Production of Quality Amaranth Flour From Amaranth Grains
 |
| Super Fine Amaranth Flour |
 |
| White Variety Amaranth Grain |
 |
| Superfine Amaranth Grain Flour |
 |
| Red Variety Amaranth Grain |
Introduction
Flour and Baking Properties. The baking properties of amaranth seed flour and blends of wheat flour can be used up to 20%. Farinograph peak time and stabilities and specific loaf volume decreased with increasing Amaranth hypochondriacu flour. Farinograph data (Lorenz, 1981) indicated a need for higher absorptions and shorter mixing times when using Amaranth hypochondriacus flour as part of composite flour in bread baking. According to Lorenz (1981), the flavour of the breads with amaranth was very pleasant and was preferred by a taste panel over the flavour of white bread. At substitution levels of 10 and 15%, the grain of the bread was more open, the texture not as silky, and the crumb colour slightly darker. Flour made from Amaranth cruentus perisperm resulted in bread with the best combination of higher specific loaf volume and total score (Saunders and Becker, 1984). Breads and cakes baked with waxy-type amaranth starches were of poor quality (Stone and Lorenz, 1984). Crackers prepared with tezopaco wheat and 10, 20, and 30 % amaranth flour (Sanchez-Marroquin, 1980) resulted in comparable quality to the wheat cracker at amaranth levels up to 20%. The use of amaranth flour alone resulted in poor product texture. Because of its nutritional quality, amaranth flour has been successfully utilized as a supplement to corn flour in tortillas (Sanchez-Marroquin, 1980).
Milling
Amaranth grain is very small grain which makes it harder to mill into fine flour under usual protocols for milling other small grains such as millet and wheat. Due to the hardness of the grain, amaranth flour often remains grainer when milled under usual conditions and the products made from such flour have an undesirable sandy texture which is often mistaken for soil. Under this research, efforts where concentrated to improving the milling process to ensure that the flour produced were less grainer. We started off by milling the grain using the a diesel mill with a sieve of 500 microns. When other sample were milled using an electrical mill by commercial millers using the same sieve size (500nm), the flour was finer than the one milled using the diesel mill but still did not meet the qualities of baking flours.
Pastry products made from the flour tasted fine right after baking or pan frying but had a much sandier texture when left to cool overnight. We determined that flour milled using commercial millers was not suitable for products such as bread and cakes though it was suitable for Bhajia bites, meal and porridges.
Production of amaranth based products can be preceded by the production of flour from the grain. Milling tests conducted with a hammer mill
At laboratory level, we determined that a sieve sizes of 250, and 150 microns yield flour that can be used for making pastry products with acceptable texture; however, the rate of flour extraction is low. This makes flour extraction a labor intensive process and this increases the production costs. It was also noted that amaranth grain is often contaminated with soil. Efforts should be made to ensure that the grain is well sorted before the milling process. You can design screens that can all very tiny particles of soil to pass but not the grain. You will be able to separate the soil particles from the grain. Also tried out, was including the unit operation of washing in the process line to get rid of the soil/dust. Washing separated the soil from the grain but it is an expensive unit operation in terms of time, energy, water and labor involved. The processes of re-wetting and re-drying are time wasting and makes the all process complex. It is therefore advisable to working with farmers on strategies to reduce soil in the grain through developing a proper postharvest handling protocol for the grain. Also acquiring a de-stoner is one way to go and with this, improved grain quality is expected hence reducing the time, and labor costs involved with sorting the grain by hand.
