Seminar on agri-food security
At a recent seminar organised by the SAAFoST Northern Branch at the University of Pretoria, on “Tropical Cereals as Alternatives to Dough-based Staple Foods”, we were introduced to the use of lupins as food for humans. Prof John Taylor of the Department of Food Science at UP, reported on his sabbatical visit to Curtin University in Perth, Western Australia.
During his sojourn at Curtin University, Prof Taylor worked with the Australian teams who are searching for alternative cereals to prepare for the time when we will no longer be able to grow our traditional cereals such as wheat and rice because of dwindling rainfall and desertification caused by global warming.
Try to imagine a world where there is insufficient wheat and rice to name but two of the most widely used cereal crops in the world. I am sure the recent detractors of carbohydrates who advocate high-protein, high-fat diets, and those individuals who blame all our ills on wheat and gluten, are thrilled at the prospect of a world without wheat and rice and possibly also without maize.
But the stark reality is that we need staple foods to feed our ever expanding population. Seven billion people cannot eat only meat, fish, eggs and fat, the vast majority have to keep themselves alive by eating some type of cereal grain such as rice or wheat or maize meal.
Read: 54 million kids in Africa under 5 go hungry
Impact of global warming
If global warming changes the climate in those regions of the world where these crops are cultivated, and the rainfall dwindles and our world becomes dry and arid, then it stands to reason that we are going to need new staple food sources.
Researchers are investigating the crops that used to flourish and were popular and widely used in the more arid regions of the earth, such as Africa for example. Traditional cereals like sorghum, millet and finger millet are on the brink of becoming popular again. A yeast-risen, flat bread with a spongy texture called "injera" made from a cereal known as "teff", is still widely eaten in Ethiopia, Eritrea, Somalia, Djibouti, Sudan and Yemen (where it is called "lahoh").
Researchers are now studying these cereals to try and determine if they can be used to replace wheat, rice or maize in traditional food including bread, breakfast cereals and snacks.
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The emergence of the lupin as a food
In addition to the dry-land cereals such as sorghum, a plant that is receiving a great deal of attention is the lowly lupin! Lupins have been known and grown for millennia. Lupins have mainly been cultivated as a high-protein animal feed and to improve the quality of agricultural soil since the days of the Roman Empire.
The consumption of lupins as a food was known throughout the entire Mediterranean and in the Andes region of South America. The ancient Egyptians and pre-Incan people were acquainted with lupins as a food, but it was only in the 1860s that lupins were introduced to northern Europe for the purpose of nitrification of the soil (Lupin Foods, 2014).
Read: Eating low-fat, thanks to lupin proteins
A question of taste
These early lupins did, however, have a bitter taste because they contained certain alkaloids, which did not make them particularly popular as foods for the human population. The goal of agricultural research has, therefore, been to grow a "sweet" lupin that would make it more suitable for eating by humans and animals. Once "sweet" lupins were obtained by natural selection, lupins became more acceptable to humans as a food, but they never became popular (Lupin Foods, 2014). In South Africa, for example, this plant is currently not really regarded as a source of human food.
Australians are particularly aware of global warming and the threat climate change poses to the cultivation of traditional cereal crops. In view of the fact that Western Australia, like many parts of Africa, including Southern Africa, has been suffering severe drought conditions for a decade or more, they have developed Lupinus Angustifolius or the Australian Sweet Lupin which is being grown in increasing quantities.
Food scientists are also working to develop a variety of foods containing lupins, that are acceptable to modern populations and palates. This is good news for a world facing future starvation because lupins and foods to which lupin flour, bran or meal have been added, have a promising nutritional composition (Coorow Seeds, 2014).
Read: Feast and famine in South Africa
According to Prof Taylor and Prof Vijay Jayasena , who hails from Sri Lanka, but now works on lupins for food at the School of Public Health at Curtin University in Perth, Australia, sweet lupins have an excellent nutritional composition:
- are gluten-free
- have a low-GI (glycaemic index)
- have a high dietary fibre content of up to 28% and most of this fibre is of the soluble variety which helps to lower blood fat levels
- have a very high plant protein content of between 38 to 42% and are high in essential amino acids
- have a high antioxidant content
- do not contain any cholesterol, but do have a high phytosterol content which helps to lower blood cholesterol levels
- only contain 1% starch which is a unique and unusual characteristic compared to other legumes and edible bean species
- have been developed to date by natural selection and do not contain any GMOs (genetically modified organisms)
- contain negligible amounts of so-called trypsin inhibitors (‘anti-nutritional factors’ which are found in other legumes and tend to interfere with digestion)
- contain very low concentrations of lectins and saponin (two well known gastric irritants), which cause problems when people eat soybeans even after the latter legumes have been fully processed.
- do not need to be exposed to heat or chemicals to make them edible as is the case with soybeans.
Health benefits of sweet lupin
According to Lupin Foods, sweet Australian lupin and the flour, bran and kernels made from these seeds have been found to convey the following health benefits:
- Appetite suppression which will help people to eat less food and lose weight
- Lowering the glycaemic load (GL) of carbohydrate foods
- Blood pressure reducing properties
- Improve glucose metabolism thanks to their low GI and GL thus helping to combat diabetes and obesity
- Ensure regularity because of the high fibre content
- Act as probiotics to promote the growth of beneficial bacteria in the gut which improves general health, bowel regularity and combats diseases of the digestive tract
- Benefit patients who are allergic to gluten, particularly as a source of essential amino acids
Potential negative effects of lupin-derived foods
Lupins like all other foods, have the potential to cause allergies in susceptible individuals. As more lupin products are used globally, the incidence of lupin allergy will probably increase (Information Standard, 2014).
At the seminar, Professors Taylor and Jayasena concurred that sweet lupin and products made with sweet lupin flour and other derivatives of this plant may well save the global population from starvation and improve the health of humanity thanks to their unique nutritive and health properties.
Next week we will discuss the subject of lupin allergy in more detail and also look at some of the products that are being manufactured from sweet lupin.
(Coorow Seeds (2014). Lupins for human consumption; Information Standard (2014). Lupin Allergy: The Facts; Lupin Foods (2014); Taylor J (2014). Tropical cereals as alternatives to dough-based staple foods. Lecture presented at: SAAFoST Northern Branch Sabbatical Seminar, Dept Food Science, UP. 23 January 2014.)
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