J Sci Food Agric. 2021 Jun 25. doi: 10.1002/jsfa.11404. Online ahead of print.
BACKGROUND: Ultrasound-assisted extraction of the intermediate product from the mechanical expression of the hemp (Cannabis sativa L.) seeds oil was investigated to improve the overall expression yield without compromising on the oil quality. The complementary ultrasound technology was used as an off-line treatment carried out at 20 kHz frequency and optimized with respect to amplitude (80 μm and 152 μm), sonication time (2, 10, 20 min) and to the hemp paste properties, in particular its particle size and hydration, which drive the compressibility of the press-cake.
RESULTS: Under the conditions evaluated, the optimal US treatment resulted to be the one applied on the hydrated press-cake for 2 min at 152 μm, which resulted in the oil yield of 13.4%, reporting an increase in extraction efficiency equal to 73% with respect to the control (untreated press-cake). Sonication had a positive effect on the press-cake texture and on the extracted oil antioxidant activity. Soaked samples treated for 2 min at 152 μm resulted to yield the lowest hardness. Oil recovered from soaked samples treated at 80 μm and 152 μm US for 2 min was the one with the highest antioxidant capacity.
CONCLUSIONS: The technological results gathered in the present investigation are preliminary to the design and engineering of a scaled-up equipment that combine the mechanical screw-expression and the in-line US unit. This article is protected by copyright. All rights reserved.
Source: ncbi 2