Effect of nano‐TiO2‐LDPE packaging on microbiological and physicochemical quality of Pacific white shrimp during chilled storage

Nano‐TiO₂‐modified low‐density polyethylene (NTLDPE) packaging was prepared by blending LDPE with nano‐TiO₂. The effects of NTLDPE packaging on quality of Pacific white shrimp during storage at 4 °C were investigated. Results showed that NTLDPE lowered the K value by 28.50%, while increased sensory score by 30.77% in comparison with the control. NTLDPE packaging retarded the decrease of whiteness and water holding capacity and the increase of melanosis score based on the signs of freshness and deterioration of shrimp. Furthermore, NTLDPE packaging reduced total viable counts (TVC) by 6.42% and total volatile basic nitrogen (TVB‐N) contents were 14.82% lower than that of control. TVB‐N content and TBARS value, as well as polyphenol oxidase activity and TVC, were maintained and shrimp remained a commercial acceptability for 8 days. The overall results indicated that NTLDPE packaging could preserve the quality and extend the shelf‐life of Pacific white shrimp.     

Effects of TiO2–UVC photocatalysis and thermal pasteurisation on microbial inactivation and quality characteristics of the Korean rice‐and‐malt drink sikhye

Sikhye is a popular Korean rice‐and‐malt drink. This drink is prepared using a specific traditional process and has short shelf life. Commercial processing using ultra‐high temperature affects characteristic colour and flavour attributes and disturbs the traditional method of sikhye preparation. The objective of this study was to compare the effect of TiO₂–UVC photocatalysis (TUVP) nonthermal processing with heat‐pasteurised and untreated sikhye samples during storage at 4 and 10 °C. TUVP and heat treatments were both sufficient to inhibit regrowth of total aerobic bacteria and coliform during storage. Hunter colour parameter values showed that the colour of sikhye was less affected by TUVP treatment compared to the heat treatment. Higher sensory scores for flavour, taste and overall preference were attained for low‐dosage TUVP‐treated (0.24 J cm^?2) samples than for heat‐treated samples but without a significant difference. TUVP treatment effectively controlled the microbial growth during storage at 4 °C for more than 18 days which was reported a serious microbiological safety issue. In summary, TUVP showed its suitability for commercialisation possibilities of fresh sikhye drink by inactivating the main micro‐organisms and thus increasing significantly its shelf life with minimum impact on quality characteristics.     

纳米二氧化钛改性及其在皮革工业中应用的研究进展

简述了纳米二氧化钛的性质,重点综述了纳米二氧化钛的改性方法及其在皮革制造业中应用的研究进展。对不同改性方法进行了比较,指出其发展方向,并展望了纳米二氧化钛在皮革中的应用前景。     

纳米TiO2光催化器件的研究进展

印染废水成分复杂、难降解,是工业废水的主要污染源之一.光催化技术是一种新兴的高效节能现代污水处理技术,利用光催化器件解决废水处理问题必然成为未来的发展方向.综述了纳米TiO2的负载、器件用纳米TiO2结构单元的制备方法以及纳米TiO2器件的研究情况.     

High Concentration of Epigallocatechin‐3‐Gallate Increased the Incidences of Arrhythmia and Diastolic Dysfunction Via β2‐adrenoceptor

Epigallocatechin‐3‐gallate (EGCG) is the major and most potent representative in green tea, which has been proved to modulate myocardial contractility. Whether EGCG has some negative effects on cardiac function is not known. In the present study, we investigated the effects of EGCG at different doses on cardiac contraction and explored whether β₂‐adrenoceptor (β₂AR) was involved in EGCG‐induced cardiac effects. Isolated rat hearts were mounted on the Langendorff system and perfused with different concentrations of EGCG in low or normal calcium Krebs–Henseleit (KH) buffer. The contraction of hearts was measured. Ventricular myocytes were cultured with EGCG and isoprenaline (ISO, 10^?7 M) for 12 h. ICI118,551 (55 nM) was used to inhibit β₂AR. Cardiomyocyte shortening, viability, and responsiveness to ISO (10^?9 M) were measured. EGCG dose dependently enhanced contractility of perfused heart in low calcium KH buffer. In the normal calcium KH buffer, EGCG at low dose (20 μM) increased heart contraction, while at high dose (50 μM), it increased the incidences of arrhythmia and diastolic dysfunction. In isolated ventricular myocytes, EGCG at the concentration of 0.001 to 1.0 μΜ did not affect their contraction. However, the responsiveness to ISO and the survival of myocytes were increased by EGCG (0.01 μM). The increased responsiveness was partially abolished by ICI118,551. The data obtained in this study demonstrated that EGCG at low dose conferred cardioprotection, yet at high dose increased the incidences of arrhythmia and diastolic dysfunction. β₂AR was involved in EGCG‐induced cardiac effects.     

SO32– effects the 5‐hydroxymethyl‐2‐furaldehyde content in ammonium sulphite–glucose solutions

Effects of sulphite concentration on ammonium sulphite–glucose solution’s pH value and browning intensity were studied. Results showed both the solution’s pH value and browning intensity changed significantly in relation to the increases in SO₃^2– concentration. 5‐hydroxymethyl‐2‐furaldehyde was measured by nuclear magnetic resonance and HPLC. This study indicates that the changes of 5‐hydroxymethyl‐2‐furaldehyde content accompanied changes in browning intensity. Moreover, adding ammonium sulphite significantly reduced the 5‐hydroxymethyl‐2‐furaldehyde content. The mechanism may be that SO₃^2– limits the formation of N‐glucosamine, an important precursor for forming 5‐hydroxymethyl‐2‐furaldehyde, by reacting with glucose, which could not form an imine in further reaction.