Energetic neutral atoms assisted development of kithul (Caryota urens) starch–lauric acid complexes: A characterisation study

Influence of crystalline properties on starch functionalization from the perspective of various physical modifications: A review

The relationship between structural properties and functional characteristics of starch remains a hot subject among researchers. The crystalline property is a substantial characteristic of starch granules, undergoing different changes during modification techniques. These changes are closely related to the functional properties of modified starches. Physical modifications are eco-friendly techniques and are widely adopted for starch modifications. Therefore, understanding the impact of changes in crystalline properties during different physical modifications on starch functionality is the ultimate way to improve their industrial utilization. However, the existing literature still lacks the elucidation of changes in functional properties of starch in accordance with its crystalline properties during different physical treatments. Hence, this review summarizes the effects of the most important and widely used physical modifications on starch crystalline properties, highlighting the alterations in various functional properties such as hydration, pasting, gelatinization, and in vitro digestibility resulting from changes in crystalline characteristics in a single comprehensive discussion. Furthermore, the current review gives direction for envisaging the functionalization of starches based on deviations in the crystalline properties during several physical treatments.

The effect of cold plasma on starch: Structure and performance

The inherent side effects of the physico-chemical properties of native starches often severely limit their use in food and non-food industries. Plasma is a non-thermal technology that allows rapid improvement of functional properties. This review provides a comprehensive summary of the sources and mechanisms of action of cold plasma and assesses its effects on starch morphology, crystal structure, molecular chain structure and physicochemical properties. The complex relationship between structure and function of plasma-treated starch is also explored. Potential applications of plasma-modified starch are also discussed in detail. The outcome of the modification process is influenced by factors such as starch type and concentration, plasma source, intensity and duration. The properties of starch can be effectively optimised using plasma technology. Plasma-based technologies therefore have the potential to modify starch to create a range of functionalities to meet the growing market demand for clean label ingredients.

Hydrogel properties of non-conventional starches from guabiju, pinhão, and uvaia seeds

The physicochemical properties of starch vary depending on the botanical sources, thereby influencing the gelatinisation/retrogradation properties and subsequently affecting the hydrogels characteristics. This study aimed to assess the influence of botanical sources influence on starch and hydrogel properties using non-conventional starch derived from guabiju, pinhão, and uvaia seeds. Hydrogels were prepared by starch gelatinisation followed by 6 h ageing period at room temperature (20 ± 2 °C) and subjected to five freeze-thaw cycles. Pinhão starch exhibited a higher viscosity peak and breakdown, along with a lower final viscosity and setback, compared to guabiju and uvaia starches. The significantly different pasting properties influenced the porous microstructure, water absorption (p-value: 0.01), and resistance of the hydrogels (p-value: 0.01). The guabiju starch hydrogels showed a uniform pore structure without cavities, whereas pinhão and uvaia starch hydrogels exhibited agglomerated and spongy pore structures. Furthermore, the guabiju starch hydrogel demonstrated the lowest water absorption (4.56 g/g) and the highest compression resistance (1448.50 g) among all the studied starch hydrogels. In contrast, the pinhão starch hydrogel showed the highest water absorption (7.43 g/; p-value: 0.01) among all studied starch hydrogels. The hardness of uvaia starch hydrogel did not differ significantly from the guabiju and pinhão starch hydrogel. The different non-conventional starches reveal important variations in the hydrogels characteristics. This provides insights into how amylose and amylopectin interact and present alternatives for using these unique starch-based hydrogels in diverse applications.

Improvement of Prebiotic Properties and Resistant Starch Content of Corn Flour (Zea mays L.) Momala Gorontalo Using Physical, Chemical and Enzymatic Modification. Trop Life Sci Res 2023;34:255-278. [PMID: 38144387 PMCID: PMC10735265 DOI: 10.21315/tlsr2023.34.2.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Probiotics are a non-digestible food ingredient that promotes the growth of beneficial microorganisms in the intestines. One of the functional food ingredients, Momala corn flour, is a source of prebiotics with a resistant starch content of 4.42%. Thi s study aimed to improve the prebiotic properties and resistant starch content of modified corn flour (MCF) Momala Gorontalo by using physical, chemical, and enzymatic modification processes. The research methods include physical modification (heat moisture treatment, annealing, autoclaving-cooling cycling, microwave), chemical modification (acid hydrolysis), and enzymatic modification (debranching pullulanase). The results showed that the modified by heat moisture treatment (HMT) increased RS levels 1-fold, annealing modification (ANN) 8.9-fold, autoclaving-cooling one cycle modification (AC-1C) 2.9-fold, autoclaving-cooling two cycles modification (AC-2C) 2.0-fold, microwave modification (MW) 1.3-fold, acid hydrolysis (HA) modification 5.0-fold, and debranching pullulanase (DP) modification 3.8-fold compared with corn flour control without modification. The value of the prebiotic activity of MCF hydrolysed acid (HA) is 0.03, and debranching pullulanase (DP) is 0.02 against Enteropathogenic Escherichia coli (EPEC). The prebiotic effect value of MCF HA and DP were 0.76 and 0.60, respectively. The prebiotic index value of MCF HA and DP were 0.60 and 0.48, respectively. This study confirms that MCF HA and DP are good prebiotic candidates because they have resistant starch content, low starch digestibility, and resistance to simulated gastric fluid hydrolysis than unmodified corn flour.

Impact of microwave irradiation on chemically modified talipot starches: A characterization study on heterogeneous dual modifications

In this study, the effect of chemical modifications such as oxidation, esterification and crosslinking was investigated alone and in combination with microwave irradiation on a non-conventional starch with 76% starch yield acquired from the trunk of matured talipot palm. The single- and dual-modifications imparted significant changes in the morphological, crystalline, pasting and rheological properties and digestibility of talipot starch. Characteristic peaks were observed in single- and dual-oxidized, esterified and crosslinked starches indicating their respective functional groups. All modifications significantly decreased (p ≤ 0.05) the relative crystallinity (RC) of talipot starches except for crosslinking, and the least RC (11.33%) was observed in microwave irradiated esterified starch. Microwave irradiation prior to chemical modifications showed a significant impact in the swelling and solubility of talipot starches. The decreased setback viscosity and increased light transmittance in single- and dual-microwave irradiated talipot starches showed their lowered retrogradation tendency, suitable for frozen foods. The resistant starch (RS) content was majorly improved in all heterogeneously dual modified talipot starches by incorporating more functional groups owed to structural and crystalline destruction in starch granules upon microwave irradiation. The highest RS content (45.02%) was observed in microwave irradiated esterified uncooked talipot starch.

Effect of Thermal Pretreatments on Phosphorylation of Corypha umbraculifera L. Stem Pith Starch: A Comparative Study Using Dry-Heat, Heat-Moisture and Autoclave Treatments

Talipot starch, a non-conventional starch source with a high yield (76%) from the stem pith of talipot palm (Corypha umbraculifera L.) was subjected to three different thermal treatments (dry-heat, heat-moisture and autoclave treatments) prior to phosphorylation. Upon dual modification of starch with thermal treatments and phosphorylation, the phosphorous content and degree of crosslinking significantly increased (p ≤ 0.05) and was confirmed by the increased peak intensity of P=O and P-O-C stretching vibrations compared to phosphorylated talipot starch in the FT-IR spectrum. The highest degree of crosslinking (0.00418) was observed in the autoclave pretreated phosphorylated talipot starch sample. Thermal pretreatment remarkably changed the granule morphology by creating fissures and grooves. The amylose content and relative crystallinity of all phosphorylated talipot starches significantly decreased (p ≤ 0.05) due to crosslinking by the formation of phosphodiester bonds, reducing the swelling power of dual-modified starches. Among all modified starches, dry-heat pretreated phosphorylated starch gel showed an improved light transmittance value of 28.4%, indicating reduced retrogradation tendency. Pasting and rheological properties represented that the thermal pretreated phosphorylated starch formed stronger gels that improved thermal and shear resistance. Autoclave treatment before phosphorylation of talipot starch showed the highest resistant starch content of 48.08%.

Talipot palm (Corypha umbraculifera L.) a nonconventional source of starch: Effect of citric acid on structural, rheological, thermal properties and in vitro digestibility

Starch from talipot palm trunk (Corypha umbraculifera L.), a new starch source, was treated with different citric acid concentrations (5%, 10%, 20%, and 40% of the dry weight of starch) to produce citrate starch. The influence of citric acid treatment on physicochemical, pasting, structural, thermal, rheological, and digestibility properties of talipot palm starch were studied. A new peak at 1728 cm^-1 was observed in the Fourier-transform infrared spectroscopy (FTIR) spectra of citric acid-treated starches, which confirmed the formation of an ester bond between starch molecule and citric acid. The crystalline pattern of talipot palm starch was unaffected by citric acid treatment, whereas the relative crystallinity decreased from 16.35% to 3.06%. The Rapid Visco Analysis of starch treated with citric acid did not show any characteristic peaks, however, the untreated starch showed a peak viscosity of 3646 cP. The gelatinization parameters decreased with an increase in the degree of substitution, and the enthalpy of gelatinization (ΔH_gel) decreased from 11.19 J/g to 6.37 J/g. The in-vitro digestibility of talipot palm starch was decreased by citric acid treatment, and that of the slowly digestible starch (SDS) and resistant starches (RS) increased significantly (p ≤ 0.05) from 31.71% to 39.43% and 37.55% to 53.38%, respectively.