Phoebe Xiurong Qi

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In this work, the surface structures of biochars, derived from three types of biomass, switchgrass (SG), hardwood (HW) and softwood (SW) through either fast pyrolysis (FP) in a fluidized-bed reactor (at 500 °C) or slow pyrolysis (at 500° and 700 °C), were studied in detail, and compared with that of the activated carbons obtained by steam activation of the(More)
To understand the mechanism of protein folding and to assist rational design of fast-folding, non-aggregating and stable artificial enzymes, it is essential to determine the structural parameters which govern the rate constants of folding, kf. It has been found that -logkf is a linear function of the so-called chain topology parameter (CTP) within the range(More)
Although extrusion technology has contributed much to increasing the effective utilization of whey, the effect of extrusion conditions on the functional properties of the proteins is not well understood. In this work, the impact of extrusion temperature on the physical and chemical properties, molecular structures, and protein quality of texturized whey(More)
Recent advances in the field of protein chemistry have significantly enhanced our understanding of the possible intermediates that may occur during protein folding and unfolding. In particular, studies on alpha-lactalbumin have led to the theory that the molten globule state may be a possible intermediate in the folding of many proteins. The molten globule(More)
We have solubilized and separated polysaccharides from sugar beet pulp (SBP) into three fractions with steam assisted flash extraction (SAFE). For pectin, recovery ranged from 8 to 14%, degree of methy-esterification 66-73%, crude protein 1.3-1.7%, M(w) 262-318 kDa, η(w) 0.22-0.23 dL/g, Rg(z) 36-39 nm and Rh(z) 41-42 nm. For alkaline soluble(More)
Whey protein concentrates (WPC) and isolates (WPI), comprised mainly of β-lactoglobulin (β-LG), α-lactalbumin (α-LA) and casein glycomacropeptide (GMP), are added to foods to boost nutritional and functional properties. Supercritical carbon dioxide (SCO₂) has been shown to effectively fractionate WPC and WPI to obtain enriched fractions of α-LA and β-LG,(More)
The effect of homogenization alone or in combination with high-temperature, short-time (HTST) pasteurization or UHT processing on the whey fraction of milk was investigated using highly sensitive spectroscopic techniques. In pilot plant trials, 1-L quantities of whole milk were homogenized in a 2-stage homogenizer at 35°C (6.9 MPa/10.3 MPa) and, along with(More)
Bovine beta-casein (beta-CN) with its C-terminal truncated by chymosin digestion, beta-CN-(f1-192), was examined and characterized using circular dichroism (CD) under various temperature conditions. CONTIN/LL analysis of the CD data revealed significant secondary structure disruption in beta-CN-(f1-192) relative to its parent protein,beta-CN, in the(More)
In a case study, we monitored the physical properties of 2 batches of whey protein concentrate (WPC) under adverse storage conditions to provide information on shelf life in hot, humid areas. Whey protein concentrates with 34.9 g of protein/100g (WPC34) and 76.8 g of protein/100g (WPC80) were stored for up to 18 mo under ambient conditions and at elevated(More)
Changes in the structural and thermal stability of β-lactoglobulin (β-LG) induced by interacting with sugar beet pectin (SBP) have been studied by circular dichroism (CD), Fourier transform infrared, and steady-state as well as time-resolved fluorescence spectroscopic techniques. It has been demonstrated that SBP not only is capable of binding to native(More)