Screw Press Research Articles

Essential oil of black pepper (Piper nigrum) and cardamom (Amomum sublatum roxb) as a natural food preservative for plum RTS

Ready-to-serve (RTS) drinks and fruit juices are crucial due to their high calorie, fiber, and vitamin content. However, their limited shelf life and rapid nutrient loss raise food safety concerns. Applied artificial preservatives may be allergic and cause adverse health effects on humans; consequently, worldwide concern about using natural preservatives instead of artificial ones. This study's main focus is to replace artificial preservatives by applying essential oils from black pepper (Bp) and cardamom (Cd) as natural preservatives in plum RTS drinks. The essential oil was extracted by hydro-distillation using a Clevenger type apparatus and stored at 4 to 6 °C. Following, plum juice was extracted by a screw press juice extractor and afterward maintained at 0.3 % acidity and 15°-brix (°Bx) total soluble solid (TSS), finally, pasteurized at 90 °C for 10 min and stored at refrigeration temperature. After preparation of RTS, it was divided into four equal batches of 250 cm3 with no additives (A), 0.100 cm3 ethanol (B), samples C and D were prepared with 0.090 cm3 of ethanol and 0.010 cm3 of essential oils of Bp and Cd. The samples were stored at a refrigerated temperature of 4 to 6 °C and analysis of pH, % titratable acidity, mg of ascorbic acid, TSS, % total sugar, % reducing sugar, free radical scavenging activity (%RSA), total microbial count, and yeast-mold count were carried out at a fixed interval of 7 days for 28 days. Overall, significant variations were observed in the blank sample compared with the sample containing the essential oils of Bp and cardamom Cd during the storage period of 28 days. These findings highlighted valuable insights into the essential oils of Bp and Cd exhibit the preservative effect in plum RTS; ultimately, cardamom essential oil exhibits the best preservative effect on plum RTS.

Extraction and purification of seaweed protein from Ulva sp. - Challenges to overcome

Ulva sp. has gained attention as a promising and sustainable protein source, due to its high essential amino acid content. This study investigated traditional extraction methods using a double screw press followed by acid or heat precipitation. Furthermore, the screw pressing was combined by a novel purification method that combines mild heat treatment with microfiltration for removal of chlorophyll, to produce white Ulva protein. The double screw press followed by acid precipitation or heat denaturation showed low total protein yields, with 14% of the biomass protein extracted, of which half was soluble. The highest total protein yield (5.5%) was achieved with acid precipitation at pH 2, while heat denaturation at 90 °C resulted in a total protein yield of 4.1%. Acid precipitation proved to be effective with ∼ 81% precipitation of solubilized protein compared to ∼ 43% for heat denaturation. While microfiltration effectively retained chlorophyll in the retentate, the recovery of protein in the permeate remained challenging. SDS-PAGE analysis of proteins in different microfiltration-fractions showed that larger protein complexes (>250 kDa) were unable to transmit through the membranes, resulting in a maximum recovery of 24.9% of the feed-protein in the permeate. Further refinement of Ulva fractionation protocols is imperative for improvement.

EFFECT OF PROCESSING TECHNIQUES ON FUEL BRIQUETTES

Densification of agroforestry biomass for energy production has positively impacted the energy sector across the globe. Wood fuel consumption has led to deforestation and degradation. Recently, much has been discussed on biomass briquetting technologies and their influence. However, knowledge about appropriate technique for briquetting to achieve high-quality briquettes is yet to be explored. Thus, efforts were made to critically evaluate briquetting techniques on briquettes’ combustion performance properties. The Water Boiling Test was used in the determination of various parameters. High (screw press); and low (drum agglomerator and hand making) pressure briquetting techniques were distinctly different in ignition time (minutes), time to boil (minutes) burning rate (g/min), specific fuel consumption (g/ml) and power output (kW) values as (1.3,1.0,0.9; 14, 12, 11: 0.8, 1.1, 1.3; 0.11, 0.13, 0.15; and 1.8, 1.4, 0.75). Briquetting technology, based on pressure, is thus a factor that influence performance properties of briquettes. This knowledge is therefore useful when converting waste biomass into briquettes as alternate energy source towards realization of Sustainable Development Goal #7 on affordable and clean energy.

Analysis of Screw Press Machine Performance Using the Overall Equipment Effectiveness Method at PT Agro Synergy Nusantara

PT Agro Sinergi Nusantara PKS Aceh Seujahtera is a company engaged in the plantation and processing of oil palm fruit, where the production is in the form of crude palm oil (CPO), palm kernel and fiber. This factory has 2 horizontal type sterilizers with a capacity of 40 tons each. One machine that has a vital role in the production process is the screw press. Based on the results of observations and interviews with the company, it was found that the screw press machine was often damaged in the production process, as a result the production process was stopped and production results were not optimal, besides that the company would also experience losses. The purpose of this research is to measure the performance of the Screw Press Machine at PT Agro Sinergi Nusantara by calculating OEE through 3 main factors, namely Availability Ratio, Performance Effeciency Ratio, and Quality Ratio and determining corrective actions that can improve the performance of the Screw Press machine. The results of the performance analysis on the screw press machine obtained an Availability Ratio value of 84.52%, Performance Effeciency Ratio of 86.68%, Quality Ratio of 100%, and OEE of 73.37%. Based on a comparison with the Word Class Ideal Standard, only the Quality Ratio value meets the standard while the Availability Ratio, Performance Effeciency Ratio, and OEE have not met, meaning that the overall performance of the Screw Press Machine has decreased and has not met the Word Class Ideal Standard and it is necessary to improve the performance of the machine. Recommendations for improvements that can be made to improve the performance of the screw press machine again are to carry out routine maintenance on machine components so that damage can be prevented before severe damage occurs and cause longer downtime, conduct training for workers so that they can develop themselves and know more about the machine and the responsibilities that must be carried out, reinforce the implementation of routine and scheduled maintenance (preventive maintenance), and increase supervision during the FFB sorting process.

Effects of screw pressing conditions on fodder radish seed oil yield, throughput, and fatty acid profile

AbstractThis study aims to explore the influence of screw frequency, nozzle diameter, and press head temperature on critical crude fodder radish seed oil (FRSO) yield, throughput, and fatty acid composition. A quadratic equation, developed using response surface methodology, fitted the experimental data for oil yield. It was substantiated by a non‐significant lack‐of‐fit, commendable coefficient‐of‐determination (R2 = 0.782), and a modest mean relative percentage deviation (±7.27%). The analysis of variance pinpointed the statistical significance of press head temperature, nozzle size, and the squared term of press head temperature. The highest FRSO yield (17.61%)—corresponding to an extraction efficiency of 51.3% was found with a screw frequency of 50 Hz, at 80°C, and an 8 mm nozzle. A linear model highlighted that all three pressing factors significantly influenced the FRSO throughput. FRSO consists of C18:1 (30.9%), C22:1 (20.8%), C18:2 (14.9%), and C18:3 (11.9%), aligning with the compositions reported in other studies on fodder radish oils.Practical applicationsEffective control of cold pressing parameters is paramount to maximize oil yield and throughput during the oil extraction process and to ensure the appropriate oil quality. A comprehensive understanding of the intricacies of this process, while carefully considering key parameters, which is essential to ensure efficiency, is achieved through a combination of experimental and statistical methods. This study marks the inaugural attempt to optimize screw pressing for fodder radish seeds while conducting a comparative analysis with hydraulic pressing and the Soxhlet extraction method, focusing on oil yield, throughput, and fatty acid composition within the system by employing a modeling approach for oil extraction. Through the utilization of the response surface methodology coupled with various experimental designs, the processing conditions are successfully optimized. The valuable data gathered can aid equipment design for an efficient, eco‐friendly oil extraction process. Furthermore, the oil extracted under the optimized conditions met the quality standards.

DETERMINING THE WEIGHT OF OIL EXTRACTED WITH A SCREW PRESS USING A STRAIN GAUGE SENSOR, HX711 MODULE, AND ARDUINO

This research presents an automated system for quantifying oil extracted from a screw press, leveraging a strain gauge sensor and HX711 module in synergy with the Arduino platform. This innovative setup measures the target mass of extracted oil, wherein the collected data is further processed by an Arduino microcontroller. User-defined measurement parameters, such as specific oil mass, dictate when the system terminates the screw press operation. Hitting the set oil mass triggers the Arduino microcontroller to halt the press, allowing for the conservation of raw materials and energy, and consequently ensuring product quality consistency. Conversely, if the desired mass value remains unreached, the extraction continues until fulfillment of target outcomes. This approach optimizes press use, manifesting in maximum efficiency and selectivity in the production process. It demonstrates how such a control system can automate measurement and production supervision, thus fostering optimal screw press operation. The article suggests the solution for integrating Arduino, HX711 module, and strain gauge sensor to measure the weight of the oil extracted through the screw press. The strain gauge and HX711 module were programmed within the Arduino Integrated Development Environment, enabling the accurate measurement of extracted oil mass and data transference to the Arduino controller. A housing bracket 3D model for the strain gauge and HX711 module within the existing screw press was also created using 3D modelling and subsequently printed and implemented. This aids reliable sensor fitting and ensures system stability for oil mass measurement. This study demonstrates the potential for implementing this advancement within pre-existing press infrastructures with minimal changes. Our methodology offers prospective enhancements in quality and efficiency, notably within the oil production domain.

Physicochemical Characterisation of Seeds, Oil and Defatted Cake of Three Hempseed Varieties Cultivated in Spain.

The increasing use of hempseed in food products highlights the need for a comprehensive database for scientific research and industrial applications. In food development, information about the techno-functional properties of raw materials plays a crucial role in determining the suitability of each product for specific applications. Thus, this study aims to characterise three hempseed varieties (Ferimon, Henola and Uso-31), comparing their physicochemical and nutritional compositions. Moreover, the study investigates the impact of hempseed varieties on the techno-functional, physical and thermal properties of the partially defatted hempseed flours (PDHFs) obtained from single screw pressing (SSP) oil extraction. The fatty acid and tocopherol profiles of the dehulled seeds and oil were also analysed. Significant variations in yield and physical properties were observed among hempseed varieties, influenced by genetics, adaptation to agro-climatic conditions and cultivation systems. Despite its lower yield (kg/ha), Uso-31 exhibited superior 1000-seed weight, dehulling yield and larger mean seed size (1.79 ± 0.02 mm). Hempseed oil was rich in unsaturated fatty acids, particularly linoleic (51.2-53.4 g/100 g oil) and α-linolenic (14.88-18.97 g/100 oil) acids, showing variations in γ- and α-tocopherols depending on the variety. The variety also influenced the least gelation concentration (LGC) and techno-functional properties such as water absorption capacity (WAC), emulsifying activity (EA) and emulsion stability (ES). SDS-PAGE and DSC measurements indicated the presence of 11S and 7S globulin proteins with denaturation temperatures above 87.8 °C. These findings confirm that the studied hempseed flours are valuable techno-functional and nutritional ingredients suitable for sustainable food formulations.

Analisa Kinerja Mesin Ripple Mill dengan Beban 30 Ton/Jam

The growth of oil palm agricultural land until 2017 was 234 479. Ha, with a production productivity figure of 437 292 tons. (BPS 2017) The development of oil palm plants has been developed in several regions in Indonesia and has become a superior plantation crop. Because it has quite high economic value. One factor that needs to be considered in the company's progress is the issue of smoothness. The production process is greatly influenced by the performance of the machines used. PT. Merbaujaya Indahraya is a subsidiary company of PT. MIG is engaged in processing fresh palm fruit bunches into Crude Palm Oil and Palm Kernel Oil. Fresh fruit bunches are obtained from core gardens and farmers. Core garden with 4 sections of MI Group gardens (MI, Binanga Mandala and Heksa). with a capacity of 30 tons/hour. Processing palm oil into CPO (Crude Palm Oil) has several stations including Loading ramp, Sterilizer, Thresser, Screw Press, clarification, and Kernel. The ripple mill machine is a palm kernel processing machine that is located at the kernel station and is prone to damage, where in the ripple mill machine, the seeds enter between the rotor and the ripple plate being pressed so that they collide with each other and break the shell from the core. So that the core is separated from the shell. This research aims to analyze the performance of the ripple mill machine. From the results of the analysis, an efficiency level of 80% was obtained, with 4 samples taken and varying collection times of around 2 hours within 1 (one) day of production.

Developing a novel technology for slurry management by project-based learning

Farming is responsible for 30% of global anthropogenic emissions. A novel technology, aligning with current regulations of covering slurry stores, has been developed for processing anaerobic digestate liquor, which is obtained from the screw press stage. Instead of using hazardous chemicals, such as sulfuric acid, to capture ammonia and greenhouse gases, the artifact contains calcium chloride as deliquescent salt. Preliminary simulations in Aspen Plus® v12 showed that the absorption of NH3 and carbon dioxide during the solid–liquid separation was feasible and the resulting clean brine could be used as chemical amendment of untreated slurry. The characterization of the performance of the artifact was organized following a project-based learning active teaching method, for a group of 3 students (17-year-olds) of secondary education, as part of the In2ScienceUK program. The collection of empirical data allowed the contents of the curriculum to be contextualized, enhancing environmental awareness of participants. A titrimetric method was employed to determine the content of NH3 and CO2 in the brine, and the granulation of the dewatered liquor with the fibers of anaerobic digestate was investigated by determining the compression strength required to break the pellets. The operation capacity of the prototype was found to be 250 m3 of liquor per year, at a cost of £1/m3. The use of the filtered brine as chemical amendment also represented an additional 5.60 grams of ammoniacal nitrogen and 0.96 grams of inorganic carbon per cubic meter of unprocessed slurry. The concentrated liquor was a good binding agent that provided the pellets with a compressive strength of 207.00 ± 26.36 N, which was above the threshold value for commercialization purposes (50 N). The advances in the development of the prototype enhanced the suitability of the technology for industrial scale applications but hindered the adoption of subsequent editions of this pedagogic tool.

Analysis of the oil extraction process and prospects of automation of screw press operation

Over the last few years, vegetable oils have become an integral food part of the vast majority of the planet's population. In order to preserve all valuable substances in vegetable oils, it is necessary to correctly choose the rational parameters of the oil extraction process. The main purpose of this research is to analyze the influence of various factors on the quantitative and force parameters of the oil extraction process and substantiate the prospective directions of automation of the screw press operation. The research methodology is focused on mathematical modeling of the pressing process and analyzing the stress-strain characteristics of the pressed material (sunflower seeds and cake) at different operational conditions and design parameters of the screw. The obtained results are presented in the form of analytical dependencies of the press output (productivity), extraction pressure, and consumed power on the screw rotational frequency and screw flight pitch. The corresponding graphical dependencies are plotted for visualization of the obtained results with reference to the existing household press LiangTai LTP200. The conclusions on the prospective directions of automation of the screw press operation are drawn. Particularly, the necessity of regulating the temperature of the pressing chamber and extracted oil by means of applying additional heating and cooling devices is substantiated. As well, the sensors that monitor the mass of the extracted oil and the consumed current of the electric motor are proposed to be installed. The rotational frequency of the screw is suggested to be adjustable by applying the frequency converter controlled by the additional electronic system based on the data obtained from the sensors. The paper may be used by scientists and engineers working on designing screw presses and improvement of their performance characteristics. Further investigations on the subject of this research may be focused on experimental verification of the qualitative and quantitative parameters of the extracted oil depending on the type of the seeds or kernels to be pressed, and operational parameters of the press (screw rotation frequency, temperature of the pressing chamber, etc.).

The Dewatering Performance of a Compact Screw Press Manure Separator for Non-Typical Substrates

The dewatering of substrates is one of the key tasks in the handling of material flows in a circular economy. Besides belt filters, sedimenters, and decanters, screw presses are frequently used to reduce the water content of substrates. However, screw presses available on the market are usually designed for high throughputs (>5 m3/h). The dewatering of smaller feed rates (<1 m3/h), however, requires more compact solutions. For this reason, a compact screw press (short screw length), which is normally used in agriculture for cow manure dewatering, was investigated in this work, as there exist no publications on this type of compact screw press. A mobile test setup was developed and loaded with different material such as digested sludge from a wastewater treatment plant, commercially available potting soil, wood shavings, and biological waste. The dry matter content of the feed material, the feed material itself, the screw rotational speed, and the weight setting (pressure) at the back plate were varied, and the effects on the dewatering result were recorded. A significant influence on the dewatering result was found for the weight setting, the type of substrate (particle size), and the dry substance content of the feed material. The tests confirmed that the compact screw press separator is suitable for the dewatering of wood shavings and biological waste (with an increase in dry matter percentage of up to 7.7%). The direct dewatering of potting soil and digested sludge is not possible and can only be implemented by using structural support material. This study fills the gap between published work on large screw presses and potentially new application fields of compact screw press manure separators, which, until now, have only been used in agriculture.

Predicting oil content of Australian beauty leaf tree kernel samples using near infrared spectroscopy combined with chemometrics

This study was conducted to evaluate the ability of near infrared (NIR) spectroscopy to estimate oil content, and per cent of cake, resin and residue in beauty leaf tree ( Calophyllum inophyllum L.) kernel samples. Fruits were collected from various geographical locations of tropical Australia (from Rockhampton to Darwin) and air dried before the kernels were manually separated from the fruits. Kernel samples were oven dried, crushed (5–10 mm) and their NIR spectra collected using a Fourier transform (FT) NIR instrument where the same batch of kernels were used to extract oil using a screw press. Calibration models between the NIR spectra and reference data were developed using partial least squares (PLS) regression. The cross-validation statistics including the coefficient of determination (r2) and standard error in cross validation (SECV) were 0.83 (SECV: 2.39%) for oil content, 0.89 (SECV: 2.81%) for cake, 0.88 (SECV: 1.92%) for resin and 0.79 (SECV: 2.15%) for residue, respectively. This research showed that NIR spectroscopy can be used as an alternative, faster and low-cost technique to predict oil content, per cent of cake, resins and residues in various genotypes of beauty leaf tree. Further studies should be carried out to increase the sample size and chemical variation, as well as to evaluate different methods of oil extraction (e.g., solvent extraction) to improve the reliability of the calibration models.

Mono- and Co- solvency based transesterification of Caryota urens seed oil

This study aims to comprehensively evaluate the reaction parameters and fuel properties of biodiesel derived from underutilized waste Caryota urens seed oil (CUO) using mono- and co-solvency-based transesterification. The CUO was extracted through both solvent extraction at the laboratory scale and mechanical screw press for large-scale purposes, with a maximum oil content of 7.76 ± 1.52% (wt%) reported. Transesterification of CUO was carried out using methyl, ethyl, and methyl-ethyl-based reaction systems employing KOH as a base catalyst and ethanol as a co-solvent. The highest yields were achieved under optimized reaction conditions: molar ratio of 1:9, catalyst concentration of 0.75, 0.6, and 0.6 wt%, reaction temperatures of 60, 75, and 70 °C, reaction times of 135, 90, and 40 min, and methanol to ethanol ratio of 4.5/4.5. Notably, the addition of ethanol in an equivalent ratio to methanol altered the reaction kinetics and product distributions, encouraged reactions at higher temperatures without any loss of solvent loss, reduced the overall reaction time, enhanced the overall ester yield, and exhibited the most favourable fuel properties. In fact, fuel properties of both CUO ethyl and methyl-ethyl esters, evaluated as per ASTM D6751 standards, reported enhanced calorific value (40.14 and 39.67 MJ/kg), cetane number (69.29 and 68.27), kinematic viscosity (5.27 and 5.03 mm2/s), and reduced density (870.76 and 871.41 kg/m3) than compared to CUO methyl esters. The findings of this research indicate that CUO esters, regardless of their form, hold significant potential as a promising source of biodiesel fuel.

Virgin callpohyllum oil as a antioxidant potential and potential cosmetic active ingredient

Nyamplung seed oil has active compounds that can be utilized as the foundation for medications or cosmetics. The purpose of this study is to ascertain the impact of pressing temperature and drying duration on the production of VCphO, a cosmetic preparation, from nyamplung fruit. In this work, Virgin Callophyllum Oil (VCphO) was mechanically extracted at room temperature and heat using a screw press with drying fruit 3, 5, 7 days compare with oven drying. We looked at the pH and phytochemical composition of VCphO. Investigations also looked on antibacterial and antioxidant effects. The yield was unaffected greatly by hot or cold pressing. Pressing at room temperature results in a low acid number, making it the ideal treatment. The pH range of VCphO is 4 to 5.48, which is similar to skin pH. VCphO includes high levels of antioxidants (48–57 %) and total phenols (1–2.6 mg GAE/g sample). Terpenoids, quinon, flavonoids, and phenols are steroid chemicals that demonstrate the antioxidant and antibacterial properties of VCphO. VCphO has a very strong antibacterial against bacteria p.acnes and is weak on s.epidermis bacteria. Based on this, VCphO has the potential to be used in pharmacology.

Determination of Hopper Fullness of Smart Screw Press Using Machine Learning

Problem statement. This research addresses the challenge of accurately determining the fullness of the hopper within a screw press for optimal oil extraction efficiency and quality. Existing weight or volume-based measurement methods can often struggle with determining the feed hopper fullness due to variable oil weights during extraction stages, material heterogeneity, environmental influences and imprecise instrument calibration. Purpose. The study proposes a novel solution via the application of machine learning, specifically aiming to develop and validate a technique that uses acoustic signals to calculate screw press bowl load. Methodology. To implement this solution, the study uses quantitative research, data collection and data analysis, supervised learning. The method is based on the processing of audio data received from microphones located near the auger and the use of machine learning algorithms, such as sound classification. Model training process was facilitated by ML tool Arduino. Findings. The results of this study, facilitated by effective data analysis via ML tools, demonstrate that the evaluated filling level of the screw press hopper can effectively be determined by the sound signals produced and corresponding machine learning algorithms. Originality. The distinct advantage of this approach lies in its ability to automate the monitoring and operational control process of the oil press, thereby improving device efficiency and resource conservation. Practical value. The proposed approach allows to automate the process of determining the fullness of the bowl and monitor the condition of the auger by its sound characteristics. This solution can be utilized in the oil production industry to enhance the productivity of the screw presses. This research underscores the promise of machine learning applications and the potential for future research focusing on improving model adaptability and developing predictive maintenance systems. These future investigative scopes could essentially revolutionize monitoring and operational practices within the oil extraction industry.

The Impact of Screw Pitch Types on Screw Feeder Performance on Floating Fish Feed Machine

One of the important parts of the floating pellet machine, a tool often used in Indonesia to produce fish feed, is the screw press. The largest contributor to the overall production cost in fish farming is fish feed. Floating pellet machines usually require two motors and have large machine dimensions due to the use of two constant-pitch screw feeders. The purpose of this study was to optimize the performance of the floating fish feed machine with one screw press and one drive motor, with the screw feeder selected as the variable-pitch type. The simulation method was used to compare the mass flow rate produced by each screw pitch and the pressure value parameters on the screw. Based on the results of the study, by using the same fish feed machine base, changing the screw pitch type from the constant type to the variable type, provides an increase in the quality of the fish feed produced to be denser and not easily destroyed, and its buoyancy increases.

Mathematical model of the influence of geometric parameters of the shaft on the productivity of the screw press

The objective of the article is to describe influence of geometric parameters of the shaft on the screw press productivity. This study refines existing mathematical models, emphasizing the impact of geometric dimensions on press productivity. The research culminates in presenting a versatile screw press design tailored for diverse oil-containing raw materials. This design optimization aims to enhance oil extraction efficiency and offers crucial insights for the agro-industrial sector, supporting sustainable and high-quality food production.

Bioactive Constituents in Cold-Pressed Plant Oils: Their Structure, Bioactivity and Chromatographic Analysis.

Cold-pressed oils are oils prepared from pressing plant materials with a screw or hydraulic press, yielding oils with little contamination of harmful chemicals and high content of nutrients and functional constituents. Cold-pressed oils have gained increasing recognition as food supplements for preventing and ameliorating body deterioration due to ageing and the progression of lifestyle diseases or non-communicable diseases. This article aimed to review their structure, bioactivity, and chromatographic analysis of the mostly found functional compounds in cold-pressed oils, including phytosterols, carotenoids, tocols (tocopherols and tocotrienols), phenolic compounds (flavonoids, phenolic acids, tannins, stilbenes, and lignans), and squalene.

Statistička optimizacija hladnog pužnog presovanja semena krmne rotkvice u odnosu na sadržaj rezidualnog ulja u pogači, efikasnost ekstrakcije i kapacitet prese

Fodder radish (Raphanus sativus L. var. oleiformis Pers) is a promising biofuel source. Response surface methodology was used to optimize screw pressing of fodder radish seeds. The key parameters were nozzle diameter, press head temperature, and screw frequency. A quadratic model accurately predicted the minimum residual oil content in the press cake (20.7%), close to the actual one (22.1 ± 0.7%), using an 8 mm nozzle diameter, 80 °C press head temperature, and 40 Hz screw frequencies. All three process factors are statistically significant, but nozzle diameter had the most influence. An extended linear model identified all three process factors as significant for seed throughput, with screw frequency having a greater impact. The maximum seed throughput was achieved with a 12 mm nozzle, 80 °C press head temperature, and 60 Hz screw frequency (predicted 8.17 g/ min, actual 8.08 g/min).

Yield, Physicochemical Properties, and Fatty Acid Profile of Vegetable Oil Extracted From Seed Coats of Strychnos pungens Soler. Fruits Collected in Chikomba, Zimbabwe.

The study examined Strychnos pungens Soler. (family LOGANIACEAE) fruit as a potential source of vegetable oil. Ripe fruits collected from a forested site in Zimbabwe were processed to determine the partitioning of fresh and dry fruit biomass. The oil was extracted from the seed coat using a hand-operated screw press, and its physiological properties were analyzed. Seeds contributed the most to the fresh weight of the fruit, followed by the shell and pulp. The seed coat was a significant component of the seeds. The seed coat, but not the pulp of the fruit, was found to contain screw press-extractable oil, the yield of which was substantial, amounting to around 39% of the dry weight of the seed coat. The oil was found to have a high free fatty acid content and a moderate iodine value (83 gI2/100 g), indicating a degree of unsaturation. Furthermore, the oil contained carotenoids and tocols, which serve as antioxidants that help to protect the oil from oxidation. The oil had a high content of monounsaturated oleic acid (78.3%), which is known for its stability and health benefits. The low levels of saturated and polyunsaturated fatty acids make it a high oleic oil. The volatile profile of the oil included compounds with pleasant fruity aromas that enhance its flavour and fragrance. The results highlighted the need for waste management strategies if S. pungens is industrialized as an oil crop. Significant waste, including shells, pulp, cake residue, and seed kernels, would need proper handling and valorisation. In summary, the research showed that S. pungens has the potential to be a valuable source of high-quality vegetable oil with good oxidative stability and health benefits, primarily due to its high content of oleic acid and antioxidant compounds.