Protein Processing in Food and Bioproduct Manufacturing and Techniques for Analysis

This chapter reviews some non-traditional processing methods that have been developed to modify starch properties for a wide variety of end-use applications. Annealing and heat-moisture treatments modify the swelling and pasting properties of starch granules and have been investigated as methods for increasing the percentage of resistant starch in foods. High-pressure treatments also reduce the gelatinization temperature, thus enabling starch-containing foods to be processed without the detrimental effects of high temperature on heat-sensitive components. Protein-based sources of food spoilage can also be inactivated by high-pressure processing. Microwave processing is more rapid and uniform than conventional thermal heating and thus enables reactions of starch to take place with shorter reaction times. Ultrasonic treatment has been used to reduce the molecular weight of starch due to high-shear cavitation. Since bond cleavage occurs near the center of gravity, the degraded starch products have narrow molecular weight distributions and minimal contamination with low molecular weight material. Shorter reaction times have been observed when ultrasound was used during the preparation of starch derivatives, and ultrasonic treatment has also been used to enhance glucose production from flour and corn meal, thus leading to increased ethanol production during saccharification and fermentation. Supercritical CO2 has been used as an environmentally friendly method for extracting contaminants from starch, for extracting lipids from wheat flour, and as a reaction medium for preparing starch derivatives. Expanded foams have also been prepared from starch by adding supercritical CO2 during extrusion.