Effect of Plasma-Activated Water on Shewanella putrefaciens Population Growth and Quality of Yellow River Carp (Cyprinus carpio) Fillets.

ABSTRACT: Plasma-activated water (PAW) is a new sanitizer that has received considerable attention for application in food industries. This research aimed to evaluate the effect of PAW on the inactivation of Shewanella putrefaciens and quality attributes of Yellow River carp (Cyprinus carpio) fillets. The carp fillet samples were immersed in sterile deionized water (SDW) or SDW activated by plasma discharge for 120 s (PAW120) for 1.5, 3.0, 4.5, or 6.0 min. After being treated by PAW120 for 6 min, the population of S. putrefaciens on carp fillets was significantly (P < 0.05) decreased by 1.03 log CFU/g. Compared with SDW-treated samples, the L* value of PAW120-treated carp fillets was increased and the a* value was decreased after PAW120 treatment, whereas there was no significant (P > 0.05) difference in the b* value. Compared with SDW, PAW120 caused no significant (P > 0.05) changes in sensory properties and texture attributes of carp fillets including hardness, springiness, gumminess, and cohesiveness. However, 6-min PAW120 treatment caused a significant increase in the lipid oxidation level and a decrease in the pH value of the carp fillets. This work provides a basis for the potential application of PAW in the preservation of aquatic products.

Eggshell and Histology Provide Insight on the Life History of a Pterosaur with Two Functional Ovaries.

The counterpart of a previously described non-pterodactyloid pterosaur with an egg revealed the presence of a second egg inside the body cavity of this gravid female. It clearly shows that pterosaurs had two functional oviducts and demonstrates that the reduction of one oviduct was not a prerequisite for developing powered flight, at least in this group. Compositional analysis of one egg suggests the lack of a hard external layer of calcium carbonate. Histological sections of one femur lack medullary bone and further demonstrate that this pterosaur reached reproductive maturity before skeletal maturity. This study shows that pterosaurs laid eggs even smaller than previously thought and had a reproductive strategy more similar to basal reptiles than to birds. Whether pterosaurs were highly precocial or needed parental care is still open to debate.