil and Argentina) where 35% and 46%, respectively, of the 2011/12 total supply of beans was harvested. Further details are given in Table 1 and discussed below. It is only recently (2002/03) that total production in South America has exceeded that from the United States. In 2006/07 world production of soybeans was 236 million tonnes, but the figure fell in the two following years to 212 million tonnes due to declines first in USA and then in Argentina. The products of soybean agriculture are traded as beans and also as extracted oil and meal and these must always be distinguished.

In 2011/12, 95% of total soybean production was crushed (somewhere) and 38% was exported mainly to China and EU-27. These two countries/regions import 63 and 13%, respectively, of all traded beans. Among the three large American producers the United States crushes some of its beans for oil and meal and exports some as beans. This applies also to Brazil. In contrast, Argentina crushes most of its soybeans and exports oil and meal rather than beans.

Soybean oil is second only to palm oil in level of production and is an important oil used widely, mainly but not entirely, for food purposes. It is an unsaturated oil rich in linoleic (typically 53%) and linolenic acids (typically 8%), but these two essential acids are not present in the optimum ratio which should be around 5:1. Both these polyunsaturated fatty acids have valuable nutritional properties, but linolenic acid in particular contributes to oxidative instability, so soybean oil is generally subject to light hydrogenation to halve the content of this acid thereby enhancing shelf life. Oil bred to have a lower content of linolenic acid has become popular. For use in spreads the oil has to be partially hydrogenated to raise its content of solid triacylglycerols. This leads to the formation of saturated acids and unsaturated acids with trans unsaturation. The latter are now recognised as worse than saturated acids in their cholesterol-raising activity. Alternative recipes have been devised that reduce the requirement for partially hydrogenated fat. This is a problem particularly for the USA where fat consumed as food comes almost entirely from soybean oil. Another problem with the US soybean-based diet is the high omega-6:omega-3 ratio when a much lower ratio is desirable. In particular there is need for an increased intake of long-chain polyunsaturated fatty acids from marine sources. The figures in the Tables relating to soybean oil do not recognise those variants in which the fatty acid content has been changed by genetic or conventional seed breeding procedures.

Table 1

 

 Table 2

 

The production (million tonnes and % of world total) of soybeans in USA, Brazil, and Argentina is given in Table 3 for the 11 years 2001/02 to 2011/12. The general increases in production levels are interrupted through marked falls in production in USA in 2007/08 and in Argentina in 2008/09. Over the 10-year period soybean production in the USA, Brazil and Argentina rose from around 150 to over 200 million tonnes. Around 80% of world production of soybeans now comes from these three countries, though the largest producer, USA, has declined in dominance while Brazil and Argentina have risen and the South American countries together have produced more soybean than the USA since 2002/03.

 

 Table 3

The figures for 2008/09 differ from the trend with very low production in Argentina because of severe drought conditions. Production returned to trend in 2009/10.