Machines can make arrowroot processing easier and more profitable

Arrowroot, locally known as “uraro” is an important tuber crop for the rural sectors and its potential as food and feed crop is immense. Its flour is used in making biscuits and pastries, as extenders and thickeners in noodles, soups, sausages, and meat products.

A broiler ration with 25% arrowroot flour can effectively substitute for 69% of the usual corn requirement in feeds.

In view of this, the Bicol University (BU) in cooperation with the Department of Agriculture (DA) Marinduque and KOLBI, a private manufacturer, tested from 2004 to 2006 a mechanized system of processing arrowroot. A pilot plant was established at Rejano’s bakery in Brgy. Banahaw, Sta. Cruz, Marinduque through funding support from the Department of Science and Technology (DOST)’s Small Enterprises Technology Upgrading Program (SETUP).

The granulator extrudes the tubers into granules thereby increasing starch recovery from 12% to 18%. It has a capacity of 200 kg/hr and is operated by a 1hp electric motor.

The centrifuge removes excess water from the settled starch. The machine accommodates 12 kg per 12-minute centrifugation. It has a 14-inch diameter basket made of cloth and a 1.5-hp electric motor.

The multi-crop tray type batch dryer accommodates 250 kg/batch of starch. Drying takes 4-6 hr at 55-65^oC. It is an LPG-fueled dryer convertible to rice hull-fired burner.

According to researchers, the whole system can process an average of 1,000 kg/day fresh arrowroot, with only 2-3 persons operating the machines.

The Process
Producing flour or starch from arrowroot generally involves cleaning, washing, grating, crushing, grinding, juice extraction, water removal, and drying.

Arrowroot tubers are cleaned and washed through the mechanical washer. The washed tubers are placed into the chopper of the grater or granulator, then through the crusher- juice extractor-mill. This produces arrowroot juice with starch and arrowroot meal.

The starch is allowed to settle. Afterwards, excess water from the settled starch is removed through centrifuge. Drying follows using the multi-crop tray type batch dryer. The arrowroot meal on the other hand is washed then dried. The final products would be dried starch and dried meal.

Costs and Returns
Based on the study, manual process costs P33/kg excluding drying, which is done intermittently. With the mechanized system, cost of operation is estimated at P2/kg from washing to water removal while drying costs P1.50/kg fresh tubers. The operational cost is estimated at P7 assuming the price of fresh arrowroot tuber is P3.50/kg.

Analysis shows a 41.53% return on investment (ROI) from 960 hr/yr use. Added value of processed arrowroot is estimated at P2.20/kg.

Economics of production at various handling options show that a hectare planted to arrowroot with estimated harvest of 20,000 kg could generate an estimated income of P70,000.00 if sold fresh at P3.50/kg.

Manually processed flour at 10% recovery and sold P60.00/kg could generate P120,000. In the mechanical process, if 120 tons will be processed in six months, added value would be P240,000 aside from the P1.2 million revenue from direct sales.

Generally, mechanizing arrowroot processing is economically viable.

This project won first place in the development category of last year’s regional symposium held by the Bicol Consortium for Agriculture Resources Research and Development (BCARRD). (Ofelia F. Domingo, PCARRD and Arnulfo P. Malinis and Christopher O. Pacardo, Bicol University)