Effect of high pressure homogenization treatment on the rheological properties of citrus peel fiber/corn oil emulsion.

BACKGROUND: Citrus fiber is a main component in the peel of citrus and contains natural dietary fiber. It is often used as a functional additive to improve the texture or nutritional property of food. It is also widely used to reduce the content of absorbable fat in sausages and other meat products, and to improve food stability as an emulsifier. In this research, the dynamic rheological properties (linear and non-linear) of citrus peel fiber/corn oil (CF/CO) emulsion system under high pressure homogenization (HPH) treatment was investigated. RESULT: Rheological results illustrated HPH treatment significantly increased the apparent viscosity of the emulsion, reduced the activation energy of the emulsion and distinctly improved the viscoelasticity of the emulsion. Meanwhile, HPH treatment increased the linear viscoelastic region of the sample, and the behavior of the emulsion converted from strain thinning (without HPH treatment) to weak strain overshoot (with HPH treatment). Lissajous curves indicated the viscosity of the sample increased first and then decreased with strain increasing and the third harmonic contributed much more to the first harmonic compared with the fifth harmonic. Chebyshev stress decomposition revealed that, as strain increased, the samples with HPH treatment showed internal-cycle strain hardening behavior first, then turned to internal-cycle softening behavior. CONCLUSION: HPH treatment can significantly improve the processing performance of CF/CO emulsion as well as the stability against large periodic oscillations in food processing. © 2020 Society of Chemical Industry.

Spongian diterpenes from Chinese marine sponge Spongia officinalis.

3-Nor-spongiolide A (1), belonging to the extremely rare 3-nor-spongian carbon skeleton, and spongiolides A (2) and B (3), having γ-butenolide instead of furan ring as usual for ring D, together with six related known metabolites were isolated from South China Sea sponge Spongia officinalis as its metabolic components. Their structures were elucidated on the basis of extensive spectroscopic analysis. The absolute configurations of three new compounds 1-3 were determined by ECD calculations.

Asymmetric Total Synthesis of Distaminolyne A and Revision of Its Absolute Configuration.

The first total synthesis of a marine derived polyacetylene, distaminolyne A, and its enantiomer were achieved from the commercially available undec-10-en-1-ol. A key proline-catalyzed asymmetric α-aminooxylation of an aldehyde intermediate was used to introduce the chiral center en route to the enantiomerically pure 1,2-amino alcohols. The absolute configuration of both synthesized enantiomers of distaminolyne A was confirmed by using chiral derivatizing agents, leading to revision of the natural product absolute configuration from 2S to 2R. Antibacterial, pancreatic lipase (PL) inhibitory, and protein-tyrosine phosphatase 1B (PTP1B) inhibitory activities were evaluated.