The composite films comprising pea starch (St) and ε-polylysine (PL) as the matrix and glycerol and sodium alginate as the plasticizers were investigated. The rheological properties, mechanical properties, Fourier transformed infrared spectroscopy, water vapor permeability (WVP), oil permeability, microstructure, thermogravimetry (TGA), and antimicrobial properties of the composite films were analyzed. The properties of the composite films with different mass ratios of St/PL varied significantly. First, the five film solutions were different pseudoplastic fluids. Additionally, as the mass ratio of PL increased, the tensile strength of the blends decreased from 9.49 to 0.14 MPa, the fracture elongation increased from 38.41 to 174.03%, the WVP increased, and the oil resistance decreased substantially. The films with a broad range of St/PL ratios were highly soluble; however, the solubility of the film with a St/PL ratio of 2:8 was reduced. Lastly, the inhibition of E. coli, B.subtilis, and yeast by the films increased with increasing mass ratios of PL, and the inhibition of B.subtilis was the strongest.

As a typical green leafy vegetable, pakchoi suffers greatly from postharvest loss. This study investigated the impact of sucrose on quality and energy metabolism of postharvest pakchoi. Sucrose could delay leaf yellowing and preserve higher chlorophyll and decrease weight loss rate and respiration rate during pakchoi storage. Compared with control, the sucrose‐treated group retained higher energy level as indicated by higher contents of adenosine triphosphate (ATP) and adenosine diphosphate (ADP), as well as higher activities of cytochrome c oxidase (CCO), succinic dehydrogenase (SDH), and adenosine triphosphatase (ATPase). Moreover, sucrose could induce the expression of BrATP4 , BrAtpB , BrSDH1 , and BrCOX5/6 , while BrSDH6 was repressed. Correlation analysis results presented that ATP was significantly positively correlated with ADP, energy charge (EC), and H ⁺ K ⁺ ‐ATPase, and CCO presented positive correlation with BrCOX5/6 . Higher chlorophyll was related to higher energy status of postharvest pakchoi. Above findings demonstrated that sucrose might delay pakchoi senescence and yellowing by maintaining higher energy, energy metabolism–related enzyme activities, and gene expression levels.

Provable security has been widely used for analyzing the security of cryptosystems. Its main idea is to reduce the security to some well-defined computational assumption. The reduction process is called the security proof. In this paper, we find a flaw in the security proof of BDOP-PEKS and PEKS-STAT, present a new conclusion for the security of BDOP-PEKS, and give a security proof. The flaw in the security proof of PEKS-STAT can be fixed in the same way. Finally we conclude some steps of security proof, and emphasize that the probability is as important as the construction.