The nutritional value of cassava
Fresh cassava roots: The edible rate of 30-40% dry matter weight of fresh sample, 27- 36% starch, sugar total 0.5 to 2.5% (of which 71% sucrose, glucose13% fructose 9%, mantose 3%), total metall 0,5-2,0% protein, fiber 1.0%, fats by 0.5%, 0.5-1.5% minerals, vitamin A is about 17 mg / 100g, vitamin C 50 mg / 100 g, energy 607 KJ / 100g, nutrient limiting factor is Cyanogenes, deduction rates 22-25% starch, flour particle size 5- 50 micron, 15-29 amylose %, maximum adhesion 700- 1100 BU, gelatinized temperature 49-73 C (Christopher Wheatley, Gregory J.Scott, Rupert Best and Siert Wiersema 1995). As quoted by Hoang Kim, Pham Van Bien 1996, led the data analysis data of Vietnam (Le Ruler 1966, the University of Agriculture and Forestry, 1987, Nguyen Duc Pearl 1963, Breeding Institute, 1983), China ( Bangguo Zheng et al, 1988), Philippines (Jose A. Eusebio 1978, Truong Van Den 1989), India (Hirshi and Nair 1978) and CIAT (GG Gomez et al, 1985) showed similar results.
The root is rich in carbohydrate, energy, minerals, vitamin C, small tapioca beads smooth, high adhesion but poor fat and poor especially protein, amino acid content of the unbalanced, excess amino acids arginine but lacking contain sulfur. Depending on the varieties, planting, harvesting some months after planting and analysis techniques that total dry matter and crude protein, fat, minerals, fiber, sugar, flour change.
Dry chips are generally of two types: dry cassava chips and cassava bark no bark. Dry chips with bark include: shell meat, cassava, cassava core and probably a wooden casing. Peel cassava not only includes meat cassava and cassava core. Data distribution of cassava quality of Vietnam does not cover the average: 90.01% reaching DM, crude protein 2.48%, 1.40% crude fat, crude fiber 3.72%, ash 2 , 04%, 78.59% protein derivatives not, Ca 0.15%, 0.25% P. Dry chips shelled 90.57% dry matter, crude protein 4.56%, 1.43% crude fat, crude fiber 3.52%, ash 2.22%, 78.66% protein derivatives not , Ca 0.27%, P 0.50%
Mashed cassava flour and tapioca starch. Mashed cassava flour handmade approximately 87.56% dry matter, crude protein 3.52%, 1.03% crude fat, crude fiber 1.37%, 1.38% ash, protein derivatives not 83, 89%, Ca 0.11%, P 0.11% (Golden, Pham Van Bien 1996). Tapioca is colored white. Tapioca County observations on the scanning electron microscope SEM 5-40 nm in size, shapes, mostly round, smooth surface, a side with conical depressions and a small knob in the middle . Cassava starch amylopectin content and average molecular weight higher amylose starch of corn, wheat, potato, high viscosity, low tendency to degenerate, high reliability gene Golden Kingdom, Wu Ke Suong Nguyen Chain Union, 2005). The chemical composition and nutritional value of cassava starch is evident in Table 1:14. Companies processing starch usually available on stock quality products for the customers of the company.
Cassava leaves have a high protein content (20-25% dry matter) with multiple carbohydrate, minerals and vitamins. Cassava leaf protein had sufficient essential amino acids, lysine but rich in methionine deficiency. In addition to cassava leaf nutrients, also contain toxic amounts [HCN] significantly. The sweet cassava varieties with 80-110 mg HCN / 1kg of fresh leaves. The bitter cassava contains 160-240 mg HCN / 1kg of fresh leaves. Sweet cassava leaves are a nutritious vegetable that contains more protein, calcium, carotene, vitamin B1, C but note carefully boiled to reduce HCN. Bitter cassava should not eat, but should be boiled pickled or dried cassava flour to make coordination with other baking powder, the remaining HCN negligible.
Toxins HCN: Cassava contains toxic quantities in glucoside form C10H17O6N with chemical formula. This toxin was first discovered in 1885 by Peckolt and called manihotoxin. Then, Dunstan and Henry had dissociated current toxic substances like intoxicants of some kind they Beans (Bui Huy Dap, 1987). This poison bitterness present in almost all parts of plants and all varieties (Narty, 1973). Under the action of hydrochloric acid gastric juice containing either enzyme, substances decompose and release acid cyanhydric (Cyanogenes) is toxic to people:
C6H17O6N + H2O ===> C6H12O6 + (CH3) 3 + HCN
Linamarin glucose acid Acetone cyahydric
HCN is toxic to people and animals. Toxic dose for adults is 20 mg HCN. The dose can cause lethal poisoning is 1,4mg HCN / 1 kg body weight. For children, the elderly and the sick, toxic and lethal dose even lower (Hoang Phuong, 1978). Poisoning mechanism is due to HCN absorbed into the blood, combined with molecules of the blood, hinders the transport of O2 and CO2 emissions, should patients with dyspnea.
Agent in bitter cassava HCN concentrations vary from 15 - 400ppm..Tuy under varieties, soil conditions, mode of cultivation and harvest time but have different HCN. The bitter cassava HCN levels of toxins than the sweet varieties. peel flesh tubers and roots more toxic amounts. In the sweet cassava tubers, content is about 3- 42 mg glycozit HCN / 1kg, in bitter cassava tubers to 13-150 mg HCN / 1 kg
