Development of glucomannan-chitosan interpenetrating hydrocolloid networks (IHNs) as a potential tool for creating satiating ingredients

Preparation and Characterization of Lactobacilli-Loaded Composite Films with Sustaining Antipathogenic Activity and Preservation Effect

Bioactive composite films were obtained by adding Lactobacillus paracasei into a hydroxypropyl cellulose (HPC)-konjac flour (KF) matrix through a casting method. The mechanical, optical, and barrier properties were tested to determine the influence of the addition of lactobacilli into complex films. For purpose of evaluating the surface morphology of the composite films, scanning electron microscopy and atomic force microscopy were carried out. Fourier transform infrared spectroscopy and X-ray diffraction analyses were conducted to evaluate intermolecular interactions and crystallinity, respectively. Moreover, the microbial viability of the lactobacilli and the antibacterial activities of the bioactive films against pathogenic organisms were measured. The results indicated that the mechanical properties, crystalline properties, oxygen permeability, and color characteristics were not notably altered; nevertheless, the gloss and water vapor barrier properties were relatively weakened by the incorporation of L. paracase. The HPC-KF-L. paracasei films were effective in inhibiting both gram-positive (Listeria monocytogenes, Staphylococcus aureus) and gram-negative (Escherichia coli, Salmonella typhimurium) pathogens, and the films can retain physical property and antibacterial activity within a storage period of 30 days. The composite films, acting as suitable carriers for L. paracasei and possessing noteworthy bacteriostatic activities, could be developed as bioactive packaging for preserving food.

PRACTICAL APPLICATION

For the sake of the high desires of consumers for food safety and quality, the development of innovative bioactive packaging has attracted wide attention. In this work, the prepared films containing lactic acid bacteria showed great physical property, antipathogenic activity, and fresh-keeping property preservation, and have great application potential in fresh food preservation.

Self-assembled gelatin-ι-carrageenan encapsulation structures for intestinal-targeted release applications

In this work, natural biopolymeric encapsulation structures were developed through the self-assembly of gelatin and ι-carrageenan in aqueous solutions. The interactions of this binary system and of a ternary system containing a polyphenol-rich extract were deeply explored for the development of intestinal delivery systems. The processing of the structures (extrusion vs. freeze-drying) greatly influenced release properties, explained by the specific interactions between gelatin and polyphenols, thus allowing for tuning the processing conditions depending on the desired target application. Release was further controlled by incorporating a divalent salt, giving raise to extract-loaded ι-carrageenan/gelatin capsules with adequate release profiles for intestinal targeted delivery. These results demonstrate the potential of exploiting biopolymer interactions for designing bioactive delivery systems using environmentally friendly processes which do not involve the use of toxic or harsh solvents or cross-linkers.

Aggregation and rheological behavior of soluble dietary fibers from wheat bran

The present study assesses the aggregation behavior of wheat bran arabinoxylan-rich soluble dietary fiber (SDF) fractions with diverse molecular weight and substitution in order to provide useful information to prevent the formation of a block network. In the present work, dynamic and static light scattering, diffusing wave spectroscopy, small amplitude dynamic rheology, atomic force microscopy, and the water-holding and swelling capacities were evaluated to assess the SDF aggregation behavior induced by intrinsic and extrinsic factors. Furthermore, the rheological behavior was explained by the physically cross-linked or interpenetrating hydrocolloid network established during SDF self-aggregation, dependent on its molecular structure. The results indicated that the SDF fractions exhibiting a high molecular weight and a lower substitution degree and di-substituted ratio led to more significant aggregation due to the formation of disordered tangles coupled with a more solid-like behavior. The obtained information will prove useful for the development of more stable and compatible SDF fractions.