Properties of the avocado oil extracted using centrifugation and ultrasound-assisted methods.

The aim of this work was to evaluate the technologies effect of cold extraction by centrifugation (CE) and ultrasound-assisted (US-CE) methods without adding water, on the avocado oil yield, nutritional composition, physicochemical characteristics, oxidative stability (oxidation temperature and time, besides activation energy) and accelerated shelf life regarding hexane extraction (control). The US-CE improved the physicochemical properties such as acidity, peroxides, and iodine indexes regarding CE and Control. US-CE improved the yield, nutritional quality of fatty acids, oxidative stability, shelf life, and ω-6/ω-3 ratio regarding CE. Furthermore, US-CE improved the ratio yield/time extraction of the oil and increased the oxidation temperature regarding control. The main advantage of oils extracted using CE and US-CE concerning control was higher oxidative stability. The most representative polyunsaturated fatty acids identified in all treatments were γ-linolenic and conjugated α-linolenic acids. α-linolenic acid was only detected in US-CE and control. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-00940-w.

Effect of high-intensity ultrasound on the technofunctional properties and structure of jackfruit (Artocarpus heterophyllus) seed protein isolate.

The influence of high-intensity ultrasound (HIU) on the technofunctional properties and structure of jackfruit seed protein isolate (JSPI) was investigated. Protein solutions (10%, w/v) were sonicated for 15min at 20kHz to the following levels of power output: 200, 400, and 600W (pulse duration: on-time, 5s; off-time 1s). Compared with untreated JSPI, HIU at 200W and 400W improved the oil holding capacity (OHC) and emulsifying capacity (EC), but the emulsifying activity (EA) and emulsion stability (ES) increased at 400W and 600W. The foaming capacity (FC) increased after all HIU treatments, as opposed to the water holding capacity (WHC), least gelation concentration (LGC), and foaming stability (FS), which all decreased except at pH 4 for FS. Tricine sodium dodecyl sulfate polyacrylamide gel electrophoresis (Tricine-SDS-PAGE) showed changes in the molecular weight of protein fractions after HIU treatment. Scanning electron microscopy (SEM) demonstrated that HIU disrupted the microstructure of JSPI, exhibiting larger aggregates. Surface hydrophobicity and protein solubility of the JSPI dispersions were enhanced after ultrasonication, which increased the destruction of internal hydrophobic interactions of protein molecules and accelerated the molecular motion of proteins to cause protein aggregation. These changes in the technofunctional and structural properties of JSPI could meet the complex needs of manufactured food products.