Influence of particle size distribution on nutritional composition, microstructural and antioxidant properties of orange and purple‐fleshed sweet potato flour

Oat husk (OH; hull) is a by-product generated from oat processing and is rich in insoluble fibre and phenolic compounds. The aim of this work was to study the particle size distribution, antioxidant activity, and phenolic profile of micronized OH. For this purpose, the hull was first sterilized using superheated steam and was then ground using an impact classifier mill. The particle size distribution (PSD) of the ground husk was determined using the laser diffraction method and the parameters characterizing the PSD of the ground husk, and its antioxidant activity were calculated. In addition, UPLC-MS/MS analysis of phenolic acids was also performed. Micronization of the sterilized husk effectively decreased the size of the particles, and with the increasing speed of the rotor and classifier, the median size of the particles (d50) decreased from 63.8 to 16.7 µm. The following phenolic acids were identified in OH: ferulic, caffeic, p-hydroxybenzoic, vanillic, syringic, and synapic acid. Ferulic acid constituted about 95% of total phenolic acids. The antioxidant activity of the obtained extracts increased as the particle size of the micronized husk decreased. The highest half maximal inhibitory concentration (EC50 index) was found for chelating power, and the lowest was found in the case of radical scavenging activity against DPPH.

Download Full-text

A Novel Functional Emulsifier Prepared with Modified Cassava Amylose with Octenyl Succinic Anhydride and Quercetin: Preparation and Application in the Pickering Emulsion

Molecules ◽

10.3390/molecules26226884 ◽

2021 ◽

Vol 26 (22) ◽

pp. 6884

Author(s):

Hailing Zhang ◽

Haiming Chen ◽

Shan Jiang ◽

Xiaoning Kang

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Succinic Anhydride ◽

Structural Characteristics ◽

Antioxidant Properties ◽

Oxidation Stability ◽

Infrared Spectrometry ◽

Octenyl Succinic Anhydride ◽

Carbohydrate Polymer

An emulsifier with a targeted antioxidant effect was prepared using the inclusion complexes of octenyl succinic anhydride (OSA)-modified cassava amylose (CA) and quercetin (Q). The designed emulsifier, a carbohydrate polymer-flavonoid complex, exhibited both amphiphilic and antioxidant properties. To investigate the physical and oxidation stabilities of the prepared emulsion, three types of emulsions were prepared: primary emulsions stabilized by enzyme-modified starch, secondary emulsions stabilized by OSA-CA, and tertiary emulsions stabilized by Q-encapsulated complexes (OSA-CA/Q). The structural characteristics of CA, OSA-CA, and OSA-CA/Q were investigated by scanning electron microscopy, Fourier transform infrared spectrometry, and small-angle X-ray scattering analysis. The stabilities of the emulsions were evaluated based on their particle size distribution, zeta potential, creaming stability, and peroxide value. The results showed that the secondary and tertiary emulsions exhibited a relatively narrower particle size distribution than the primary emulsions, but the particle size distribution of the tertiary emulsions was the narrowest (10.42 μm). Moreover, the secondary and tertiary emulsions had lower delamination indices than the primary emulsions after 7 days of storage. The results obtained from the antioxidant experiments indicated that OSA-CA/Q exhibited good oxidation stability for application in emulsion systems.

Download Full-text