A review on the physicochemical properties of starches modified by microwave alone and in combination with other methods.

Native starches are unsuitable for most industrial applications. Therefore, they are modified to improve their application in the industry. Starch may be modified using enzymatic, genetic, chemical, and physical methods. Due to the demand for safe foods by consumers, researchers are focusing on the use of cheap, safe and environmentally friendly methods such as the use of physical means for starch modification. Microwave heating of starch is a promising physical method for starch modification due to its advantages such as homogeneous operation throughout the whole sample volume, shorter processing time, greater penetration depth and better product quality. More recently, the use of synergistic methods for starch modification is being encouraged because they confer better functionality on starch than single methods. This review summarizes the present knowledge on the structure and physicochemical properties of starches from different botanical origins modified using microwave heating alone and in combination with other starch modification methods.

Quality attributes of breads from high-quality cassava flour improved with wet gluten.

This study investigated the physical, chemical, and sensory attributes of breads produced from preheated high-quality cassava flour (PCF) and its composite with wheat flour (CWF). Wet gluten was added to the PCF and CWF for production of bread, while bread from wheat served as the control. Flour functionality was determined prior to bread production. The moisture contents of the flour samples were in the range of 12.80 to 14.21%, and PCF exhibited water absorption capacity (1.12 mL/g) comparable to that of wheat flour (WF) (1.10 mL/g). There were significant (P < 0.05) differences in color characteristics, except in L* values and breads produced from WF and CWF were similar in specific volume (3.85 to 4.21 mL/g) and firmness (2.04 to 2.64 N). Breads from WF and CWF exhibited similar crumb microstructure, though gas bubbles in the sample from PCF appeared less developed. Wheat bread had significantly (P < 0.05) higher calorie, crude protein and crude fat, but lower crude fiber, ash, and carbohydrate compared to other bread samples. Sensory evaluation showed that bread from PCF was not significantly different from 100% wheat bread in crust color, texture, and overall acceptability but was impaired in flavor. The study revealed the feasibility of bread baking from preheated cassava flour with added gluten extract. The bread produced had some quality attributes comparable to that of wheat bread. PRACTICAL APPLICATION: Bread from wheat-cassava composite flour with added gluten was similar to wheat bread in specific volume and firmness while sample from cassava flour with added gluten compared favorably well with wheat bread in crust color, texture, and overall acceptability. Findings from the study present wheat gluten extract as a viable component to be used in nonwheat flours for bread making. This could be a basis to further add value to the gluten churned out as a by-product in the wheat starch industry.