Quality Edible Oil Research Articles

Nutritional value of Sesamum indicum L. was improved by Azospirillum and Azotobacter under low input of NP fertilizers

BackgroundSesame (Sesame indicum L.) is well-known as a versatile industrial crop having various usages and contains 50–55% oil, 20% protein, 14–20% carbohydrate and 2–3% fiber. Several environmental factors are known to adversely affect yield and productivity of sesame. Our overall aim was to improve the growth, yield and quality of sesame cv. TS-3 using plant growth promoting rhizobacteria (PGPR) and saving the nitrogen and phosphate fertilizers (NP) by 50%. Field experiment (randomized complete block design) was conducted during the months of July to October of two consecutive years 2012–2013. Azospirillum (AL) and Azotobacter (AV) were applied as seed inoculation alone as well as along with half of the recommended dose of nitrogen (N) and phosphate (P) fertilizers (urea and diammonium phosphate) at the rate of 25 kg/ha and 30 kg/ha respectively.ResultsHere we report that A. lipoferum along with half dose of NP fertilizers (ALCF) were highly effective in increasing the agronomic and yield traits of sesame as compared to the control. A. vinelandii plus NP fertilizers (AVCF) exhibited higher seed oil content. Minimum acid value, optimum specific gravity and modified fatty acid composition were observed in ALCF treatment. Increase in oleic acid by ALCF is directly linked with improved oil quality for health benefits as oleic acid is the fatty acid which creates a balance between saturation and unsaturation of oil and for the hypotensive (blood pressure reducing) effects.ConclusionIt is inferred that ALCF treatment improved plant growth, seed yield and oil quality of sesame pertaining to good quality edible oil production.

Novel cis-acting regulatory elements in wild Oryza species impart improved rice bran quality by lowering the expression of phospholipase D alpha1 enzyme (OsPLDα1).

Rice bran oil is good quality edible oil, rich in antioxidants and comprised typically of oleic-linoleic type fatty acids. However, presence of a highly lipolytic enzyme Phospholipase D alpha1 (OsPLDα1) increases free fatty acid content in the oil which further leads to stale flavor and rancidity of the oil, making it unfit for human consumption. In this study, we compared the upstream regions of OsPLDα1 orthologs across 34 accessions representing 5 wild Oryza species and 8 cultivars, to uncover sequence variations and identify cis-elements involved in differential transcription of orthologs. Alignment of the upstream sequences to the Nipponbare OsPLDα1 reference sequence revealed the presence of 39 SNPs. Phylogenetic analysis showed that all the selected cultivars and wild species accessions are closely related to the reference except for three accessions of O. rufipogon (IRGC89224, IRGC104425, and IRGC105902). Furthermore, using exon-specific qRT-PCR, OsPLDα1 expression patterns in immature grains indicated significant differences in transcript abundance between the wild species accessions. In comparison to the control, lowest gene expression was observed in IRGC89224 accession (0.20-fold) followed by IRGC105902 (0.26-fold) and IRGC104425 (0.41-fold) accessions. In-silico analysis of the OsPLDα1 promoter revealed that the copy number variations of CGCGBOXAT, GT1CONSENSUS, IBOXCORE, NODCON2GM, OSE2ROOTNODULE, SURECOREATSULTR11, and SORLIP1AT cis-elements play an important role in the transcriptional activities of orthologous genes. Owing to the presence of ARFAT and SEBF elements only in the IRGC89224 accession, which had the lowest gene expression as well, these putative upstream regulatory sequences have been identified as novel cis-elements which may act as repressors in regulating the OsPLDα1 gene expression. The accessions identified with low OsPLDα1 expressions could be further deployed as potential donors of ideal OsPLDα1 allele for transfer of the desired trait into elite rice cultivars.

Genetic diversity in Sesamum indicum L.

Sesame (Sesamum indicum L.), is the most ancient and important oilseed crop for its good quality edible oil. Much variability among genotypes exists in sesame which helps the breeder to choose good parents in hybridization. In the present study, 30 genotypes were studied for 12 morphological traits. Correlation analysis exhibited that seed yield per plant was positive and significantly correlated with capsules per plant and 1000-seed weight. Apart from morphological data, initial genotyping was conducted for 32 microsatellites but finally only polymorphic primers were selected for genetic diversity study. Estimated polymorphism information content (PIC) value ranged from 0.07 to 0.87 and SSR 24 showed to be highest at 0.87. The dendrogram was constructed using the software NTSYS Pc Ver. 2.20 based on morphological and molecular data. Geographical diversity did not corroborate with genotypic diversity as the cluster composition revealed that genotypes belonging to different geographical origin grouped in the same cluster.

A novel, low-cost and throughput selfing technique in sesame

Sesame (Sesamum indicum L.) is an oilseed crop, highly valued for its quality edible oil and direct confectionery uses. Though sesame is a self-pollinated crop, the opened flowers attract several groups of bees which promote cross pollination. Genetically pure seed obtained by ensuring self-pollination is an essential requirement for fixing the traits in genotypes, and for employing them in molecular and genomic studies. As of now, bagging technique is followed for selfing and this is not only tedious but also detrimental to the developing flowers. In order to overcome the limitations of the traditional selfing technique, a novel selfing technique has been developed using liquid glue, which is low cost, less labour intensive and high throughput method. This technique has no seasonal limitations and is applicable across any region where sesame is grown.

Assessment of sunflower germplasm for phytoremediation of lead-polluted soil and production of seed oil and seed meal for human and animal consumption

Phytoremediation is a valuable technology for mitigating soil contamination in agricultural lands, but phytoremediation without economic revenue is unfeasible for land owners and farmers. The use of crops with high biomass and bioenergy for phytoremediation is a unique strategy to derive supplementary benefits along with remediation activities. Sunflower (Helianthus annuus L.) is a high-biomass crop that can be used for the phytoremediation of polluted lands with additional advantages (biomass and oil). In this study, 40 germplasms of sunflower were screened in field conditions for phytoremediation with the possibility for oil and meal production. The study was carried out to the physiological maturity stage. All studied germplasms mopped up substantial concentrations of Pb, with maximum amounts in shoot > root > seed respectively. The phytoextraction efficiency of the germplasm was assessed in terms of the Transfer factor (TF), Metal removal efficiency (MRE) and Metal extraction ratio (MER). Among all assessed criteria, GP.8585 was found to be most appropriate for restoring moderately Pb-contaminated soil accompanied with providing high biomass and high yield production. The Pb content in the oil of GP.8585 was below the Food safety standard of China, with 59.5% oleic acid and 32.1% linoleic acid. Moreover, amino acid analysis in meal illustrated significant differences among essential and non-essential amino acids. Glutamic acid was found in the highest percentage (22.4%), whereas cysteine in the lowest percentage (1.3%). Therefore, its efficient phytoextraction ability and good quality edible oil and meal production makes GP.8585 the most convenient sunflower germplasm for phytoremediation of moderately Pb-contaminated soil, with fringe benefits to farmers and landowners.

Diversity in Sesame Accessions

Sesame known to be the most ancient oilseed crop in the world and well recognized for good quality edible oil due its high PUFA content, antioxidant properties, excellent nutritional and medicinal properties. The present investigation aims at analyzing the genetic diversity of 205 genotypes for 8 morphological characters. Phenotypic coefficients of variation exhibited a bit higher values but maintained a close relation with genotypic variation and genotypic co-efficient of variation for all the traits, indicating low G×E interaction. A combination of high heritability (broad sense) and high genetic advance indicate preponderance of additive gene action which is fixable. Additive gene action was prominent for the traits like no of capsules/plant, seed yield/plant, and primary branches/plant. Hierarchical cluster analysis based on agro-morphological traits results revealed that the inter cluster distance in most cases was larger indicating wider diversity among the germplasm of different groups. The maximum inter cluster distance was found between clusters V and III, followed by clusters V and II, clusters VI and II. The principal component analysis revealed that capsule number and 1000-seed weight had a strong relation with seed yield, suggesting the need for more emphasis on these components for increasing the seed yield in sesame.

Screening of early maturing soybean genotypes for production of high quality edible oil

Screening of early maturing soybean genotypes for production of high quality edible oil

Assessing the Potential of Rain-Water Harvesting (in situ) for Sustainable Olive (Olea europaea L.) Cultivation in Water-Scarce Rain-Fed Areas

The improvement of water productivity in olive cultivation and its production on sustainable basis in areas marked as water deficit. The most essential, natural and cheapest water resource in such water-prone areas of the world is rainfall. The collection and constructive use of rain-water runoff, also known as water harvesting, has the potential to cope with the water scarcity in the semi-arid and dry, sub-humid regions of the world to sustain olive production. Among all the available micro-irrigation techniques, construction of micro catchments can help farmers to produce crops such as olive orchards with minimum water resources. Research experiments were conducted at Barani Agricultural Research Institute (BARI), Pakistan situated in region where the climate is semi-arid subtropical and the annual rainfall varies from 500-1000 mm. To compare water productivity of different micro-catchment methods, three field plots with three different shapes i.e., square, rectangular, and triangular (V shape) were constructed with 3-5% slope. Olive trees, due to their expensive premium quality edible oil and natural adaptability to grow in marginal lands and better drought tolerance, were used as subject crop to evaluate the performance of micro catchments rain water harvesting techniques. Results concluded that micro catchment structures showed significantly better yield (8-9%) as compared to control and are best suitable to sloppy terrene. Only three supplement irrigations were required for sustainable olive plant cultivation through drip/bubbler irrigation system. Average effective rainfall of both years was 594 mm from which 505 mm (85%) was used by olive plants in micro catchments. Conclusively, micro-catchment structure can be utilized as efficient technique to harvest rain water and sustainable cultivation of olive in semi-arid and arid climates.

Management of collar rot ( Sclerotium rolfsii Sacc.) in sunflower (Helianthus annuus L.)

Sunflower (Helianthus annuus L.) is an important short duration crop which can be grown in all seasons and produces high quality edible and industrial oil, besides animal feed and fodders. Sclerotium rolfsii cause both pre and post-emergence mortality of young seedlings besides inciting collar rot in adult plants is considered to be potential biotic limiting factor for cultivation of sunflower. Keeping this fact in view, few fungicides and bio-agents were tested as seed treatment and soil application to manage the collar rot of sunflower under screen house and field conditions. Results indicated that use of fungicides and bio-agents as seed and soil treatments significantly reduced the incidence of collar rot. Under screen house conditions, maximum disease control (75.15 %) was obtained by Vitavax power (carboxin + thiram ) @ 2g/kg seed followed by captan 50 WP @ 3g/kg (70.35%). Trichoderma harzianum @ 20g/kg soil application showed maximum control of the disease (40.62%) as compared to untreated control. Results of studies conducted under field conditions revealed that seed treatment with captan 50 WP @ 3g/kg seed was found most effective treatment in controlling the disease incidence (73.38 %). Among the different bio-agent evaluated, Pseudomonas fluorescensas as soil application gave maximum disease control (55.11 %) of collar rot of sunflower and also maximum seed yield

Induction of shoot regeneration in cotyledon explants of the oilseed crop Sesamum indicum L.

Sesamum indicum is an ancient oilseed crop known for its high quality edible oil and its medicinally important lignans. The crop is said to be recalcitrant to plant tissue culture thus limiting the use of modern biotechnology for its genetic improvement. We present here a protocol describing plant regeneration through adventitious shoot formation from cotyledons dissected from sesame seeds soaked for four hours in water. Subculturing of the cotyledons after two weeks of culture on to a fresh Murashige and Skoog medium leads to differentiation of adventitious shoots from the proximal cut end of the explant. Culture of cotyledons on a medium containing 9% sucrose for a couple of weeks prior to transfer to MS medium supplemented with 3% sucrose induced a higher frequency of shoot regeneration. The highest frequency of 25% adventitious shoot regeneration was observed for S. indicum variety UMA. This variety also turned out to be the best among the ten genotypes tested for shoot regeneration through tissue culture. While addition of IAA marginally improved regeneration, silver nitrate was found essential for enhancing the frequency of shoot regeneration. The regenerated shoots formed roots on full strength MS medium supplemented with 1 mg/l IBA and the rooted plants were established in soil.

Utilization of Molecular, Phenotypic, and Geographical Diversity to Develop Compact Composite Core Collection in the Oilseed Crop, Safflower (Carthamus tinctorius L.) through Maximization Strategy.

Safflower (Carthamus tinctorius L.) is a dryland oilseed crop yielding high quality edible oil. Previous studies have described significant phenotypic variability in the crop and used geographical distribution and phenotypic trait values to develop core collections. However, the molecular diversity component was lacking in the earlier collections thereby limiting their utility in breeding programs. The present study evaluated the phenotypic variability for 12 agronomically important traits during two growing seasons (2011–12 and 2012–13) in a global reference collection of 531 safflower accessions, assessed earlier by our group for genetic diversity and population structure using AFLP markers. Significant phenotypic variation was observed for all the agronomic traits in the representative collection. Cluster analysis of phenotypic data grouped the accessions into five major clusters. Accessions from the Indian Subcontinent and America harbored maximal phenotypic variability with unique characters for a few traits. MANOVA analysis indicated significant interaction between genotypes and environment for both the seasons. Initially, six independent core collections (CC1–CC6) were developed using molecular marker and phenotypic data for two seasons through POWERCORE and MSTRAT. These collections captured the entire range of trait variability but failed to include complete genetic diversity represented in 19 clusters reported earlier through Bayesian analysis of population structure (BAPS). Therefore, we merged the three POWERCORE core collections (CC1–CC3) to generate a composite core collection, CartC1 and three MSTRAT core collections (CC4–CC6) to generate another composite core collection, CartC2. The mean difference percentage, variance difference percentage, variable rate of coefficient of variance percentage, coincidence rate of range percentage, Shannon's diversity index, and Nei's gene diversity for CartC1 were 11.2, 43.7, 132.4, 93.4, 0.47, and 0.306, respectively while the corresponding values for CartC2 were 9.3, 58.8, 124.6, 95.8, 0.46, and 0.301. Each composite core collection represented the complete range of phenotypic and genetic variability of the crop including 19 BAPS clusters. This is the first report describing development of core collections in safflower using molecular marker data with phenotypic values and geographical distribution. These core collections will facilitate identification of genetic determinants of trait variability and effective utilization of the prevalent diversity in crop improvement programs.

Antioxidative Activities of Both Oleic Acid and Camellia tenuifolia Seed Oil Are Regulated by the Transcription Factor DAF-16/FOXO in Caenorhabditis elegans.

BackgroundTea seed oil is a high quality edible oil, yet lacking sufficient scientific evidences to support the nutritional and medical purposes. We identified major and minor components in Camellia tenuifolia seed oil and investigated the antioxidative activity and its underlying mechanisms in Caenorhabditis elegans.Principal FindingsThe results showed that the major constitutes in C. tenuifolia seed oil were unsaturated fatty acids (~78.4%). Moreover, two minor compounds, β-amyrin and β-sitosterol, were identified and their antioxidative activity was examined. We found that oleic acid was the major constitute in C. tenuifolia seed oil and plays a key role in the antioxidative activity of C. tenuifolia seed oil in C. elegans.ConclusionsThis study found evidences that the transcription factor DAF-16/FOXO was involved in both oleic acid- and C. tenuifolia seed oil-mediated oxidative stress resistance in C. elegans. This study suggests the potential of C. tenuifolia seed oil as nutrient or functional foods.

Promising features of mango (Mangifera indica L.) kernel oil: a review.

Mango kernel contains about 15% good quality edible oil, that is comparable to soybean and cottonseed, which contain about 18-20% oil. Mango kernel oil (MKO) has lower free fatty acids, carotenoid content and peroxide value, and is usually used without any processing, which is otherwise mandatory for commercial vegetable oils. Palmitic, stearic and oleic acids are the major fatty acids, triglyceride composition and fatty acid profile suggest wide range of trans free options. With 32-36°C melting point, MKO is solid at room temperature, thus, does not require partial hydrogenation for application in foods. MKO can be used as an alternative of cocoa butter, which is used in chocolates and confectionaries. Total phenolic contents and induction period of MKO is greater than many commercial vegetable oils; thus, it can be used as an alternative of synthetic antioxidants for the preservation of fats and oils. Mangiferin, chlorogenic acid, quercetin and caffeic acid are the major phenolic compounds present in MKO. Functional properties of MKO can be further improved through fractionation, transesterification and interesterification for increased industrial applications.

A case study on the genetic origin of the high oleic acid trait through FAD2-1 DNA sequence variation in safflower (Carthamus tinctorius L.).

The safflower (Carthamus tinctorius L.) is considered a strongly domesticated species with a long history of cultivation. The hybridization of safflower with its wild relatives has played an important role in the evolution of cultivars and is of particular interest with regards to their production of high quality edible oils. Original safflower varieties were all rich in linoleic acid, while varieties rich in oleic acid have risen to prominence in recent decades. The high oleic acid trait is controlled by a partially recessive allele ol at a single locus OL. The ol allele was found to be a defective microsomal oleate desaturase FAD2-1. Here we present DNA sequence data and Southern blot analysis suggesting that there has been an ancient hybridization and introgression of the FAD2-1 gene into C. tinctorius from its wild relative C. palaestinus. It is from this gene that FAD2-1Δ was derived more recently. Identification and characterization of the genetic origin and diversity of FAD2-1 could aid safflower breeders in reducing population size and generations required for the development of new high oleic acid varieties by using perfect molecular marker-assisted selection.

Development of Genomic Microsatellite Markers in Carthamus tinctorius L. (Safflower) Using Next Generation Sequencing and Assessment of Their Cross-Species Transferability and Utility for Diversity Analysis.

BackgroundSafflower (Carthamus tinctorius L.), an Asteraceae member, yields high quality edible oil rich in unsaturated fatty acids and is resilient to dry conditions. The crop holds tremendous potential for improvement through concerted molecular breeding programs due to the availability of significant genetic and phenotypic diversity. Genomic resources that could facilitate such breeding programs remain largely underdeveloped in the crop. The present study was initiated to develop a large set of novel microsatellite markers for safflower using next generation sequencing.Principal FindingsLow throughput genome sequencing of safflower was performed using Illumina paired end technology providing ~3.5X coverage of the genome. Analysis of sequencing data allowed identification of 23,067 regions harboring perfect microsatellite loci. The safflower genome was found to be rich in dinucleotide repeats followed by tri-, tetra-, penta- and hexa-nucleotides. Primer pairs were designed for 5,716 novel microsatellite sequences with repeat length ≥ 20 bases and optimal flanking regions. A subset of 325 microsatellite loci was tested for amplification, of which 294 loci produced robust amplification. The validated primers were used for assessment of 23 safflower accessions belonging to diverse agro-climatic zones of the world leading to identification of 93 polymorphic primers (31.6%). The numbers of observed alleles at each locus ranged from two to four and mean polymorphism information content was found to be 0.3075. The polymorphic primers were tested for cross-species transferability on nine wild relatives of cultivated safflower. All primers except one showed amplification in at least two wild species while 25 primers amplified across all the nine species. The UPGMA dendrogram clustered C. tinctorius accessions and wild species separately into two major groups. The proposed progenitor species of safflower, C. oxyacantha and C. palaestinus were genetically closer to cultivated safflower and formed a distinct cluster. The cluster analysis also distinguished diploid and tetraploid wild species of safflower.ConclusionNext generation sequencing of safflower genome generated a large set of microsatellite markers. The novel markers developed in this study will add to the existing repertoire of markers and can be used for diversity analysis, synteny studies, construction of linkage maps and marker-assisted selection.

Techno-economic optimization of the subcritical fluid extraction of oil from Moringa oleifera seeds and subsequent production of a purified sterols fraction

Moringa oleifera tree is found in many tropical areas, and its seed contains up to 40% of good quality edible oil where sterols are also present. In this work a techno-economic study encompassing the coproduction of oil and sterols from M. oleifeira seeds was accomplished using the RSM–COM approach. The oil is produced by subcritical fluid extraction (SFE) while the purification of the associated sterols is accomplished by a patented technology based on distillation.Besides the expenses and investment associated to the SFE, the respective costs and investment for the preliminary drying of biomass and final separation of sterols from bulk oil were also taken into account. Under optimized extraction pressure and time of 350bar and 1.3h, respectively, oil cost was estimated to be 2.76 € kgoil−1 for a SFE unit comprising two extractors of 1m3 capacity. For the coproduction of sterols with 89.4wt.% purity, the minimum costs were 5.60 € kgsterols−1. The overall annual production under optimum conditions was 558.9tons of oil and 1.9tons of sterols, leading the whole integrated process to a net income of 15.87M€year−1. In conclusion the proposed combined process is feasible, and this essay opened the way to exploit M. oleifera by subcritical fluid extraction under the scope of biorefinery premises.

Physicochemical properties, phenolic acids and volatile compounds of oil extracted from dry alhydwan (<em>Boerhavia elegana Choisy</em>) seeds

In this study, the chemical composition, physicochemical properties, phenolic acids and volatile compounds of alhydwan (Boerhavia elegana Choisy) seed oil were evaluated. The crude oil content was 11.49%, ash 6.88%, moisture 6.12%, protein content 14.60%, total carbohydrate 24.77% and fiber 36.13%. The oil contain a high quantity of unsaturated fatty acids (74.63 mg·100 g−1) with oleic (C18:1) (57.77%), palmitic (C16:0) (18.65%) and linoleic (C18:2) (12.88%) acids as the most abundant. The relative density was 0.88 and the iodine value 105.59. The color analysis showed a value of 28.33 Y+1.43 R. The oil also had a high relative oxidative stability. The tocol composition showed that α-tocotrienol, γ-tocopherol and γ-tocotrienol were in a higher concentration than the rest. Seven phenolic acids (caffeic, vanillic, galic, p-coumaric, ascorbic, cinnamic and ferulic) were detected, with ascorbic acid as the predominant one (5.44 mg·100 g−1). In relation to the volatile composition, 48 compounds were found with Z-10-Pentadecen-1-ol (56.73%); Hexadecenoic acid, Z-11- (18.52%); 9,12-Octadecadienoic acid (Z,Z)- (3.93%) and 9,12-Octadecadienoic acid (Z,Z)-, 2-hydroxy-1-(hydroxymethyl) ethyl ester (3.04%) as the most abundant. These findings demonstrated the potential of alhydwan seeds to be used as a good source of quality edible oil.

Physico - Chemical Characteristics of Egyptian Ben Seed Oil (Moringa Oleifera Lam. ) Extracted by Using Aqueous Enzymatic Technique

Moringaoleifera Lam. is a multipurpose tree cultivated to use as vegetable spice for cooking and cosmetic and as a medicinal plant. Owing to the use of these seeds and its oil as food, some characteristics were studied. The seeds oil of the Egyptian ben (Moringaoleifera) was extracted by an aqueous-enzyme-assisted technique using an olive two-phase decanter mill. The enzyme was chosen following a preliminary study conducted on the enzymatic extraction which showed protease to be the best enzyme with the highest oil recovery value. Chemical and physico-chemical characteristics and fatty acid compositions of the extracted oil were determined. The mature seeds contained 40.84% (crude protein), 33.48% (crude fat), 11.55% (carbohydrate), 9.96% (crude fiber) and 4.17% (ash) as dry matter. The chemical and physico-chemical characteristics of the extracted oil were:refractive index (20°C), 1.4665; density (20°C), 0.9122 g/cm³; smoked point, 207°C; color (1-in. cell) 3.6 R - 35 Y; saponification value, 194.4; unsaponifiable matter, 0.58%; acidity (as oleic acid), 1.4%; total Phenols, 466.8 ppm and total Tocopherols, 71 ppm. The oxidative stability of Moringaoleifera seed oil was determined and found to be, Peroxide value, 5.44 meqO2/Kg; Thiobarbituric acid, 0.874 malonaldhyde/kg oil; Rancimate induction period, 304.8 hr and Specific extinction at 232nm, 1.3720 and 270 nm, 0.1018. Results obtained also showed that, the Moringa oil is highly unsaturated 77.61 %, due to its high content of oleic acid (72.29%). These results strongly suggested the potential use of Moringa oil as high quality edible oil and for industrial applications. Keywords: Aqueous enzymatic extraction, Fatty acid composition,Moringa seed oil, Physico-chemical characteristics, Oxidative stability.

A Novel and Efficient Method for Purification of Tert-Butylhydroquinone

Tert-butylhydroquinone is a high quality edible-oil antioxidant. tert-Butylhydroquinone has many advantages such as high activity, low mammalian toxicity, and high thermal stability. This article proposes a novel and efficient method for the purification of tert-Butylhydroquinone. The purification has two steps. A mixture of hydroquinone (wt%: 16.4%), tert-Butylhydroquinone (wt%: 68.1%), and 2, 5-ditert-butylhydroquinone (wt%: 15.5%) is washed with water to separate hydroquinone. A highly-purified tert-Butylhydroquinone (purity: > 97.0%),is then obtained by separating 2, 5-ditert-butylhydroquinone from crude tert-Butylhydroquinone using formic acid as solvent in the yield of 96.3%.

Chemical composition, thermal stability and antioxidant properties of tea seed oils obtained by different extraction methods: Supercritical fluid extraction yields the best oil quality

A comparison study has been performed for tea seed oils (TSO) extracted from different methods and sources, which were oil from cold‐pressing of tea seeds [TSO(CP)], oil from supercritical fluid extraction of seeds [TSO(SCF)], and oil from supercritical fluid extraction of tea seed cake [TSCO(SCF)]. The chemical composition, thermal stability, antioxidant properties, and physicochemical properties of the oils were determined. The main ingredient in seed and cake was fat, fiber, total sugar, and considerable amounts of amino, 74.59 and 93.25 g/100 g protein, respectively were found. The results also indicated that oleic acid and linoleic acid were the dominant unsaturated fatty acids in tea seed oils, irrespective of extraction methods and sources. The TSO(SCF) contained the highest levels of squalene, lupeol, and total sterols whereas TSCO(SCF) and TSO(CP) had higher contents of total phenolics and α‐tocopherol. The TG/DTG curves showed TSO(CP) and TSO(SCF) were more thermally stable than TSCO(SCF), and the antioxidant activity assays demonstrated that TSO(CP) and TSCO(SCF) exhibited stronger radical scavenging ability. The overall physicochemical properties of the tested oils indicated that TSO(SCF) had the best oil quality. This work may be useful to food oil industry to produce high quality tea seed oils through utilization of suitable oil extraction methods and raw materials.Practical applications: The growing consumption of green tea promoted the increased production of tea seed, which has totaled as much as 1.6 million tons annually since 2011. As an important source of edible oil, the exploitation rate of tea seed is insufficient (≤1%) in China. This study indicates that oil extracted from tea seed as well as cold‐pressing cake can be exploited for high quality edible oil because of similar fatty acid composition and better bioactive compound composition (e.g., α‐tocopherol, total phytoterols, and lupeol) compared to olive oil. Further, the evaluation of thermal stability provides basis for oil's refining to prepare salad oil, mayonnaise, etc. TSO(SCF) and TSCO(SCF) both had good antioxidant activity, which is applicable in the industry of skincare.A comparison study has been performed for tea seed oils (TSO) extracted from different methods and sources, which were oil from cold‐pressing of tea seeds [TSO(CP)], oil from supercritical fluid extraction of seeds [TSO(SCF)], and oil from supercritical fluid extraction of tea seed cake [TSCO(SCF)]. The chemical composition, thermal stability, antioxidant properties, and physicochemical properties of the oils were determined.