Structural, thermal, and morphological characteristics of cassava amylodextrins

Changes of crystalline structure and physicochemical properties of Pueraria lobata var. thomsonii starch under water deficit

Crystal type is an important physicochemical property of starch. However, it is currently unclear whether changes in crystal type affect other properties of starch. This study discovered that water deficit resulted in an increase in small starch granules and transparency in Pueraria lobata var. thomsonii, while causing a decrease in amylose content and swelling power. Additionally, the crystal type of P. Thomsonii starch changed from CB-type to CA-type under water deficit, without significantly altering the short-range ordered structure and chain length distribution of starch. This transformation in crystal type led to peak splitting in the DSC heat flow curve of starch, alterations in gelatinization behavior, and an increase in resistant starch content. These changes in crystalline structure and physicochemical properties of starch granules are considered as adaptive strategies employed by P. Thomsonii to cope with water deficit.

The application of starch-based edible film in food preservation: a comprehensive review

Using renewable resources for food packaging not only helps reduce our dependence on fossil fuels but also minimizes the environmental impact associated with traditional plastics. Starch has been a hot topic in the field of current research because of its low cost, wide source and good film forming property. However, a comprehensive review in this field is still lacking. Starch-based films offer a promising alternative for sustainable packaging in the food industry. The present paper covers various aspects such as raw material sources, modification methods, and film formation mechanisms. Understanding the physicochemical properties and potential commercial applications is crucial for bridging the gap between research and practical implementation. Finally, the application of starch-based films in the food industry is discussed in detail. Different modifications of starch can improve the mechanical and barrier properties of the films. The addition of active substances to starch-based films can endow them with more functions. Therefore, these factors should be better investigated and optimized in future studies to improve the physicochemical properties and functionality of starch-based films. In summary, this review provides comprehensive information and the latest research progress of starch-based films in the food industry.

Cassava Starch Films Containing Quinoa Starch Nanocrystals: Physical and Surface Properties

Quinoa starch nanocrystals (QSNCs), obtained by acid hydrolysis, were used as a reinforcing filler in cassava starch films. The influence of QSNC concentrations (0, 2.5, 5.0, 7.5 and 10%, w/w) on the film's physical and surface properties was investigated. QSNCs exhibited conical and parallelepiped shapes. An increase of the QSNC concentration, from 0 to 5%, improved the film's tensile strength from 6.5 to 16.5 MPa, but at 7.5%, it decreased to 11.85 MPa. Adequate exfoliation of QSNCs in the starch matrix also decreased the water vapor permeability (~17%) up to a 5% concentration. At 5.0% and 7.5% concentrations, the films increased in roughness, water contact angle, and opacity, whereas the brightness decreased. Furthermore, at these concentrations, the film's hydrophilic nature changed (water contact angle values of >65°). The SNC addition increased the film opacity without causing major changes in color. Other film properties, such as thickness, moisture content and solubility, were not affected by the QSNC concentration. The DSC (differential scanning calorimetry) results indicated that greater QSNC concentrations increased the second glass transition temperature (related to the biopolymer-rich phase) and the melting enthalpy. However, the film's thermal stability was not altered by the QSNC addition. These findings contribute to overcoming the starch-based films' limitations through the development of nanocomposite materials for future food packaging applications.

Morphological and physicochemical characterization of starches from underground stems of Trimezia juncifolia collected in different phenological stages

In this study, starches from underground stems of Trimezia juncifolia were evaluated during dry season (DSS), wet season (WSS) and sprouting (SS). Results evidenced that drought stress did not interfere with the yield, amylose content and degree of polymerization (DP) of amylopectin. However, the extraction yield in SS was 58% lower, being observed and increase of 7.5% in the content of amylose, and 13.5% in DP values for SS amylopectin, with a predominance of A-chains. The amount of total sugar, the starch granules size as well as solubility and swelling properties varied as function of the phenological status. Also, starch granules changed from A-type polymorph in DSS and SS to a C_A-type in WSS. Nevertheless, it was observed a crystallinity reduction from 56% in DSS to 37.1% in SS. In addition, thermograms evidenced the presence of amylose-lipid complexes, with endothermic transition temperatures being affected by drought stress and sprouting. Finally, results demonstrate that underground stems from T. juncifolia have adaptative strategies involving changes in the morphological and physicochemical properties of the starch granules.