Pasting, rheological, and retrogradation properties of low-amylose rice starch with date syrup

Effects of proanthocyanidins on the pasting, rheological and retrogradation properties of potato starch

BACKGROUND

Proanthocyanidins (PAS) were complexed with potato starch (PS) to prepare polyphenol-starch complexes. The pasting, rheological and retrogradation properties of the complexes were investigated.

RESULTS

The addition of PAS markedly affected the pasting, rheological and retrogradation properties of PS, especially at a concentration of 5% (w/w). Rapid viscosity analysis indicated that PAS significantly changed the viscosity, breakdown and setback value of PS. The rheological results showed that PAS decreased the flow behavior index and consistency coefficient, but increased the viscoelasticity of PS. Differential scanning calorimetry and X-ray diffraction indicated that PAS delayed the retrogradation of PS. Furthermore, scanning electron microscopy indicated that the morphologies of retrograded PS gels were greatly altered to a less compact structure with the presence of PAS. Moreover, Fourier transform infrared spectroscopy elucidated that PAS interacted with PS via a noncovalent interaction, and inhibited the retrogradation of PS.

CONCLUSIONS

The findings suggested that supplementing PS with PAS might be an effective and convenient method for modifying the physicochemical properties of PS. © 2021 Society of Chemical Industry.

Rheological Analysis of the Structuralisation Kinetics of Starch Gels

Using the method of dynamic–mechanical analysis, the structuralisation kinetics of condensed starch solutions, cooled down to the temperature of 20 °C, was investigated. A close correlation of spatial crosslinking with local processes of macromolecule associations was discovered. It was found that depending on the concentration intervals of starch solutions, equilibrium nodes of the spatial network assume the form of either single or double hexagonal structures made up of bispiral chain associates. The increase of gel crosslinking, together with the passage of time, is the result of increasing the node functionality of the spatial network.

Molecular structure of different prepared pyrodextrins and the inhibitory effects on starch retrogradation

Pyrodextrins with different molecular size were prepared by dry heating native corn starch with and without hydrochloric acid (HCl) at 180 °C for 0.5, 3, and 5 h. Those with HCl treatment displayed much smaller molecular size, narrower size distribution, and higher proportion of the chains with the degree of polymerization (DP) ~24-400 than the counterparts without HCl treatment. Pasting and rheological tests showed that the addition of pyrodextrins with HCl treatment displayed lower overall and setback viscosity, and reduced gel development and gel strength in comparison of those without HCl treatment. Differential scanning calorimetry (DSC) and wide-range X-ray (WXRD) data suggested that the pyrodextrin sample prepared by heating native starch with HCl at 180 °C for 5 h (A₅) displayed the most effective inhibition on starch long-term retrogradation. This study could supply a pathway by applying pyrodextrins to both increase nutrition value and retard starch retrogradation for bakery and beverage industry.

Functionality of Native Starches in Food Systems: Cluster Analysis Grouping of Rheological Properties in Different Product Matrices

Industrial application of starch as a texture-forming agent is primarily limited to preparations obtained from waxy corn and potatoes. The main reason behind this is its functionality, which depends mostly on rheological properties. However, in food product matrices, these properties change. Despite the vast amount of information on the rheological properties of various starches, the rational choice of thickener appears to be an extremely difficult task. The aim of the work is to systemize the information on the rheological properties of most popular starches in matrices of various food products, applying principal component and cluster analyses. The investigated material is potato and corn starch of the normal and waxy varieties. Binary mixtures containing salts or sweetening agents, as well as four different food products (ketchup, mayonnaise, pudding, and jelly), are investigated. It was found that compared to normal varieties, waxy starches reveal many similar rheological properties in all investigated models and food systems. Furthermore, in most applications, one waxy starch variety may be substituted by another, with no significant impact on the rheological properties and texture of the food product. Moreover, waxy starch preparations are less altered by the presence of cosolutes, i.e., salts and sugar alcohols. Starch model systems were proven to be useful only for rapid thickener screening tests and cannot be recommended as a final reference for the quality design of food products.