Alternative Oil Source Research Articles

Phenotypic Examination of Camelina sativa (L.) Crantz Accessions from the USDA-ARS National Genetics Resource Program.

Camelina sativa (L.) Crntz. is a hardy self-pollinated oilseed plant that belongs to the Brassicaceae family; widely grown throughout the northern hemisphere until the 1940s for production of vegetable oil but was later displaced by higher-yielding rapeseed and sunflower crops. However, interest in camelina as an alternative oil source has been renewed due to its high oil content that is rich in polyunsaturated fatty acids, antioxidants as well as its ability to grow on marginal lands with minimal requirements. For this reason, our group decided to screen the existing (2011) National Genetic Resources Program (NGRP) center collection of camelina for its genetic diversity and provide a phenotypic evaluation of the cultivars available. Properties evaluated include seed and oil traits, developmental and mature morphologies, as well as chromosome content. Selectable marker genes were also evaluated for potential use in biotech manipulation. Data is provided in a raw uncompiled format to allow other researchers to analyze the unbiased information for their own studies. Our evaluation has determined that the NGRP collection has a wide range of genetic potential for both breeding and biotechnological manipulation purposes. Accessions were identified within the NGRP collection that appear to have desirable seed harvest weight (5.06 g/plant) and oil content (44.1%). Other cultivars were identified as having fatty acid characteristics that may be suitable for meal and/or food use, such as low (<2%) erucic acid content, which is often considered for healthy consumption and ranged from a high of 4.79% to a low of 1.83%. Descriptive statistics are provided for a breadth of traits from 41 accessions, as well as raw data, and key seed traits are further explored. Data presented is available for public use.

Isolation and characterization of Botryococcus braunii from a freshwater environment in Tenggarong, Kutai Kartanegara, Indonesia

Abstract. Nugroho RA, Subagyono DJN, Arung ET. 2020. Isolation and characterization of Botryococcus braunii from a freshwater environment in Tenggarong, Kutai Kartanegara, Indonesia. Biodiversitas 21: 2331-2336. The use of microalgae as an alternative source of oil has gained much attention in recent years. The present study was conducted to isolate and characterize microalgae Botryococcus braunii from a freshwater environment, located in Tenggarong, Kutai Kartanegara, East Kalimantan, Indonesia. B. braunii were cultured and determined their growth in terms of biomass yield and the presence of lipid globules by red Nile staining. Dry biomass, phosphate, and protein content of cultured B. braunii were measured at 3 days of intervals for 24 days. Biomass yield, hydrocarbon, carotenoid, and chlorophyll content were determined at the pH range of 6, 6.5, 7, 7.5, and 8 and various CO2 concentrations. The result showed that B. braunii collected from freshwater in Tenggarong can produce lipid globules. The highest growth of B. braunii was reached at day 15, while the optimal phosphate content was on the 12th day, and the protein was relatively stable during culture. The optimal weight of B. braunii biomass was reached at pH 7 and 4% CO2 and the highest hydrocarbon content was obtained at pH 8 and 4% CO2. The highest chlorophyll and carotenoid contents were obtained 4% CO2. In conclusion, B. braunii collected from Tenggarong was successfully cultured and able to produce lipid globules. The optimal conditions for its growth and production of hydrocarbon, phosphate, protein, chlorophyll, and carotenoid were at pH of 7-8 and 4% CO2.

Fatty acids profiles and estimation of the biodiesel quality parameters from Rhodotorula spp. from Antarctica.

Oleaginous yeasts are a renewable and alternative source of oil for third-generation biodiesel. This work aimed to evaluate the effects of glucose concentration (30-100g L-1) on growth, lipid synthesis, and fatty acids (FA) profile of three Rhodotorula spp. (R. glacialis R15, R. glutinis R4, and R. glutinis R48) isolated from Antarctica, and estimate the key quality parameters of the biodiesel produced by yeasts to confirm their potential as feedstocks for third-generation biodiesel synthesis. Yeasts accumulated 50-69.5% of lipids (w/w) under nitrogen-limitation and glucose-excess (C/N = 40-133). Glucose concentration increase influenced positively lipid accumulation (69.5% w/w) and FA profile of R. glacialis R15. Lipid accumulation (53% on average) of R. glutinis strains was not significantly affected by glucose concentration; content of saturated (~ 30%) and polyunsaturated FA (~ 29-30%) was slightly influenced. FA profiles of lipids synthesized by R15, R4, and R48 are similar to vegetable oils used in biodiesel industry with C16 and C18 FA (95-99%) as the major components, and contain mainly oleic (C18:1), palmitic (C16:0), and linoleic (C18:2) acids, which are suitable for biodiesel synthesis. Estimated fuel properties for biodiesel produced by R15, R4, and R48 satisfied all the criteria established by ASTM D6751 and EN 14214 with good cetane number, iodine value, and oxidation stability. An improvement in biodiesel quality of R15 was observed with the glucose increase. The best global properties of biodiesel from R4 were obtained with 30g L-1 of glucose. Rhodotorula spp. from Antarctica are promising candidates for third-generation biodiesel synthesis.

Comparative assessment of the physicochemical and biochemical properties of native and hybrid varieties of pumpkin seed and seed oil (Cucurbita maxima Linn.)

The hybrid variety of Cucurbita maxima is commercially available and frequently used as food in Bangladesh compared to the native variety. Although the seeds of Cucurbita maxima have nutritional and therapeutic values, people in Bangladesh typically throw them away as waste. If we can explore their physicochemical and biochemical properties, this will add new knowledge to nutrition and food science. Thus, in this study, we compare the physicochemical and biochemical properties of native and hybrid varieties of pumpkin seed and seed oil. Solvent extraction methods were used to obtain oil. The physicochemical properties of the extracted seed oils were examined by titration methods and proximate compositions of pumpkin seeds were determined using the standard method. Tocopherols were analyzed by HPLC and fatty acids were identified by GC/MS as N-acylpyrolidines. The specific gravity, refractive index, viscosity, acid value, saponification value, iodine value and ester values were determined and among them iodine values and acid values were significant (p < 0.05) at native but saponification and ester values were very highly significantly (p < 0.001) at hybrid. The comparative lipid content in the seed of native variety was higher than hybrid (p < 0.01) and protein contents were higher but not significant. However, crude fiber content was higher in the hybrid (p < 0.01). There was no significant differences of moisture, ash, sugar and starch contents in between the two varieties. The total tocopherol, contents were very high (p < 0.001) in native. In hybrid, saturated fatty acids -capric acid, myristic acids were more (p < 0.001) but in native unsaturated fatty acid linoleic and linolenic acids were predominant (p < 0.05). Owing to the considerable differences in the physicochemical composition, the fatty acids and other properties, this study may suggest that the both varieties of pumpkin seed oil may be an alternative good source of edible oil.

Single Cell Oil Production from Waste Biomass: Review of Applicable Industrial By-Products

Abstract Single cell oil (SCO) is an attractive alternative source of oil, which, depending on the fatty acid composition, can be used as a feedstock for biodiesel production, as an ingredient for pharmaceuticals or as a source of essential fatty acids for human and animal consumption. However, the use of SCO is limited due to use of relatively expensive food or feed products in the cultivation of SCO producing microorganisms. In order to reduce SCO production costs, the use of cheaper feedstock such as biodegradable agro-industrial wastes are necessary. At the same time, the microbial treatment of biodegradable wastes ensures the neutralization of environmentally harmful compounds and reduces the negative impact on the environment. Oleaginous microorganisms are capable of fermenting a variety of industrial by-products, waste products and wastewaters, however further discussion on properties of the waste materials is necessary to facilitate the selection of the most appropriate waste materials for SCO production. Thus, this review compares various industrial waste products that can be used as cheap feedstock for the cultivation of SCO producing microorganisms. Industrial waste products, by-products and wastewaters are compared according to their global availability, current use in competing industries, required pre-fermentation treatments, oleaginous microorganism cell concentrations and SCO yields.

Laboratory evolution strategies for improving lipid accumulation in Yarrowia lipolytica.

Oleaginous microorganisms are of high biotechnological interest being considered as alternative sources of oil (single cell oil-SCO). Current research for increasing productivity of oleaginous microorganisms is focused on the overexpression of genes implicated in lipid synthesis, the inactivation of genes implicated in storage lipid turnover, and on the suppression of competitive to lipid biosynthesis pathways. An alternative strategy, described here, relies on evolution of Yarrowia lipolytica under alternating environments that promote growth, encourage storage lipid synthesis, and reward high energy-containing cells. Derived populations were characterized biochemically, especially on their ability to accumulate lipids, and compared with the starting strain. Interestingly, lipid-accumulating ability early in the evolution was decreased compared with the starting strain. Subsequently, oleaginous lineages dominated, leading to populations able to accumulate lipids in high amounts. A population obtained after 77 generations was able to accumulate 44% w/w of lipid, which was 30% higher than that of the starting strain. We conclude that evolution-based strategies can be utilized as a robust tool for improving lipid accumulation capacity in oleaginous microorganisms.

Cultivation modes for microbial oil production using oleaginous yeasts – A review

Microbial oil has been a valuable alternative oil source with applications in the food, cosmetics and biofuels sectors. As concerns for the environment grow, microbially-synthesized oil has emerged as a potential contributor for sustainable production of biodiesel. However, the high costs of its production hinder its large-scale application. Main bottleneck to industrial lipid production is the cost of the fermentation stage. Therefore, it is imperative to design cultivations with little operating requirements and high yields, adjusted to an oleaginous system. This paper provides an overview of the latest advances in oleaginous yeast cultivation in bioreactors. Focus is given to oleaginous yeasts and de novo lipid accumulation due to their high lipid accumulating ability, robustness and versatility across a range of substrates. The advantages and disadvantages of different cultivation modes, feeding patterns and impact on biomass and lipid yield are critically reviewed. The role of biochemical engineering in facilitating understanding of the lipid accumulation kinetics, lipid productivity and its importance as predictive scale up tool is highlighted through a review of existing equations. Perspectives for further bioprocess improvement through kinetic modelling, and valorisation through utilisation of by-products are also discussed.

Chemical composition and bioactive compounds of Cucurbitaceae seeds: Potential sources for new trends of plant oils

Studies were conducted on the chemical composition of ‘Essahli’ pumpkin seeds, ‘Ananas’ melon seeds and ‘Crimson’ watermelon seeds varieties. ‘Essahli’ pumpkin seeds were found to contain the highest oil (35.53 ± 4.26%) and protein contents (40.00 ± 3.84%). Furthermore, the ‘Crimson’ watermelon seeds witnessed the highest fiber content (48.26 ± 5.26%). The chemical composition of cold pressed seed oils was investigated. Linoleic acid (C18:2) was the main fatty acid in the seed oil fractions, followed by oleic (C18:1), palmitic (C16:0) and stearic acids (C18:0). Melon seed oil presented considerable amounts of phytosterols in which sitosterol was the major sterol accounting for 3248.48 mg/kg oil and exhibited both highest oxidative stability (3.8 ± 0.41 h) and antioxidant activity (IC50 = 52.55 ± 5.08 μg/g). The chromatographic analysis of phenolic compounds showed that phenolic acids were the most important group in the melon seed oil with predominance of ferulic acid (134.83 μg/g). The obtained results revealed that Cucurbitaceae seeds presented an alternative source of plant oil, which may serve as raw material for food applications.

Refined cottonseed oil as a replacement for soybean oil in broiler diet.

With the shortage of common vegetable fat sources, such as soybean oil (SBO), it is urgent to find alternative oil sources for broiler producers. The objective of this study was to evaluate the potential of refined cottonseed oil (CSO) as a replacement for SBO in broiler diets. A total of 180 chickens at 1 d of age were randomly assigned to five treatments of six replicates. One treatment was the basal diet (control), and the other four experimental diets were formulated from the basal diet by replacing (w/w) 25%, 50%, 75%, and 100% of the SBO with refined CSO (only containing 0.2% cyclopropenoid fatty acids, and no free gossypol was detected). At the end of week 6, blood samples were obtained from the jugular vein and the breast muscle was aseptically isolated from two birds per replicate. The results showed that substitution of CSO for low‐level SBO had no significant effect (p > 0.05) on broiler performance during the starter period (week 1–3), while 50% level of CSO inclusion significantly increased (p < 0.05) ADG and improved FCR compared with the control group during the finisher period (week 4–6). Broilers fed 100% CSO diets had lower (p < 0.05) levels of serum total protein (TP), albumin (ALB), cholesterol (CHO) concentrations, and serum alkaline phosphatase (AKP) activity than that of the control broilers. Furthermore, the serum antioxidant status appeared to be enhanced by CSO. Additionally, high levels of CSO (75 and 100%) significantly increased the proportions of C14:0 and C18:0 but decreased the proportions of C18:1n9t, C18:2n6c, and ∑ n‐6 polyunsaturated fatty acids in breast muscles of broilers. Overall, the SBO could be replaced with refined CSO up to 50% in diets for broilers without adversely affecting the performance, liver functions, and breast muscle fatty acid composition of these broilers.

Production of eicosapentaenoic acid (EPA, 20:5n-3) in transgenic peanut (Arachis hypogaea L.) through the alternative Δ8-desaturase pathway.

An important alternative source of fish oil is its production by plants through metabolic engineering. To produce eicosapentaenoic acid (EPA, 20:5n-3) in peanut through the alternative Δ8-pathway, a plant expression vector containing five heterologous genes driven by the constitutive 35S promoter respectively, namely, ∆9-elongase (Isochrysis galbana), ∆8-desaturase (Euglena gracilis), ∆5-desaturase (Mortierella alpina), ∆15-desaturase (Arabidopsis thaliana) and ∆17-desaturase (Phytophthora infestans) were transferred into peanut through Agrobacterium-mediated transformation method. The gas chromatography results indicated that the average content of EPA in the leaves of the transgenic lines was 0.68%, and the highest accumulation of EPA in an individual line reached 0.84%. This finding indicates that it is feasible to synthesize EPA in peanut through metabolic engineering and lays the foundations for the production of very-long-chain polyunsaturated fatty acids (VLCPUFAs) in peanut seeds.

Chemical composition and oral toxicity assessment of Anisophyllea boehmii kernel oil: Potential source of new edible oil with high tocopherol content.

Anisophyllea boehmii is an indigenous and wild species in Burundi. Its fruits are edible and commercialized in local markets. This study investigates chemical quality, composition and toxicity test of A. boehmii kernel oil from two sites in eastern Burundi. Results of the present study reveal A. boehmii kernels to be an oil-rich source, yielding up to 29% of oil. Fatty acid composition analysis classifies these oils as palmitic. In fact, the main fatty acids are palmitic acid (36.47-39.55%) and oleic acid (18.83-22.21%). The analysis of minor compounds shows high tocopherols (485-657 mg kg-1), phenols (82-135 mg kg-1) and β-carotene (144-234 mg kg-1) content. The physicochemical parameters analyzed make A. boehmii kernel a source of good quality oil. Furthermore, acute oral toxicity test reveals no toxicity of A. boehmii kernel oil. Results of the present study are decisive in adoption of A. boehmii kernel oil as an alternative source of edible oil.

Determining the oxidative stability and quality of tiger nut (Cyperus esculentus) oil and its antioxidant activity during microwave heating

Introduction: The emphasis on high-oleic vegetable oils is prominent in human communities all over the world. That being said, the high level of monounsaturated fatty acid (oleic acid) in tiger nut (Cyperus esculentus) oil shows that it is resistant to oxidative stability. The purpose of this study, therefore, was to see if tiger nut oil can be exploited for use as an alternative or supplementary source of high-quality and nutritious cooking oil. Materials and methods: In this study, Color, RI, viscosity, PV, p-AV, FFA, TPC, at 233 and 269 nm, thermal behavior, TAG and FAC were used to evaluate the oil after microwave heating. Results: The PV, p-AV, FFA, TPC and specific extinction were increased during the microwave heating. Significant differences (p &lt; 0.05) were detected for peroxide, anisidine, acid value, polar compounds and specific extinction. During microwave heating, the amounts of peroxide, anisidine and TOTOX values increased from initial value 3.06, 0.72 and 6.84 for unheated oil to 4.11, 10.02 and 18.25 after 15 min heating respectively. Free fatty acid changed from 0.10 to 0.12% during microwave heating. Amount of unsaturated fatty acids decreased during the heating significantly. During microwave heating the antioxidant activity was significantly decreased (p&lt;0.05) from 68.60 to 19.66 (for unheated tiger nut oil and after 15 min heating in high concentrations by DPPH test, respectively). Conclusions: This may indicate that it can bear thermal treatments in such culinary methods as frying, and it can thus be concluded that tiger nut oil is stable in heating processes, especially frying.

Determinar de la estabilidad oxidativa y la calidad del aceite de chufa (Cyperus esculentus) y su actividad antioxidante durante el calentamiento por microondas

Introduction: The emphasis on high-oleic vegetable oils is prominent in human communities all over the world. That being said, the high level of monounsaturated fatty acid (oleic acid) in tiger nut ( Cyperus esculentus ) oil shows that it is resistant to oxidative stability. The purpose of this study, therefore, was to see if tiger nut oil can be exploited for use as an alternative or supplementary source of high-quality and nutritious cooking oil. Materials and methods: In this study, Color, RI, viscosity, PV, p-AV, FFA, TPC, at 233 and 269 nm, thermal behavior, TAG and FAC were used to evaluate the oil after microwave heating. Results: The PV, p-AV, FFA, TPC and specific extinction were increased during the microwave heating. Significant differences (p < 0.05) were detected for peroxide, anisidine, acid value, polar compounds and specific extinction. During microwave heating, the amounts of peroxide, anisidine and TOTOX values increased from initial value 3.06, 0.72 and 6.84 for unheated oil to 4.11, 10.02 and 18.25 after 15 min heating respectively. Free fatty acid changed from 0.10 to 0.12% during microwave heating. Amount of unsaturated fatty acids decreased during the heating significantly. During microwave heating the antioxidant activity was significantly decreased (p<0.05) from 68.60 to 19.66 (for unheated tiger nut oil and after 15 min heating in high concentrations by DPPH test, respectively). Conclusions: This may indicate that it can bear thermal treatments in such culinary methods as frying, and it can thus be concluded that tiger nut oil is stable in heating processes, especially frying.

Utilization of Solid Waste as a Substrate for Production of Oil from Oleaginous Microorganisms.

The overwhelming demand of oil and fats to meet the ever increasing needs for biofuel, cosmetics production, and other industrial purposes has enhanced a number of innovations in this industry. One such innovation is the use of microorganisms as alternative sources of oil and fats. Organic solid waste that is causing a big challenge of disposal worldwide is biodegradable and can be utilized as substrate for alternative oil production. The study evaluated the potential of isolated yeast-like colonies to grow and accumulate oil by using organic solid waste as substrate. Of the 25 yeast-like colonies isolated from the soil samples collected from three different suburbs in Kampala district, Uganda, 20 were screened positive for accumulation of lipid but only 2 were oleaginous. The NHC isolate with the best oil accumulation potential of 48.8% was used in the central composite design (CCD) experiments. The CCD experimental results revealed a maximum oil yield of 61.5% from 1.25 g/L cell biomass at 10 g/L of solid waste and temperature of 25°C. The study revealed that organic solid waste could be used as a substrate for microbial oil production.

Alternative Cutting Fluids for Metal Cutting Operations

In machining operation, the life of the tool is important as lot of heat energy is generated during machining process. Due to the heat developed the surface finish, dimensional accuracy and life of the material, which is machined is affected .There are different approaches under study to find an alternative. Thus neem oil and water melon seed oil was studied and made as an alternative as cutting fluids in order to improve the life of the tool, improve surface finish in work piece, prevent corrosion in a steel, maintaining dimensional accuracy. Rather than coating the tool to machine high strength alloys, it found to be a simple alternative. Physiochemical properties such as viscosity, flash point, pour point, specific gravity were studied. Specific gravity of Neem seed oil was 0.9304 and Water Melon seed oil was 0.9324. The flash point for Neem seed oil was obtained as 1750C, Water melon seed oil 130°C. Based on the property results machining operation is carried out at different spindle speeds with various ratio of both the oils and water. The best results were obtained with more absorption of heat energy and temperature was reduced than the current machining process, which will be explained briefly in the paper. All the oils – water emulsion ratios were effective as coolants and comparable to the petroleum oils. As in current machining process petroleum oil is used as a coolant but the availability and cost of the petroleum oils is critical. Thus there is a need for an alternative source of oil which could reduce the cost, increase its availability, prevents environmental pollution and should be a renewable one. Neem oil and water melon oil satisfies those conditions and it is not prone to workers as petroleum oil results is skin irritation and imbalance in health. In the current situation many industries are in need for alternative coolants to make the tools better usage for longer time period so it adds value to the work piece quantitatively and qualitatively and it helps in economic aspect of country too.

Development of omega-3-rich Camelina sativa seed oil emulsions.

Camelina sativa seed is an underutilized oil source rich in omega‐3 fatty acids; however, camelina oil is not fully explored for food applications. Its high omega‐3 content makes it susceptible to oxidation, which may limit food applications. Therefore, the main objective of this study was to investigate the potential of camelina seed oil to form physically and oxidatively stable emulsions as a potential delivery system for omega‐3 fatty acids. Effects of homogenization conditions, namely, pressure (15 MPa‐30 MPa), number of passes (1,3,5, and 7), and type of homogenizers (high pressure and high shear) on the structural properties and stability of camelina seed oil emulsions stabilized with whey protein isolate were studied. High homogenization pressure (30 MPa) and number of passes (>3) reduced the particle size (278 nm) and formed more physically and oxidatively stable emulsions compared to high shear homogenization; high shear homogenization generated bigger oil particles (~2,517 nm). Apparent viscosity and consistency index (k) decreased with increasing pressure, number of passes, and shear rate. Emulsions prepared with high pressure homogenization at both 15 and 30 MPa with 3 and more passes did not exhibit any peroxide formation over 28 days. Results indicated that camelina seed oil is a promising alternative oil source to form stable omega‐3‐rich emulsions for food applications.

Fatty acids and beyond: Fillet nutritional characterisation of rainbow trout (Oncorhynchus mykiss) fed different dietary oil sources

A considerable body of literature exists concerning the use of marine-derived raw materials in aquaculture feed formulations and the resulting modifications of the health promoting qualities of farmed fish. However, these investigations and reports are fundamentally limited to fatty acids and little is known regarding the other nutritional characteristics of cultured fish and seafood products. This knowledge gap, often coupled with inaccurate or incomplete media reports, generates consumer confusion and mistrust in relation to farmed fish quality. The aim of the present study was therefore to characterise not only the fatty acid composition, but also the resulting protein, amino acid and micronutrient composition of rainbow trout fed diets containing fish oil or vegetable oils. To achieve this, triplicate groups of rainbow trout (Oncorhynchus mykiss) were subjected to two distinct vegetable oil- based diets (one rich in alpha-linolenic acid, 18:3n-3, ALA and the other rich in linoleic acid, 18:2n-6, LNA) and a traditional n-3 long chain polyunsaturated fatty acid (LC-PUFA) rich, fish oil-based diet over a 126 day period. Growth performance and feed utilisation parameters as well as tissue fatty acid composition, amino acid composition, vitamin, mineral and trace element concentration in fish fillets were subsequently assessed. Expectedly, major differences were evident between treatments in relation to fatty acid composition, where for the most part fillet composition reflected that of the diet. Notably, no differences were observed regarding fillet amino acid composition, as was also the case for the vast majority of vitamins, minerals and trace elements. Therefore, with the exception of the fatty acid profile and vitamin A concentration, other beneficial nutritional qualities of fish are fundamentally maintained and unaffected when alternative oil sources are implemented in aquaculture feed formulations, maintaining cultured rainbow trout a nutritious and nourishing product for human consumption.

Technology for public outreach of fuel oil production from municipal plastic wastes

Improving public understanding and awareness is often considered as one of key factor on the waste-to-energy implementation. In order to improve awareness on plastic separation from household waste, an education and public outreach activity has been initiated by involving the development of pyrolysis technology for producing liquid oil. The technology is an integrated system of pyrolysis machine and shredding machine. The system need to cope with challenge of flexibility and easy transportation from one community-based waste recycle (waste bank) to another for campaign or education purpose. The technology is expected to exhibit the benefit of plastic waste to be converted as an alternative source of burnable oil for household.

Chemical composition and bioactive compounds of Cucumis melo L. seeds: Potential source for new trends of plant oils

Abstract Studies were conducted on the chemical composition of melon (Cucumis melo L.) seeds, Maazoun variety. Melon seeds were found to contain (on a dry weight basis): moisture (7.16%), oil (30.65%), protein (27.41%), ash (4.83%), carbohydrate (29.96%), fibers (25.32%) and considerable amounts of antioxidant substances as phenolic compounds. The major mineral elements were: potassium, magnesium and calcium. The chemical composition of oil extracted from melon seeds was investigated. The main fatty acids of melon seed oil were linoleic acid and oleic acid. The chromatographic analysis of phenolic compounds showed that flavonoids were the most important group with predominance of amentoflavone (32.80 μg/g). Besides, melon seed oil presented considerable amounts of phytosterols in which β-sitosterol was the major sterol accounting for 206.42 mg/100 g. The seed oil was also found to be rich in tocopherols with a predominance of β+γ-tocopherol fraction. The obtained results revealed that melon seeds presented an alternative source of plant oil which may serve as raw material for food applications.

Effects of alternative oil sources in feed on growth and fatty acid composition of juvenile giant river prawn (Macrobrachium rosenbergii)

To relieve the pressure on the future use of fish oil (FO), alternative oil sources need to be explored. Alternative oil sources were evaluated—Schizochytrium sp. (SZ) and soybean oil (SO)—on the growth performance and flesh quality of juvenile river prawn, Macrobrachium rosenbergii. Five experimental diets differed in the types of oil used (oil comprised 3% of dietary ingredients): 3% FO, 1% SZ + 2% SO, 1.5% SZ + 1.5% SO, 2% SZ +1% SO and 3% SZ. After 60 d of the experiment, the survival rates of prawns fed non-FO diets did not significantly (p > 0.05) differ from those fed the FO diet (77.82 ± 4.45–93.38 ± 0.00%). Moreover, prawns fed diets containing both SZ and SO had significantly (p < 0.05) better growth performance than those fed a single oil source. Prawns fed 2% SZ+1% SO showed the best final weight, percentage weight gain, absolute daily weight gain, specific growth rate and feed conversion ratio (p < 0.05) while those fed 1.5% SZ +1.5% SO or 3% SZ had the highest survival. Tissues of prawns fed the non-FO diets contained higher amounts of n−6 polyunsaturated fatty acid (PUFA) but were lower in n−3 long-chain PUFAs (eicosapentaenoic acid and docosahexaenoic acid) than those fed the FO diet. Among the non-FO groups, prawns fed 3% SZ had the most similar flesh fatty acid profile to those fed 3% FO. Substitution of FO with combinations of SZ and SO significantly improved growth performance and feed utilization. The study recommended diets containing 2% SZ + 1% SO or 1.5% SZ + 1.5% SO for M. rosenbergii juveniles.