The effect of use of freeze-thawed pork on the properties of Bologna sausages with two fat levels

The rheological characteristics, microstructure and thermal stability of meat emulsions, made with two levels of fat (7.6% and 20.3%) and prepared from either fresh meat or meat subjected to one or three freeze-thaw cycles, were measured. Lower fat contents were accompanied by a significant reduction in the binding property, shear force and hardness of the products. Both low fat and use of freeze-thawed meat produced structures with a less dense matrix, freeze-thawing altered the microstructure of the meat sausages and reduced shear force, hardness, chewiness and thermal stability. These effects were particularly apparent in the higher-fat product.     

Kinetics of enzymic hydrolysis of cassava flour starch — optimization and modelling

This study was conducted to model the kinetics of cassava flour hydrolysis by Miles Taka-Therm L–170 alpha amylase and Diazyme L–200 glucoamylase to produce glucose syrup. Maximum starch concentration was 33% due to a controlled process of flour gelatinization by gradual temperature increase, and parallel starch hydrolysis by thermostable alpha amylase activity, preventing excess viscosity. The time of hydrolysis was two and half hours of alpha amylase activity and 36 h of glucoamylase activity with the final yield of 90–93% of glucose. Exponential hyperbolic models were obtained to predict the kinetic of hydrolysis both amylase and glucoamylase, with a generalized correlation coefficient >0.94.     

Determination of OH Extinction Coefficients in R2O-B2O3-SiO2 Glasses (R = Li, Na, K)

Infrared spectra of glasses of the system R₂O-B₂O₃-SiO₂ were investigated. The extinction coefficients of the hydroxyl absorption band ("free OH") were calculated by a method proposed for alkali borate glasses. The results confirmed the applicability of this method to homogeneous and phase-separated alkali borosilicate glasses. The variation of the hydroxyl absorption band position was interpreted according to the structural characteristics of the studied glasses.     

Protein extraction from lupin seeds: microstructural aspects and hypothesis of mechanism

Protein was extracted into water (pH 8.0, 1 h) from defatted lupin seed kernel particles (mean θ, 1425 μm). Intact and extracted particles were examined by scanning and transmission electron microscopy. The inner surface of the cell wall initially showed several small holes considered as possible sites of plasmodesmata. During extraction, protein bodies first became disrupted into smaller microstructures and then protein dissolved. Wide passages were formed between cells which allowed transport of protein. The molecular weight of proteins in solution did not change with time, suggesting that bulk flow rather than selective transport predominated.     

POSTMORTEM SHORTENING OF LAMB LONGISSIMUS OXIDATIVE AND GLYCOLYTIC FIBERS

Percentages of lamb M. longissimus thoracis et lumborum fiber types were approximately 66 oxidative and 34 nonoxidative, without significant differences among muscle regions. The effects of skeletal restraint and muscle region on sarcomere shortening during rigor development were found to be highly significant; sarcomeres of caudal-ventral location were stretched by skeletal restraint while the rest were all shortened. In excised muscles, both fiber type and postmortem temperature exerted a highly significant effect on sarcomere shortening. Oxidative fibers showed a more intense shortening, already evident at temperatures well above those causing cold shortening. While shortening of glycolytic fibers was gradually more intense as treatment temperature decreased from 20 to 0°C, a maximum contraction of about 40% was reached at 15°C in oxidative fibers and lower temperatures did not cause any further shortening. Average fiber shortening was found to be highly correlated to meat toughening.     

Ascorbic acid loss and sensory changes in intermediate moisture pineapple during storage at 30–40°C

Kinetics of ascorbic acid loss as a function of storage temperature (30, 35 and 40°C) and water activity of intermediate moisture pineapple slices at a _W of 0.92, 0.95 and 0.97 was modelled. Loss was faster at higher a _W but storage temperatures of 30 - 40°C had little effect at the same a _w. Colour changes were larger than flavour changes. Spoilage was only a problem at high a _w.     

THE USE OF OZONATION TO REDUCE THE POTENTIAL FOR FORMING TRIHALOMETHANE COMPOUNDS IN CHLORINATING RESORCINOL,PHLOROGLUCINOL AND 1,3 CYCLOHEXANEDIONE

This study concerns the ozonation of Resorcinol, Phloroglucinol and 1,3 Cyclohexanedione in the presence of bromide ion in a bubble column, prior to chlorination. Preozonation in aqueous solutions reduces the potential for forming chlorinated trihalomethane compounds. At organic concentrations greater than 10^?4?M a short ozonation time increases the potential for forming trihalo compounds. At longer ozonation times the reverse is true. Finally the influence of mass transfer and chemical reaction on the ozone absorption rate have been evaluated following the film theory.