Protein
structure of the coagulum, is preheated and then brought to 85-90° C by steam injection. 2. This causes coagulation of almost all the proteins with which are entrained the pigments, fat-soluble vitamins, lipids and minerals. Separation of the coagulum 1. The coagulum is centrifuged from the rest of the solution (brown juice). 2. This curd contains more than 50 % of crude protein of which 80 % is true protein, accompanied by some free amino-acids or peptides. 3. Heat coagulation extracts on average 8 % of the original DM of the crop and 20 – 25 % of its protein. Drying and storage 1. The curd, as paste, having been mechanically separated from most of the brown juice is dried on a fluidised bed. 2. The PX Super is pelleted and stored in sealed silos’ cells under inert gas, awaiting distribution. 3. For human feeding, the product called Extrait foliaire (Leaf concentrate) is crumbled. 4. The crumbs (on average with moisture content of 8%) must be kept dry, away from air, heat and light. They are bagged hermetically immediately. 5. To protect pigments and vitamins an antioxidant is added. 6. For animal feed : Ethoxyquin (150 mg/kg) 7. For human feed: Ascorbic acid (500 mg/kg). Co-product usage 1. The brown juice, still containing 13 – 15 % of the original DM (soluble N, mineral salts and sugars, mainly) is mixed with the fibrous residue. Table: Composition of lucerne leaf concentrate Components Moisture Crude protein Fat Glucides Fibre Minerals Vitamins
Contents (g per 100g) 8 50-60 9-10 6 6 13-14 0.09
2. The mixture is dried in high temperature air in a rotating drum. 3. The co-product is ground, pelleted and stocked for marketing. 4. It contains 16-20 % protein, 25-30 % cellulose and 100-150 mg carotene/ kg. It is excellent fodder for cattle and rabbits. Village production 1. Using a simplified system applicable in developing countries. 2. Lucerne is washed, straight after harvest, in clean water, 3. It is then pulped and pressed in cheap and simple machines that can be made in good local workshops, 4. The green juice containing the proteins is brought quickly to the boil. 5. The floating protein curd is creamed off and then pressed to dewater it. 6. The moist cake obtained can then be eaten directly or be dried, crumbled and kept in sealed packets. 7. The co-product fibre can be used fresh by animals or sun-dried for later use. 8. The brown juice can either be drunk by animals or used as fertiliser. 9. The quantity of protein recovered in this way is somewhat lower than that achieved industrially (about 5 %). 10. The pressing is much less effective. 11. LC is dried. Use of LC as animal feed 1. This LC, called PX 1 has been used in France since then and is given to particular types of animal. It is nutritionally effective for monogastric animals such as the pig, due to the low content of indigestible fibre and richness in protein, vitamins and pigments (See Table). 2. Used as the poultry for its pigmenting ability (for the coloration of chicken flesh and egg yolks). Energy value LC 1. Gross calorific value: 4700 kcal/kg. 2. Metabolisable energy (poultry) : 2600 kcal/kg 3. Metabolisable energy (pigs) : 3700 kcal/kg
Leaf protein would be made from leaves that are the by-product of some other crop. In the temperate zone the obvious sources are pea and bean haulms from canneries, and the tops from early potatoes and sugar-beet. Because the protein is washed, both neutral and acid, leaves that are toxic in the raw state, can be used
Advantages 1. It encourages height and weight gain. 2. It raises Hb levels and reduces or eliminates anaemia. 3. It raises serum retinol levels and thus prevents the maladies associated with vitamin A deficiency. 4. It encourages normal brain growth in children. 5. It improves general clinical status and lowers both the frequency and severity of infections. 6. No long term side effects have been found. Sweet Potato The sweet potato leaves used as a source of vegetabe protein and xanthphyll pigment. The leaves were pulped and blended with water. The juice extracted with hydraulic press. The juice is heated to 830C, then cooled and centrifuged. The depending upon the age of plant, from 32-49% of the total cude leaf protein (N x 6.25) is recovered in the pellet. Dried leaf protein concentrate contained 35-45% protein and 0.12-0.15% xanthophyll. They are rich in Ca, Mg, Fe, Mn and Zn. The amino acid pattern is deficient in sulfur amino acid. The amino acid pattern does not change with age of plant. Xanthopyll does not destroy enzyme system in the leaves. Cassava Leaves Cassava leaf yields about as much
AgriBusiness & Food Industry w May 2013
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