Screw Press Research Articles

Systems analysis of digestate primary processing techniques

In this paper, we performed technology assessment and systems analysis of primary digestate processing techniques to provide a comprehensive analysis of their environmental and cost performance. We compiled more than 100 observations from large-scale biogas plants and considered digestate based on manure, crops and agro-wastes, and food waste under the geographical contexts of Sweden and Belgium. Centrifuge, screw press, and rotary drum were identified as suitable primary processing techniques. We analyzed the climate impact, energy use, and operational cost of digestate management under these scenarios: no processing, partial processing (solid–liquid separation) and full processing (solid–liquid separation followed by ammonia stripping). As expected, the suitable digestate processing varied with the context, transport was often the most critical cost factor, and emissions from storage reduced the climate savings from the use of biofertilizers. However, treating liquid fraction became a main contributor to cost and climate impact under the Belgian conditions. Consequently, the possibility for local application of liquid fraction as biofertilizer could prevent costs and impacts associated with its further treatment. The main novelty of this work is in its integrative and comprehensive approach toward the choices and impacts of primary processing of digestate. We tried to bridge many individual case studies, drew from experiences of biogas plants in different geographical contexts, assessed suitable processing techniques for different digestate types, and analyzed the environmental impacts and cost of digestate management from a life cycle perspective. We believe that such integrated approaches would help decision-making for increased sustainability of the biogas sector.

Extraction of Virgin Coconut Oil from Dehydrated Coconut Meat using Mechanical Screw Press

Extraction of Virgin Coconut Oil from Dehydrated Coconut Meat using Mechanical Screw Press

Comparison of supercritical CO2 and screw press extraction methods for producing oil from Camellia sinensis var. assamica seeds: Physicochemical properties and antioxidant activity

The quality of Assam tea seed oil obtained by supercritical CO2 extraction was evaluated and compared to that of tea obtained using a screw press. Supercritical CO2 extraction produced a higher oil yield (12.94–16.53 % w/w) compared to the screw press method (9.96–12.18 % w/w). Using a higher temperature for supercritical CO2 and screw press extraction caused a decrease in the saponin content from 32.12 to 25.07 mg saponin equivalents/g oil and from 39.28 to 35.60 mg saponin equivalents/g oil, respectively, and for supercritical CO2 extraction also increased the flavonoid content from 0.84 to 1.75 mg/mL quercetin equivalents but did not affect the flavonoid yield for screw press extraction (1.02–1.07 mg/mL quercetin equivalents). The tannin content obtained from supercritical CO2 and screw press extraction was not significantly different (31.67–36.30 and 29.49–32.12 mg/mL tannin equivalents, respectively). Increasing the temperature of supercritical CO2 extraction resulted in a decrease in acid value and free fatty acids. No significant differences in acid value or free fatty acids were observed for oil extracted using the screw press method. Iodine and saponification values of oil obtained by supercritical CO2 extraction decreased when the extraction temperature increased, and screw press oil had higher iodine and saponification values when the temperature was increased. All of the extracted Assam tea seed oils, obtained by both methods, overwhelmingly contained oleic acid (48.55–50.14 %), linoleic acid (24.14–25.52 %), and palmitic acid (18.74–19.95 %). In addition, an increase in temperature promoted the extraction of phenolic compounds for both extraction methods (9.21–22.01 mg GAE/100 g oil), resulting in an increase in the antioxidant capacity of the extracted oil. These results indicate that supercritical CO2 extraction could be competitive with the screw press method, providing an environmental approach and enhancing the quality of the oil obtained.

Development and Performance Evaluation of a Variable-Pitch Tapered-Shaft Screw Press for Palm Oil Extraction

Palm fruit oil extraction is a difficult task to undertake. Screw press technology offers a solution to its extraction. However, most screw press available requires high power input for effective operation, thus affecting cost. Therefore, there is a need for improvement in order to limit cost and increase extraction efficiency. This work focuses on development of a variable-pitch tapered-shaft (VATS)screw pressfor enhancing palm fruit oil extraction efficiency. The VATS screw press machine consists of three main components including the hopper, the steamer, and the pressing unit, and was operated at temperature of 90, 110 and 130°C, shaft speed of 30, 45, and 60 rpm and heating time of 10, 15, 20 minutes. The performance evaluation carried on the machine includes oil yield, extraction efficiency and extraction loss. The results showed that the average oil yield, extraction efficiency and extraction loss were 83.72, 97.73 and 2.37% respectively. Whereas, a higher machine efficiency of 94.45% was obtained at a temperature of 130°C, shaft speed of 60 rpm, and heating time of 15 minutes. It is hoped that the information on the design concept for VATS screw press for palm fruit oil extraction will be useful for the vegetable oil industry.

Variasi Dimensi Pencetak Pakan Ikan Lele Dengan Kapasitas 40 Kg/Jam

Indonesia is the second most biodiverse country after Brazil in Latin America. However, in the fisheries sector, Indonesia can be called the first richest country. There are approximately 2,000 species of fish found in Indonesian waters. Dumbo catfish (Clarias gariepinus) is one type of freshwater fish that is busy being cultivated by people in Indonesia, especially in the province of East Java, especially in Bangkok Village, Gurah District, Kediri Regency. Problems that often occur in fish farming are feed and complain about the high price of commercial feed so that freshwater fish cultivators can spend about 60-70% of the total cost required for cultivation. After reviewing the problems faced by catfish cultivators, the researchers have a solution for these problems, namely by designing a fish feed printing device with a screw press mechanism with a capacity of 40 kg/hour. In this design process, the method used is the design and development method. Based on the test results from the design of the fish pellet extruder machine with a capacity of 40 kg/hour, it can be concluded with a pellet molding machine with a variety of die (mold) with a diameter of 2 mm and 4 mm, the material is made of iron plate with a thickness of 1.8 mm. For driving the cutting blades using an electric motor with a power of 1.5 and a rotation of 1400 rpm with a rotation of 360º. The cutting knife uses stainless steel with a thickness of 0.8 mm. And the results of the machine test with a printed capacity is 39.83 kg/hour.

Characterization of Volatile Flavor Compounds in Supercritical Fluid Separated and Identified in Gurum (Citrulluslanatus Var. colocynthoide) Seed Oil Using HSME and GC-MS.

In this study, the volatile compound profiles of gurum seed oil were determined using two methods: supercritical CO2 extraction (SFE) and the screw press process (SPP). For volatile compounds extraction and identification, headspace solid-phase micro-extraction (HS-SPME) and GC–MS were used, respectively. A total number of 56 volatile compounds were revealed and identified in oil extracted by SFE, while only 40 compounds were detected in extracted oil by SPP. Acids, aldehydes, esters, ketones, furans, and other components were present in the highest ratio in oil extracted by SFE. In contrast, alcohols and alkenes were found in the highest proportion in oil extracted by SPP. In this study, it was observed that SFE showed an increase in the amounts of volatile compounds and favorably impacted the aroma of gurum seed oil. The results reveal that different extraction methods significantly impact the volatile components of gurum seed oil, and this study can help evaluate the quality of the oil extracted from gurum seeds.

A holistic approach to pressure almond oil production

PurposeAlmond oil is a gourmet product with functional food characteristics owing to its high almond oil content and high nutritional quality. One of the primary constraints on its production is the lack of information regarding oil extraction from an industrial perspective, including by-products generation.Design/methodology/approachThe performance, quality and composition characteristics were analyzed, both from the physical-chemical and organoleptic point of view, of the almond oils obtained through two pressure systems: screw press (SP) and hydraulic press (HP). To ensure the success of almond oil production at a commercial scale, in this work, an economic study of the costs of the process was carried out as a complementary part of optimizing the production of virgin almond oil.FindingsPhysicochemical analysis showed little difference, just in total sterols (HP 2069, SP 2153) and some quality indexes (K232: HP 1.63, SP 2.13; peroxide index: HP 1.74, SP 0.95), in contrast to sensory analysis. Consumer judges valued roasted almond oil extracted using a HP the best. The production cost of the oil extracted with the SP was €23.05/l. With the HP it was €25.13/l, owing to the lower oil yield in the extraction. The most expensive treatment was for the HP with toasted almonds (€27.76/l), owing to the greater need for processing.Originality/valueProduction costs derived from the method used have received little attention. This paper presents data that allow for the transference between academic and industrial ambit and their economic viability.

Characteristics and Antioxidant Activity of Walnut Oil Using Various Pretreatment and Processing Technologies.

This study was the first time the effects of pretreatment technology (microwave roasting, MR; oven roasting, OR; steaming roasting, SR) and processing technology (screw pressing, SP; aqueous enzymatic extraction, AEE; subcritical butane extraction, SBE) on the quality (physicochemical properties, phytochemical content, and antioxidant ability) of walnut oil were systematically compared. The results showed that the roasting pretreatment would reduce the lipid yield of walnut oil and SBE (59.53–61.19%) was the processing method with the highest yield. SR-AEE oil provided higher acid value (2.49 mg/g) and peroxide value (4.16 mmol/kg), while MR-SP oil had the highest content of polyunsaturated fatty acid (73.69%), total tocopherol (419.85 mg/kg) and total phenolic compounds (TPC, 13.12 mg/kg). The DPPH-polar and ABTS free radicals’ scavenging abilities were accorded with SBE > AEE > SP. SBE is the recommended process for improving the extraction yield and antioxidant ability of walnut oil. Hierarchical cluster analysis showed that processing technology had a greater impact on walnut oil than pretreatment technology. In addition, multiple linear regression revealed C18:0, δ-tocopherol and TPC had positive effects on the antioxidant ability of walnut oil, while C18:1n-9, C18:3n-3 and γ-tocopherol were negatively correlated with antioxidant activity. Thus, this a promising implication for walnut oil production.

KETENCİK [Camelina sativa (L.) Crantz] YAĞI BİYODİZELİNİN ve KARIŞIM YAKITLARININ FİZİKOKİMYASAL ÖZELLİKLERİNİN ARAŞTIRILMASI

Son yıllarda, bitkisel yağların biyoyakıt kaynağı olarak biyodizel üretimi için kullanılması, yağlı tohumlu bitkilerin öneminin artmasını sağlamıştır. Biyodizel üretiminde kullanılabilecek potansiyel bitkilerden birisi de ketenciktir [Camelina sativa (L.) Crantz]. Brassicacea familyası içerisinde yer alan tek yıllık bir bitki olan ketencik, yaygın olarak bilinen 6 Camelina türünden (C. sativa, C. laxa, C. rumelica, C. microcarpa, C. hispida ve C. anomala) biridir. Bu çalışmada, ketencik tohumlarından vidalı pres vasıtasıyla ketencik ham yağı elde edilmiş ve bu yağın yağ asidi bileşenleri incelenmiştir. Biyodizel üretimi, ketencik ham yağından, transesterifikasyon yöntemi ile iki aşamalı olarak (B100) gerçekleştirilerek, ketencik biyodizeli hacimce farklı oranlarda %20 (B20), %7 (B7) ve %2 (B2) dizel yakıtı ile harmanlanmıştır. Bu yakıtların, fizikokimyasal özellikleri; (kinematik viskozite, yoğunluk, su içeriği, kalorifik değer, parlama noktası, bulutlanma noktası, soğuk filtre tıkanma noktası, bakır şerit korozyonu, renk) B100 saf biyodizel yakıtı için EN 14214, B20 yakıtı için EN 16709, B7 ve B2 yakıtları için ise EN 590 standartlarına göre karşılaştırılmıştır. Elde edilen sonuçlara göre, ketencik biyodizeli (B100) ve karışım yakıtlar (B20, B7 ve B2) dizel motorlarda modifiye edilmeden kullanılabilecek yakıt özelliklerine sahip olduğu söylenebilir.

Investigation of optimal processing parameters of palm kernel oil extraction under uniaxial loading towards food security and energy sustainability

The present study evaluates the optimal conditions for palm kernel oil extraction under uniaxial compression loading. The response surface regression technique was used to test the independent variables, which were the force, vessel diameter and speed at three levels separately. The kernel oil yield was observed as the dependent variable where a regression model was described using the analysis of variance (ANOVA) at 5% probability level. The observed palm kernel oil yield was found to be 22.61% whereas the optimized value was 22.99%. The corresponding extraction (deformation energy) was calculated to be 1.24 kJ. The lack-of-fit of the regression model was non-significant (P > 0.05) implying its adequacy. The force, vessel diameter and speed at the levels of 200 kN, 60 mm and 4 mmmin-1 were identified as the optimum parameters for obtaining high percentage palm kernel oil under uniaxial compression. The findings would be validated in a mechanical screw press type Farmet Duo at a laboratory scale to optimize the palm kernel oil extraction process at small-to large -scale production.

Technology innovation and business model of palm oil miniplant for food and energy

Palm oil is Indonesia’s main export commodity and has many contributions to the economy. Palm Oil Mill is built by private or state-owned company with the minimum capacity of 30 tph and far from smallholder plantations. Transportation costs and delays have caused the quality of fresh fruit bunch decrease and prices have dropped in the farmer level. This study aimed to design a palm oil mini plant by evaluating existing technology, innovating process, and equipment design, also analyzing financial aspect. The methods used in this research were literature study, laboratory test, interview, and observation. The selected process technology was sterilization using steam (t = 90 minutes, T = 130°C, P = 300 kPa), threshing with rotating speed of 21 rpm, heating method in the digester (t = 14 minutes, T = 90°C, v = 23 rpm), extraction of oil palm fruit with a screw press machine (P = 4500 kPa, v = 11 rpm). The process of refining Crude Palm Oil (CPO) gone through 3 stages, namely degumming with water degumming, neutralization using deacidification, and fractionation using the dry method to produce Refined Palm Oil (RPO). Technological innovations were carried out in vertical sterilizers with the addition of water to the sterilizer when loading the fruits, the use of augers and improvements to the sterilization system. The value propositions of palm oil miniplant business model are the ease of bureaucracy, flexibility of small-scale industry, high quality (FFA<5%), and competitive prices. The supply chain flow starts from independent smallholder plantations to oil palm miniplants without going through collectors. The products are CPO, RPO which high antioxidants activity because of tocopherols and carotenoids content, and Palm Kernel (PK). The financial feasibility analysis of palm oil mini plant resulted in an NPV of IDR 15,068,339,048, IRR of 28%, BCR of 11,7 and PBP of 2,8 years. This study showed that the palm oil mill mini plant is financially feasible to build.

Influence of Pelletizing Conditions on Fabricated System Performance, Physical and Mechanical Properties of a Cassava Flour Based Fish Feed

Conventional screw press fish pelleting machines are commonly used as a method of producing fish feed, but often affect the product properties. Manual pelletizers using hydraulic press instead of screw in a cassava flour-based diet can be easily processed, which can improve handling and storage. The influence of the pelletization parameters on some properties of cassava-based pellets was the focus of this study. The conditioning factors analyzed were: die size (4, 6 and 8mm), temperature (30, 60 and 90&lt;sup&gt;o&lt;/sup&gt;C), cassava inclusion (5, 10, 15 and 20%) and the influence of the mash moisture content (35, 40 and 45%) on the process and product responses. The quality of the pellets was evaluated in view of current standards. Second-order polynomials were applied to demonstrate the responses as a function of process factors. The studied factors had significant effects on the process response (throughput) and pellet properties (durability and bulk density). Majority of the values of throughput, bulk density and durability of the produced pellets attained the standard limits. Pelletizer operated optimally with processing parameter at 6.0 mm die size, 60°C temperature, 40% moisture content and 20% cassava inclusion rate resulted in pellet temperature (64.4°C), moisture content (34.21%), throughput (932.26 g h&lt;sup&gt;-1&lt;/sup&gt;), bulk density (0.36 g cm&lt;sup&gt;-1&lt;/sup&gt;), durability (99.1%) and hardness (0.30 kN). Pelleted feed using a manual press device under high cassava containment improves the properties of the product. Therefore, the applicability of the response surface method to optimize the process variables is sufficient.

EFFECT OF THREE FEEDSTOCKS MIX ON BRIQUETTES’ PHYSICAL AND COMBUSTION PROPERTIES

Significant quantities of biomass are available in Africa for conversion into domestic energy sources. However, they are underutilized due to poor physical and combustion properties. Knowledge about the effect of briquettes with three feedstocks has not been fully studied. Thus, the main objective of this study was to assess effect of three feedstocks mix on briquettes’ physical and combustion properties. The feedstocks; rice husk- maize cobs and bagasse were carbonized in a drum kiln and mixed at different ratios (1:1:1, 1:2:2, 1:3:3, 2:1:2, 2:2:3, 2:3:1, 3:1:3, 3:2:1 and 3:3:2) before densification using screw press technique. Briquettes were sampled for Laboratory testing. At the optimal ratio, 3:2:1, physical properties; moisture content and density values were 6.43% and 904 kg/m3 respectively. Results showed values of 3.63% for ash content, 18.56% for volatile matter, 77.81% for fixed carbon and 29.04 MJ/kg for calorific value. Number and type of feedstocks are thus factors influencing physical and combustion characteristics of briquettes in converting agricultural wastes to useful energy application. Findings from this study are therefore useful to briquettes users, as a source of clean energy, in making right choices on feedstocks mix ratios during densification thus realization of Sustainable Development Goal (SDGs #7).

Failure Analysis of the Screw Press Machine

In this paper, an analysis of the mechanical components of the Screw Press Machine is carried out in the form of an analysis of the design of mechanical components, maintenance cycles and remaining life. From the design analysis of mechanical components, it is known that the stresses that occur in the screw are in the form of nominal shear stresses of 18.18 N/mm², axial stresses of -10.41 N/mm², bending stresses of 54.66 N/mm², and shear stresses acting on the base screw of 65.41 N/mm². The number of press cycles that occur in one hour is 121 cycles. Number in the press cycle that occurs in the worm screw press is 2.625x105 cycles. In field conditions with pressure fluctuating between 30-40 bars, the life time of using a worm screw press is around 2169.43 hours.

Determining optimal technological modes for pressing oil from melon seeds to justify rational engineering and structural solutions

This paper considers the process of squeezing oil from melon seeds in a screw oil press, using the method of planning a full-factor experiment. To study the interaction of various factors affecting the process of squeezing oil from melon seeds, mathematical methods of experiment planning were applied. Melon seeds were used as the object of the study. The results of studying the physical and mechanical indicators of melon seeds are reported; the rational modes of pressing melon seeds have been determined; the aerodynamic indicators of melon seeds have been defined in order to design a cold-pressed press for melon seeds. Ventilation modes have been substantiated; the soaring coefficient for melon seeds was derived. The coefficient of resistance for a melon seed is 1.54. The highest critical velocity values for melon seeds were 6.4, for kernels 4.67, and for husks 3.94, respectively, with seed moisture content of 24.08 %. The dependence of the oil yield on huskness has been determined. It is established that in the process of pressing there is a decrease in the oil content of the oil seed meal as it moves from the receiving chamber to the exit from the press, at the same time there is a compaction of the compressed product. Based on the study’s results, a plant for squeezing oil from melon seeds was designed. As a result of solving the problem with the vector optimization criterion, optimal intervals of input parameters were obtained: the initial humidity of the raw material is 9.15...10.27 %, the speed of rotation of the oil press screw is 0.843...0.895 s–1, the clearance for the yield of cake is 0.750...0.800, the oil seed meal temperature at pressing=87...89 °С, the huskness of the starting product is 7.13...7.23 %

Towards a biorefinery processing waste from plantain agro-industry: Assessment of the production of dairy cattle feed through process simulation

The aim of this work was to design and analyse techno–economically and nutritionally the production of nutrient blocks and silage from waste of Dominico–Hartón plantain through process simulation in the framework of the design of a future biorefinery based on residues from plantain agro-industry. All systems were scaled to flows that would be realistically encountered in full–scale production systems, and several scenarios covering the production of supplementary feed blocks, fermented blocks, and silage for cattle feeding were considered. Plantain waste composition was determined experimentally. SuperPro Designer was used to simulate the process flowsheets. Process net present values were estimated using a project life of 15 years and an interest rate of 5.36%. Results suggested that fresh residues from plantain agro-industry are not recommended for dairy cattle consumption due to their high contents of moisture and neutral and acid detergent fibres, which provide few nutrients. Amending the residues with 19% maize forage resulted in a far better feed, with an estimated nutritional content of (on a dry basis): 28.34% neutral detergent fibre, 17.08% acid detergent fibre, 30.40% non–fibrous carbohydrates, and 34.52% moisture. The process flowsheets were modified by including a new step for moisture extraction as well. The feasible process for utilising plantain waste with the highest net present value (15.0 M$) was the production of supplementary feed blocks using screw press moisture extraction technology. This process can be incorporated as an alternative processing pathway into the design of a biorefinery using plantain waste as feedstock. • Plantain waste mixture is not suited for feeding dairy cattle due to high moisture. • This mixture may be adjusted by adding maize forage for feeding dairy cattle. • Nutrient blocks are an attractive alternative to valorise plantain residues. • Feasible process to produce supplementary feed blocks from waste was designed. • Process designed could be integrated into a biorefinery processing plantain waste.

Study of effects of addition of charcoal and binder derived from taro on physiochemical properties of briquettes made from tree leaves

Tree leaves are abundantly available naturally, providing a low-cost raw material for energy sources. Tree leaves are voluminous, cannot give controlled burning, have low calorific value, and are difficult to handle and transport. The objective of this study was to improve the physicochemical properties of briquettes made from dry leaves in a low-power screw press machine by adding charcoal and binder. The natural binder used in this work was wild Colocasia esculenta (taro) tuber.In the present study, briquettes were made from Polyalthia longifolia tree leaves mixed with charcoal at three different ratios. The binder was prepared using three other methods and combined with pulverized leaves and charcoal at three levels. Taguchi's method of optimization was used; the controllable factors were (1) Charcoal percentage, (2) Binder percentage (3) Binder preparation methods. The percentage contribution of each controllable factor was reported along with empirical models for each parameter under study. Gas emission analysis was done for CO,NOx and SO2. It is found that charcoal addition was the most influential factor for calorific values, Fixed carbon content, volatile matter, and ash content. In contrast, the binder was the most significant factor for mechanical properties such as compressive strength and shatter resistance. Addition of charcoal improved the emission quality of the fuel.

Effect of different extraction methods on micro-component composition and oxidative stability of oil produced from African pear (Dacryodes edulis) mesocarp Oil

Three different methods, including Soxhlet, traditional and screw press, were used to extract oil from African pear pulp. The oils were analysed for selected minerals and phytonutrients; stored for 4 weeks and analysed for oxidative changes. The micro-components results ranged from 0.00 to 41.50% for chlorophyll, 0.00 to 1.25 µg/100g for total carotenoids, 0.02 to 0.04 mg/100g for iron, 0.00 to 0.01 mg/100g for copper, and 18.25 to 208.50 mg/100g for vitamin E. The oxidative stability results showed that peroxide values ranged from 0.13 to 2.69 meq O2/kg in week 1 to 0.92 to 3.62 meq O2/kg in week 4; FFA ranged from 0.36 to 7.04% in week 1 to 0.39 to 11.47% in week 4; density ranged from 0.89 to 0.91 g/cm3 in week 1 to 0.91 to 0.98 g/cm3 in week 4; viscosity ranged from 17.17 to 51.57 RVU in week 1 to 20.31 to 55.05 RVU in week 4 and thiobarbituric acid level ranged from 0.02 to 1.11 mg/g in week 1 to 0.09 to 1.31 mg/g in week 4. Soxhlet extraction method produced oil of best quality with significantly (p &lt; 0.05) higher mineral and phytonutrient contents, and of a longer storage stability.

Separation efficiency of different solid-liquid separation technologies for slurry and gas emissions of liquid and solid fractions: A meta-analysis

Solid-liquid separation (SLS) technology is widely used in the slurry management in animal farms. This study conducted a comprehensive meta-analysis of 45 published articles to evaluate the differences in separation efficiencies (SEX-SF) of various SLSs and the changes of gas emissions before and after the separation during on-farm slurry storage. The results indicated that the SEX-SF of the untreated raw slurry and acidified slurry were consistently greater than those of the digested slurry, and centrifugation resulted in greater SEX-SF than the other mechanical methods. Both measured and simulated data showed that the centrifuge technology had greater reductions in greenhouse gas (GHG) emissions relative to the screw press (56.1–58.0% vs. 38.9–40.2% for untreated slurry, and 29.7–30.2% vs. 22.5–23.2% for digested slurry), mainly due to CH4 reduction. Additionally, we identify the need for further assessment of the environmental risks that are associated with SLSs for the development of an optimal slurry management chain.

Increasing the Efficiency of Gac (Momordica cochinchinensis Spreng) Aril Oil Extraction by Commercial Pectinase Pretreatment and Microwave Dehydration

The objectives of this research were to determine the optimal conditions for using commercial pectinase (Pectinex® Ultra SP-L) and microwave dehydration to increase the efficiency of gac (Momordica cochinchinensis Spreng) aril oil extraction by using a screw press, to find mathematical models to predict the yields, extraction efficiencies, and β-carotene and lycopene contents in gac aril oil that varied with the enzyme concentrations, enzyme incubation temperatures, and microwave drying powers, and to validate the mathematical models. A Box-Behnken experimental design for three factors, including enzyme concentrations (0.01, 0.11, and 0.21% w/w), enzyme incubation temperatures (30, 45, and 60 °C), and microwave drying powers and times (450 W for 28 min, 600 W for 20 min, and 800 W for 14 min), was applied to determine the optimal conditions for increasing the efficiency of gac (Momordica cochinchinensis Spreng) aril oil extraction using commercial pectinase and microwave dehydration pretreatments before pressing with a screw press. It was found that the optimal conditions for extracting oil from gac aril based on the highest values of yield (12.14%), extraction efficiency (72.92%), and β-carotene and lycopene contents (104.64, and 27.90 mg/100 g oil, respectively) and the lowest of microwave energy consumption (720 kJ) were an enzyme concentration of 0.13% (w/w), enzyme incubation temperature of 45 °C and microwave drying power of 600 W for 20 min. To validate the mathematical models, the predicted yields, extraction efficiencies, and β-carotene and lycopene contents were compared to the experimental data and the deviants were less than 10%, which indicated that the model predictions were reliable.