A method for gel grade determination and application evaluation of two citrus pectins.

Citrus paradisi Macf. cv. Changshanhuyou and Citrus paradisi Macf. cv. Star Ruby are two emerging processed citrus fruits. The processing produces lots of peel wastes rich in pectin. While more attentions were paid on pectin's functional properties, the quality about commercial application like gel grade was little investigated. In this study, we established a method for gel grade determination based on texture analyzer, the new method is economical and can be used on a large scale in the laboratory. The commercial application related qualities of two citrus pectins were also studied in detail. The results showed that the yields of Changshanhuyou and Star Ruby pectins (CHP and SRP) were 20.23 % and 18.33 %, respectively. The indexes of CHP and SRP mostly were in line with the commodity standards, except the dry weight loss. The gel grades of CHP and SRP determined by the new method were 109.9 and 96.8, respectively. The CHP aqueous solution exhibited higher apparent viscosity and better performance in stabilizing acidified milk drink (AMD) compared with commercial pectin. From the view of commercial application related qualities and functional properties, CHP could be a good potential commercial pectin.

Study on Black Spot Disease Detection and Pathogenic Process Visualization on Winter Jujubes Using Hyperspectral Imaging System.

In this work, the potential of a hyperspectral imaging (HSI) system for the detection of black spot disease on winter jujubes infected by Alternaria alternata during postharvest storage was investigated. The HSI images were acquired using two systems in the visible and near-infrared (Vis-NIR, 400-1000 nm) and short-wave infrared (SWIR, 1000-2000 nm) spectral regions. Meanwhile, the change of physical (peel color, weight loss) and chemical parameters (soluble solids content, chlorophyll) and the microstructure of winter jujubes during the pathogenic process were measured. The results showed the spectral reflectance of jujubes in both the Vis-NIR and SWIR wavelength ranges presented an overall downtrend during the infection. Partial least squares discriminant models (PLS-DA) based on the HSI spectra in Vis-NIR and SWIR regions of jujubes both gave satisfactory discrimination accuracy for the disease detection, with classification rates of over 92.31% and 91.03%, respectively. Principal component analysis (PCA) was carried out on the HSI images of jujubes to visualize their infected areas during the pathogenic process. The first principal component of the HSI spectra in the Vis-NIR region could highlight the diseased areas of the infected jujubes. Consequently, Vis-NIR HSI and NIR HSI techniques had the potential to detect the black spot disease on winter jujubes during the postharvest storage, and the Vis-NIR HSI spectral information could visualize the diseased areas of jujubes during the pathogenic process.

Assessment of the optical properties with physicochemical properties and cell wall polysaccharides of 'Korla' pear flesh during Alternaria alternata-induced disease development.

Cell wall polysaccharides and physicochemical properties are the major quality characteristics of fruit, but they are significantly affected by the postharvest disease. In this study, the influence of Alternaria alternata-induced disease on the contents of cell wall polysaccharides and physicochemical properties in 'Korla' pear flesh during storage, as well as their relationships of the optical absorption (µa) and reduced scattering (µs') were explored. The infected pear had lower individual sugars, covalent-soluble pectin, cellulose and hemicellulose contents than the healthy ones. The successive decreases of µa and increases of µs' in pears were observed while the process of pathogen infection. Path-coefficient analysis indicated the ionic-soluble pectin was the main reason responsible for the change of µs' in infected pear at 675 nm and 980 nm. This study indicated the optical properties have the possibility to present the physicochemical characteristics and cell wall polysaccharides of pears during postharvest pathogen infection.

Detection of Alternaria alternata infection in winter jujubes based on optical properties and their correlation with internal quality parameters during storage.

In this work, a single integrating sphere system was applied to characterize the optical absorption (µa) and reduced scattering (µs') properties (550 - 1050 nm) in winter jujube flesh infected by Alternaria alternata during storage at 4 and 20 °C, respectively. Meanwhile, physical (L*, a*, weight loss) and biochemical characteristics (soluble solids content, titratable acids, chlorophyll, total phenolic, and ascorbic acid) of winter jujubes were measured. Among them, chlorophyll, weight loss and ascorbic acid were highly correlated with µa at 680 nm, 690 nm, while chlorophyll and a* had the best correlations with µs' at 700 - 920 nm. These optimal optical properties were proved efficiently contributed to the disease detection of winter jujubes after 12 days at 4 °C and 3 days at 20 °C during storage, with satisfactory discrimination accuracies (acc > 93.75 %). Consequently, optical properties in Vis-NIR region were available to detect the postharvest disease in winter jujubes.

Dietary supplementation with polysaccharides from Ziziphus Jujuba cv. Pozao intervenes in immune response via regulating peripheral immunity and intestinal barrier function in cyclophosphamide-induced mice.

Ziziphus Jujuba cv. Pozao has been consumed as a traditional fruit with regional characteristics in China for a long time; however, fewer studies on polysaccharides from Ziziphus Jujuba cv. Pozao (JP) have been documented. This study aimed to evaluate the effect of oral administration of JP on cyclophosphamide-induced ICR mice for 28 days. The results showed that oral administration of JP could significantly improve the lymphocyte proliferation in the spleen and decrease the proportion of CD3+ and CD4+ and the ratio of CD4+/CD8+ in cyclophosphamide-induced mice in a dose-dependent manner. JP treatment also increased the levels of IL-2, IL-4, IL-10, IFN-γ, and TNF-α in serum and the intestine, and the improvement effects were proportional to the dose of JP. Similarly, JP significantly increased the levels of IgA and SIgA, as well as the expressions of Claudin-1 and Occludin in the intestine. Particularly, the expressions of Claudin-1 and Occludin were the best in the M-JP group. Furthermore, JP positively regulated the gut microbiota as indicated by the enriched microbiota diversity. At the phylum level, the relative abundance of Firmicutes was significantly decreased by JP, while that of Bacteroidetes was increased by JP treatment. More importantly, the ratio of Firmicutes/Bacteroidetes was significantly increased. And a high dose of JP is the most effective. At the genus level, the abundances of the Bacteroidales-S24-7-group, Lachnospiraceae, Alloprevotella, Alistipes and Bacteroides were increased by JP treatment. These results provided evidence for the regulating effect of JP on the peripheral immunity and intestinal barrier function in cyclophosphamide-induced hypoimmune mice.

Anti-atherosclerosis of oligomeric proanthocyanidins from Rhodiola rosea on rat model via hypolipemic, antioxidant, anti-inflammatory activities together with regulation of endothelial function.

BACKGROUND: Rhodiola rosea has been used as a traditional medicine for a long history. Previous studies on oligomeric proanthocyanidins from Rhodiola rosea (OPCRR) have showed that it exhibited significant free radical-scavenging activities, antioxidant activities in aging mice and lipid lowering effects. HYPOTHESIS/PURPOSE: We hypothesized that OPCRR can improve the atherosclerosis pathological in rats. In the present study, we investigated the effects of OPCRR on the serum lipid profiles, oxidant stress status, inflammatory cytokines and atherosclerotic mediators, and endothelial dysfunction as well as changes in abdominal aorta of atherosclerosis rats. METHODS: The major components of OPCRR were analyzed by using infrared spectrum and HPLC-ESI-MS. The atherosclerosis rat model was induced by high fat and vitamin D3 feeding for 9 weeks and two OPCRR doses (60 and 120 mg/kg b.w.) were orally administered daily for 9 weeks. The rats were then sacrificed and the blood was collected via abdominal aorta and serum was separated by centrifugated for biochemical analysis. Part of the aorta tissues were excised immediately for histopathological examination and western blotting. RESULTS: Compared to model group, OPCRR treatments significantly decreased the serum lipid profiles including total cholesterol, total triglycerides, low-density lipoprotein cholesterol (LDL-C) and ox-LDL and increased the high-density lipoprotein cholesterol (HDL-C); significant increased serum antioxidant enzymes (SOD and GSH-Px) and decrease of MDA content as a product of lipid peroxidation; lowered serum levels of TNF-α, IL-1ß, IL-6, ICAM-1 and VCAM-1 and enhanced IL-10 level; increased the serum release of nitric oxide and expression of iNOS in aortic, whereas decreased the expression of eNOS. CONCLUSION: OPCRR can improve the progress of atherosclerosis by regulation of lipid metabolism, restoring of the antioxidant capacities, and attenuation of pro-inflammatory cytokines and chemcytokines release, and improving the endothelial dysfunction indicated by nitric oxide system.