PAPERmaking! FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 2, Number 1, 2016
applied to the paper. Two procedures have proved valuable for starch degradation in the paper mill: enzymatic and thermo-oxidative degradation. The objective of this study was to determine achievable efficiencies of cavitation in preparing degraded starch for surface application on paper. Biodegradable and non-retrogradable eco-films based on starch – glycerol with citric acid as crosslinking agent, Paula González Seligra et al , Carbohydrate Polymers , 138. Biodegradable and non-retrogradable starch – glycerol based films were obtained using citric acid (CA) as crosslinking agent at 75°C. This material allowed decreasing water vapour permeability (WVP) more than 35%, remained amorphous for at least 45 days as a result of the network formed by the CA that avoided starch retrogradation and maintained the degradability in compost, occurring only six days after the films without citric acid. Infrared spectroscopy as a tool to characterise starch ordered structure — a joint FTIR – ATR, NMR, XRD and DSC study, Frederick J. Warren et al , Carbohydrate Polymers , 139. Starch has a heterogeneous, semi-crystalline granular structure and the degree of ordered structure can affect its behaviour in foods and bioplastics. Here, the authors subject 61 starch samples to structural analysis, and systematically correlate FTIR spectra with other measures of starch structure. They demonstrate that FTIR is a tool that can quantitatively probe short range interactions in starch structure. Small differences in amylopectin fine structure may explain large functional differences of starch, Eric Bertoft et al , Carbohydrate Polymers , 140. Four amylose- free waxy rice starches were found to give rise to gels with clearly different morphology after storage for seven days at 4°C. The thermal and rheological properties of these gels were also different. This was remarkable in light of the subtle differences in the molecular structure of the amylopectin in the samples. Addition of iodine to the amylopectin samples suggested that not only external chains, but also the internal chains of amylopectin, could form helical inclusion complexes. It is suggested that these internal helical segments participate in the retrogradation of amylopectin, thereby stabilising the gels through double helical structures with external chains of adjacent molecules. Albeit few in number, such interactions appear to have important influences on starch functional properties. Insights into the hierarchical structure and digestion rate of alkali-modulated starches with different amylose contents, Dongling Qiao et al , Carbohydrate Polymers , 144. Combined analytical techniques were used to explore the effects of alkali treatment on the multi-scale structure and digestion behaviour of starches with different amylose/amylopectin ratios. STOCK PREPARATION Energy and paper recycling: Modelling the time and energy requirements for low consistency batch repulping, F. Saville et al , Canadian Journal of Chemical Engineering , 94 (3). An analytical model for low-consistency repulping linking pulp material properties, consistency, temperature, and rotor and vat geometry is provided, which allows for accurate prediction of the time and energy required for repulping in both a 0.25m 3 laboratory-scale repulper and a 15m 3 industrial-scale repulper. Improving the material efficiency of recycled furnish for papermaking through enzyme modifications, P.K. Verma et al , Canadian Journal of Chemical Engineering , 94 (3). Fibre fines and fibrils within recycled cellulosic pulp have high amorphous cellulose
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Technical Abstracts
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