Association Between Family Atmosphere and Internet Addiction Among Adolescents: The Mediating Role of Self-Esteem and Negative Emotions.

Objectives: Family atmosphere is a significant predictor of internet addiction in adolescents. Based on the vulnerability model of emotion and the compensatory internet use theory, this study examined whether self-esteem and negative emotions (anxiety, depression) mediated the relationship between family atmosphere and internet addiction in parallel and sequence. Methods: A total of 3,065 Chinese middle school and high school students (1,524 females, mean age = 13.63 years, SD = 4.24) participated. They provided self-reported data on demographic variables, family atmosphere, self-esteem, anxiety, depression, and internet addiction through the Scale of Systemic Family Dynamic, Self-Esteem Scale, Self-Rating Anxiety Scale, Self-Rating Depression Scale, and Internet Addiction Test, respectively. We employed Hayes PROCESS macro for the SPSS program to scrutinize the suggested mediation model. Results: It revealed that self-esteem, anxiety, and depression mediated the relationship between family atmosphere and internet addiction in parallel and sequence. The pathway of family atmosphere-self-esteem-internet addiction played a more important role than others. Conclusion: The present study confirmed the mediating role of self-esteem and negative emotions between family atmosphere and internet addiction, providing intervention studies with important targeting factors.

Physiological and biochemical changes during fruit maturation and ripening in highbush blueberry (Vaccinium corymbosum L.).

The sweetness of blueberry fruit increases over time, as acids are converted to sugars, and full flavor development is formed by harvest. We comprehensively analyzed the changes and correlation in physiological and biochemical characteristics of blueberries at different maturity stages, including texture, quality, taste and energy change. Our analysis revealed that total anthocyanin content increased and firmness decreased as fruit ripened. Percent moisture, titratable acid (TA), chlorophyll and carotenoid content also decreased, while total soluble solids (TSS), pH, TSS/TA ratio, vitamin C, soluble proteins, and ethylene production all increased. Antioxidant enzyme activity gradually increased during ripening but energy-related metabolites decreased. The flavor attributes of sweetness, bitterness, and sourness were readily perceived using an electronic tongue and a total of 76 volatile compounds were detected by GC-MS. In summary, the maturation of blueberries was correlated with increases of anthocyanins, nutrients, antioxidant activity, taste and aroma, but negatively correlated with energy metabolism.

Quality Changes in Black Chokeberry Juice Treated by Thermal-Assisted High Hydrostatic Pressure during Cold Storage.

The effects of thermal-assisted high hydrostatic pressure (TAHHP), high hydrostatic pressure (HHP), and thermal pasteurization (TP) treatments on the quality of aronia juice were evaluated in this study. The results showed that TAHHP and HHP significantly decreased the aerobic plate counts of aronia juice. No significant differences in terms of physicochemical properties, such as pH and total soluble solids, were observed between aronia juice treated with high pressure or thermal pasteurization treatment after 28 days of storage. TAHHP and HHP affected the colour and antioxidant characteristics of aronia juice, though to a significantly lower extent than TP. This result demonstrates that TAHHP and HHP can better maintain the original quality of aronia juice than TP. In summary, both TAHHP and HHP can maintain the microbiological safety and original quality characteristics of aronia juice. TAHHP can effectively increase the safety and duration of cold storage of aronia juice, and hence is highly useful for the juice industry.

Integrative Physiological and Transcriptome Analysis Reveals the Mechanism for the Repair of Sub-Lethally Injured Escherichia coli O157:H7 Induced by High Hydrostatic Pressure.

The application of high hydrostatic pressure (HHP) technology in the food industry has generated potential safety hazards due to sub-lethally injured (SI) pathogenic bacteria in food products. To address these problems, this study explored the repair mechanisms of HHP-induced SI Escherichia coli O157:H7. First, the repair state of SI E. coli O157:H7 (400 MPa for 5 min) was identified, which was cultured for 2 h (37 °C) in a tryptose soya broth culture medium. We found that the intracellular protein content, adenosine triphosphate (ATP) content, and enzyme activities (superoxide dismutase, catalase, and ATPase) increased, and the morphology was repaired. The transcriptome was analyzed to investigate the molecular mechanisms of SI repair. Using cluster analysis, we identified 437 genes enriched in profile 1 (first down-regulated and then tending to be stable) and 731 genes in profile 2 (up-regulated after an initial down-regulation). KEGG analysis revealed that genes involved in cell membrane biosynthesis, oxidative phosphorylation, ribosome, and aminoacyl-tRNA biosynthesis pathways were enriched in profile 2, whereas cell-wall biosynthesis was enriched in profile 1. These findings provide insights into the repair process of SI E. coli O157:H7 induced by HHP.

Synergetic Inactivation Mechanism of Protocatechuic Acid and High Hydrostatic Pressure against Escherichia coli O157:H7.

With the wide application of high hydrostatic pressure (HHP) technology in the food industry, safety issues regarding food products, resulting in potential food safety hazards, have arisen. To address such problems, this study explored the synergetic bactericidal effects and mechanisms of protocatechuic acid (PCA) and HHP against Escherichia coli O157:H7. At greater than 200 MPa, PCA (1.25 mg/mL for 60 min) plus HHP treatments had significant synergetic bactericidal effects that positively correlated with pressure. After a combined treatment at 500 MPa for 5 min, an approximate 9.0 log CFU/mL colony decline occurred, whereas the individual HHP and PCA treatments caused 4.48 and 1.06 log CFU/mL colony decreases, respectively. Mechanistically, membrane integrity and morphology were damaged, and the permeability increased when E. coli O157: H7 was exposed to the synergetic stress of PCA plus HHP. Inside cells, the synergetic treatment additionally targeted the activities of enzymes such as superoxide dismutase, catalase and ATPase, which were inhibited significantly (p ≤ 0.05) when exposed to high pressure. Moreover, an analysis of circular dichroism spectra indicated that the synergetic treatment caused a change in DNA structure, which was expressed as the redshift of the characteristic absorption peak. Thus, the synergetic treatment of PCA plus HHP may be used as a decontamination method owing to the good bactericidal effects on multiple targets.

Exploring the biochemical properties of three polyphenol oxidases from blueberry (Vaccinium corymbosum L.).

Purification of blueberry polyphenol oxidase (PPO) has not been substantially progressed for a long time, which leads to little further study. We purified three PPOs from blueberries for the first time by modified Native-Page. The PPO-2 consists of two subunits (68 and 36 kDa), whereas PPO-3 and PPO-4 contain only one subunit (36 kDa). The optimum pH and temperature of PPO-2, PPO-3, and PPO-4 were 5.8-6.2 and 40 °C-45 °C with catechol as a substrate. The optimal substrates for them were all catechol (Km = 14.91, 7.19, and 11.20, respectively). High-pressure processing (HPP) had a limited inhibitory effect on the three PPOs. The activities of PPO-2, PPO-3, and PPO-4 were significantly reduced with increased SDS concentration. The binding of substrate to catalytic cavity is related to the residues His76, His209, His213, Gly228, and Phe230. The carbonyl group of residue Gly228 is one of the key sites for screening substrates.

Antimicrobial capacity of ultrasound and ozone for enhancing bacterial safety on inoculated shredded green cabbage (Brassica oleracea var. capitata).

The high frequency and incidence of foodborne outbreaks related to fresh vegetables consumption is a major public health concern and an economic burden worldwide. This study evaluated the effect of individual and combined application of ultrasound (40 kHz, 100 W) and ozone on the inactivation of foodborne Escherichia coli and Salmonella, as well as their impact on cabbage color and vitamin C content. Plate count, scanning electron microscopy (SEM), and flow cytometry (FCM) following single or double staining with carboxyfluorescein diacetate and (or) propidium iodide were used to determine bacterial inactivation parameters, such as cell culturability, membrane integrity, intracellular enzyme activity, and injured and dead cells. The results of FCM and SEM showed that ultrasound treatment affected bacteria mainly by acting on the cell membrane and inactivating intracellular esterase, which resulted in bacterial death. Furthermore, when combined with ozone at 1.5 mg/L, the maximum reduction of bacterial populations was observed at 8 min with no damage on the surface of treated leaves. Therefore, fresh products sanitization using a combination of ultrasound and ozone has the potential to be an alternative for maintaining the color and vitamin C content of green cabbage.

Effect of cold plasma on blueberry juice quality.

This work focusses on the effects of cold plasma, a novel, non-thermal technology, on the quality of blueberry juice, such as inactivation of Bacillus, anthocyanins, phenolics, vitamin C, antioxidant activity and color change. Oxygen concentration (0, 0.5% and 1%) of ionized gas was firstly confirmed to be the main factors for CP treatment, besides treatment time (2, 4 and 6 min). The increment of treatment time and oxygen concentration significantly promoted an increasing trend of death for Bacillus. Compared with thermal treatment, the content of phenolics was significantly increased by CP treatment, and also CP treatment could better keep the original color of blueberry juice. In terms of anthocyanin and vitamin C, relatively shorter exposure time to CP was more suggested. In antioxidant tests, increment of oxygen concentration resulted in the increasing trends of antioxidant activity in DPPH and ABTS assays.

Separation and preparation of 6-gingerol from molecular distillation residue of Yunnan ginger rhizomes by high-speed counter-current chromatography and the antioxidant activity of ginger oils in vitro.

Molecular distillation residue (MD-R) from ginger had the most total phenol content of 247.6mg gallic acid equivalents per gram (GAE/g) among the ginger oils. High-speed counter-current chromatography (HSCCC) technique in semi-preparative scale was successfully performed in separation and purification of 6-gingerol from MD-R by using a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (10:2:5:7, v/v/v/v). The target compound was isolated, collected, purified by HSCCC in the head-tail mode, and then analyzed by HPLC. A total of 90.38±0.53mg 6-gingerol was obtained from 600mg MD-R, with purity of 99.6%. In addition, the structural identification of 6-gingerol was performed by EI/MS, (1)H NMR and (13)C NMR. Moreover, the orders of antioxidant activity were vitamin E (VE)>supercritical fluid extraction oleoresin (SFE-O)=MD-R=6-gingerol>molecular distillation essential oil (MD-EO) and butylated hydroxytoluene (BHT)=VE>6-gingerol>MD-R=SFE-O>MD-EO, respectively in 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging and ß-Carotene bleaching.

Comparison of membrane-bound and soluble polyphenol oxidase in Fuji apple (Malus domestica Borkh. cv. Red Fuji).

This study compared membrane-bound with soluble polyphenol oxidase (mPPO and sPPO, respectively) from Fuji apple. Purified mPPO and partially purified sPPO were used. mPPO was purified by temperature-induced phase partitioning and ion exchange chromatography. The specific activity of mPPO was 34.12× higher than that of sPPO. mPPO was more stable than sPPO at pH 5.0-8.5. Although mPPO was more easily inactivated at 25-55 °C, it is still more active than sPPO in this temperature range. The optimum substrate of mPPO was 4-methyl catechol, followed by catechol. L-cysteine had the highest inhibitory effects on mPPO followed by ascorbic acid and glutathione. Surprisingly, EDTA increased mPPO activity. The results revealed that purified mPPO is a dimer with a molecular weight of approximately 67 kDa.