Effects of Cationization on Functional Properties of Pea and Corn Starches

A current review of structure, functional properties, and industrial applications of pulse starches for value-added utilization

Pulse crops have received growing attention from the agri-food sector because they can provide advantageous health benefits and offer a promising source of starch and protein. Pea, lentil, and faba bean are the three leading pulse crops utilized for extracting protein concentrate/isolate in food industry, which simultaneously generates a rising volume of pulse starch as a co-product. Pulse starch can be fractionated from seeds using dry and wet methods. Compared with most commercial starches, pea, lentil, and faba bean starches have relatively high amylose contents, longer amylopectin branch chains, and characteristic C-type polymorphic arrangement in the granules. The described molecular and granular structures of the pulse starches impart unique functional attributes, including high final viscosity during pasting, strong gelling property, and relatively low digestibility in a granular form. Starch isolated from wrinkled pea-a high-amylose mutant of this pulse crop-possesses an even higher amylose content and longer branch chains of amylopectin than smooth pea, lentil, and faba bean starches, which make the physicochemical properties and digestibility of the former distinctively different from those of common pulse starches. The special functional properties of pulse starches promote their applications in food, feed, bioplastic and other industrial products, which can be further expanded by modifying them through chemical, physical and/or enzymatic approaches. Future research directions to increase the fractionation efficiency, improve the physicochemical properties, and enhance the industrial utilization of pulse starches have also been proposed. The comprehensive information covered in this review will be beneficial for the pulse industry to develop effective strategies to generate value from pulse starch.

Cationic starches in paper-based applications-A review on analytical methods

This review focuses on cationic starches with a low degree of substitution (<0.06) which are mainly used for production of paper-based products. After a brief introduction on starch in general, cationization pathways and importance of cationic starches in paper production, this review emphasizes on the analytical challenges from different perspectives. These include the different length scales of starches when in solution: the macromolecular level, their assembly into nm aggregates and finally hydrocolloids with hundreds of nanometers of diameter. We give an overview on the current state of the art on the analysis of such challenging samples and aim at providing a guideline for obtaining and presenting reliable analytical data.

Physicochemical behaviour of chitin gels

Syneresis of chitin gels formed in the course of N-acetylation of chitosan in hydroalcoholic media has been studied. A critical cross-linking density related to a critical acetylation degree for which the gel undergoes weak syneresis and swells in water was shown (degree of acetylation (DA) 88%). Above this value, the weight loss during syneresis increases with DA. Conversely, syneresis decreases on increasing the polymer concentration, but disappears at a macroscopic level for a polymer concentration close to the critical concentration of entanglement in the initial solution. An increase in temperature favours the formation of hydrophobic interactions and new inter- and intramolecular hydrogen bondings. Due to the weak polyelectrolyte character of chitin, the weight of the gel depends on the pH and ionic strength of the media. Swelling-deswelling experiments show that the swelling of the gel is not fully reversible in relation with the formation of new cross-links during the depletion of the network. Our results reveals that the balance between segment-segment and segment-solvent interactions as well as the molecular mobility play the major role.

Functional properties and enzymatic digestibility of cationic and cross-linked cationic ae, wx, and normal maize starch

The functional properties and enzymatic digestibility of cationic and cross-linked cationic ae, wx, and normal maize starches were studied. Cationization reduced the endothermic transition temperatures (T(o), T(p), and T(c)), however, it increased peak viscosity, swelling power, solubility, clarity, and digestibility of all the starches compared to the corresponding native starch. After cationization, the enthalpy of waxy and normal starches was little changed but ae starch showed a decrease. For gel texture, cationization increased the hardness, adhesiveness, and springiness of all the starches, except for the hardness and adhesiveness of normal starch which showed a decrease, and the springiness of waxy starch did not show much change compared to the corresponding control starch. Cross-linking of cationic starch increased the endothermic transition temperatures, as well as peak viscosity. However, it reduced the swelling power and solubility, clarity, and enzymatic digestibility of all the cationic starches.