Phenolic compounds participating in mulberry juice sediment formation during storage

Stability of Bioactive Compounds and Antioxidant Activity in Rosehip Juice (Rosa spp.)

Rosehip fruits, characterized by their high concentrations of bioactive compounds and antioxidant activity (AA), have been traditionally used to make jams, infusions, and juices. Thus, the objective of this research was to evaluate the stability of rosehip juice by determining the concentrations of bioactive compounds and total phenols and the AA using chromatographic and spectroscopic methods. The stability of the juice was evaluated with three treatments and different storage conditions, namely, unpasteurized-refrigerated, pasteurized-room temperature, and pasteurized-refrigerated, and measurements were taken for eight months. Individual and total phenolic compounds, evaluated by chromatographic methods, reported differences until the end of this study. The total phenolic compounds by Folin-Ciocalteu method presented an average decrease of 57% in the three treatments in relation to the initial conditions. On the other hand, the ascorbic acid content decreased considerably, disappearing at week six. Furthermore, for the unpasteurized-refrigerated and pasteurized-refrigerated samples, a correlation was found between flavonols, total phenols, ascorbic acid, and antioxidant activity determined by the TEAC method. For the pasteurized-room temperature samples, correlations were found between the levels of several flavonols, hydroxycinnamic acid, total phenols, and ascorbic acid and the antioxidant activity determined by the CUPRAC method. The stability of the compounds was mainly correlated with the storage conditions of the juice and not with pasteurization. The highest stability was observed for the unpasteurized-refrigerated and pasteurized-refrigerated samples. Although the concentrations of the compounds evaluated decreased during this study, significant levels of AA persisted, providing beneficial characteristics for consumer health.

Improving the quality of mandarin juice using a combination of filtration and standard homogenization

Cloud loss and pulp precipitation are serious quality defects of mandarin juice (MJ) which brake on industrialization and need to be overcome by developing stabilization process. Therefore, filtration (FT) and standard homogenization (SH) on improving the cloud stability of MJ and minimizing the loss of major qualities were investigated. The FT-SH combined treatment effectively decreased the minimal particle size below 15 μm and sedimentation rate by 17.30%-74.40%, and increased the cloud value from 7.97% to 332.57%, results in more uniformity and cloud stability of MJ. Moreover, FT reduced the pectin methylesterase (PME) activity by 34.19%-50.96%, browning (ΔE^∗ < 3), free and bound phenol contents (27.81% and 59.13%), and aroma intensity (p < 0.05). SH released the free phenols from bound phenols association with cloudiness. The optimum stabilization condition was considered as the 100-mesh + 20 MPa that was obviously improved the cloudiness and minimizing the color, polyphenol and aroma loss.

Mulberry vinegar attenuates lipopolysaccharide and interferon gamma-induced inflammatory responses in C6 glial cells

The present study evaluated the effect of mulberry vinegar (MV) on the regulation of the inflammatory responses using C6 glial cells. Treatment with lipopolysaccharide (LPS) and interferon-γ (IFN-γ) induced the nitric oxide and reactive oxygen species generation, while pre-incubation with MV inhibited these formations in a concentration-dependent manner. MV treatment also decreased the production of pro-inflammatory cytokines, such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α in C6 glial cells stimulated by LPS/IFN-γ. Compared to the LPS/IFN-γ-treated control group, the MV-treated group exerts downregulation in the protein expressions of inducible nitric oxide synthase and cyclooxygenase-2, through inhibition of nuclear factor-κB activation. Protein expressions of glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1 were also decreased in the MV-treated group. These findings suggest that MV prevents neuroinflammation by regulating the NF-κB signaling pathway and glial activation. PRACTICAL APPLICATION: Mulberry fruits (Morus alba L.) have been commonly consumed as juice or jam. It is a rich source of anthocyanins that might be associated with beneficial effects on human health, including the anti-oxidant, anti-inflammatory, anti-obesity, and anti-diabetic effects. Mulberry vinegar was produced by alcohol and acetic fermentation of mulberry juice, and they possessed a protective effect against LPS/IFN-γ-stimulated inflammatory responses in glial cells via regulation of glial activation and NF-κB signaling pathway (i.e., downregulation of iNOS, COX-2, TLR4, p-IκB, and NF-κB p65 protein expressions). Although further research especially animal and clinical trials are still necessary, the present study will be helpful to scale-up the production of functional vinegar with neuroprotective and anti-inflammatory properties using mulberry.

Analysis of Key Chemical Components in Aqueous Extract Sediments of Panax Ginseng at Different Ages

Panax ginseng beverages have been some of the most popular plant drinks among consumers in recent years, but they become turbid and sediment are easily formed during production and marketing, these are some of the key issues that affect the quality of the beverages. In this study, we analysed the physicochemical properties of sediments in aqueous extracts of 3- to 6-year-old ginseng, and by tracing the sediment formation process from 0-40 days, we observed that the sediment was gradually beginning on day 10. The solid content of ginseng aged 5 and 6 years was significantly higher than that of ginseng aged 3 and 4 years. There was no significant difference in the sediment amount sediment in the extracts of ginseng of different ages. The light transmittance of the extracts after centrifugation was significantly higher than before centrifugation. Colour-difference analysis found that there was a significant positive correlation between ginseng age and colour-difference value (ΔE). Chemical composition analysis showed that total sugar and proteins were the main components of the sediment. In addition, ginsenosides, amino acids and minerals were also involved in sediment formation to different degrees. A stepwise regression model was established through principal component analysis (PCA), and the regression equation for predicting the sediment amount was obtained as follows: sediment amount (mg/mL) = 2.906 - 0.126 × C_{Total saponins} - 0.131 × C_{Free amino acids}.

Changes in content of bioactive constituents and antioxidant activity of riceberry after food processing and degradation kinetics during storage

The effect of roasting temperature (70, 120, 140°C) and food processing (soaking, steaming, and roasting) on the content of bioactive constituents (total phenolic content, total flavonoid content, total anthocyanin, and γ-oryzanol) and antioxidant activity of processed riceberry were investigated. In addition, the degradation kinetics of bioactive constituents and antioxidant activity during storage were assessed using zero-order and first-order kinetic models. Results showed riceberry roasted at 120°C had the highest total anthocyanin content and antioxidant activity. In addition, riceberry obtained from roasting exhibited the highest bioactive compound and antioxidant activity. Besides, first-order kinetic was confirmed as the best-fitted model to describe degradation of bioactive constituents and antioxidant activity of processed riceberry during storage. This finding suggested that roasting at 120°C was chosen as an optimum condition to maximize the content of bioactive constituents and antioxidant activity and kinetic models provided a better understanding of antioxidant property reduction of processed riceberry during storage. PRACTICAL APPLICATION: Riceberry is an abundant source of bioactive constituents with beneficial health effects leading to a development of functional food product. However, processing may negatively affect biological properties of riceberry and bioactive constituent degradation of processed riceberry during storage has not been previously reported. Therefore, different processes were investigated to determine the effect on bioactive constituents and antioxidant activity of riceberry, and the degradation kinetic model of bioactive constituents during storage was also studied. Optimum processing is appropriate to design riceberry containing high concentration of bioactive constituents and antioxidant activity, which could be considered as a functional diet for health-conscious consumer.

Cranberry (Vaccinium macrocarpon) Juice Precipitate Pigmentation Is Mainly Polymeric Colors and Has Limited Impact on Soluble Anthocyanin Loss

Anthocyanins degrade in fruit juice during storage, reducing juice color quality and depleting the health-promoting components of juice. Common water-soluble products of anthocyanins' chemical degradation are known, but little is known about the contribution of the insoluble phase to loss processes. Cranberry juice and isolated anthocyanins were incubated at 50 °C for up to 10 days to determine polyphenol profiles and degradation rates. Anthocyanin-proanthocyanidin heteropolymers were analyzed via Matrix Assisted Laser Desorption/Ionization (MALDI)- Time of Flight (TOF) Mass Spectrometry (MS). Formation of soluble protocatechuic acid accounted for 260 ± 10% and insoluble materials for 80 ± 20% of lost soluble cyanidin-glycosides in juice, over-representations plausibly due to quercetin and (epi)catechin in cranberry juice and not observed in the values of 70 ± 20% and 16 ± 6% in the purified anthocyanin system. Loss processes of soluble peonidin-glycosides were better accounted for, where 31 ± 2% were attributable to soluble vanillic acid formation and 3 ± 1% to insoluble materials in cranberry juice and 35 ± 5% to vanillic acid formation and 1.6 ± 0.8% to insoluble materials in the purified anthocyanin system. Free anthocyanins were below quantifiable levels in precipitate, implying most anthocyanins in precipitate were polymeric colors (PCs). PCs in the precipitate included cyanidin- and peonidin-hexosides and -pentosides covalently bonded to procyanidins. Therefore, formation of cranberry juice precipitate does not deplete a large portion of soluble anthocyanins; rather, the precipitate's pigmentation results from PCs that are also present in the soluble phase.

Formation and Characterization of Irreversible Sediment of Ginseng Extract

Sediment is a key issue in the beverage industry. This study confirmed that reversible and irreversible sediments were formed during low-temperature storage of ginseng extract. The first 30 days of storage are the critical period for sediment formation. As the time of storage extends, the chemical composition changes. The composition interaction model verified that the cross-linking of protein-pectin, protein-oxalic acid and Ca2+-pectin was the main cause of the turbidity of ginseng extract. Based on the characterization of irreversible sediment (IRS), there are typical structures of proteins, polysaccharides and calcium oxalate dihydrate (COD) crystals. Glucose, galacturonic acid, aspartate, glutamic acid, leucine, Ca, K, Al, Mg, Na and Fe are the main monomer components. Effective regulation of these ingredients will greatly help the quality of ginseng beverages.

Identification of Stabilization of Malvid Anthocyanins and Antioxidant Stress Activation via the AMPK/SIRT1 Signaling Pathway

Vitis amurensis Rupr. "Beibinghong" is abundant in anthocyanins, including malvidin (Mv), malvidin-3-glucoside (Mv3G), and malvidin-3,5-diglucoside (Mv35 G). Anthocyanins offer nutritional and pharmacological effects, but their stability is poor. Interaction of malvid anthocyanins with caffeic acid through ultrahigh pressure technology produces stable anthocyanin derivatives. This study aims to identify the structure of stable mallow-like anthocyanins and to determine the effect of these stable anthocyanins on human umbilical vein endothelial cells (HUVECs) with H₂O₂-induced oxidative damage and the signaling pathway involved. The products of malvid anthocyanins and caffeic acid bonding were identified and analyzed using ultra-high performance liquid chromatography-quadrupole-Orbitrap mass spectrometry (UPLC-Q-Orbitrap MS/MS). The bonding products were malvidin-3-O-guaiacol (Mv3C), malvidin-3-O-(6″-O-caffeoyl)-glucoside (Mv3CG), and malvidin-3-O-(6″-O-caffeoyl)-5-diglucoside (Mv3C5G). An oxidative stress injury model in HUVECs was established using H₂O₂ and treated with Mv, Mv3G, Mv35 G, Mv3C, Mv3CG, and Mv3C5G at different concentrations (10, 50, and 100 μmol/L). Results showed that the above compound concentrations can significantly increase cell proliferation rate and reduce intracellular reactive oxygen species at 100 μmol/L. The effects of the most active products Mv and Mv3C on the AMP-activated protein (AMPK)/silencing information regulator-1 (SIRT1) pathway were analyzed. Results showed that Mv and Mv3C significantly increased SOD activity in the cells and significantly upregulated the expression of SIRT1 mRNA, SIRT1, and p-AMPK protein. However, they did not significantly change the expression of AMPK protein. After the silent intervention of siRNA in SIRT1 gene expression, the upregulation of SIRT1 and p-AMPK protein by Mv and Mv3C was significantly inhibited. These results indicate that stabilization malvid anthocyanins exerts an antioxidant activity via the AMPK/SIRT1 signaling pathway.

Optimization of pectinase-assisted extraction condition of mulberry (Morus alba L.) fruit using response surface methodology and its effect on anthocyanin synthesis pathway-related metabolites

Mulberry (Morus alba L.) fruit (MF) is a rich source of functional compounds, such as anthocyanin. However, during solvent extraction, these compounds are not fully dispersed into the substrate, leading to incomplete extraction. Moreover, raw MF rapidly ripens and deteriorates after harvesting; hence, innovative methods to process MF are needed. Here, a pectinase-assisted extraction method is developed to liberate polyphenols and anthocyanins from cell wall matrices in MF. We optimized the procedure to maximize water solubility index (WSI), total phenolic (TP) content, and total anthocyanin (TA) content using a central composite design to perform a response surface methodology (RSM) analysis. The optimal conditions predicted by the RSM were a 1:5 w/v material/water ratio with 3.5% pectinase (v/w) and 1.5% citric acid (w/w) for 113 min at 50°C. Under these conditions, the WSI, TP, and TA were significantly higher compared with those in the untreated control. The results well matched (within 5% differences) with the predicted RSM values. Furthermore, metabolite analysis revealed that the levels of cyanidin-3-O-glucoside, delphinidin hexoside, and quercetin were higher in pectinase-assisted MF extraction compared with the untreated control. This work demonstrated that pectinase-assisted extraction using citric acid could be an efficient technique to enhance the value of MF and its potential applications in the food industry. PRACTICAL APPLICATION: A pectinase-assisted extraction method was optimized to enhance the WSI, TP, and TA yields from MF extracts. The optimal conditions were predicted to be 1:5 w/v material/water ratio, 3.5% pectinase (v/w), and 1.5% CA (w/w) with a 113 min reaction time at 50°C. Under these conditions, WSI, TP, and TA were significantly increased compared with the untreated control. These results suggested the potential of mulberry plants for use in the food industry via the development of a simple, efficient process to extract functional compounds from MF.