PET和PA纤维的原液染色与纺织品染色:对立还是互补

比较了PET和PA纤维的原液染色与纺织品染色.详细描述了原液染色和纺织品染色的优缺点.讨论了汽车用染色物品的着色和色彩协调.介绍了Clariant产品(瑞士)公司开发的"可染色的"颜料.     

Process optimization and stability of d-limonene nanoemulsions prepared by catastrophic phase inversion method

The aim of this study was to optimize the process and stability of d-limonene nanoemulsions. The nanoemulsions were prepared by catastrophic phase inversion method using Tween 80 as surfactant. According to the results, the SOR value would considerably affect the turbidity and the mean particle diameter of emulsions. At a high concentration of surfactant (S/O = 1.5), d-limonene nanoemulsions could be obtained. In addition, the formation of nanoemulsions may be primarily related to the viscosity of oil phase. When the oil phase contained less than 15% (w/w) olive oil, the nanoemulsions could be prepared. The turbidities and the mean particle diameters of d-limonene nanoemulsions with adding the same concentration of different plant oils were similar. Furthermore, it can be found that adding olive oil could enhance the stability of d-limonene nanoemulsion system and decrease Ostwald ripening rate, and the Ostwald ripening rate of d-limonene nanoemulsion at 4 °C was higher than that at 28 °C.     

Food-compatible method for the efficient extraction and stabilization of cranberry pomace polyphenols

Cranberry pomace is a byproduct of cranberry processing and is comprised of seeds, skins and stems of the cranberry fruit. While cranberry pomace contains beneficial polyphenols, including proanthocyanidins and anthocyanins, it is not a palatable source of these compounds and is typically discarded. In this study, we have developed and optimized a method to extract polyphenols from cranberry pomace using aqueous ethanol, a food grade solvent. Biochemical characterization of the pomace extract showed the presence of a broad range of polyphenols also present in cranberry juice concentrate. By co-drying cranberry pomace extract with a protein-rich food matrix, such as soy protein isolate (SPI), we have developed a method to produce a cranberry polyphenol–SPI complex (CBP-SPI) containing 10% cranberry polyphenols. Unlike dried cranberry pomace extract alone, proanthocyanidins, anthocyanins and total polyphenols were found to be highly stable at 37 °C in the CBP-SPI powder. The extraction and stabilization of cranberry pomace polyphenols using SPI provides an innovative approach for utilizing pomace in the development of novel food ingredients.     

Effects of organic carbon supply rates on uranium mobility in a previously bioreduced contaminated sediment

Bioreduction-based strategies for remediating uranium (U)-contaminated sediments face the challenge of maintaining the reduced status of U for long times. Because groundwater influxes continuously bring in oxidizing terminal electron acceptors (O2, NO3(-)), it is necessary to continue supplying organic carbon (OC) to maintain the reducing environment after U bioreduction is achieved. We tested the influence of OC supply rates on mobility of previously microbial reduced uranium U(IV) in contaminated sediments. We found that high degrees of U mobilization occurred when OC supply rates were high, and when the sediment still contained abundant Fe(III). Although 900 days with low levels of OC supply minimized U mobilization, the sediment redox potential increased with time as did extractable U(VI) fractions. Molecular analyses of total microbial activity demonstrated a positive correlation with OC supply and analyses of Geobacteraceae activity (RT-qPCR of 16S rRNA) indicated continued activity even when the effluent Fe(II) became undetectable. These data support our hypothesis on the mechanisms responsible for remobilization of U under reducing conditions; that microbial respiration caused increased (bi)carbonate concentration and formation of stable uranyl carbonate complexes, thereby shifted U(IV)/U(VI) equilibrium to more reducing potentials. The data also suggested that low OC concentrations could not sustain the reducing condition of the sediment for much longer time. Bioreduced U(IV) is not sustainable in an oxidizing environment for a very long time.     

Determination of anthocyanins in various cultivars of highbush and rabbiteye blueberries

Anthocyanins were identified and quantified in various cultivars of blueberries grown in Australia. Those were Crunchie, Star and Sharpe (highbush, Vaccinium corymbosum L.) and Climax, Powderblue and Brightwell (rabbiteye, Vaccinium ashei). A method was developed involving liquid chromatography–mass spectrometry and UV–visible spectroscopy. The repeatability of injection was less than 2% relative standard deviation (RSD) while the repeatability of sample preparation was less than 10% RSD in most cases. The method was linear between 7% and 100% of the original concentration. The anthocyanin profile was similar in all cultivars but proportions of each compound were cultivar-dependent. Highbush had more early eluting peaks, i.e. more polar anthocyanins, than rabbiteye cultivars. Delphinidin, petunidin and malvidin were the major contributors to total anthocyanin content. Climax had the highest total anthocyanin content (13.7 ± 1.4 g cyanidin 3-glucoside equivalent kg⁻¹ dry weight) and antioxidant activity (using 2,2-diphenyl-1-picrylhydrazyl as a free radical) of all tested cultivars. Rabbiteye had significantly higher total anthocyanin content than the highbush cultivars.     

Effect of muscle,ageing time and modified atmosphere packaging conditions on the colour,oxidative and microbiological stability of packed beef

The objective of this study was to evaluate the influence of two different vacuum ageing times (7 and 14 days) and the impact of the modified atmosphere packaging (MAP) configuration (gas/product ratios: 0.5 and 1 and gas composition: 70% O₂ + 30% CO₂ and 40% O₂ + 30% CO₂ + 30% N₂) on the quality of fresh beef during subsequent storage at 4 °C. For this purpose, three separate experiments were performed. For each experiment, two different muscles (Longissimus dorsi and Biceps femoris) were sampled from four double‐muscled Belgian Blue beef carcasses. Next to colour, also the evolution in microbial load, pH, O₂ and CO₂ in the headspace and lipid oxidation at the meat surface were evaluated. A vacuum ageing for 14 days compared with 7 days resulted in a higher initial microbial load on the day of MAP packaging, which resulted finally in a significantly shorter shelf life. This ageing effect was less pronounced on the colour stability and lipid oxidation of the meat samples. No significant influence of the packaging configuration on any of the analysed parameters (colour, microbial load, pH and lipid oxidation at the meat surface) was observed.     

Product-oriented flavor research: learnings from the past, visions for the future

In the past flavor research and the development of new flavorings were constantly driven by the interaction of flavor analysis, structure elucidation, and chemical synthesis accompanied by sensory. Highly potent flavor compounds were identified in numerous food products and helped to establish a powerful toolbox for flavorists. Nowadays we experience the merging of various scientific disciplines, for example medicine, biology, chemistry, and various technologies in the field of flavor research, which shows direct impact on our understanding of flavors. At the same time modern life has profoundly changed our eating habits. This situation generates new challenges for product development teams, which represent all facets of technologies. This paper will illustrate different examples for the evolution of product-oriented flavor research and future trends.     

Interactive Effects of Milk Fat Globule and Casein Micelle Size on the Renneting Properties of Milk

The size of the casein micelles (CM) and the milk fat globules (MFG) vary depending on farming factors, such as seasonal variation and stage of lactation, and cow genetics. The MFG and CM size of milk can influence the renneting behavior and texture of manufactured dairy products. In this work, we investigated the combined effects of MFG and CM size on the onset of gelation, the maximum rate of gelation, the value for G′_60 min (the final storage modulus) and G″_60 min (the final loss modulus), and tan δ upon renneting. Fractionation of MFG on the basis of size was carried out using laboratory-based centrifugation, whereas milk of predominantly large (184–218 nm) or small (147–159 nm) CM was selected naturally on-farm. Casein micelle size had the dominant effect on curd firmness and gelation rates of milk, where small CM milk formed rennet gels earlier and resulted in a firmer gel than milk with large CM. However, MFG size also influenced the renneting properties. The strongest rennet gels were obtained when large MFG (3.88–5.78 μm) was combined with small CM (153–159 nm). Selecting milk on the basis of the microstructure of key milk components could be achieved by natural selection of dairy cows or via fractionation technologies. Selection may provide a useful tool for efficient manufacturing of different dairy products based on the desirable characteristics specific to each.     

Capsule formation by nonropy starter cultures affects the viscoelastic properties of yogurt during structure formation

The aim of this work was to study the structure formation of yogurt made with cultures containing ropy Lactobacillus delbrueckii ssp. bulgaricus (R), capsule-forming nonropy Streptococcus thermophilus (CNR), and noncapsule-forming nonropy cultures (NCNR). Similar gelation profiles were shown for milk fermented by ropy and nonropy lactic cultures. The gelation point occurred at lower pH values in milk fermented with R or NCNR compared to that of milk fermented with CNR culture. Differences between capsule forming ropy and nonropy cultures were observed in the aggregation behavior of the caseins. Gels made with R culture had the highest maximum in loss tangent (tan delta). However, this maximum occurred at the highest pH value when CNR culture was used. The earlier gelation of milk fermented by the encapsulated nonropy strain of Strep. thermophilus resulted in increased structure rearrangement as the pH dropped, interfering with the formation of a more compact structure.