Interactions between debranched starch and emulsifiers, polyphenols, and fatty acids.

Debranching modifications of waxy corn starch with pullulanase can generate short-chain amylose or debranched starch (DBS), which is easy to recrystallize. Herein, we firstly investigated the regulation of recrystallization behaviors of DBS by studying the interactions between DBS and emulsifiers, polyphenols, and fatty acids. Sodium dodecyl sulfate at the 3.0% level had strong interactions with DBS. When the concentration of epigallocatechin gallate was 15%, the enthalpy change (ΔH) of DBS was close to 0 J/g and the relative crystallinity of DBS was 0, clearly indicating the strong interactions between epigallocatechin gallate and DBS. When the concentration of caproic acid, caprylic acid, and capric acid increased from 0 to 20.0%, the ΔH of DBS decreased from 11.38 ± 0.01 to 3.90 ± 0.63, 1.39 ± 0.21, and 3.98 ± 0.83 J/g, respectively. The interactions between emulsifiers, polyphenols, and fatty acids and DBS could affect physiochemical properties of DBS in varying degrees.

Effect of pullulan on oil absorption and structural organization of native maize starch during frying.

The oil-absorption behavior of native maize starch (NMS) during frying was investigated in the presence or absence of pullulan (PUL) using a LF-NMR method. The morphology, long-range order, short-range order, and thermal properties of fried NMS-PUL mixtures were further evaluated using SEM, XRD, ATR-FTIR, and DSC, respectively. Pullulan addition significantly reduced the oil content of the fried starch samples: 0.395, 0.310, 0.274, and 0.257 g/g in NMS with addition of 0, 1, 3, and 5% PUL, respectively (p < 0.05). SEM analysis showed that the intact granular morphology of the starch granules was preserved upon addition of pullulan. The XRD, FTIR, and DSC results showed that pullulan protected both the short-range double helices and long-range crystalline structure of the granules during frying. As a result, fried NMS-PUL mixtures were denser than fried NMS, thus inhibiting oil absorption during frying. These results may have important implications for creating healthier reduced-fat fried food products.

Green preparation and characterization of starch nanoparticles using a vacuum cold plasma process combined with ultrasonication treatment.

In this study, starch nanoparticles (SNPs) were fabricated via a facile and green method involving a vacuum low-temperature plasma process combined with rapid ultrasonication treatment using waxy corn starch (WCS) and potato starch (PS). Morphology, size, crystalline structure, thermal property, and stability analyses of the SNPs were systematically performed. The obtained SNPs exhibited good uniformity and almost perfect spherical and square shapes. The zeta potential and Fourier transform infrared spectroscopy results confirmed that the SNPs were covered with negative carboxyl groups (zeta potential ranging from -21.8 ±â€¯1.06 to -9.78 ±â€¯0.89 mV). The gelatinization enthalpy of SNPs from PS significantly decreased, changing from 16.63 ±â€¯0.91 to 9.81 ±â€¯0.19 J/g. However, the crystal patterns of SNPs from the WCS and PS after plasma and ultrasonic treatments did not change. The crystallinity of SNPs from PS decreased from 45.2% to 16.5%. This novel approach to preparing SNPs is low cost, simple and green. The developed SNPs could have great potential in the food, biomedical, and material industries.

Retrogradation behavior of debranched starch with different degrees of polymerization.

Retrogradation is inevitable during the storage of starchy products. Retrogradation behavior of starches (e.g., amylopectin and amylose) has been widely investigated. We firstly studied the retrogradation behavior of short linear glucan debranched from amylopectin with different degrees of polymerization (DP). With increasing DP, the retrogradation enthalpy change (ΔH) of debranched starch (DBS) increased. At a DBS to water ratio of 1:2 and a storage time of 0 min, the retrogradation ΔH of DBS samples (DP 11.96, 12.62, and 13.36) reached up to 6.03 ±â€¯0.41, 8.03 ±â€¯0.53, and 12.80 ±â€¯1.57 J/g, respectively. The greater the short-chain length, the more rapid the retrogradation of DBS. The peak temperature of retrograded DBS (101.95-111.53 °C) with a DBS to water ratio of 1:2 stored at 50 °C was greater than that stored at 4 °C. The retrogradation of DBS was rapid, taking only 0-120 min, corresponding to ultra-short-term retrogradation.

Effect of annealing on the structural and physicochemical properties of waxy rice starch nanoparticles: Effect of annealing on the properties of starch nanoparticles.

Annealing offers a facile and green approach to the modification of starch. This study was the first to investigate the effect of annealing on the properties of waxy rice starch nanoparticles (SNPs). The spherical morphology of SNPs hardly changed after annealing, and the nanoscale size of the SNPs was maintained in the range of 50-120 nm. The relative crystallinity of modified SNPs increased from 53.71% to 63.46% after annealing at 55 °C for 48 h. The annealing treatment increased the melting temperature from 78.3 °C to 95.7 °C, but decreased the melting range from 30.8 °C to 25.3 °C. The increased 1047 cm-1:1022 cm-1 ratio suggested that annealing resulted in an efficient packing of double helices. This work suggests that annealing, a safe and green method, produces modifications which can improve the properties of SNPs and therefore expand their applications in the fields of food, nutraceuticals, and other materials.

Preparation of Borax Cross-Linked Starch Nanoparticles for Improvement of Mechanical Properties of Maize Starch Films.

Recently, starch nanoparticles have attracted widespread attention from various fields. In this study, a new strategy for preparing covalent-cross-linked starch nanoparticles was developed using boron ester bonds formed between debranched starch (DBS) and borax. The nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). The obtained nanoparticles were spherical with a size of 100-200 nm. The formation of boron ester bonds was confirmed by FTIR. The as-prepared starch nanoparticle exhibited a low relative crystallinity of 13.6%-23.5%. Compared with pure starch film, the tensile strength of starch film with 10% starch nanoparticles increased about 45%, and the elongation at break percentage of starch film with 5% starch nanoparticles increased about 20%. The new strategy of forming starch nanoparticles by using boron ester bonds will advance the research of carbohydrate nanoparticles.

Characterization of Cationic Modified Debranched Starch and Formation of Complex Nanoparticles with κ-Carrageenan and Low Methoxyl Pectin.

The functional modifications of debranched starch (DBS) has been attracting the interest of researchers. This study marks the first time that DBS was modified by cationization through the use of (3-chloro-2-hydroxypropyl) trimethylammonium chloride with the introduction of cationic functional groups. The physicochemical properties and structural characteristics of cationized debranched starch (CDBS) were systematically assessed. The results demonstrate that the maximum degree of substitution (DS) value obtained was as high as 1.14, and the corresponding CDBS exhibited significantly higher zeta potential values: approximately +35 mV. The minimal inhibitory concentration values of the CDBS of DS 1.14 against Escherichia coli and Staphylococcus aureus were 6 and 8 mg mL-1, respectively. In addition, nanoparticles were successfully prepared with a combination of CDBS and low methoxyl pectin (LMP) and a combination of CDBS and κ-carrageenan (CRG). The maximum encapsulation efficiency of nanoparticles for (-)-epigallocatechingallate can reach 87.8%.

Fabrication and Characterization of Starch Nanohydrogels via Reverse Emulsification and Internal Gelation.

Biopolymer-based nanohydrogels have great potential for various applications, including in food, nutraceutical, and pharmaceutical industries. Herein, starch nanohydrogels were prepared for the first time via reverse emulsification coupled with internal gelation. The effects of starch type (normal corn, potato, and pea starches), amylose content, and gelation time on the structural, morphological, and physicochemical properties of starch nanohydrogels were investigated. The diameter of starch nanohydrogel particles was around 100 nm after 12 h of retrogradation time. The relative crystallinity and thermal properties of starch nanohydrogels increased gradually with an increasing amylose content and gelation time. The swelling behavior of starch nanohydrogels was dependent upon the amylose content, and the swelling ratios were between 2.0 and 14.0, with the pea starch nanogels exhibiting the lowest values and the potato starch nanogels exhibiting the highest values.