Functional Properties of Soybean Food Ingredients in Food Systems

Jideani, V.A. 2011. Functional properties of soybean food ingredients in food systems. In Ng, T.B. (ed). Soybean biochemistry chemistry and physiology. Rijeka: InTech: 345-366.The food system is the transformation of raw materials into healthy food products within biophysical and socio-cultural contexts which results in production, processing, distribution, preparation and consumption of food. Food systems include components of food availability, access and utilization which underpin food security (Gregory et al., 2005). The expanding world population has resulted to a greater pressure for the consumption of plant products in foods with aesthetic and organoleptic appeal; consequently resulting in a great emphasis on the need for food ingredients with multiple functional properties. The role of soybean as a traditional food item in Far East is well recognized where it is used to make tofu, tempeh and soymilk. Advances in food technology resulted in the development of a variety of edible soy products including concentrates, isolates and extruded-expanded products; the consequence of which is increased soy consumption by populations of technically developed regions of the world (Young and Scrimshaw, 1979). Soybean is crushed into oil and defatted meal. The meal is usually used as an animal feed; a smaller percentage is further processed into food ingredients including soyflour, concentrates, isolates and textured protein. These are soy protein products used as food ingredients because of their multiple functional properties. Functional properties have been defined as “those physical and chemical properties that influence the behavior of proteins in food systems during processing, storage, cooking and consumption” (Kinsella 1976). The functional behavior of proteins in food is influenced by some physicochemical properties of the proteins such as their size, shape, amino acid composition and sequence, net charge, charge distribution, hydrophobicity, hydrophilicity, type of structures, molecular flexibility/rigidity in response to external environment such as pH, temperature, salt concentration or interaction with other food constituents (Damodaran 1997). The functional properties are the intrinsic physicochemical characteristics which affect the behavior of a food ingredient in food systems during processing, manufacturing, storage and preparation. Such functional properties include water holding, oil binding, emulsification, foam capacity, gelation, whipping capacity, viscosity and others

MODELLING THE TIME-DEPENDENT RHEOLOGICAL PROPERTIES OF OIL-IN-WATER EMULSIONS STABILIZED WITH GELATINIZED BAMBARA GROUNDNUT FLOUR

The contribution of emulsion main components to the time-dependent rheological properties of oil in water emulsion stabilized by gelatinized bambara groundnut flour (BGNF) was studied. Sunflower oil-in-water emulsions were prepared and stabilized with gelatinized BGNF. Weltman time-dependent rheological model was used to assess the time-dependent properties of oil-in-water emulsion stabilized with gelatinized BGNF and model’s suitability was judged by the coefficient of determination, R2, root mean square error, RMSE and standard error, SE.  All emulsions were thixotropic in nature. The time-dependent behaviour of the emulsions was well described by Weltman model (high R2 and low RMSE and SE values).  The mean of parameter A and B values of Weltman model were in the range 11.68 – 315.44 Pa and 0.52 – 25.54 Pa respectively. Both the shear rate of shearing and emulsion main components (BGNF and Sunflower oil (SFO)) greatly influenced the time-dependent model parameters.  The results provided the information on the influence of emulsion components and shear rate on rheological properties of BGNF-stabilized emulsions for product and process development

Nutritional, Health, and Technological Functionality of Lupin Flour Addition to Bread and Other Baked Products: Benefits and Challenges

Lupin is an undervalued legume despite its high protein and dietary fiber content and potential health benefits. This review focuses on the nutritional value, health benefits, and technological effects of incorporating lupin flour into wheat-based bread. Results of clinical studies suggest that consuming lupin compared to wheat bread and other baked products reduce chronic disease risk markers; possibly due to increased protein and dietary fiber and bioactive compounds. However, lupin protein allergy has also been recorded. Bread quality has been improved when 10% lupin flour is substituted for refined wheat flour; possibly due to lupin-wheat protein cross-linking assisting bread volume and the high water-binding capacity (WBC) of lupin fiber delaying staling. Above 10% substitution appears to reduce bread quality due to lupin proteins low elasticity and the high WBC of its dietary fiber interrupting gluten network development. Gaps in understanding of the role of lupin flour in bread quality include the optimal formulation and processing conditions to maximize lupin incorporation, role of protein cross-linking, antistaling functionality, and bioactivity of its γ-conglutin protein