Influence of Sugars on Heat Inactivation, Injury and Repair of Saccharomyces cerevisiae

The type of sugar in the heating and recovery media affected the rate of inactivation and repair capability of a Chablis strain of Saccharomyces cerevisiae. The rate of heat inactivation decreased with decreasing a_w in glucose and fructose but not in sucrose solutions. At any a_w the order of susceptibility to inactivation of yeast cells was consistently: fructose, glucose, and sucrose. In fructose, a major proportion of the survivors exhibited sublethal injury. When suspended in solutions containing the various sugars after heating and incubated for up to 18 hr prior to plating, the type of sugar in the solution influenced the ability of cells to repair injury.     

OSMOTIC DEHYDRATION OF FRUIT

Influence of the osmosis time on the stability of processed cherries ("Vittoria", "Durone Nero I" and "Starking" cultivars) was studied.
The cherries were osmo-dehydrated for two, four, six hours, vacuum packed, pasteurized and then analyzed for ascorbic acid, glucose, fructose and maltose content by HPLC, for pH, total titrimetric acidity, dry matter, color and for organoleptic characteristics, during the process and up to six months of storage.
The dehydration of the fruit and the exchange with the osmotic syrup took place chiefly during the first two hours of the process. No substantial differences were noted though, in the cherries, processed at different time, both for chemical and organoleptic characteristics. Color data showed the importance of the variety in order to obtain good products. Thus it was concluded that a two hours'osmodehydration process is suitable to achieve very acceptable products.     

The RhoA nuclear localization changes in replicative senescence: New evidence from <i>in vitro</i> human mesenchymal stem cells studies

All non-immortalized mesenchymal stem cells have a limited proliferative potential, that is, replicative senescence (RS) is an integral characteristic of the life of all mesenchymal stem cells (MSCs). It is known that one of the important signs of RS is a decrease of cell motility, and that violations of migration processes contribute to the deterioration of tissue regeneration. Therefore, the characterization of the properties of the cell line associated with RS is a prerequisite for the effective use of MSCs in restorative medicine. One of the key proteins regulating cell motility is the small GTPase RhoA. The main purpose of this work was to study the nuclear-cytoplasmic redistribution of the RhoA protein during RS in MSC lines recently obtained and characterized in our laboratory. The study found that a comparative analysis of the intracellular localization of RhoA in three cell lines (MSCWJ-1, FetMSC, DF2) showed a decrease in the nuclear localization of RhoA during RS.     

Optimization of Vapor Induced Puffing in Apple Dehydration

Vapor induced puffing during high temperature fluidized bed (HTFB) dehydration of apple cubes was optimized using response surface methodology (RSM). Osmoblanching in sugar syrup prevented enzymatic browning. Successtil puffing was achieved by creating a surface barrier to vapor by dipping the cubes in starch solution and manipulating the temperature and time of exposure in the HTFB. Optimum conditions for minimum bulk density with acceptable levels of nonenzymatic browning included dipping osmoblanched apple cubes in 1% starch solution, followed by HTFB drying 11 min at 157°C. Product bulk density exhibited a minimum while nonenzymatic browning values did not display an optimum. Minimum value of bulk density predicted by RSM and browning values were very close to those verified experimentally for product processed under the identified optimum conditions.