Papers by Keyword: Ripening

Abstract: Rheological properties, crystallization and ripening phenomena have been investigated for three different steel grades in the semi-solid state. For each steel grade detailed investigation has been performed via differential scanning calorimetry to quantify the solid fraction as a function of temperature. The experimental procedure for all samples has been as follows: the completely liquid samples were cooled with a constant rate under constant shearing to temperatures corresponding to solid fractions of 30 and 40%. Tracking the viscosity during this procedure allowed analyzing the crystallization kinetics and final ripening process, which differ for the different steel grades. Evaluating the viscosity data on the base of a combination of convection dominated ripening model and a modified Krieger-Dougherty equation gives valuable information of the microstructural evolution. This is validated by additionally quenching samples.

Abstract: The effects of high-pressure (HP) treatments (200, 300, 400 and 500MPa for 10 min, 2P to 5P) applied on day 1 to accelerate the ripening of hard cheeses. The proteolysis, lipolysis, texture and sensory properties were studied in 90 days at 10°C. HP treatments increased proteolysis and sensory properties at all stages of ripening in all treated cheeses, furthermore, higher hydrolysis and sensory properties were found in 3P cheeses. However, HP treatments had no positive effects on cheeses lipolysis development, especially, in 5P cheeses.

Abstract: Anthocyanins are the main pigments in flowers and fruits. In most cases, anthocyanin accumulation in fruit is highly controlled by the developmental level. In this study, the cDNA fragments of three genes, chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS), which are involved in the flavonoid pathway, were isolated from total RNA of strawberry ripe fruit by using polymerase chain reaction technique and labeled as probes to determine the expression of anthocyanin biosynthetic genes. Northern analysis showed that a correlation between anthocyanin accumulation and expression of the flavonoid pathway genes during the ripening of strawberry fruits. At the early stages of fruit development, the mRNA levels encoding CHS, DFR, ANS were high probably responsible for the accumulation of condensed tannins, but the levels decreased dramatically when fruits turned white from green. During the stage of pigment accumulation, their mRNA levels increased strongly to be involved anthocyanin biosynthesis. Difference of CHS in mRNA abundance was correlated with differential accumulation of anthocyanins throughout the process of fruit development. Therefore, CHS could be a key structure gene involved in anthocyanin synthesis. Furthermore, the co-ordination of expression of anthocyanin biosynthetic genes implied a common regulatory mechanism controlling the expression of structural genes in the flavonoid pathway.

Abstract: Chinese jujube (Zizyphus jujuba M) fruit at the postharvest stage was easily have a dramatic decline in quality. The effect of 1-MCP and CaCl2 in delaying fruit ripening and improving storage quality was investigated through this study. Chinese jujube fruit were harvested and then treated with 1µL L-1 1-MCP for 24 h at 20°C, immersed in 1% CaCl2 solution for 10min and their combination, then kept 0 °C and 80–90% RH after treatment. Results indicated that 1-MCP and CaCl2 were effective in terms of senescence inhibition during storage and compared to control, and the performance of 1-MCP was little better. Fruit treated with 1-MCP and CaCl2 had ability to maintain firmness, soluble solid concentration (SSC), weightlessness, membrane permeability. The ethylene production rates of jujube fruit were effected significantly by treatment with 1-MCP, not affected by CaCl2 treatment like control samples, however, they both had a visible influence on the content of MDA compared fruit with untreated. Furthermore, treatment with 1-MCP + CaCl2 resulted in additive beneficial effects on ripening inhibition of the fruit and maintaining the qulity of Chinese jujube fruit.

Abstract: An in-situ observation method for structures at high temperature is developed. The new observation device can reveal grain boundaries at high temperature and enables dynamic observation of these boundaries. Grain growth while maintaining microstructure at high temperature is observed by the new observation device with only one specimen for the entire observation, and grain sizes are quantified. The quantifying process reveals two advantages particular to the use of the new observation device: (1) the ability to quantify grain sizes of specified sizes and (2) the results of average grain size for many grains have significantly less errors because the initial structure is the same for the entire observation and the quantifying process. The new observation device has the function to deform a specimen while observing structures at high temperature, so that enables it to observe dynamic recrystallization of steel. The possibility to observe recrystallization is also shown.

Abstract: The influence of nonequilibrium vacancy distribution, generated by a difference of intrinsic fluxes of components under limited efficiency of vacancy sinks/sources, on various diffusion processes, is analyzed. Interdiffusion, reactive diffusion, reactive phase growth under electric current, spinodal decomposition, collapse of compound nanoshells, ripening are considered.

Abstract: Understanding porosity coarsening is essential for controlling the properties of sintered materials and for producing high density or near net shape parts. As porosity is interconnected up to relative densities in excess of 80% or even 95%, measuring, monitoring and modelling of the growth of individual pores is relevant only at very high relative densities. This paper tries to convey two essentials of porosity coarsening: (i) characterization of the geometry of the pore space in the lower range of densities is possible by using stereological parameters, and (ii) coarsening of porosity takes place during all sintering stages by various mechanisms. Porosity coarsening has been reported in metals, ceramics and glasses. Recent and classical approaches, experimental results with two dimensional model arrangements as well as computer simulations of formation and opening of particle contacts are discussed. The effect of porosity dimensions on the properties of sintered materials and measures for preventing and provoking porosity coarsening are briefly addressed.