Effects of cross-linked tapioca starches on batter viscosity and oil absorption in deep-fried breaded chicken strips

In this study, the effectiveness and feasibility of using various degrees of cross-linked tapioca starches in batter and breading formulations to reduce oil absorptions in deep fried chickens were investigated. Shear flow behaviour, water retention capacity (WRC), pick-up as well as cooked yield of the prepared batters were also examined. Flow curves showed that all studied batters were pseudoplastic, i.e. having shear thinning characteristics. In addition, it was found that the substitution of 20% (w/w) cross-linked starches for wheat flour in the batter formulation significantly reduced the consistency index and WRC of the batters. However, batter pick-up and cooked yield values were insignificantly affected. Oil uptake of fried chicken crusts was determined using differential scanning calorimetry due to its specific advantages over the conventional solvent extraction method. In comparison to the control (wheat) formulation, crusts of fried chicken samples obtained from the formulations containing 20% (w/w) cross-linked starch showed significantly lower oil content by at least 17% relative oil reduction. The highest relative oil reduction was found in the batter containing the highly cross-linked tapioca starch. Furthermore, an increase in water content in the batter formulations resulted in a reduction in the batter pick-up, cooked yield and oil absorption. The degree of cross-linking which in turn resulted in the limited starch granule disintegration is the predominant factor in the reduction of oil content for deep-fried battered food.     

Fluorescent polyelectrolytes as protein sensors

This review discusses recent advances in protein sensing using fluorescent polyelectrolytes that are mainly water‐soluble conjugated polymers. A quencher‐labeled substrate or fluorophore‐labeled substrate is generally used as a probe. In the presence of an enzyme, the linker between substrate and quencher/fluorophore is cleaved and fluorescence of the polymer is either ‘turned on’ or ‘turned off’. Fluorescence behavior of these conjugated polymers is highly sensitive to conformation of the polymeric chains. Since upon binding with proteins the conformation is perturbed and fluorescence is affected, these polyelectrolytes have been used to study conformational changes in proteins. The conformation‐dependent fluorescence is also a limitation for these sensors in some cases and non‐conjugated polyelectrolytes have been shown to provide an alternative. Copyright © 2006 Society of Chemical Industry