Modified tapioca to find use as encapsulation material?

"The results of this study indicate laboratory prepared acid modified tapioca starch after treated with steam pressure has the potential for use as wall material," wrote author Jarunee Loksuwan from the Thammasat University in Thailand.

"The low-surface carotene contents were also observed for this modified tapioca starch which indicates better microencapsulation efficiencies."

Indeed, with the fear of commodification continuously looming, food manufacturers are turning to microencapsulation technologies as a way of achieving much-needed differentiation and enhancing product value.

Tapping into key and emerging consumer trends with innovative techniques is becoming increasingly important for food manufacturers.

Changing consumer trends and tastes are primarily responsible for driving innovation in the microencapsulation market, says market analyst Frost & Sullivan.

Since food manufacturers constantly monitor such trends, food ingredients companies are always looking for ways to meet these ever-changing demands, thereby promoting the need for novel microencapsulation technologies.

"Numerous wall materials or encapsulating agents are available for food application," explained Loksuwan.

"Gums arabic, hydrolyzed starches, and emulsifying starches are most commonly used as wall materials.

Some proteins such as whey proteins, sodium caseinate, and gelatin are also used as wall materials."

However, each of these materials has advantages and disadvantages, with cost being the biggest stumbling block for materials like gum arabic (E414 in the EU) that is susceptible to variations due to political and climatic factors in the primary producing countries like Sudan and Nigeria.

The new study, published in the journal Food Hydrocolloids and presented last year at Food Colloids 2006 hosted by the Nestlé Research Center, sought to evaluate the potential of acid modified tapioca starch as an encapsulation material using beta-carotene as a model ingredient.

A patented method of was used to prepare the acid modified tapioca starch (Thailand Petty Patent No. 2146), which involved an initial hydrolysis stage by mixing with sulphuric acid and subsequent neutralisation with sodium carbonate, prior to filtering washing and drying.

The use of the modified tapioca starch as an encapsulating material was compared to maltodextrin and native tapioca starch.

The study, supported by National Research Council of Thailand, used pure beta-carotene to test encapsulating potential and reports that modified tapioca starch encapsulated significantly more of the carotenoid (82 per cent) than native starch (68 per cent) and maltodextrin (47 per cent).

"These results indicated that, of the wall material studied, modified tapioca starch treated with steam pressure had the highest encapsulation efficiency," said Loksuwan.

The modified tapioca starch also showed a higher cold-water solubility than its native starch when prepared as spray-dried powders, said Loksuwan.

The modified tapioca starch produced granules with a wider range of particle sizes, from 5 to 30 micrometres, compared to the native tapioca starch that had more uniform granules ranging in size from 2 to 18 micrometres.

"Results obtained suggest that the modified tapioca starch can be considered as potential wall material for encapsulation of beta-carotene," concluded the researcher.

Increasing interest in tapioca starch was highlighted recently by Cargill, the largest agricultural firm and one of the largest private companies in the world, acquired Thai-based Chai Charoen Tapioca Flour Factory Company that specialises in developing and producing native tapioca starches primarily for the food industry.

Source: Food Hydrocolloids (Elsevier) Volume 21, Pages 928-935 "Characteristics of microencapsulated beta-carotene formed by spray drying with modified tapioca starch, native tapioca starch and maltodextrin" Author: J. Loksuwan