We investigated the effects of a pulsed electric field (PEF) treatment on microbial inactivation and the physical properties of low-fat milk. Milk inoculated with Escherichia coli, Saccharomyces cerevisiae, or Lactobacillus brevis was supplied to a pilot-scale PEF treatment system at a flow rate of 30 L/h. Pulses with an electric field strength of 10 kV/cm and a pulse width of 30 μs were applied to the milk with total pulse energies of 50-250 kJ/L achieved by varying the pulse frequency. The inactivation curves of the test microorganisms were biphasic with an initial lag phase (or shoulder) followed by a phase of rapid inactivation. PEF treatments with a total pulse energy of 200 kJ/L resulted in a 4.5-log reduction in E. coli, a 4.4-log reduction in L. brevis, and a 6.0-log reduction in S. cerevisiae. Total pulse energies of 200 and 250 kJ/L resulted in greater than 5-log reductions in microbial counts in stored PEF-treated milk, and the growth of surviving microorganisms was slow during storage for 15 d at 4℃. PEF treatment did not change milk physical properties such as pH, color, or particle-size distribution (p<0.05). These results indicate that a relatively low electric-field strength of 10 kV/cm can be used to pasteurize low-fat milk.

Ceric(IV) ammonium nitrate-mediated oxidative cycloaddition of 1,3-dicarbonyls to vinyl sulfides afforded substituted dihydrofurans with sulfide groups in moderate yields. This new synthetic method has been applied to the synthesis of benzo[b]naphtho[2,3-d]furan-6,11-dione and furanoflavone natural products such as millettocalyxins C and pongol methyl ether.

An efficient protocol for the construction of diverse isatin derivatives was developed starting from 3-diazoquinoline-2,4-diones via ring contraction reaction.

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The reaction proceeds via domino Wolff rearrangement, decarboxylation, bromination, substitution, and dehydration.