Mechanical Pressing Research Articles

Flaxseed oil: Extraction, health benefits and products

Flaxseed is rich in ?-linolenic acid (ALA), lignans, proteins and dietary fibers, which has been considered as an important food ingredient. As one of most functional ingredients in flaxseed, flaxseed oil could provide many potential health benefits, such as cardiovascular protection, anti-tumor, anti-inflammatory, live protection, diabetes treatment, etc. Besides mechanical pressing and solvent extraction for flaxseed oil, various new extraction processes, for example, microwave-assisted extraction, supercritical CO2 extraction, subcritical extraction, three-phase partitioning, enzyme-assisted three-phase partitioning, etc., have been investigated. Currently, flaxseed oil has been incorporated into some regular food formulations including liquid or solid powder drink, meat products, baking foods, etc. However, due to high ALA in flaxseed oil, it is a great challenge for the development of flaxseed-oil based products. In present paper, the latest development of the extraction of flaxseed oil, the potential benefits of flaxseed oil, and flaxseed oil-based foods, were reviewed. Regarding the studies of flaxseed oil in our group was also highlighted.

A comparative and economic study of the extraction of oil from Baru (Dipteryx alata) seeds by supercritical CO2 with and without mechanical pressing

The present study evaluated the effect of supercritical fluid extraction (SFE) assisted by cold pressing (SFEAP) on the overall yield, extraction kinetics, composition of baru seed oil and manufacturing cost (COM). The best extraction conditions were determined in extraction assays combining different pressures (150–350 bar) and temperatures (35 and 45 °C). The extraction yield by SFEAP (28.6 g oil/100 g baru seed) was approximately 31% higher than that obtained by SFE (21.9 g oil/100 g baru seed), according to the kinetic study with the best extraction conditions (350 bar and 45 °C). The extraction yield observed under this condition allowed us to obtain a lower COM for both techniques (SFE was US$ 118.32/kg baru oil and SFEAP was US$ 87.03/kg baru oil) compared to lower pressures and temperatures. The oil obtained under all extraction conditions was rich in unsaturated fatty acids and other bioactive compounds. The extraction of baru seed oil by SFEAP resulted in a higher yield and lower manufacturing cost than SFE.

Optimization of Cold Extraction Parameters for Some Non-Edible Vegetable Oils

Non-edible vegetable oils (NEVOs) have a huge potential for many industrial applications. Most of them are expressed by mechanical pressing, but data on the different operating conditions to achieve optimal extraction yields and high-quality oil are scarce. Hence, the objective of this study was to optimize cold extraction parameters of Balanites aegyptiaca , Ceiba pentandra , Jatropha curcas , and Moringa oleifera oils by increasing the oil recovery. Optimal holding time, applied pressure, compression speed, and press cage charge were determined for whole and crushed oleaginous material. Under the optimal operating conditions, the oil recovery (%. d.b.) from whole (crushed) oilseeds was 73.4 (69.8) B.aegyptiaca kernels, 38.2 (41.2) C.pentandra seeds, 38.2 (42.5) J.curcas seeds, 71.3 (69.5) J.curcas kernels, and 51.4 (22.5) M.oleifera seeds. The extracted NEVOs have a high content of unsaturated fatty acids (oleic, linoleic, and linolenic). M.oleifera oil was particularly rich in oleic (70.38%), palmitoleic (2.39%), vaccenic (6.09%), and arachidic (4,14) acids. The oil quality of cold-pressed NEVOs satisfies the requirements set by the DIN 51605: 2010-10 norm for plant oil-based fuels regarding phosphorus and water-volatile matter contents, density, and kinematic viscosity. Valuable material properties of the B.aegyptiaca , C.pentandra , J.curcas and M.oleifera oils make them an ecological and renewable resource for multipurpose applications.

Valorization of argan oil: all you need to know about argan oil from Morocco

This work makes it possible to study the argan oil which has extracted by several extraction methods (artisanal, mechanical pressing of roasted almonds, mechanical pressing of unroasted almonds, solvent extraction, pulped by a goat), after extraction, a detailed Physico-chemical study was done on this oil to certify its quality, the study of this work makes it possible to achieve an official standard for argan oil and studies the influence of the extraction method and the origin of production on the chemical composition. The study shows that roasting appears as a parameter influencing the acidity value of argan oil. Analysis of the peroxide index shows that the samples of argan oil extracted by the artisanal method and that those pulped by goats have a higher peroxide content. The sterol composition as per the data in the literature. They are essentially Δ-7-stigmasterols. The main products are schottenol and spinasterol. The composition of fatty acids and sterols shows no significant variation. These results are consistent with those reported in the literature. This shows that the origin and the method of extraction do not influence the nutritional qualities of argan oil. The results for the tocopherols show that the extraction method (plump by a goat) and roasting can influence the composition of the tocopherols. On the other hand, the sample obtained by the artisanal method has a lower content of total tocopherols. Roasting decreases the total content of α-tocopherol. After this study, it is urgent to ensure the quality of this oil, so Physico-chemical analyzes were carried out to detect fraud in pure argan oil. Finally, we determined the influence of the fruit form of the argan tree (spindle-shaped, apiculate, oval, spherical) on the Physico-chemical parameters of argan oil.

Inclined Ultrathin Bi2O2Se Films: A Building Block for Functional van der Waals Heterostructures.

As an emerging ultrathin semiconductor material, Bi2O2Se exhibits prominent performances in electronics, optoelectronics, ultrafast optics, etc. However, until now, the in-plane growth of Bi2O2Se thin films is mostly fulfilled on atomically flat mica substrates with interfacial electrostatic forces setting obstacles for Bi2O2Se transfer to fabricate functional van der Waals heterostructures. In this work, controlled growth of inclined Bi2O2Se ultrathin films is realized with apparently reduced interfacial contact areas upon mica flakes. Consequently, the transfer of Bi2O2Se could be facile by overcoming weaker electrostatic interactions. From cross-sectional characterizations at the Bi2O2Se/mica interfaces, it is found that there are no oxide buffer layers in existence for both in-plane and inclined growths, while the un-neutralized charge density is apparently decreased for inclined films. By mechanical pressing, inclined Bi2O2Se could be transferred onto SiO2/Si substrates, and back-gated Bi2O2Se field effect transistors are fabricated, outperforming previously reported in-plane Bi2O2Se devices transferred with the assistance of corrosive acids and adhesive polymers. Furthermore, Bi2O2Se/graphene heterostructures are fulfilled by a probe tip to fabricate hybrid phototransistors with pristine interfaces, exhibiting highly efficient photoresponses. The results in this work demonstrate the potential of inclined Bi2O2Se to act as a building block for prospective van der Waals heterostructures.

Evaluación de la toxicidad aguda y composición química de aceite refinado de Moringa oleifera cultivada en México

El aceite de Moringa oleifera está compuesto principalmente de ácido oleico, linoleico y α-linolénico, también contiene fosfolípidos y otros componentes minoritarios, como enzimas, alcaloides y glucosinolatos, compuestos que pueden generar características no deseadas y/o toxicidad, sin embargo, éstos pueden eliminarse mediante un proceso de refinación. El objetivo de este trabajo fue evaluar el efecto de la refinación química sobre la toxicidad aguda, la composición de ácidos grasos, y las propiedades fisicoquímicas del aceite de semilla de M. oleifera de una variedad mexicana, para ésto, el aceite se extrajo por prensado mecánico de las semillas para someterse a refinación química. Al aceite crudo y refinado se les determinó toxicidad aguda probada en un modelo murino, así como también el perfil de los ácidos grasos, los índices de yodo, saponificación y peróxido, además de la acidez, y capacidad antioxidante. Los resultados mostraron que el aceite de semilla de M. oleifera no presentó toxicidad aguda en el intervalo de 300-2,000 mg/kg; por lo que podría ser utilizado para consumo humano. El proceso de refinación no tuvo efecto significativo (p < 0.05) sobre el contenido del ácido oleico (69%), linoleico (0.74%) y α-linolénico (1.97%). Después del proceso de refinación, aumentó el valor del índice de yodo y de saponificación, mientras que el índice de peróxido, la acidez, el contenido de β-caroteno y la capacidad antioxidante disminuyeron.

Highly transparent, low sheet resistance and stable Tannic acid modified-SWCNT/AgNW double-layer conductive network for organic light emitting diodes

In this paper, we used tannic acid (TA) functionalized carbon nanotubes (TCNTs), and silver nanowires (AgNWs) to construct a new type of transparent conductive film (TCF) with a double-layered conductive network structure. The hybrid film exhibits excellent light transmittance, high electrical conductivity, ultra-flexibility, and strong adhesion. These outstanding performances benefit from the filling and adhesion of hydrophilic TCNT layers to the AgNW networks. Besides, we introduced the post-treatment process of mechanical pressing and covering polymer conductive polymer PEDOT:PSS, which obtained three layers of TCNT/AgNW/PEDOT hybrid film and greatly improved the comprehensive properties. The hybrid film can reach a sheet resistance of 9.2 Ω sq−1 with a transmittance of 83.4% at 550 nm wavelength, and a low root mean square (RMS) roughness (approximately 3.8 nm). After 10 000 bends and tape testing, the conductivity and transmittance of the hybrid film remain stable. The resistance of the film has no significant degradation after 14 d of exposure to high temperature of 85 °C and humidity of 85%, indicating excellent stability. The organic light-emitting diodes (OLEDs) with TCNT/AgNW/PEDOT hybrid film as anode exhibit high current density and luminosity, confirming this process has considerable potential application in photovoltaic devices.

Digestibility and water quality investigations on the processed peanut (Arachis hypogaea) meal fed barramundi (Lates calcarifer) at various inclusion levels

The present study compared the nutrient compositions of peanut seed (Arachis hypogaea) subjected to three processing techniques; mechanical pressing, fermentation and germination. The study also evaluated the effect of inclusion level (0%, 15 %, 30 % and 60 %) on nutrient digestibility of these meals by juvenile barramundi (Lates calcarifer) and the subsequent discharge of nutrients to the rearing water. A diet containing no peanut meal served as a reference diet. Barramundi of average weight of 31.2 ± 1.2 g were fed on 10 test diets for 4 weeks. Germination processing significantly (p < 0.05) lowered the carbohydrate and hydrolysed fat contents of peanut meal and its protein level. Fermentation and germination significantly affected the protein quality of peanut meal producing a greater proportion of short peptides (<35 kDa) than achieved by mechanical pressing. Fermented peanut meal at any inclusion level resulted in significantly increased ADC of protein, while 60 % inclusion of mechanically pressed and germinated PM reduced the diet ADC of protein. Ionic phosphate (PO4−), chemical oxygen demand (COD) and total suspended solids (TSS) of rearing water of holding barramundi fed peanut meal-based diets were not different to the reference diet measured two, four and six days after water circulation of tanks was stopped. However, after six days, NH4+ decreased in tanks of barramundi fed fermented peanut meal diet while it increased in tanks fed mechanically pressed peanut meal and of those 60 % germinated peanut meal. Overall, it can be concluded that fermentation processing of peanut meal improves its protein digestibility, increases the production of short chain peptides and reduces the concentration of NH4+ entering holding water compared to diet using germinated or mechanically pressed peanut meal.

Effect of Four Grape Varieties on the Physicochemical and Sensory Properties of Unripe Grape Verjuice

Verjuice is a sour-tasting juice obtained from the mechanical pressing of unripe grapes. The significance of verjuice as food product includes but not limited to its richness in antioxidant compounds, its usage as an alternative to lemon and vinegar, and also its production which can reduce the losses of lower quality grapes and waste from grape thinning. In this study, a survey for the common Lebanese traditional preparation methods for verjuice was done and physicochemical properties of four Lebanese verjuice varieties Tfayfihi, Baytamoni, Black, and Obeideh along with their sensory evaluation by consumers were studied. Results showed that “Black” grape verjuice has the highest density (1.01 ± 0.003 g/L), titratable acidity (4.51 g/L ± 0.03), total soluble solids (5.38°Brix ± 0.3), and polyphenol content (676.1 mg/L ± 6.8); verjuice processed from the Baytamoni grape variety has the highest browning index (0.432 ± 0.002) and color intensity (1.18 ± 0.007); “Obeideh” grape verjuice has the highest pH (2.55 ± 0.006); and “Tfayfihi” grape verjuice has the highest radical scavenging potential (91.76% ± 0.43) and moisture content (95.85% ± 0.19). Both “Tfayfihi” and “Black” grape verjuice has the highest total suspended solids (40 g/L ± 1.3 and 40 g/L ± 2.9, respectively) among all studied verjuice. There is no difference in taste between the four verjuice varieties which we studied, but there is a color preference for the “Tfayfihi” verjuice. The use of different varieties of grapes in the processing of verjuice affects the physicochemical and sensory properties and results in selection of grape varieties being favorable in the processing of verjuice with respect to factors such as polyphenol content and color of the final product.

Digestibility of amino acids and concentrations of metabolizable energy and net energy are greater in high-shear dry soybean expellers than in soybean meal when fed to growing pigs.

Soybean expellers may be produced by dry extrusion and mechanical oil pressing of soybeans, but there is limited information about the nutritional value of expellers produced via this procedure. Therefore, 2 experiments were conducted to test the hypothesis that standardized ileal digestibility (SID) of CP and amino acids (AA), apparent total tract digestibility (ATTD) of energy and total dietary fiber (TDF), and concentrations of DE, ME, and NE are greater in soybean expellers than in soybean meal (SBM) when fed to growing pigs. Pigs were the offspring of Line 359 boars mated to Camborough females (Pig Improvement Company, Hendersonville, TN). In experiment 1, nine growing barrows (initial BW: 55.98 kg ± 13.75 kg) with T-cannulas installed in the distal ileum were allotted to 1 of 3 diets using a triplicated 3 × 3 Latin square design with 3 periods. Two diets were formulated to contain 35% soybean expellers or 33% SBM as the sole source of AA. A N-free diet was used to determine basal endogenous losses of AA. Ileal digesta were collected on days 6 and 7 of each 7-d period. Results indicated that the SID of most indispensable and dispensable AA were greater (P < 0.05) or tended (P < 0.10) to be greater in soybean expellers than in SBM. In experiment 2, a corn-based diet and 2 diets based on corn and each of the 2 soybean products were formulated. Twenty-four growing barrows (initial BW: 44.88 kg ± 2.17 kg) were allotted to 1 of the 3 diets with 8 pigs per diet. Urine and fecal samples were collected for 4 d after 5 d of adaptation. Results indicated that the ATTD of energy and TDF was not different between soybean expellers and SBM, but the ATTD of TDF in the 2 soybean products was greater (P < 0.05) than in corn. Concentrations of DE and ME in soybean expellers were greater (P < 0.05) compared with corn or SBM. Soybean expellers had greater (P < 0.05) calculated NE compared with SBM, but there was no difference in NE between corn and soybean expellers. In conclusion, values for SID of most AA and DE, ME, and NE in soybean expellers were greater than in SBM.

Mechanical and Enzyme Assisted Fractionation Process for a Sustainable Production of Black Soldier Fly (Hermetia illucens) Ingredients

This study aimed at effective fractionation of Hermetia illucens into lipid and protein, taking into account the insects’ anatomy. A hybrid approach was developed, separating the exoskeleton by mechanical pressing and fractionating the slurry by sonication and enzymatic treatment. Microscopy showed the peripheral fat bodies were tightly attached to muscle fibers. Blanching caused protein aggregation and entrapment of fat in the protein matrix, resulting in 25.0% loss in fat extraction, compared to only 3.3% loss for unblanched larvae. After centrifugation of the juice obtained from unblanched larvae a cream layer rich of lipids and proteins, a supernatant with soluble protein, and a pellet including mainly insoluble protein were obtained. Blanched juice centrifugation formed a lipid fraction, a reduced cream layer, and more pellet. Whereas sonication hardly affected the fractionation, enzymatic treatment resulted in solubilisation of pellet protein and an increased lipid layer. Absence of blanching is very effective to extract more lipids (>80%) from whole larvae in the form of a cream layer, while blanched-enzymatic treatment extracted most lipids in a clear lipid layer (>40%). For all treatments around 50% of protein was recovered in the residue and the other 50% mainly in the pellet after centrifugation.

Green and eco-friendly chemical exfoliation of two-dimensional nanosheets in the C2H4O3-based system under the assistance of microwave irradiation

Eco-friendly exfoliation of two-dimensional nanosheets from their layered bulks is very attracting but still remains a big challenge. Here, we report a novel preparation route of two-dimensional nanosheets through soaking the bulk layered material in the C2H4O3-based chemical exfoliation system followed by microwave irradiation. This route has demonstrated the effective exfoliation of two-dimensional nanosheets (graphene nanosheets, BNNS and MoS2NS) from their layered bulks in a green and eco-friendly way. The average layer-number of the obtained graphene nanosheets, BNNS and MoS2NS is 4, 6 and 5, respectively, behaving a few-layer feature. Interestingly, when the graphene paper is prepared from the exfoliated graphene nanosheets by simple vacuum filtration and mechanical pressing, its average electrical conductivity is up to 7.36 × 105 S/m and the EMI SE value reaches to 61 dB, both among the highest for the graphene papers reported previously. Since there exists no serious fragmentation of layered materials during the whole exfoliation, the present exfoliation strategy is more competent in preparing the large-sized two-dimensional nanosheets over those conventional green routes.

Highly Ordered and Dense Thermally Conductive Graphitic Films from a Graphene Oxide/Reduced Graphene Oxide Mixture

Summary We report a new approach to making highly dense, oriented, and crystalline graphite films from heat-treated and pressed graphene oxide (G-O). By introducing small-diameter reduced graphene oxide (rG-O) flakes into the graphene oxide starting material, we found that after heat treatment at 3,000°C, the sample density and atomic order substantially improved over a film composed, at the outset, only of pure G-O flakes. A subsequent mechanical press increased the density but reduced the atomic order. A second 3,000°C heat treatment restored the graphitic structure with graphitization metrics exceeding even those of the first heat treatment. The optimized graphitic film with an original concentration of 15 wt % reduced G-O in G-O gave well-oriented graphitic films with a density of 2.1 g cm−3, cross-plane thermal conductivity of 5.65 W m−1 K−1, and in-plane thermal conductivity of 2,025 ± 25 W m−1 K−1.

Preliminary study of cocoa powder’s polyphenol extraction by food grade solvent

Cocoa contains polyphenol substances, namely flavan-3-ols, i.e. catechin, epicatechin, and proanthocyanidin. Its polyphenol antioxidant activity is larger than that of other sources, like green tea, apple, etc. Polyphenol of cocoa can be extracted from cocoa powder which is defatted partially by mechanical pressing (mechanical defatting) before, so that there is little of cocoa fat which still presence in cocoa powder by approximately 11% (w/w). However, the fat has characteristic as interference of polyphenol extraction. Generally, the non-food grade non-polar solvent are used to take the fat before extracting polyphenol, i.e. hexane, petroleum ether, and etc. By the research, it was studied about directly extraction of partially defatted cocoa powder’s polyphenol by food grade solvent without defatting process previously. The chosen solvent comprised water, acidified water (citric buffer), 50% ethanol, and 80% ethanol. Besides it, the study was also focused on extraction temperature that varied in room temperature (22°C) and 50°C. The parameter evaluated in this study were total phenolic content (TPC) and antioxidant activity expressed as antiradical power (ARP). The results showed the directly extraction of polyphenol consists of steps, i.e. extraction, centrifugation, first filtering, chilling, and second filtering. The highest of total phenolic content (TPC) was obtained from extraction conducted by 50% ethanol at temperature of 50°C and the highest antiradical power was obtained from extraction conducted by 50% ethanol at temperature of 22°C.

Low‐Resistant Electrical and Robust Mechanical Contacts of Self‐Attachable Flexible Transparent Electrodes with Patternable Circuits

AbstractFlexible, transparent, conductive electrodes are key elements of emerging flexible electronic and energy devices. Such electrodes should form an intimate physical contact with various active components of flexible devices to ensure stable, low‐resistant electrical contacts. However, contact formation techniques are based largely on conventional soldering, conductive pastes, mechanical clamping, and thin film deposition. These generally result in damaged, contaminated, bulky, and uncontrollable contact interfaces. A self‐attachable, flexible, transparent, and conductive electrode that is based on a distinctive design of regular grid patterns into which bioinspired adhesive architectures and percolating Ag nanowires are integrated is proposed. Based on this integrated design, the proposed electrode forms reliable, low‐resistant electrical contacts; strong mechanical adhesive contacts; and ultra‐clean, damage‐free contact interfaces with active device components by attaching onto the components without using additional conductive pastes, mechanical pressing, or vacuum deposition processes. The contact interfaces of the electrode and device components remain stable even when the electrode is extremely bent. Moreover, specific electronic circuits can be generated on the electrode surface by a selective deposition of Ag nanowires. This enables simple interconnections of diverse electronic components on its surface.

Critical Role of Degree of Polymerization of Cellulose in Super-Strong Nanocellulose Films

Summary Translation of the outstanding mechanical performance of individual nanocellulose to macroscopic nanocellulose films can be achieved by various alignment techniques. However, attention has seldom been paid to the degree of polymerization (DP) of cellulose that plays a pivotal role in increasing the mechanical strength of nanocellulose films. In this work, nanocellulose film with superior tensile strength (1,014.7 ± 69.1 MPa) is presented by a cellulose DP protection strategy. An alkaline sulfite-anthraquinone-methanol pulping is applied to not only rapidly remove most of lignin and hemicellulose from wood blocks, which facilitates the formation of hydrogen bonds among neighboring fiber cell walls in subsequent mechanical pressing, but also to significantly suppress the decomposition of cellulose DP. Such strong nanocellulose film sheds light on unlocking the exceptional mechanical potential of cellulose and has the potential for use in advanced applications traditionally dominated by nonrenewable materials such as plastics, glass, and metals.

Physicochemical Characterizes of Argan Oil (Argania spinosa L.) Affected by Roasting and Pulping by Goats

Present study investigates the influence of roasting and pulping by goats on the quality of argan oil (Argania spinosa L.). To carry out this work, 4 different samples selected by their method of extraction (by mechanical pressing from argan fruits pulped by goats). The study of the physicochemical characteristics of the 4 samples shows that the roasting of the almonds of the argan fruit and the pulping by the goat appear as a parameter can increase the value of the peroxide index and the acidity. It’s also found that pulping by goats can decrease the value of fatty acids (linoleic C18: 2) and the percentage of triglycerides (LLL, LOO and OOO) in argan oil. The result of sterols clearly shows that roasting is reduced the total sterols. The study of the concentration of benzo-α-pyrene suggests that roasting does not produce significant amounts of benzo-α-pyrene. Also, present findings shows that roasting and pulping by goats appears as a parameter influencing the acid value of argan oil. In fact, the acidity value is higher in the argan oil samples prepared from roasted almonds and pulped by goats. Finally, the present study indicated that the high quality of argan oil can be extracted by mechanical pressing and which is not pulped by goats and, therefore, current results may support the marketing of the oil argan.

Oils rich in alpha linolenic acid: chemical composition of perilla (Perilla frutescens) seed oil

In this paper, the main chemical properties of Perilla seed oil (PO) obtained by mechanical pressing of Perilla seeds are reported. The analysis of fatty acid composition has highlighted a very high amount of (n-3) α-linolenic acid (ALA), more than 60%, higher than other ALA rich oils such as linseed and sacha inchi oils and similar to chia oil. PO has an important sterol (higher than 3000 mg/kg) and vitamin E (approx. 870 mg/kg) content, while biophenols are in quite low concentration. The analyzed sample showed a very low acid and peroxide value and this is the demonstration that, following the proper technological procedures, it is possible to obtain high quality oils even in presence of high α-linolenic acid concentrations.

Characterization of Fatty Acids in Cereals and Oilseeds from the Republic of Serbia by Gas Chromatography – Mass Spectrometry (GC/MS) with Chemometrics

This study investigates the potential of fatty acid profiles of various industrial crops to discriminate them based on their botanical origin. All of the analyzed plants were grown on experimental fields at Rimski Šančevi, Republic of Serbia. Cereal samples (corn, wheat, barley, and oat) were milled into flour and lipid fractions were extracted using n-hexane. Lipid fractions of oilseed samples (rape, flax, safflower, and pumpkin) were obtained by mechanical pressing. The fatty acids present in lipid fractions, were derivatized into corresponding volatile methyl esters (FAMEs) and determined on a gas chromatography/mass spectrometry instrument (GC-MS). Peaks of eluting compounds were simultaneously identified using mass spectra libraries, giving a match quality of over 90%. The peaks of molecular ions of methyl esters of 9 dominant fatty acids were extracted, and their abundances used to create numerical matrices for further data processing. Chemometric multivariate data analysis tools—principal component analysis (PCA), cluster analysis (CA), principal coordinate analysis (PCoA) and linear discriminant analysis (LDA), were used to extract significant variables, visualize discriminations, and classify between analyzed plant samples. The applied tools demonstrated separations of analyzed cereals in three groups: corn, oat and the samples of small grains—wheat and barley. In the case of oilseeds a clear separation between all four plant species was obtained. This work represents a new concept of the application of fatty acid analysis in developing authentication methods for industrial crops and their staple food products.

EFFECT OF ECOFRIENDLY BIO-BASED SOLVENTS ON OIL EXTRACTION FROM GREEN COFFEE BEAN AND ITS INDUSTRIAL PRESS CAKE

Abstract Oil recovery, retention index, and thermodynamic parameters of green coffee beans (GCB) and its press cake (PC) extraction using bio-based solvents were investigated. The extraction parameters investigated were temperature (35 to 55 °C), type of material (coffee beans and press cake), and type of solvent (ethanol, acetone, and ethyl acetate), at a fixed solvent to solid mass ratio (5:1) (w/w). The fatty acid profile of the ethanolic extract was assessed for both GCB and PC, and compared to the oil obtained from the mechanical pressing. It was observed that higher temperatures affected positively the extraction yields, especially when acetone and ethanol were employed, allowing a recovery up to 90% and 56.7% for GCB and PC, respectively. The solution retained in the raffinate phase from the GCB extraction was greater than that for the PC. For all operational levels, the ∆H and ∆S were positive. ∆G decreased with increasing temperature. Palmitic and linoleic acids were predominant in all types of oil. The oil obtained by pressing showed higher content of linoleic acid (45.32%), while the solvent-extracted oil from GCB had more palmitic acid (34.79%), and the PC oil presented intermediate levels of all the methyl esters.