Invention for Rice-based Bakery Products

Bakery products are considered as one of the most commonly consumed food category worldwide. Generally, wheat flour is the major ingredient and the gluten proteins (gliadin and glutenin) present in it are capable to form a viscoelastic network that causes to entrap the leavening gas within the dough mass itself during fermentation. This biological activity imparts to form a well-porous crumb structure with a fine texture. However, according to nutritional, health and economic point of views, the substitution of wheat flour with rice and other non-glutinous flour sources has gained a huge interest.

Since rice flour is dearth in gluten proteins, a dough mass prepared from rice flour is encountered with an issue in entrapping the leavened gas during the fermentation. Thus, it is extremely difficult to produce a well-porous crumb structure for bakery products using rice flour. Hence, it is a real barrier, and many bakery-food products processors are confronted with this problem. Therefore, the scope of this invention was to entrap the leavening gas of a rice-based dough mass during fermentation as much as possible by developing an alternative mechanism to compensate the role of the gluten network in the wheat dough. Thus, a pressure adjustable fermentation chamber was developed to undertake the fermentation and gelatinization of rice-based composite flour under pressurized conditions.

Fermentation Chamber

The results of this invention revealed that conducting the fermentation and gelatinization under 1.0kg/cminitial air pressure condition inside this fermentation chamber was capable to improve the leavened gas retention capacity of rice-based dough mass with a more stable and less breakable crumb structure and a uniform crumb cells distribution. A patent right was also awarded for this method by the National Intellectual Property Office of Sri Lanka (Patent No: 20177).

The gelatinized product obtained from this invention is similar to the steamed bread, which is a common food item in East Asian, Southeast Asian, and South African countries. And this product is also a good option for breakfast and can be consumed easily with other supplementary cuisines such as curries, butter. So also, this steamed product can be sliced and baked to obtain a crispy biscuit too.

Steamed bread and biscuits developed from the study

The results of this study further demonstrated that the leavened gas retention capacity and the texture of the developed products can be further improved by incorporating Cassava starch. Nevertheless, to improve the nutritional and health benefits of the products, certain cereal flours such as corn flour and green gram flour, as well as certain underutilized functional food ingredients such as dehydrated drumstick (Moringa oleifera) leaves powder and dehydrated Spirulina powder can also be incorporated in composite form.

This study further proved that Madan (Syzygium cumini) bark decoction, which is rich in antiglycation and antioxidant activities and commonly used in Ayurveda medicine to treat diabetes mellitus, can also be used to make the dough of the developed products. The quality of the decoction incorporated products is similar to basic products and the decoction significantly contributed to improving the total phenolic content and the antioxidant activity.

This invention can also be simply domesticated by using the domestically available pressure cooker by filling paddy husks and piling as much as dough containers possible. Thereafter, these dough containers should be allowed to ferment under pressure condition created by the leavening gas itself and the rest processes are similar to the aforementioned.

This research study was conducted under the supervision of Prof S. B. Navaratne and Prof (Mrs). C. M. Navaratne, for the Ph.D. of Miss. H. A. Rathnayake at the Department of Food Science and Technology, Faculty of Applied Sciences, University of Sri Jayewardenepura. This study was funded by the National Science Foundation, Sri Lanka (Grant number: TG/2017/Tech-D/03) and the Research Council, University of Sri Jayewardenepura (Grant number: ASP/01/RE/SCI/2019/12).

Prof. S. B. Navaratne
Prof. (Mrs). C. M. Navaratne
H. A. Rathnayake