Cassava (Manihot esculenta Crantz) popularly known as Tapioca, is one of the major tuber crops cultivated in India. Cassava fibrous residue, popularly referred as Thippi, is a fibrous residue left after starch is extracted from the cassava tubers. During the manufacture of cassava starch and sago (sabudana), thippi is generated to the tune of 15-20 % of the cassava tubers processed. The fibrous slurry containing about 20 % solids and 80 % water is retained on various mesh-sieves during separation of starch milk from the rasped material. It contains about 50-60 % starch on dry weight basis while the starch granules in it are located in the unruptured root cells and thus cannot be extracted easily. It is interesting to note that the starch content of the thippi is lower in the samples from large scale industry as compared to that from cottage and small -scale units. This indicated that the rasping process employed in cottage and small-scale cassava starch and sago industries is less efficient and need improvements for higher recovery of starch from cassava tubers.
Approximately 60,000 tonnes of cassava starch factory residue (CFSR), a cellulo-starch co-product, are produced by the cassava starch factories in India every year (Divya nair et al. 2012). It is composed of 56–60% starch, 15–18% cellulose, 4–5% hemicelluloses, 1.5–2.0% protein, and 0.4–0.5% reducing sugars, with a low level of lignin (2–3%) and pentosans (2%). The composition of cassava starch factory residue (Thippi) is presented in Table 1.
Table 1. Composition of cassava starch factory residue (Thippi) (g/100g dry weight)
Parameters
|
Value
|
Moisture
|
9.52
|
Lipids
|
0.83
|
Fiber
|
14.88
|
Ash
|
0.66
|
Carbohydrates
|
63.85
|
(Source: Divya Nair et al. 2012)
Applications of Thippi
The low level of cellulose and high level of hemi-celluloses coupled with high starch content make Thippi an ideal substrate for production of value added products such as glucose, high fructose syrup, single cell proteins, animal feed and ethanol.
Thippi has unique composition makes it an attractive raw material for various applications:
Animal Feed: Thippi can be used as a nutritious feed supplement for livestock, particularly poultry and cattle. Cassava pellets made from Thippi are largely used as animal feed in European countries. Thailand is the major exporting country of cassava pellets.
Organic Fertiliser: Rich in nutrients, Thippi can be composted and used as a natural fertiliser, reducing the need for synthetic fertilisers.
Biofuels: Thippi can be converted into bio-ethanol, providing a sustainable alternative to fossil fuels.
Paper and Pulp Industry: The high fiber content in Thippi makes it an ideal raw material for the production of paper, cardboard, and other cellulose-based products.
Food Industry: Thippi can be used as a thickening agent, stabiliser, or texture modifier in various food products, such as soups, sauces, and baked goods.
Benefits of Utilising Thippi: The utilisation of Thippi offers numerous benefits, including:
Reduced Waste: By using Thippi, the cassava starch industry can significantly reduce its waste output, contributing to a cleaner environment.
Improved Resource Efficiency: Thippi utilisation promotes resource efficiency by converting a waste product into valuable commodities.
Enhanced Food Security: Thippi-based animal feed and organic fertilisers can improve food security by increasing crop yields and promoting sustainable agriculture practices.
Job Creation: The development of Thippi-based industries can generate employment opportunities in rural areas, promoting economic growth and social development.
Sustainable Development: The use of Thippi as a raw material supports sustainable development by reducing the industry's reliance on non-renewable resources and minimising environmental impact.
Cassava Starch Factory Residue (Thippi) is a valuable resource that offers a wide range of applications, from animal feed and organic fertilisers to biofuels and food products. By promoting the use of Thippi, we can contribute to a more sustainable future, reduce waste, and create new opportunities for economic growth and social development.
(Krishnakumar belongs to ICAR-Central Tuber Crops Research Institute, Thiruvananthapuram, Kerala; Sajeev belongs to ICAR-Central Tuber Crops Research Institute, Thiruvananthapuram, Kerala; Jyothi belongs to ICAR-Central Tuber Crops Research Institute, Thiruvananthapuram, Kerala; Pradeepika belongs to ICAR-Central Tuber Crops Research Institute, Thiruvananthapuram, Kerala; Velmurugan belongs to Tapioca and castor research station, Tamil Nadu Agricultural University, Yethapur, Salem, Tamil Nadu. They can be reached at krishnakumar.t@icar.gov.in)