Project Title: Utilization of Microorganisms And Enzymes For The Production And Improvement Of Starch - Based Foods And Food Ingredients.
In the last few years there has been a resurgence of interest for research on starch globally. Research has focused on developing technologies that can lead to new products. In the U.S. in particular, R & D efforts on starch has increased substantially over the last few years. There is a wide variety of starch sources but native starches have rather restricted uses. The application of biotechnology to improve the properties of starch and to develop starch-based products has contributed towards this increase in research activity on starch.
In Malaysia, the main sources of starch are sago and tapoica. However, other potential sources of starch include rice, sweet patato, yam, breadfruit and banana. Currently most of the industrial starches (mainly in modified form) are imported. At the moment only sago and tapioca starch processing is being carried out industrially. Most of the previous research has used sago, tapoica or important corn as raw materials but they have not really concentrated on biotechnology related products and processes for food. The main starch-based industrial biotechnology related products are glucose syrup, alcoholic beverages and flavor enhancer (monosodium glutamate). There is also potential for application of biotechnology in the utilisation and treatment of the waste water generated. It is therefor felt that there is vast potential for exploiting our agricultural resources, to produce more value added products for both the local and export markets, reduce dependence on imported products, fully utilise biotechnology for the production of more natural food products and ingredients and finally to help our local starch based food industries.
The objectives of the Food Biotechnology Programme are to use biological catalysts, namely enzymes and cells, to prepare and develop new or improved foods, to produce or modify food ingredients from local resources and to develop and improve food processing and analytical methods. Thus the aim of this project is to utilise microorganisms and enzymes to produce and improve starch-based foods and food ingredients. This includes developing the technology for the production of food ingredients, modified food ingredients, functional foods, improvement of processing methods and solving problems currently faced by food processors through biotechnology.
The food processing industry nowadays is more sophisticated and there are demands for food ingredients that are specifically designed for the food and the process. Thus there is a large demand for modified ingredients, especially starch-based products ehich are now mainly imported as well as 'halal' food ingredients and binders. The binders or encapsulating materials have application not only in the food industry but also for pharmaceutical products. There is also a vast market for convenience foods such as ready-to-serve chilled and frozen products, but two of the main problems are improvement of quality and extension of shelf life of the starch-based raw materials. These are serious problems faced by the food industry and there is an urgent need to develop technologies for overcoming them. Much work can be done in these areas to assist the food industry.
Conversion and utilization of starch through the use of microorganisms and enzymes will result in the development of a wide range of technologies and value-added products. Potential products that can be produced as a result of this project include enzymatically modified starches for use as thickeners, edible films for improving shelf life of ffodsand coatings for snacks to prevent sogginess and the production of new fermented foods and beverages. Technologies for the production of pullulans from starch, instead of the traditionally used sugar, using sebmerged fermentation techniques and for the production of cyclodextrins will be developed. Pullulans and cyclodextrins are food ingredients that can be used as fat replaces, calorie-reduced admixtures, stabilisers, binders and encapsulating materials. The development of technologies for the bioconversion of starch to fermentation intermediates and substrates as well as for a continuos process for the production of fermentation media for food ingredients will also be carried out. This has important implications in widening the range of raw materials that can be used for fermentation without the problem of product build-up and inhibition . In view of the global trend for more healthful and natural products, there will be increasing demand for natural food ingredients derived through biotechnology.
It is therefore important that can research should be carried out in this area to develop technologies for the diversification, conversion and utilisation of local starch resources including the less utilised starches and to develop value-added products, through the application of biotechnology. The direct beneficiaries of this project will be the local food and the fermentation industries, apart from the researchers who will benefits in term of research knowledge and experience. All these efforts are geared towards the aims of maximising the utilisation of local resources, development of export oriented products and development of technologies to assist the local food industry, in line with the 7th Malaysia Plan.
Project achievements:
1) Pullulan production
Acid and enzymatic hydrolysis of starch were carried out. In both types of hydrolysis various concentrations of starch slurry were used ranging from 15-40%(w/v). Starch conversion rates to glucose were found in the range of 70-85%. Development and improvement of pullulan production were carried out using shake-flasks at 28°C for 72h. The results showed that the sugar from hydrolysate was converted into pullulan as indicated by thickening of the medium. Submerged fermentation trials in a 2L bioreactor were carried out at a temperature 28°C; pH, 5.5; airflow rate, 1.51/min and aeration 150rpm. The fermentation was completed in 48-72h. The results obtained from both shake-flask and 2L bioreactor showed that the conversion rate of sugar to pullulan were lower compared to trials with pure sucrose as a carbon source. Pullulan in powdered form was obtained.
2) Production of cyclodextrin
The saccharification process of sago starch was established. Optimum conditions for synthesis of alpha-, beta- and gamma-cyclodextrin using cyclomaltodextrin glucanotransferase (CGTase) enzyme were established and the purity of the products obtained were checked. Trials to use cyclodextrin for debitterring were carried out and the results obtained showed that the cyclodextrin was quite effective.
3) Modified starches
Modified rice starch/flour produced using microbial amylase was evaluated for improving the shelf-life of dodol. The keeping quality with respect to texture of the product was superior to that of the control. Trials to develop formulations incorporating various levels of anti-staling enzymes to improve the shelf-life of steamed rice cake (red bean "pau") were conducted. It was found that the quality of the red bean pau was improved and its shelf-life could be prolonged to 48 hrs. Similarly the shelf-life of coconut buns could be prolonged to 72 hrs at room temperature. High amylose sago, tapioca and sweet potato starches were produced by enzymatic process. The high amylose starch mixture was evaluated for coating of french fries to retard sogginess. Modified starch/flour for traditional rice products in the dried form were also developed.
Benefit of the Project
1. Technologies / Products
- Technology for production of microbial pullulan by Aureobasidium pul/ulans using tapioca as substrate
- Method for production of cyclodextrin from sago starch as feed stock using cyclomaltodextrin glucanotransferase (CGTase) enzymes
- Modified starch from rice, high amylose sago, tapioca and sweet potato starches for application in food product and coating. Method to prevent starch retrodegradation in two traditional products.
- Development of a continuous biological fermentation process for the production of fermentation media based on sago starch
- Amylomyces starter cultures suitable for rice and sweet potato fermentation. Bioconversion process for rice and sweet potato using the selected cultures.
2. Publications :
- A total of 10 papers have been published in Seminar/Conference Proceedings and another 3 in Scientific Journals
Project Status
- Completed
Programme Coordinator: Yeaih Quee Lan (MARDI)
Project Leader: Dr. Abidin Hamid (MARDI).
Institutional Project Leaders:
Assoc. Prof. Dr. Othman Hassan (UKM)
Dr. Arbakariya Ariff (UPM)
IInstitution:
Malaysian Agricultural Research and Development Institute (MARDI).
Universiti Kebangsaan Malaysia
Universiti Putra Malaysia (UPM).