The Volatile Compounds Change during Fermentation of Saccharina japonica Seedling.

It is important to eliminate the fishy odor and improve the aroma quality of seafood. In this study, the Saccharina japonica (S. japonica) seedling, which is a new food material, was investigated for the effects of fermentation with Saccharomyces cerevisiae (S. cerevisiae) through sensory evaluation, GC-MS, and odor activity value (OAV) analysis. GC-MS analysis revealed the presence of 43 volatile compounds in the unfermented S. japonica seedling, with 1-octen-3-ol, hexanal, and trans-2,4-decadienal identified as the main contributors to its fishy odor. After fermentation with S. cerevisiae, 26 volatile compounds were identified in the S. japonica seedling. Notably, the major malodorous fish compounds, including 1-octen-3-ol, hexanal and trans-2,4-decadienal, were no longer present. The results indicate that fermentation with S. cerevisiae is an effective method for removing fishy malodor compounds and enhancing the volatile components with fruity, sweet, green, and floral notes in the Saccharina japonica seedling. This process facilitates the elimination of fishy malodor and enhance the fruity, sweet, green, and floral notes of S. japonica seeding and other seaweeds.

Development of antimicrobial packaging materials by incorporation of gallic acid into Ca2+ crosslinking konjac glucomannan/gellan gum films.

Antibacterial films were prepared by incorporating konjac glucomannan (KGM) and gellan gum (GG) as a matrix, glycerin as a plasticizer, CaCl2 as a cross-linking agent, and gallic acid as a natural antibacterial agent. Structure was analyzed by using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thermal stability of the blends was higher than pure GG, due to Ca2+ crosslinking between GG and KGM. Water contact angle and water vapor permeability were analyzed to determine hydrophobicity of films. Morphological studies revealed that surface compactness and homogeneity of blended films increased with KGM content. The addition of KGM improved the mechanical strength of films significantly. Moreover, KGM improved the release capacity of the blended films, while enhancing antimicrobial activity against Escherichia coli and Staphylococcus aureus. The antioxidant properties of gallic acid embedded in films were measured. Composite films containing 70 wt% KGM (Ca-KG7) displayed the best properties. These findings suggest an alternative method for synthesis of GG-based packaging films with improved properties.

Fabrication of chitosan-coated konjac glucomannan/sodium alginate/graphene oxide microspheres with enhanced colon-targeted delivery.

Microspheres play an increasingly important role in the food and medicine industries. In this study, konjac glucomannan (KGM)/sodium alginate (SA)/graphene oxide (GO) solution was injected into CaCl2 solution under high-voltage static electricity assistance to fabricate microspheres. Then, chitosan (CS) was coated on the surface of the microspheres to enhance their stability. SEM images confirmed that increasing voltage decreased the particle size of microspheres obviously. Furthermore, GO was beneficial in maintaining the full structure of freeze-dried microspheres, and the CS membrane improved the surface of the microspheres with no relatively obvious gully. Results indicated that KGM interacted with SA by hydrogen bond, and GO improved this interaction in microspheres. Furthermore, swelling tests showed that the microspheres exhibited different swelling properties in different media, and the CS membrane could improve the stability of microspheres in simulated intestinal fluid and simulated colon fluids. Moreover, GO could greatly improve the ciprofloxacin (CPFX) loading efficiency of microspheres, and achieving a sustained release effect of CPFX. Thus, CS-coated KGM/SA/GO microspheres showed great potential application in drug and/or nutrition factor colon-targeted delivery.

Effects of konjac glucomannan on the structure, properties, and drug release characteristics of agarose hydrogels.

Pure agarose (AG) hydrogels have strong rigidity and brittleness, which greatly limit their applications. Therefore, in this study, konjac glucomannan (KGM) was used to improve the properties of AG hydrogels. The effect of KGM on the structure and properties of AG hydrogels was investigated by rotational rheometry, Fourier Transform Infrared Spectroscopy, X-ray Diffraction, and Scanning Electron Microscopy. The results showed that the flexibility of the composite hydrogels increases with KGM concentration, which may be attributed to a synergistic interaction between KGM and AG resulting in a compact network structure. In vitro drug release behavior of composite hydrogels was investigated under different environments using model drug ciprofloxacin. The results showed that the encapsulation, drug loading efficiencies, and sustained release capacity of AG hydrogels were enhanced by the incorporation of KGM. These results suggested that KGM has the potential to enhance the properties and drug release characteristics of AG hydrogels.

Mussel-inspired fabrication of konjac glucomannan/microcrystalline cellulose intelligent hydrogel with pH-responsive sustained release behavior.

Intelligent hydrogels are attractive biomaterials for various applications, however, fabricating a hydrogel with both adequate self-healing ability and mechanical properties remains a challenge. Herein, a series of novel intelligent konjac glucomannan (KGM)/microcrystalline cellulose (MCC) hydrogels were prepared vis the mussel-inspired chemistry. MCC was firstly functionalized by the oxidative polymerization of dopamine, and the intelligent hydrogels were obtained by mixing aqueous solutions of KGM and functionalized MCC (PDMCC). By introducing PDMCC, a more compact interconnected porous structure formed for the resulting hydrogels. The self-healing ability and mechanical properties of intelligent hydrogels were dependence on the PDMCC content. Compared with KGM hydrogels, KGM/PDMCC hydrogels exhibited a more distinct pH sensitivity and a lower initial burst release, which was attributed to the compact structure and strong intermolecular hydrogen bond interaction between PDMCC and KGM. These results suggest that the KGM/PDMCC intelligent hydrogels may be promising carriers for controlled drug delivery.

Mussel-Inspired Fabrication of Konjac Glucomannan/Poly (Lactic Acid) Cryogels with Enhanced Thermal and Mechanical Properties.

Three-dimensional nanofibers cryogels (NFCs) with both thermally-tolerant and mechanically-robust properties have potential for wide application in biomedical or food areas; however, creating such NFCs has proven to be extremely challenging. In this study, konjac glucomannan (KGM)/poly (lactic acid) (PLA)-based novel NFCs were prepared by the incorporation of the mussel-inspired protein polydopamine (PDA) via a facile and environmentally-friendly electrospinning and freeze-shaping technique. The obtained KGM/PLA/PDA (KPP) NFCs were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and compressive and tensile test. The results showed that the hierarchical cellular structure and physicochemical properties of KPP NFCs were dependent on the incorporation of PDA content. Moreover, the strong intermolecular hydrogen bond interactions among KGM, PLA and PDA also gave KPP NFCs high thermostability and mechanically-robust properties. Thus, this study developed a simple approach to fabricate multifunctional NFCs with significant potential for biomedical or food application.