Extraction and Characterization of Pectin from Jerusalem ArtiChoke Residue and Its Application in Blueberry Preservation

Properties of konjac glucomannan/curdlan-based emulsion films incorporating camellia oil and the preservation effect as coatings on 'Kyoho' grapes

The strategy of emulsion coating was used for grape preservation. Camellia oil (CO) was incorporated with KGM/curdlan (KC) to fabricate KC-CO emulsion systems. KC-CO emulsions were analyzed by droplet size distribution and confocal laser scanning microscopy (CLSM), and KC-CO films were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), mechanical properties, dissolution, gas permeability, water contact angle (WCA). KC-CO coating was used for preservation of 'Kyoho' grapes. The results indicated that the addition of CO had a positive effect on KC system. CO could form a uniform emulsion with KC, and the droplets were evenly dispersed in the KC matrix. KC-CO films displayed a continuous microstructure, and elongation at break (EAB) was improved, while tensile strength decreased. The dissolution, water vapor permeability (WVP), and WCA were significantly enhanced, while the permeability of oxygen and carbon dioxide exhibited no advantage compared with KC film. KC-CO-10 possessed optimal properties and was selected as an emulsion coating for preservation. The results suggested that KC-CO-10 significantly maintained the appearance, total solid and acid content of 'Kyoho' grapes, and delayed the weight loss and firmness decrease. This study contributed to the understanding of polysaccharide-lipid emulsion system and the applications.

Nano-emulsification essential oil of Monarda didyma L. to improve its preservation effect on postharvest blueberry

The reduction in blueberry harvest due to pathogen infection was reported to reach 80%. Essential oil (EO) can provide a new way to preserve blueberry. Here, in search for plants volatiles with preservation ability, a novel device was designed for the screening of aromatic plants led to the discovery of hit plant Monarda didyma L. Consequently, antifungi activity of M. didyma EO (MEO) and its nano-emulsion (MNE) were tested. 2 species of pathogenic fungi were isolated from blueberries, namely Alternaria sp. and Colletotrichum sp. were used as the target strains. In the in vitro activity test, the pathogenic were completely inhibited when the EO was 4 µL or 1.0 µL/mL. Compared with EO, MNE exhibited superior antimicrobial activity. Moreover, MNE can cause serious morphological changes and result in a decrease in the rot and weightlessness rate of blueberry. Hence, NME represents a promising agent for the preservation of postharvest blueberry.

Application of Chitosan-Lignosulfonate Composite Coating Film in Grape Preservation and Study on the Difference in Metabolites in Fruit Wine

In order to solve the global problem of fruit rotting due to microbial infection and water loss after harvest, which leads to a large amount of food waste, this experiment uses degradable biological composite coating to prolong the preservation period of grapes. Chitosan (CH) and Lignosulfonate (LS) were used as Bio-based film materials, CH films, 1% CH/LS films and 2% CH/LS biomass composite films were synthesized by the classical casting method and applied to grape preservation packaging. Its preservation effect was tested by grape spoilage rate, water loss rate, hardness, soluble solids, titratable acid, and compared with plastic packaging material PE film. At the same time, 1H NMR technology combined with pattern recognition analysis (PCA) and partial least squares discriminant analysis (PLS-DA) was used to determine the nuclear magnetic resonance (NMR) of Cabernet Sauvignon, Chardonnay and Italian Riesling wines from the eastern foothills of Helan Mountain to explore the differences in metabolites of wine. The results of preservation showed that the grapes quality of CH films and 2% CH/LS coating package is better than the control group, the decay rates decreased from 37.71% to 21.63% and 18.36%, respectively, the hardness increased from 6.83 to 10.4 and 12.78 and the soluble solids increased from 2.1 in the control group to 3.0 and 3.2. In terms of wine metabolites, there are similar types of metabolites between cabernet Sauvignon dry red wine and Chardonnay and Italian Riesling dry white wine, but there are significant differences in content. The study found that 2% CH/LS coating package could not only reduce the spoilage rate of grapes, inhibit the consumption of soluble solids and titratable acids, but also effectively extend the shelf life of grapes by 6 days.