Structure formation in sugar containing pectin gels - influence of tartaric acid content (pH) and cooling rate on the gelation of high-methoxylated pectin.
The aim of the study was the application of a recently published method, using structuring parameters calculated from dG'/dt, for the characterisation of the pectin sugar acid gelation process. The influence of cooling rate and pH on structure formation of HM pectin gels containing 65 wt.% sucrose were investigated. The results show that the structure formation process as well as the properties of the final gels strongly depended on both parameters. With increasing cooling rates from 0.5 to 1.0 K/min the initial structuring temperature slightly decreased and the maximum structuring velocity increased. The lower the cooling rates, the firmer and more elastic were the final gels. With increasing acid content (decreasing pH from 2.5-2.0) the initial structuring temperatures were nearly constant. The final gel properties varied visibly but not systematically. Gels with the lowest and highest pH were less elastic and weaker compared to those with medium acid concentrations.
Green recovery of pectic polysaccharides from citrus canning processing water
Abstract Canned citrus segments are popularly consumed worldwide with a large global market. However, the production needs chemical treatment to remove segments membranes, producing a large amount of acidic and basic effluents with very high chemical oxygen demand (COD), causing serious environmental problems. This research is focused on the plant scale recovery of pectic polysaccharides from the above acidic and basic processing water to decrease COD and develop a new product, through steps including water reuse (alternative), two-step filtration, concentration, ethanol precipitation and ethanol recovery. The yields of polysaccharides were 0.30% and 0.45% (w/v) from reused acidic and basic water, respectively, dramatically decreasing the COD by ∼75% from ∼10,000 mg/L, and having a great estimated output value of ∼$1.8 million annually for each factory. Polysaccharides from acidic water mainly contains homogalacturonan regions with ∼50% degree of esterification, whereas that from basic water was dominated with rhamnogalacturonan I regions with almost no esterification. The high viscosity of these branching polysaccharides, combined with gelling experiment results, suggested that both polysaccharides might be potential food thickening and gelling agents with large benefits to both the environment and the economy.
Investigating the Optical properties of cd1-xznxs thin films deposited by the Dip Technique
A Thesis submitted to the Department of Physics, Kwame Nkrumah University of Science and Technology, in partial fulfillment of the requirement for the degree of 
Master of Science (Solid State Physics)