Researches Regarding the Processing of the Hemp Seed by Cold Pressing

Abstract

The hemp (Cannabis sativa L.) seeds present an important raw material resource for the industry due to processing possibilities of plants components. The hemp oil and the pressing cake resulted by the cold pressing of the hemp presents excellent alimentary and therapeutic properties. 
 The purpose of the research was to study the technology of obtaining of the hemp oil by cold pressing of the seeds, the influence of the process parameters and raw materials quality upon the products quality. 
 The pressing was made with screw press of small using press nozzle in diameters of 5, 6, 7, 8 and 10 mm. For the hemp seed there were determined the organoleptic characteristics (total volatile matter and the raw fat content by Soxhlet extraction). For the hemp oil there were determined the acid value and the peroxide value. There werde determined the working parameters of the press (the rate efficiency and the productivity of the press). 
 The results emphasized important data for the practice. The fat content of the seed was between 30,89 and 33,25 % and the volatile matter was between 90,42 and 93,68 %. The rate efficieny of the cold pressing of the hemp seed was between 23,89 and 27,69 % obtained oil, being influenced by the characteristics of the seeds. The pressing process was also influenced by the quality of the seed, presenting optimal values in the case of using pressing nozzle 8 and 10 mm in diameter. The acid values of the hemp oil was between 0,65 and 4,45 mg KOH/g oil and the peroxide values was between 0,62 and 26,91 mEg O2/g. Further studies are recommended be made and there are the initiations of ab informational programme, in order to inform the farmers and consumer about the benefic and therapeutic effects of the hemp oil upon the health.

Benefits of Cultivating Industrial Hemp (Cannabis sativa ssp. sativa)—A Versatile Plant for a Sustainable Future

“…The unique properties of the plant make it a highly valuable and sustainable crop. There are more than 25,000 hemp-based products available in markets worldwide [15]. The stalks, seeds, and leaves are converted into various construction materials, textiles, paper, food, furniture, cosmetics, healthcare products, etc.…”

Extraction techniques for bioactive compounds of cannabis

“…As far as the input sample is concerned, only a handful of manuscripts report the composition of the input sample material (either relying on Soxhlet as a reference method or on data provided by the raw-material supplier, while in some cases no specication is given), 42,[117][118][119][120][121][122][123] whereas most researchers only focus on the extracted amount of valuable compounds. Undoubtedly, the amount extracted is highly valuable information; nevertheless, the recovery of the target compounds, which is largely absent, is indicative of the performance of the developed method and, thus, a crucial factor for the evaluation of its potential economic and ecological merit in comparison to state-of-the-art approaches.…”

“…On the other hand, the yield from hemp owers and residues (overall or per extracted valuable compound or both) is most commonly reported; however, the yield is not calculated consistently. It has been calculated with reference to the input sample material, 42,78,123,124,[127][128][129][133][134][135]139,[143][144][145][146][147][148]153,[165][166][167] to the recovered extract [117][118][119]121,122,136,138,[140][141][142]162,168,169 and to the overall cannabinoid extract process, 117,125 while in some cases it is not clearly specied, 122,131,163,170 thereby, causing confusion and only leading to assumptions and misunderstandings on the part of the reader. Providing the equation on which the calculations are based, as certain publications do, 78,134,144,145,153,…”

Ultrasound‐assisted extraction of oil from hempseed (Cannabis sativa L.): Part 2

“…Among the different compared methodologies (supercritical fluid extraction, Soxhlet, percolation, ultrasonication, pyrolysis), mechanical oil expression was not accounted for. The most noteworthy advantages of hemp seed processing by cold pressing are the ease of operation and the possibility to recover a precious by‐product, the hemp spent cake 4 . The latter is still rich in proteins, fibres, phytochemicals, minerals, essential fatty acids and tocopherols and can be considered not only as a functional ingredient for several food products and snacks, but also as a precious feedstock for cosmetics, textile and pharmaceutical industries 5 …”

“…The most noteworthy advantages of hemp seed processing by cold pressing are the ease of operation and the possibility to recover a precious byproduct, the hemp spent cake. 4 The latter is still rich in proteins, fibres, phytochemicals, minerals, essential fatty acids and tocopherols and can be considered not only as a functional ingredient for several food products and snacks, but also as a precious feedstock for cosmetics, textile and pharmaceutical industries. 5 Screw type oil expellers are oil processing machineries characterized by a simple design, ease of use and a continuous operation mode.…”