Exploitable Cassava

Introduction:

• Tuber crops form an important group of staples serving as secondary food for one fifth of world population in tropics and subtropics and are the third important group of food materials after cereals and pulses.
• Cassava or Tapioca (Manihot esculenta) is one of the important tuber crops, which has higher biological efficiency as food producer and can substitute for cereals with higher carbohydrate and calorific content.
• Besides it shows potential as sources of alcohol, starch, sago flour, liquid, glucose, vitamin C and as raw materials for many other industrial products and animal feed.
• Hence this shares a place with cereals as dietary staples both in raw and processed forms. It can be grown on a wide range of soil, climates and environments and have the capacity to withstand adverse biotic and abiotic stresses.
• In India cassava is mainly grown in Kerela, Tamilnadu, Karnataka, Andhra Pradesh, and the like, over an area of 0.24 million hectares with a production 0f 6.06 million tonnes.
• Tuber crops in general are rain fed in nature. However recent studies have revealed that manifold increase in tuber production could be achieved when irrigated.
• And these crops have the potential to grow and yield even under low fertility conditions.

Productivity

• Cassava is grown in an area of 16.37 million hectares globally with an annual output of 164.75 million tonnes of tubers.
• Nigeria occupies first position in area under cassava accounting for 16.5 % of the world area producing 18.5 % of world cassava. Congo, Brazil, Thailand and Indonesia are the major cassava growing countries of the world constituting 50 % of the area under cassava, producing 64% of the world cassava.
• Though in India the acreage under cassava is low it has the highest productivity of 24.5 tonnes per hectare in the world where as the world average is 10 tonnes per hectare.
• In India, Cassava is cultivated in an area of 0.24 million hectares producing 6 million tonnes.
• Kerela, the first grower of cassava in India is the largest producer with 50 % of area and Tamilnadu accounts for 32 % of area and 9 % area is in Andhra Pradesh.

Exploitable opportunities

• Cassava offers immense scope as food, feed and industrial raw material. A wide range of instant and ready to eat food products like cassava rava and porridge can be prepared. And also used in preparation of cutlets, puffs and samosas.
• It can be used in industries for the preparation of alcohol, gums, dextrins and cold-water soluble starch.
• From this cassava starch biodegradable plastic can be produced.
• Central Tuber Crops Research Institute has evolved many processing technologies to produce value added products from cassava.

Technologies released by CTCRI:

Method to prolong shelf life of fresh cassava

• Pits are made under shade. Moist sand/soil are spread at its bottom (moisture 10-15%). Bunch of undamaged tubers along with stem are arranged layer by layer with moist sand or soil in between the layers. After arranging 3 layers, pits are covered with moist sand/soil. Remove germinated buds frequently.

Cassava Ensiling Technique

• Prepare chopped whole root cassava chips. Reduce initial cyanogens load by exposing to sunlight. Prepare cassava: rice straw silage mix in the ratio 90:10. Pack the mix is tightly into plastic silos. The ensiling process completes in a week and then stabilized silage is preserved as such in the silo till it is opened for utilization.

By product utilization of cassava waste (Thippi) as poultry feed

• Cassava flour and thippi mixed in equal proportions (1:1). Steam treat the mix for 30 minutes. Dry the mix in sunlight. Mix with dehydrated fishmeal, groundnut meal and vitamin-mineral premix. Granulate for better-feed efficiency.

Production of Ethanol from cassava starch

• Cook the fresh Cassava/ Cassava flour. Then Saccharification. After that neutralize the same and ferment it. At last distill it to get Ethyl alcohol or Stillage.

Production of Cassava rava

• Chipping of fresh cassava tubers and then drying. Then milling with hammer mill and sieving. After grading the medium fraction used as rava.

Production of Cassava Porridge

• Washing and peeling of cassava roots. Parboiling by steeping in boiling water for 10 minutes and Decanting. Sun drying the parboiled chips for 36 hours. Then Oven drying for 24 hours at 70 degree Celsius. Powdering in disintegrator and then sieving. Separating large sized fractions, medium sized fractions (rava) and small fractions (porridge powder). Large fraction again put into the disintegrator. Two tablespoon-full porridge powder could be added to hot milk after adding sugar for taste and served to infants and invalids as an energy drink.

Starch based Adhesives

• This can be prepared using cassava starch along with Polyvinyl Alcohol (PVA). The resultant adhesive has excellent sticking power in Paper-paper, paper-card board, plywood-hardwood, ceramic-wood and ceramic - ceramic systems.

Starch Succinate

• Starch succinate can be prepared by treating cassava starch with succinic anhydride 1 alkali (pH 8.5). The derivative can be used as a thickener in the food industry.

Starch based biodegradable plastic

• The process for production of starch-based plastics standardized at CTCRI is a pioneering work in Southeast Asia. It involves blending of polyolefins with tapioca/cassava or corn/maize starch in presence of a compatibilizer and other chemicals, with biodegradability ranging from 6 months to 5 years depending on the composition. This ecofriendly technology has already been transferred to 4 licensees in the states of Delhi, Haryana, Himachal Pradesh and Karnataka through the National Research Development Corporation (NRDC), New Delhi, India.

Tissue Culture

• Cassava starch has got high viscosity enabling its use as a binding material in pelletted fish feeds. Cassava with its desirable attributes like high energy value and the adhesive quality of starch can be a forerunner crop.
• CTCRI has recommended the sago (granulated cassava nylon starch) as a solidifying agent in tissue culture.

Microbial technique to extract starchy flour from cassava tubers

• A mixed culture inoculum with the microorganisms like Lactobacillus cellobiosus, Streptococcus lactis, Corynebacterium sp and Pichia membranaefaciens were developed. Inoculum's source added to cassava tubers (big pieces) and fermented for 48-72 hours. Tuber pieces are softened. Steep water decanted, fermented tubers dried, powdered and sieved to obtain starchy flour. This can be used as an ingredient in bakery products.

Mobile Starch extraction unit

• Simple electrically operated low cost starch extraction unit, which can be transported from one place to other. This unit has the provision to disintegrate the root tissues, wash out the starch from the tissue and separate the starch.
• Cassava starch finds applications in wide range of industries like textiles, corrugation box industries, paper industry besides food industry that is sago production industries

Industry needs

• It was projected that by 2015-16, cassava starch requirement in adhesive sector alone will be 3.5 Lakh tonnes followed by paper industry (2.0lakh tonnes), textile industry (78,000 tonnes) and other sectors like food, laundry, pharmaceuticals and the like, shall be 40,000 tonnes.
• So there will be a total demand of 3.12, 4.30 and 6.05 Lakh tonnes in 2006, 2010 and 2015 respectively.
• But estimated production will be only2.65, 3.09 and 3.54 Lakh tonnes in the respective years

Cassava in Future

• Cassava as such provides an ample scope for diversification and value addition. There lies a vast opportunity for non traditional uses of cassava in the form of value added foods, animal feed formulation, production of starch, sago as well as commodity chemicals like citric acid and high fructose syrup.
• It can be exploit its opportunities in the area of convenience food for which greater demand are ahead inview of women opting self - employment in various sectors.