To develop a mixed starter culture of lactic acid bacteria for maize products, this study systematically investigated the effects of adding functional sugars (fructooligosaccharides, xylooligosaccharides, inulin, and trehalose) as auxiliary ingredients at different levels (0.5%, 1.0%, and 1.5%) on the processing quality and starch structure of fermented maize dough. The dough was examined for texture properties, microstructure, gelatinization characteristics, rheological properties, thermal properties, and moisture distribution, and the particle size, molecular mass, and crystallinity of starch extracted from the dough were measured. The results revealed that FOS resulted in a more compact and uniform dough microstructure. The dough added with 1.5% FOS exhibited the lowest hardness (80.93 N) and softest texture, along with the lowest breakdown and setback values. Meanwhile, it had the best thermal stability and the lowest retrogradation tendency. Its storage modulus (G’) and loss modulus (G”) decreased most significantly. FOS promoted the conversion of quasi-bound water to bound water and consequently enhanced water-holding stability. Starch isolated from the dough with 1.5% FOS had the highest amylose content (37.0%), the smallest weight-average/number-average molecular mass ratio and radius of gyration, and the highest crystallinity (37.55%). All four functional sugars enhanced the short-range ordered structure of starch and reduced the content of amorphous regions. Inulin significantly decreased the volume-average particle size of starch but had no significant effect on the surface-area-average particle size. These findings demonstrated that the four functional sugars improve the processing properties of dough by regulating the molecular structure of starch, with FOS exhibiting the most pronounced effect. This provides a theoretical basis and technical pathway for developing high-quality fermented maize-based foods.

In this study, to enhance corn flour incorporated noodles, corn flour was treated by the addition of 16% quercetin followed by microwave irradiation at 320 W for 30 min before being used as a partial wheat flour substitute in noodles. The effect of combined quercetin-microwave treatment on the processing properties of corn flour and the quality and digestion characteristics of corn flour incorporated noodles was investigated. The results showed that the treated corn flour had lower breakdown and setback values. Texture analysis revealed that the combined treatment resulted in the lowest gel hardness (103.94 g) and the highest elasticity (0.95) of corn flour. The noodles added with the treated corn flour had higher hardness, elasticity, chewiness, and resilience, lower cooking loss, and shorter optimal cooking time compared with the noodles with untreated corn flour. In vitro digestibility tests indicated that the resistant starch content in corn flour treated by quercetin combined with microwave was 26.45%. Compared with the wheat flour noodles, the resistant starch level in the noodles with the treated corn flour increased by 47.96%. Overall, combined treatment with quercetin and microwave appears to be an effective strategy for improving the quality and processing characteristics of corn flour and its products, providing valuable insights for developing high-quality, easily processable corn-based foods.

Sarcopenia is a progressive, systemic skeletal muscle disorder associated with aging. With the increase in the global aging population, sarcopenia has become a significant health issue for the elderly. Studies have shown that natural bioactive compounds, such as polyphenols, flavonoids, and alkaloids, play an important role in alleviating the progression of sarcopenia by regulating protein homeostasis, improving mitochondrial function, inhibiting inflammation, and mitigating neuromuscular junction (NMJ) degeneration. However, due to the diversity of natural bioactive compounds and the complexity of their molecular mechanisms, their application still faces some challenges. Therefore, this article systematically reviews the literature on the pathogenesis of sarcopenia, the mechanism of action of natural bioactive compounds in alleviating sarcopenia, and their application for preventing this disease, aiming to provide scientific references for the development and application of natural bioactive compounds in the prevention and treatment of sarcopenia.

Maize kernels (cv. ‘Jidan 66’) were exposed to different intensities (2.5, 3.5 and 4.5 mT) of low-frequency static magnetic fields for different time periods (12, 24, 36, 48, 60 and 72 h) and germinated at 25 ℃ for 96 h. The changes in the growth indices, the phenolic contents, the hypoglycemic activity of phenolic compounds and the key enzyme activities related to polyphenol metabolism in germinated maize kernels were investigated. The results showed that the sprout length and germination rate of maize seeds treated at magnetic field intensity of 3.5 mT for 60 h were significantly increased, and the contents of bound and free phenols were increased by 72.72% and 47.16%, and the contents of syringic acid and p-coumaric acid were also significantly increased compared to the untreated control (P < 0.05). In addition, the activity of phenylalanine ammonia lyase (PAL), 4-coumaric acid-CoA ligase (4CL), and cinnamate 4-hydroxylase (C4H) were improved under low frequency static magnetic field, and the α-glucosidase and α-amylase inhibitory activity of bound and free phenolics were enhanced. These pieces of evidence indicated that low frequency static magnetic field can promote the growth of maize seeds and the accumulation of phenolic compounds, and improve the hypoglycemic activity of phenolic compounds in germinated maize seeds .

Newly harvested corn was stored under constant temperature (15 or 25 ℃) and relative humidity (55%). The structure and physicochemical properties of zein during postharvest ripening of corn were studied, and their relationship was analyzed. During the 56-day postharvest ripening period at 15 and 25 ℃, the free sulfhydryl content, surface hydrophobicity, particle size and polydispersity index (PDI) of zein decreased, while the disulfide bond content and absolute value of zeta-potential increased. The hydrogen bond association decreased, and more ordered β-sheets were transformed into a disordered structure, and the thermal stability and the molecular mass of α-zein subunit decreased. In addition, during postharvest ripening of corn the physicochemical properties of zein significantly changed. The solubility and water-holding capacity of zein reached their maximum on the 42^th day at 15 ℃ and on the 28^th day at 25 ℃, and the emulsifying and foaming capacity increased significantly after postharvest ripening for 14 days at both temperatures. However, the oil-holding capacity decreased. The improvement in physicochemical properties of zein during postharvest ripening of corn may be related to the reduction in protein aggregation and its flexible structure. These results showed that proper postharvest ripening of corn could modify the structure of zein and consequently improve its physicochemical properties.

In this paper, zein and gallic acid (GA) were used to prepare zein/gallic acid composite nanoparticles (ZGP) by antisolvent precipitation. Meanwhile, ZGP was used as stabilizer to prepare antioxidant Pickering emulsion. The results showed that ZGP exhibited good dispersivity in the nanometer scale and positive zeta potential. The bonding between Zein and GA was achieved mainly through hydrogen bonds, and X-ray diffraction analysis demonstrated that the resultant complex showed an amorphous structure. Thermodynamic analysis proved that the reaction between Zein and GA was spontaneous and exothermic, the surface hydrophobicitygradually decreased, and the thermal stability of ZGP increased with increasing GA addition. Furthermore, the Pickering emulsion stabilized by ZGP showed a shear thinning phenomenon typical of a non-Newtonian fluid, and the storage modulus (G’) was higher than the loss modulus (G”). During the storage period (50 ℃, 20 d), the amounts of primary and secondary lipid oxidation products both gradually decreased with an increase in GA concentration, indicating that the ZGP stabilized Pickering emulsion has antioxidant capacity and can inhibit lipid oxidation.

We investigated the changes of gel characteristics and structure of ultrasonically treated corn starch during freeze-thaw cycles, with a view to providing theoretical guidance for improving the quality of quick-frozen starch-based foods. The effects of the number of freeze-thaw cycles on the dynamic rheological and textural properties of ultrasonically modified corn starch gels were analyzed and their structures were characterized by using a rheometer, a texture analyzer, a low-field nuclear magnetic resonance (NMR) spectrometer, a Fourier transform infrared (FTIR) spectrometer and an X-ray diffractometer (XRD). The results showed that compared with native corn starch, the water separation rate of ultrasonically modified corn starch gels significantly decreased by 5.19% (P < 0.05) at the 4th freeze-thaw cycle, indicating improved freeze-thaw stability; the storage modulus and loss modulus of ultrasonically modified corn starch gels decreased, and the gel strength was weaker; the hardness significantly decreased by 10.83% (P < 0.05), and the amylose content decreased 0.15%. Moreover, the iodine binding force was weakened, the transverse relaxation time distribution curve was shifted to the left, the short-range ordered structure was weakened, and the relative crystallinity was reduced. The gel properties and the structural characterization results indicate that ultrasonic treatment can inhibit water migration and double helix structure formation in the corn starch gel system during freeze-thaw cycles and consequently improve its freeze-thaw stability.

In this study, we investigated the effect of high hydrostatic pressure (HHP) treatment on the physicochemical and structural properties of corn starch/ferulic acid (CS/FA) composite system by differential scanning calorimetry (DSC), rheometer, Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD). The results showed that HHP treatment enhanced the peak viscosity, elastic modulus G’ and viscous modulus G”, and reduced the solubility and degree of expansion (75–95 ℃), enthalpy of gelatinization, and retrogradation value of the composite system. In addition, HHP treatment increased the particle size of the composite system, and FTIR and XRD spectra showed that the short-range ordered and double helix structure of the composite system decreased after HHP treatment; the starch particles were still A-type, but the relative crystallinity decreased. In summary, HHP treatment promoted the interaction between corn starch and ferulic acid in the composite system, improved the physicochemical properties of corn starch, and reduced its ordered structure.

The effect of Armillaria mellea fermentation alone and combined with static magnetic field on the structure and physicochemical properties of zein was explored. Fourier transform infrared (FTIR) spectral analysis showed that static magnetic field treatment changed the secondary structure of the protein during the fermentation process. The analysis of ultraviolet (UV) absorption spectra and intrinsic fluorescence spectra showed that static magnetic field treatment resulted in protein unfolding and group exposure. The results of scanning electron microscopy (SEM) showed that after static magnetic field treatment, the surface of the protein became rougher with obvious pores and increased specific surface area. The results of thermodynamic analysis showed that static magnetic field treatment obviously increased the denaturation temperature of the protein, decreased the particle size, increased the absolute value of the zeta potential, and resulted in increased content of free sulfhydryl groups and decreased content of disulfide bonds. In addition, the physical and chemical properties of the protein were significantly changed by static magnetic field-assisted fermentation. The water and oil retention capacities, emulsification properties, foaming capacity and foam stability were increased significantly, reaching maximum values of 3.86 g/g, 4.22 g/g, 26.83 m²/g, 37.67% and 58.12%, respectively on the 7th day of fermentation. The emulsion stability was decreased significantly, reaching a minimum level of 34.10% on the 7th day. In summary, static magnetic field-assisted fermentation of zein by A. mellea can change its structure of and effectively improve its physical and chemical properties, thereby improving the added value and utilization rate of zein.

Ginseng residue, the by-product of the extraction of bioactive components from ginseng, is rich in dietary fiber. In this study, ginseng insoluble dietary fiber (IDF) was prepared by ginseng residues fermented with Morchella esculenta, Hericium erinaceus or Armillaria mellea in order to explore the effect of fermentation by edible fungi on the structure and functional properties of IDF. The results of scanning electron microscopy (SEM) showed that a large number of honeycomb pores appeared on the fermented fiber surface and the specific surface area increased compared with that before fermentation. The particle size of fermented fiber decreased. Fourier transform infrared (FTIR) spectroscopy showed that fermentation resulted in partial degradation of cellulose, hemicellulose and lignin in IDF. The results of X-ray diffraction showed that the fermented fiber had a higher degree of crystallinity. The results of differential scanning calorimetry (DSC) showed that the fermented fiber had better thermal stability. The results of functional characteristics showed that compared with unfermented IDF, the water-holding capacity, oil-holding capacity and water-swelling capacity of IDF fermented by Armillaria mellea increased by 74.2%, 93.6% and 124.38%, and all of the increases were higher than those in IDF fermented by the other three strains. Additionally, IDF fermented by Armillaria mellea had the highest glucose adsorption capacity (17.91–83.56 mg/g), glucose dialysis retardation index (GDRI, 30.29%–68.27%), cholesterol adsorption capacity (8.44 mg/g at pH 2.0, and 12.35 mg/g at pH 7.0), sodium cholate adsorption capacity (6.57–12.7 mg/g), nitrite adsorption capacity (1642.37 μg/g at pH 2.0, and 1249.13 μg/g at pH 7.0) and cation exchange capacity. In summary, fermentation by edible fungi can effectively improve the functional properties of ginseng insoluble dietary fiber, which will promote its application in foods.