Thermal Behavior Of Starch Research Articles

Ozone induced structural variation in OSA waxy rice starch: Effects on the thermal behavior of starch and its stabilized pickering emulsion

Waxy rice starch (St) was modified by pre-OSA esterification reaction followed by ozone treatment. The molecular structure of this modified product (OSA-OSt) was characterized, and the thermal behaviors and its stabilized Pickering emulsion were evaluated. 1HNMR and XPS results discovered that ozone initially oxidized the hydroxyl groups in the amorphous region of starch (preferentially C2/C3) along with a degree of crosslinking, enhancing the molecular orderliness. This led to an increase in water-holding capability (29.15%) and swelling power (52.8 g/g), and a decrease in solubility (0.35%). TGA, RVA, and DSC indicated that oxidation-induced crosslinking within a brief treatment period enhanced the starch's thermal stability. The structural change enabled the formation of a weak gel structure during the heating process, which displayed high thermal and freeze-thaw stability. The work proves ozone is an effective way of improving the thermal behavior of OSA-starch and its emulsion for subsequent applications in numerous food products.

Influence of thermo-mechanical treatment and skim milk components on the swelling behavior and rheological properties of starch suspensions

This study focused on the thermal behavior of starch with and without milk proteins. The effects of two thermo-mechanical treatments: at laboratory and pilot scales were studied. Three media were used for starch pasting: NaCl aqueous solution, milk permeate and skim milk. Starch granules significantly swelled more when pasted in the pilot plant or during a longer time of thermo-mechanical treatment at laboratory scale. Moreover, whereas at laboratory scale the presence of lactose or milk proteins did not modify the swelling behavior of starch, a larger increase was obtained in presence of lactose (milk permeate) and milk proteins (skim milk) at pilot scale. At least, different dependence on starch granules diameter ratio versus relative viscosities were obtained at laboratory and pilot scales. Two complementary hypotheses on milk proteins/starch interactions were proposed to explain these results. Indeed, milk proteins could impact starch swelling through an increase of starch granules frictions during thermo-mechanical treatment but also through a modification of their surface characteristics.

澱粉のあばれの制御

澱粉のあばれの制御