Physicochemical changes of maize starch treated by ball milling with limited water content

Effect of particle size of sesbania gum on its modification, structure and performances

Sesbania gum (SG), as an environmentally friendly and resourceful natural polymer, has attracted a lot of attention due to its favorable properties. The size distribution of SG powders was broadened owing to the growth. Therefore, it inevitably resulted in the differences in reaction activity, structure and properties of different SG particles. The results showed that small SG particles exhibited higher reaction activity in cross-linking, carboxymethylation and oxidation than its large counterparts. Compared with those of large SG particles, the sedimentation volume of small SG particles could be reduced by 1.1 mL, while their substitution degree of carboxymethyl groups and aldehyde content could be increased by 0.0824 and 18.11 %, respectively. The swelling capacity, freeze-thaw stability, acid and alkali resistance of small SG particles were greater than those of large SG particles, but their retrogradation was weaker than that of large counterparts. The crystalline degree of small SG particles consisting of more long molecular chains could be reduced by 9.8 % compared to large SG particles. The DSC curve of small SG particles was significantly different from that of large SG particles, while the difference in TGA curves between small particles and large particles was relatively small. The enthalpy change of small SG particle was reduced by 48.4 J/g compared to large SG particles. The peak viscosity, final viscosity, breakdown and setback of tapioca starch were obviously influenced by the addition of small SG particles. And their emulsification stability was also better than large SG particles.

Ball-milling: A sustainable and green approach for starch modification

Ball-milling is a low-cost and green technology that offers mechanical actions (shear, friction, collision, and impact) to modify and reduce starch to nanoscale size. It is one of the physical modification techniques used to reduce the relative crystallinity and improve the digestibility of starch to their better utility. Ball-milling alters surface morphology, improving the overall surface area and texture of starch granules. This approach also can improve functional properties, including swelling, solubility, and water solubility, with increased energy supplied. Further, the increased surface area of starch particles and subsequent increase in active sites enhance chemical reactions and alteration in structural transformations and physical and chemical properties. This review is about current information on the impact of ball-milling on the compositions, fine structures, morphological, thermal, and rheological characteristics of starch granules. Furthermore, ball-milling is an efficient approach for the development of high-quality starches for applications in the food and non-food industries. There is also an attempt to compare ball-milled starches from various botanical sources.

Insights into the multiscale structure and pasting properties of ball-milled waxy maize and waxy rice starches

The effects of ball-milling on the pasting properties of waxy maize starch (WMS) and waxy rice starch (WRS) were investigated from a multiscale structural view. The results confirmed that ball-milling significantly destroyed the structures of the two waxy starches (especially WMS). Specifically, ball-milling led to obvious grooves on the surface of starch granules, a decrease in crystallinity and the degree of short-range order, and a reduction in double-helix components. Meanwhile, small-angle X-ray scattering results indicated that the semicrystalline lamellae of starch were disrupted after ball-milling. Ball-milling decreased the pasting temperatures. Furthermore, ball-milled starches exhibited lower peak and breakdown viscosity and weakened tendency to retrogradation. These results implied that ball-milling induced structural changes in starch that significantly affected its pasting properties. Hence, ball-milled starch may serve as food ingredients with low pasting temperature and paste viscosity as well as high paste stability under heating/cooling and shearing.

Cationic oxidized microporous rice starch: Preparation, characterization, and properties

The combination of enzymolysis of compound enzyme, oxidation of sodium hypochlorite, and cationic etherification of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTMA) was selected for the functionalization of rice starch (RS) to better raise the performances. The results showed that the oxidation and etherification could improve the acid and alkali resistance of RS, and enhanced its thermal stability. The crystalline structure of RS was an A-type, the enzymolysis, oxidation, and etherification did not change the structural type, while the crystallinity degree of RS derivatives was all reduced. The enzymolysis, oxidation, and etherification altered the pasting properties of RS, and could effectively decrease the setback and breakdown of RS. The oxidation of sodium hypochlorite not only damaged RS particles containing no micropores, but also destroyed the particles containing the micropores. The enzymolysis and oxidation more seriously destroyed the crystalline region than cationic etherification. The oxidation could increase the enthalpy change of RS, whereas the enzymolysis and etherification decreased its enthalpy change. In addition, the enzymolysis and oxidation could lead to the evident increase in average size of RS. The cationic etherification was able to improve the adsorption of Cu²⁺ on RS, whereas the low oxidation could only slightly ameliorate the adsorption of Cu²⁺ . PRACTICAL APPLICATION: Cationic oxidized microporous rice starch as an adsorbent, slow-release agent, and flocculant will be well used in food, medicine, pesticide, papermaking, waste water treatment, and so on owing to its abundant micropores, anionic groups, and cationic groups as well as small particle size and narrow size range.

Effect of heat-moisture treatment on the structure and physicochemical properties of ball mill damaged starches from different botanical sources

The morphology, structure and physicochemical properties of ball milling (BM) damaged starches from mung bean, potato, corn and waxy corn were investigated before and after heat-moisture treatment (HMT) (100 °C, for 12 h at a moisture content of 25%). The results showed that the damaged starch (DS) content of BM modified starches was decreased by 4.49%, 10.68%, 17.11% and 22.98% after HMT for mung bean, potato, corn and waxy corn starch, respectively. The solubility and swelling power were significantly decreased, and the modified effect was depended on the type of starch, among which waxy corn starch exhibited the maximum reduction. Different degrees of aggregation and fusion of granules were found in starches modified with BM-HMT, and the extent of fusion was related to amylose content and crystalline pattern. The crystallinity of BM modified starches was increased by 6.3%, 5.9%, 17.9% and 22.4% after HMT for mung bean, potato, corn and waxy corn starch, respectively. The dual physical modification had various effects on the starches from different botanical sources, the increase in crystallinity and peak temperature (T_p) were related to the DS and amylose content, and the changes in gelatinization temperature range (T_c-T_o) were related to the crystalline pattern of starches.

Effect of Heat-Moisture Treatment on Physicochemical, Thermal, Morphological, and Structural Properties of Mechanically Activated Large A- and Small B-Wheat Starch Granules

The large and small granules of A-starch (AS) and B-starch (BS) were separated from wheat cultivar of ZM 22. It was modified by ball-milling (BM) and heat-moisture treatment (HMT) was performed after BM treatment. After BM, noticeable deformation, fragments, fissures, and grooves were observed, whereas diffusion and aggregation were detected and followed by HMT. Crystallinity of AS-BM-5h decreased to 7.8%, and no diffraction peaks were observed for BS. However, after HMT, the crystallinity of AS-BM-5h and BS-BM-5h was increased to 17.4% and 6.2%, respectively. AS-BM-HMT displayed better thermal stability. After being treated by BM previously, AS and BS showed an increase in solubility, whereas the subsequent HMT of BM-treated starches (both AS and BS) had higher solubility especially for BS with longer BM treatment time. Large-sized granules were easier to be damaged by BM, whereas small-sized granules were greatly influenced by HMT. Dual modification of BM-HMT was an effective and potential method to modify the structure of wheat starch granules and expand its industrial applications. PRACTICAL APPLICATION: This study put forward a new dual modification method in combination with BM-HMT for large A-starch and small B-starch granules. Flour processing inevitably causes some starch to be damaged by destroying the structure. How can the damaged starch structure be improved to satisfy the food processing industry? HMT was proposed to modify the mechanically activated starches because of its obvious effects on smaller BS. HMT can reduce the content of damaged starch by rearranging and reorganizing its structures. This study can provide a low-cost, convenient, and eco-friendly technology for improving damaged starch and developing its applications in food industry.

Cross-Linked Hydrophobic Starch Granules in Blends with PLA

The majority of native starch is used in the food sector and in the paper industry. Only a small amount is used in polymer engineering. One reason for the reluctance of the plastics processing industry to use starch as a filling material in polymer blends is the unsatisfactory mechanical behavior of starch when combined with thermoplastics. Another reason is the hydrophilicity of starch. In order to make these materials capable of competing, an amelioration of the mechanical properties is compulsory. By means of modifying the native starch and optimizing the compounding process, it is possible to improve the performance of starch blends, and, thus, increase the number of application areas of these materials. For this reason, native starch was modified with a cross-linking agent using a laboratory mixer. Subsequently, the modified starch and poly(lactic acid) were compounded using a co-rotating twin screw extruder. Cross-linking of the native starch in the laboratory mixer resulted in an increase in the mechanical strength of the starch blends. In addition, the blends with cross-linked starch displayed lower moisture absorption levels than blends with native starch as a filling material.