Processing and sensory properties of high-fibre bakery products

Fibre is an important dietary component that has several beneficial roles in our body. Various studies have proved that there is a relationship between the lack of fiber in the diet and the incidence of several common diseases [1]. The diseases commonly associated with low -fiber diets include coronary he art disease, diabetes mellitus, diverticular disease, colon cancer, appendicitis, and dental caries. In today's changing world, consumer's preference of taste has led to refinement of flours to make bakery products with improved textural properties and tas te. Consequently, the fiber content of diets has also reduced. Substitution of refined flours with whole grains has potential to improve the nutritional value and fiber content of the food products. Whole grains and millets such as sorghum, ragi etc. can b e used as a substitute of refined flours. Sorghum and plantain (Green banana) are rich sources of Resistant Starch (RS) and can be used in many products to increase their fiber content.

Sorghum: Sorghum is also known as jowar in India, belongs to the tribe Andropogonae of the grass family Poaceae. It is a gluten‐free cereal and can also be used for celiac patients [2]. It is rich in phytochemicals, phenolics, sterols, and anthocyanins [3]. It also provides minerals such as magnesium, copper, manganese, iron and zinc and vitamins such as thiamin, riboflavin, niacin, vitamin B ‐6 and pantothenate [4]. Sorghum can be used to make different kinds of food products.

Products like bread and cookies have been made with sorghum bran incorporated up to 15 and 30 % with out any significant differences in texture or flavor profiles compared to whole wheat products [5]. Other examples include porridges [6], germinated malt products, which include porridges and some alcoholic and non -alcoholic beverages, like Mahewu, which i s produced in Zimbabwe [7]. The germinated sorghum flour can be used in preparation of bread, muffins, biscuits etc. Another well-established use of sorghum is in production of leavened baked goods such as wheat –sorghum composite bread [8].

Plantain: Plan tain (Green banana) is a traditional product which can be dried to form flour and can be used to substitute refined flours. It is a good source of carbohydrates and dietary fiber [9]. Plantain contains higher hemicelluloses content (6.08%) than most fruits and vegetables. Apart from dietary fiber, it is also good source of some essential minerals such as potassium, and various vitamins (A, B1, B2 and C) [10]. It also has high nutraceutical potential [11]. Plantain powder or flour has been used widely as an ingredient in the food industries [12]. Many research works have proved that consumption of plantain is beneficial to human health due to its resistant starch (RS) content [13].

Health benefits of Resistant starch (RS): "Resistant starch has been defined a s the fraction of starch, which escapes digestion in the small intestine but is digested in the large intestine after 5 to 7 hours of consumption" [14]. Fermentable fiber and RS are associated with improved glucose tolerance. There is evidence that this is caused by the presence of the short chain fatty acids (SCFA) and by a peptide produced in the fermentation process [15]. Resistant starch (RS) has been proved to be beneficial for digestive health as it increases stool bulk, acts as a mild laxative, promo tes the growth of healthy bacteria in the gut [16] and reduces pH in the intestine. SCFA also reduces the risk of ulcerative colitis and colon cancer by promoting the lipid and cholesterol metabolism [17]. RS also help in the management of diabetes by redu cing the glycemic index of food Page | 48 [18], [19]. RS does not cause sensory changes in food products [20]. It provides better appearance; texture and mouth - feel than conventional fibers to food products [21].