Correlation between chain structures of corn starch and properties of its film prepared at different degrees of disorganization

Capsicum leaf protein-based bionanocomposite films for packaging application: Effect of corn starch content on film properties

The addition of corn starch (CS) enhances the interfacial adhesion of the film-forming liquids (FFLs), weakening the internal relative molecular motion. As a result, the rheological properties and zeta potential values of the FFLs were affected. A tight spatial network structure between capsicum leaf protein (CLP), lignocellulose nanocrystals (LNCs) and CS can be formed through intermolecular entanglement and hydrogen bonding interactions. The crystallinity, thermal degradation temperature, tensile strength and water contact angle of the protein-based bionanocomposite films (PBBFs) increased with increasing CS addition. This is due to the transformation of the secondary space structure of the CLP inside the PBBFs and the increase in cohesion. However, the excessive addition of CS forms aggregated clusters on the surface of PBBFs, which increases the surface roughness of PBBFs and causes more light scattering. Therefore, the brightness and yellowness values of the PBBFs increase, and the transmittance decreases.

Effects of ultrasonic and chemical dual modification treatments on the structural, and properties of cornstarch

This study aimed to explore the changes in the structural and functional properties of cornstarch modified by oxidation, esterification, and cross-linking under ultrasonic pretreatment. FT-IR and XRD characteristic peaks revealed successful access to chemical functional groups. Both ultrasonic and the three chemical treatments eroded the surface of starch granules, reducing their particle size and increasing their RC. Meanwhile, the destruction of the granules was further enhanced by the dual modification treatments. The ultrasonic pretreatment synergized and improved the swelling power, solubility, and translucency of all three chemical treatments. Further, it improved the poorer freeze-thaw stability of cross-linked starch, resulting in a lower water precipitation rate. In addition, both ultrasonic and chemical treatments significantly decreased RDS and SDS, and increased RS content. The ultrasonic-chemical dual modification had a synergistic effect on in vitro digestibility, resulting in a further increase in RS. In conclusion, this study provided ideas for developing new starch modification technology and deep processing of cornstarch, expanding its application areas and thus meeting the different needs of starch-based products.

Effect of sulfuric acid hydrolysis on the structure and Pickering emulsifying capacity of acorn starch

The acid-hydrolyzed acorn starch samples (HAS-1, HAS-2, HAS-3, and HAS-4) were prepared from natural acorn starch (NAS) at sulfuric acid concentrations of 1, 2, 3, and 4 mol/L for 2 d. The particle characteristics and structures of HAS were investigated, and Pickering high internal phase emulsions (HIPEs) based on HAS were constructed and characterized. The results showed that with an increase in sulfuric acid concentration, the size, yield, amylose content, molecular weight, and amylopectin chain length of HAS gradually decreased. HAS retained an A-type crystal structure, and its relative crystallinity and short-range order degree gradually increased with increasing sulfuric acid concentration. Acid hydrolysis treatment improved the wettability of NAS, and its effect was positively correlated with the sulfuric acid concentration. HAS-3 and HAS-4 could stabilize the Pickering HIPEs with an oil phase volume fraction of 80% at c ≥ 1.5%. The mechanical properties of the HIPEs were positively correlated with c.

Investigation of film Physical properties under various starch thermal treatments with emphasis on Retrogradation effects

This study investigated the changes in the physical properties of cornstarch-based films as they were retrogradely aged at different temperatures. Using a casting method, the films were fabricated, and their effects on the mechanical properties, thermal stability, barrier properties, and essential properties were analyzed. With prolonged aging and retrogradation periods, reductions in film thickness, solubility, water content, and water vapor permeability of 5.35%, 9.92%, 29.61%, and 20.94%, respectively, were observed. In addition, the surface roughness decreased by 44.46% for Rq (root-mean-square roughness) and 45.61% for Ra (arithmetic average roughness), while the elongation at break decreased by 72.64%. Conversely, the tensile strength, maximum degradation rate, and maximum degradation temperature increased by 116.98%, 99.5%, and 3.21%, respectively. These results provide a fundamental understanding of the changes that occur in the properties of cornstarch-based films during aging and retrogradation.

Changes in the properties of the corn starch glycerol film in a time-dependent manner during gelatinization

This study aimed to investigate the fundamental properties, solubility, mechanical properties, barrier performance, and microstructural features of films composed of corn starch and glycerol. Changes in the microstructure were analyzed to understand how they relate to the physical and chemical properties of these films. Specifically, we found that increasing the gelatinization time decreased the film thickness, solubility, water vapor permeability, and maximum degradation temperature and increased the water content. A gradual increase in the water contact angle of the corn starch-glycerol films was observed with increasing gelatinization time. This trend is likely due to the disruptive effect of gelatinization on the crystalline and amorphous structures inherent in corn starch, resulting in reduced film crystallinity, degree of order (DO) and degree of double helix (DD).

Effects of soaking glutinous sorghum grains on physicochemical properties of starch

Glutinous sorghum grains were soaked (60-80 °C, 2-8 h) to explore the effects of soaking, an essential step in industrial processing of brewing, on starch. As the soaking temperature increased, the peak viscosity and crystallinity of starch gradually decreased, while the enzymatic hydrolysis rate and storage modulus first increased and then decreased. At 70 °C, the content of amylose, the enzymatic hydrolysis rate of starch, and the final viscosity first increase and then decrease with the increase of soaking time, reaching their maximum at 6 h, increased by 53.1 %, 11.0 %, and 10.4 %, respectively, as compared with the non-soaked sample. At 80 °C (4 h), the laser confocal microscopy images showed a network structure formed between the denatured protein chains and the leached-out amylose chains. The molecular weights of starch before and after soaking were all in the range of 3.82-8.98 × 107 g/mol. Since 70 °C is lower than that of starch gelatinization and protein denaturation, when soaking for 6 h, the enzymatic hydrolysis rate of starch is the highest, and the growth of miscellaneous bacteria is inhibited, which is beneficial for subsequent processing technology. The result provides a theoretical basis for the intelligent control of glutinous sorghum brewing.

Development of cassava starch-based films incorporated with phenolic compounds produced by an Amazonian fungus

Drug-release systems have attracted attention over the last few years since they can be used as a substitute for traditional methods of drug delivery. These have the advantage of being directly administered at the treatment site and can maintain the drug at adequate levels for a longer period, thus increasing their efficacy. Starch-based films are interesting candidates for use as matrices for drug release, especially due to starch's non-toxic properties and its biocompatibility. Endophytic fungi are an important source of bioactive molecules, including secondary metabolites such as phenolic compounds with antioxidant activity. In the present study, cassava starch-based films were developed to act as release systems of phenolic compounds with antioxidant activity. The Amazonian endophytic fungus Aspergillus niger MgF2 was cultivated in liquid media, and the fungal extract was obtained by liquid-liquid partition with ethyl acetate. The starch-based films incorporated with the fungal extract were characterized in regards to their physicochemical properties. The release kinetics of the extract from the film and its antioxidant and cytotoxic properties were also evaluated. The films incorporated with the extract presented maximum release after 25 min at 37 °C and pH 6.8. In addition, it was observed that the antioxidant compounds of the fungal extract maintain their activity after being released from the film, and were non-toxic. Therefore, considering the promising physicochemical properties of the extract-incorporated films, and their considerable antioxidant capacity, the films demonstrate great biotechnological potential with diverse applications in the pharmacological and cosmetic industries.

Nutrient Composition of Indonesian Specialty Cereals: Rice, Corn, and Sorghum as Alternatives to Combat Malnutrition

Stunted growth (stunting) caused by malnutrition is a growing concern in Indonesia. The nutritional composition of cereals is important information for improving people's nutrition. This research aimed to comparatively study the nutritional values of several Indonesian local cereal crops and provide a nutritional database for promoting local food with the aim of combating malnutrition. The cereals investigated included varieties of rice, corn, and sorghum. The nutritional analysis included ash, protein, fat, carbohydrates, dietary fiber, essential amino acids, vitamins, and minerals. A purposive sampling method was performed by collecting five lots from each sampling area and forming composite samples by combining 1∼2 kg of each sample, then mixed before laboratory analysis. The results showed that colored rice, colored corn and sorghum, contain richer essential nutrients, dietary fiber, and essential amino acids compared to white rice and corn. The highest protein content was found in sorghum (13.26%), followed by corn (9.18%), and rice (8.0%). The highest energy value was also found in sorghum (380.5 kcal/100 g), followed by corn (379.9 kcal/100 g), and rice (362.1 kcal/100 g). The same sequence was seen for the mineral contents, where the zinc and iron contents were 1.57 and 2.39 mg/100 g, respectively for sorghum; 1.36 and 0.79 mg/100 g for corn; and 0.93 and 0.58 mg/100 g for rice. Accordingly, it can be concluded that sorghum has the highest nutritional value and therefore potential for combating malnutrition, while corn and rice are also highly nutritious and can be grown locally in order to combat malnutrition.