Agratech Trade: Processing of Soybeans and Maize
Agratech Trade has been hard at work in perfecting the process of processing of soybeans and maize. Louis Verhoef has written a detailed report on how the process works and how to increase your gains and yields to produce quality products for the market. We present, Agratech Trade: Processing of Soybeans and Maize. Let this be your guide to the industry!
GENERAL PRINCIPALS AND INFORMATION
FROM THE PLANT TO THE MOUTH
From the plant to edible food must be the aim. This means that the cheapest and most effective ways to produce a product and then to utilize it as edible food is to pick it from the tree or plant or pull it out of the ground wash it and eat it. Minimum handling and minimum treatment or processing must be the aim. The more complex the handling and processing treatment, the more the end product will cost, with the potential loss in nutrient value as a further negative aspect. To feed fish with soya bean protein to produce the fish that is also a protein source means that money is being wasted. Some might say that fish tastes better, but with vastly improved plant protein processing technology and move to more plant-based diets even this could be a contentious viewpoint.
Proteins in plants and animals are the same amino acid building blocks chemically.
PRODUCTION OF THE MOST IMPORTANT PLANT FOOD SOURCES
- Soybean production worldwide is at the moment: ±330 million tons
- Maize/Corn production is at the moment: ±1000 million tons.
- Maize/Corn and soybeans are the most important plants for the production of food and feed sources.
PROTEIN PRODUCTION OF SOYBEANS PER HECTARE
The production of soybean protein per hectare of farmland is more or less 12 times higher than other forms of protein from animal and plant sources (1 ha = acre/2.4711)
The protein in plant and animal sources are composed of more or less 20 amino acids that are chemically the same. Plants are utilizing Carbon Dioxide (CO2) but on the other hand, animal production contributes huge amounts of CO2 to the atmosphere. Plant protein is much cheaper to produce than animal protein. Soybeans contain 40% protein on a dry basis, whilst dry animal meat (biltong, jerky) also contains more or less 40% protein.
UTILIZATION OF SOYBEANS
Only 7 to 10 % of the world production of soybeans were used as edible food. The rest is mainly used as animal feed that is: chicken, pig, other poultry, dog and all monogastric animals. When soybeans are used for ruminating animals special preparation takes place to be available as bypass protein.
The reason for the under-utilization of soybeans as a food source is that it was originally produced as feed for monogastric animals. The other reason is that edible products from soybeans could have an unpleasant “beany” or “green bean” taste as a result of wrong processing technologies.
Anti-trypsin in soybeans
Natural soybeans contain an amino acid namely anti-trypsin that is unavailable for monogastric animals and humans. This amino acid must be processed with heat to change it to a biologically available amino acid for monogastric animals and humans.
The positive side of this characteristic is that soybeans will normally not be eaten on the land or in storage by insects, birds or animals.
Lipoxygenase enzymes in soybeans
Soybeans contain three or more lipoxygenase enzymes in different cell structures in the seed. These enzymes must be destroyed or eliminated before the soybean can be broken for further processing. If not, these active enzymes come in contact and react with various components in the soybean to form more or less 52 “beany” or “green bean” components that resulted in unpleasant after taste in the edible soybean products.
It is thus very important to utilize whole soybeans to be processed by heat. During the heat treatment processing of the whole soybean, the anti-trypsin and the lipoxygenase enzymes can be altered simultaneously.
Sucrose, raffinose and stachyose sugars in soybeans
Soybeans contain ±5% sucrose, ±1% raffinose and 4% stachyose of sugars in the seed. The sucrose can normally be digested by humans whilst the raffinose and stachyose are not digested and absorbed as nutrients by humans and monogastric animals. Alpha galactosidase enzymes can immobilize these sugars in food and feed
Lecithin or phospholipids in soybean oil
Soybeans contain between 1-3% lecithin in the ±18 % oil. The lecithin plays a very important role in the food industry as an emulsifier between water and oils. Lecithin plays also a very important role in the brain and liver of human beings.
Triglycerides and fatty acids in soybean oil
The triglycerides in soybean oil are very important in especially the margarine industry. Soybeans contain more or less 18% oil in the seed. It is also very important as providers of omega-6 (C18:2 fatty acid) and omega-3 (C18:3 fatty acid) oils that are essential for the human body.
Only three major plant products contain omega-3 fatty acids in the oil namely; soybeans, canola and linseed. Omega-3 in the diet reduces the risk of heart illnesses, prostate and breast cancers and depression amongst others. The other omega-3 fatty acids can be found in fish oils (C20:5 and C22:6 fatty acids).
Note: The C is the number of carbons in the chain in the fatty acid and the number 22 is the number of carbon atoms in the chain and the 5 or 6 indicates the number of double bonds in the chain.
Isoflavones or estrogens in soybeans
Soybeans contain more or less 0.25% isoflavones. Although these isoflavones show estrogen activity it can be demonstrated that these quantities involved would not exert physiological effects in humans. Although the Eastern countries consume large quantities of soybeans the population growth are not being influenced negatively in these countries.
Phytic acid in soybeans
Soybeans contain between 0.5 and 0.7% phytic acid in the seed. The main effect o phytic acid in soybeans is that it binds with minerals like zinc and iron and can reduce the availability of these elements in food.
BASIC COMPOSITION OF MAIZE/CORN
Maize or Corn is of utmost importance in the manufacturing of animal feed in the first place but also very important in human food. When the starch is cooked by means of an extruder 18% moisture must be added to complete the gelatinization process.
The composition of the corn/maize is:
- Whole Kernel:
- Endosperm = 82.9%
- Germ = 11.1%
- Bran = 5.3%
- Tipcap = 0.8%
- Starch = 87.6%
- Protein = 8.0%
- Fat = 0.8%
- Fibre = 3.2%
- Protein = 18.4%
- Fibre = 14.0%
- Fat = 33.2%
- Starch = 8.0%
- Other = 26.4%
- Fibre = 83.6%
- Starch = 7.3%
- Protein = 3.7%
- Fat = 1.0%
- Other = 4.4%
- Tip Cap:
- Fibre = 77.7%
- Protein: = 9.1%
- Starch = 5.3%
- Fat = 3.8%
- Other = 4.1%
PROCESSING OF SOYBEANS AND MAIZE
CHEAPEST, WHOLESOME AND TASTEFUL FOOD AVAILABLE
Chemical composition of a plate of food consists normally of four major components:
- Carbohydrates (Sugars and Starches)
- Protein (20%)
- Essential oils (7%) Omega 6 and Omega 3
Minor components like vitamins, minerals and other ingredients are normally present in agricultural products but additional vitamins and minerals can be added as a premix.
The cheapest source of fibre and carbohydrates in the world is available in maize or corn.
The cheapest source of protein and essential oils is available in soybeans.
Maize or corn and soybeans are normally cultivated alternatively all over the world due to the providing of nitrogen fixation of the soybeans in the soil.
The pre-cooked maize provides the fibre and carbohydrates in the cheapest wholesome food recipe.
The best way to cook maize/corn is by means of Extrusion technology.
A typical single screw barrel extruder for cooking of grains:
ROASTING OF WHOLE SOYBEANS
Soybeans provide the cheapest, wholesome protein and the essential oils in edible foods and animal feed. The secret to preventing soybeans to develop the beany taste in food products is to roast soybeans whole in one step.
One of the easiest ways to roast soybeans whole is by means of microwave technology. In just one step the soybeans are being roasted to change the anti-trypsin and the lipoxygenase enzymes.
The roasted soybeans then have a nutty/peanut butter taste. The roasted soybeans are then milled to provide an input product for various downstream food products.
The downstream products are:
Sauces, Soups, Smoothies, Meat extenders Breakfast cereals, Spreads, Energy bars, Flavored drinks, Desserts, Pasta, Bakery products, Soynuts, Confectionery plus many more.
The fluid bed roasting system uses a combination of microwave energy and hot air to rapidly and evenly heat grains and legumes such as soybeans.
The unit below has a capacity of 50kg per hour of roasted product.
Process controls are entered via a touch screen operator panel. Bed air velocity, microwave power and process time are all adjustable, while the product temperature is regulated. This versatility allows a wide range of products to be dried and roasted, including peanuts, soy, green beans and maize kernels among others.
Combining the rapid bulk heating achieved with microwave energy with hot air heating of the surface yields a product that is consistently heated throughout, while smaller particles are not scorched.
We hope this Agratech Trade: Processing of Soybeans and Maize brief has been helpful and useful in your research.
For further information please contact Louis Verhoef: