OBJECTIVE

The described technology focuses on production of innovative and competitive composite bread products based on sorghum. With this technology, as much as 50% wheat flour can be replaced with the locally produced sorghum. The technology can be utilized for other climate resilient Africa indigenous grains such as millet and teff.

INTRODUCTION

Challenge addressed: The bakery industry in Africa mainly produces baked products such as bread and pastries that are based on refined wheat. The wheat is mainly imported as the local wheat production capacity in most countries in Africa does not meet the demand. Currently and in the near future, urbanization and affluence in Africa will induce greater consumption of snack foods that will include sandwich and baguette bread products which will further drive an increased dependency on wheat import. This is however not sustainable if Africa wants to achieve food sovereignty and food security. Innovative technologies to enhance the utilization of locally grown climate resilient grains such as sorghums, millets and teff in bakery products are needed. Furthermore, the current climate change and wheat shortage due to war, will require Africa to consider the resilience of local food systems. This will demand investment in improving the cultivation and development of formal supply chains for drought resistant indigenous grains in order to make them more readily available to the consumers.

Technological consideration: Utilization of whole African indigenous grains in bread production represents a major technological challenge due to lack of gluten functionality which is essential for dough viscoelasticity and expansion restriction during bread baking and the overall quality of wheat bread. The high fibre content in whole grain also negatively affects the bread making process, bread volume, the appearance (shape and crust colour), crumb texture, mouthfeel, and shelf-life of breads, resulting in inadequate products when compared to bread made from 100 % refined wheat flour. To overcome these challenges, it is typical for the baking industry to utilize commercial food additives such as hydrocolloids and to keep the level of non-wheat flour below 10-15%.

Figure 1. a) bread prepared without sourdough, b) bread with sourdough without EPS), c) bread with sourdough containing EPS.

Opportunity and purpose: The University of Helsinki has developed clean label tailored sourdough technology for production of composite bread containing as much as 50% wheat with wholegrain sorghum. The tailored sourdough is produced with a starter culture that has been isolated from cereal sourdough. The starter culture is specifically selected for the ability to produce functional metabolites (exopolysaccharides (EPS) and organic acids) in situ during sourdough fermentation that enhance the processability and textural properties of the composite bread. The EPS essentially act as natural hydrocolloids and play a significant role in enhancing the structure and texture of the breads which have 50 % less gluten (Figure 1c) . With this technology, the use of food additives is avoided which tallies with current consumer demand for additive free foods with a natural image. Utilization of whole grain sorghum ensures that the final bread product is high in fibre which is currently recommended due to the well-established health effect of cereal fibre, particularly its protective effect against chronic diseases such as diabetes, cardiovascular diseases and cancer. The described technology can also be adapted for production of composite bread with teff or millet.

CONTACT INFORMATION

Name: Dr. Henry Ndegwa Maina

Address: University of Helsinki| Department of Food and Nutrition, P.O. Box 66 (Agnes Sjöberginkatu 2)| FIN-00014 University of Helsinki

Email:  henry.maina@helsinki.fi