Molecular and physico-chemical characterization of de-structured waxy potato starch

High-Protein Foods for Dysphagia: Manipulation of Mechanical and Microstructural Properties of Whey Protein Gels Using De-Structured Starch and Salts

This study focuses on understanding the effect of ionic strength on the mechanical and microstructural properties of novel composite gels containing 13% whey protein isolate (WPI) and 4% de-structured waxy potato starch (DWPS). The DWPS is a physically modified waxy potato starch treated at 140 °C for 30 min under constant shear. Thermodynamic incompatibility between WPI and DWPS was observed upon the addition of NaCl (~75 mM) or CaCl₂ (10–75 mM). The combined effects of such thermodynamic incompatibility with the changes in protein connectivity induced by varied ionic strength led to the formation of distinctive gel structures (inhomogeneous self-supporting gels with a liquid centre and weak gels with paste-like consistency) that were different from thermodynamic compatible homogeneous self-supporting gels (pure WPI and WPI + maltodextrin gels). At ≥ 250 mM NaCl, instead of a paste-like texture, a recovered soft and creamy self-supporting gel structure was observed when using DWPS. The ability to generate a range of textures in WPI gelation-based foods by using DWPS under different ionic conditions, is a feasible strategy for formulating high-protein foods for dysphagia—aimed to be either thickened fluids or soft solids. Additionally, this acquired knowledge is also relevant when formulating food gels for 3-D printing.

Ultrasonic treatment improves the performance of starch as depressant for hematite flotation

In this study, ultrasonic treatment was introduced to enhance the depressive performance of starch in the reverse flotation separation of fine hematite from quartz. It was found that after ultrasonic treatment, starch was not only able to impart a higher surface wettability of hematite, but also better reduced the degree of entrainment of fine hematite, both of which alleviated the loss of hematite to the froth. Flocculation tests together with starch property characterization were conducted to understand the underpinning mechanism. It is interesting that ultrasonic treatment of starch led to stronger and more selective flocculation of hematite, which accounted for the reduced entrainment loss of fine hematite and benefited the concentrate Fe grade. It was also found that ultrasonic treatment enhanced the dissolution and acidity of starch with a simultaneous increase in the content of amylose, which in turn could contribute to the improved depression and selective flocculation of hematite.