Composition, bioactive substances, extraction technologies and the influences on characteristics of Camellia oleifera oil: A review

Assembly of oleosin during efficient extraction: Altering the sequence of defatting solvents

During the extraction of membrane proteins from oil bodies (OBs), organic solvents dissolve the lipid core and precipitate proteins through solvent stress. Here the effects of solvent type and defatting sequence on the composition and structure of membrane proteins were investigated via SDS-PAGE, FTIR, and SEM-EDS. High purity oleosin (86 %) was obtained by treatment first with a Floch solution and then with cold acetone and petroleum ether after twice washing OBs with urea. The 3D spatial structure of oleosin was predicted using AlphaFold 2, revealing that the secondary structure of oleosin was dominated by α-helices (>60 %). Oleosin consisted of two district types, with oleosin-H (16-17 kDa) being the part of the molecule with limited water solubility, while oleosin-L (13-14 kDa) constituted the non-soluble part. The results provided a technical means of efficient extraction of Camellia oleosins and selective separation of oleosin-L and oleosin-H.

Exploring Camellia oleifera Abel seed cake as sustainable source of protein for food applications: A review

The demand for sustainable plant-based protein is rising due to concerns over the environmental impact of animal-based protein. One promising yet overlooked protein source is the seed cake generated from Camellia oleifera oil extraction (COSC), which contains 14-20 % crude protein. COSC protein (COSCP) exhibit excellent nutritional and functional properties making it a promising ingredient for innovative food products. However, its adoption remains limited. This review discusses COSCP extraction methods, functional properties, and food applications to promote its broader utilization. It also examined how oil extraction methods influence COSCP functional characteristics and explores modification techniques to enhance its functionality. COSCP has excellent functional properties, making it suitable for use as emulsifier, foaming, and gelling agents in food systems. However, cross-linking of COSCP with saponins and phenolics during seed processing compromise the protein yield, purity, and functionality and need to be addressed to fully unlock the potential of COSCP in food applications.

Can aged Camellia oleifera Abel oil truly be used to treat atopic dermatitis?

Atopic dermatitis is an inflammatory skin condition characterized by erythema, eruption, lichenification, and pruritus. Aged Camellia oleifera Abel oil, an effective empirical plant oil utilized by the Gannan Hakka people in China to alleviate the symptoms of atopic dermatitis. However, no scientific studies have been reported to prove whether this oil is truly effective. We conducted this study to confirm whether aged C. oleifera oil could alleviate the symptoms of 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis in mice. Differences in the thickness and weight of the right and left ears were measured. ELISA was used to determine the serum levels of the inflammatory factors IL-4, IgE, IFN-γ, and TNF-α. HE staining was performed to observe inflammatory cell infiltration in the mouse skin lesions. In addition, the metabolites of aged C. oleifera oils were analyzed, and molecular docking was used to assess the binding affinity of the major metabolites to filaggrin, a protein involved in skin barrier function. Animal studies showed that aged C. oleifera oil significantly improved the symptoms of atopic dermatitis. HE staining and measurement of inflammatory factor levels revealed similar results. A total of 41 metabolites were tentatively identified in the oil, with fatty acids emerging as the major metabolites. Molecular docking confirmed that the three most abundant fatty acids, i.e., oleic acid, n-hexadecanoic acid, and octadecanoic acid, bind well to filaggrin. Our results suggest that aged C. oleifera oils can be used to ameliorate the symptoms of atopic dermatitis. Fatty acids may be the major active metabolites responsible for the observed therapeutic effects by reducing transdermal water loss, increasing skin hydration, alleviating DNCB-induced skin barrier alterations, and eliminating itchy scratching caused by dry skin.

Intercropping improves the yield by increasing nutrient metabolism capacity and crucial microbial abundance in root of Camellia oleifera in purple soil

Intercropping system influences the endophytic microbial abundance, hormone balance, nutrient metabolism and yield, but the molecular mechanism of yield advantage in Camellia oleifera intercropping with peanut is not clear. In this study, the C. oleifera monoculture (CK) and C. oleifera-peanut intercropping (CP) treatments in purple soil were conducted, and the physicochemical properties, gene expressions, signal pathways and crucial microbial abundances were investigated to reveal the molecular mechanism of the yield advantage of intercropped C. oleifera. The results showed that the intercropping system increased in contents of pigment, carbohydrate, available nitrogen and phosphorus in leaf and root, as well as the abundances of Burkholderia, Ralstonia, Delftia, Pseudoalteromonas and Caulobacter, enhanced the relative expression levels of CoSPS, CoGBE, CoGlgP, CoGBSS/GlgA genes to promote sugar metabolism, decreased the relative expression levels of CoASA, CoTSB, CoPAI, CoTDC and CoCYP71A13 genes for inhibiting IAA biosynthesis and signal transduction, as well as microbial diversity, Fusarium, Albifimbria and Coniosporium abundances in root, ultimately improved the fruit yield of C. oleifera. These findings indicate that intercropping system improves the fruit yield by enhancing the nutrient metabolism capability and crucial microbial abundances in root of C. oleifera in purple soil.

UPLC-MS/MS reveals the differences in lipids composition of Camellia oleifera from northern margin distribution area

The lipids accumulation characteristics in 23Camellia oleifera lines from northern margin distribution area were investigated through quantitative lipidomics. Combined lipids content-function analysis indicated that NQ1, HT1, HT2, ZA2, ZB1, ZB2, and SN2 lines had potential to develop functional foods due to abundant glycerolipids (GLs), glycerophospholipids (GPs), fatty acids (FAs), and prenol lipids (PRs). 673 lipids components were detected, and 293 differential components were identified in NQ1, ZA2, HB1, and HT1. 4 kinds free fatty acids (FFAs) were higher in NQ1, 5 triglycerides (TGs) were higher in HT1, and 2 phosphatidyl serines (PSs) and 1 phosphatidyl glycerol (PG) were higher in ZA2. GLs, GPs, and FFAs had strong relation at intra- and inter-category level. Glycerolipid metabolism, glycerophospholipid metabolism, and fatty acid biosynthesis were the significantly differential lipids pathways. Our study elucidated lipids differences of 23 C. oleifera lines, and offered valuable references for lipids biosynthesis, directional breeding, and lipids utilization.

Effect of freeze-thaw treatment on the yield and quality of tiger nut oil

To investigate the effect of freeze-thaw (FT) process on the yield and quality of tiger nut oil, tiger nuts were subjected to 0-12 cycles of FT treatment. Results indicated that FT treatment ruptured the cell structure of tiger nut, resulting in an increase in oil yield. Acid value (2.09-2.42 mg KOH/g) and peroxide value (0.40-0.42 mmol/kg) increased with the number of FT cycles, but the increments were small. Likewise, slight differences in fatty acid composition and thermal properties between control and FT-treated samples were observed. FT treatment remarkably increased the bioactive components (e.g., vitamin E, sterols, chlorophyll and carotenoids) in the oil and extended the oxidation induction time from 1.2 to 5.57 h. FT treatment altered the volatile composition of tiger nut oil, increasing the relative content of heterocycles and pyrazines such as 2-methoxy-4-vinylphenol, trimethylpyrazine and tetramethylpyrazine. It was suggested that FT treatment prior to oil extraction was beneficial to improve the oil yield and quality.

Unraveling the Metabolomics Mysteries in Camellia Oil: From Cognition to Application

Camellia oil is a high-value edible seed oil, recommended by the Food and Agriculture Organization (FAO). It is essential to develop accurate and rapid analytical methods to authenticate camellia oil due to its susceptibility to adulteration. Recently, hyphenated chromatography-mass spectrometry, especially high-resolution mass spectrometry using chemometrics, has become a promising platform for the identification of camellia oil. Based on the compositional analysis, the fatty acid, sterol, phenol, and tocopherol profiles (or fingerprints) were utilized as predictor variables for assessing authenticity. The review systematically summarizes the workflow of chromatography-mass spectrometry technologies and comprehensively investigates recent metabolomic applications combined with chemometrics for camellia oil authentication. Metabolomics has significantly improved our understanding of camellia oil composition at the molecular level, contributing to its identification and full characterization. Hence, its integration with standard analytical methods is essential to enhance the tools available for public and private laboratories to assess camellia oil authenticity. Integrating metabolomics with artificial intelligence is expected to accelerate drug discovery by identifying new metabolic pathways and biomarkers, promising to revolutionize medicine.

Exploring the characteristics, digestion behaviors, and nutraceutical potential of the underutilized Chimonanthus praecox (L.) link kernel oil: A combined in vitro and in vivo study

Chimonanthus praecox (L.) Link kernel oil (LMO) has the potential to expand the variety of nutraceutical plant oils available and provide support for the application of functional food. This study aimed to assess the edible potential of LMO by examining its physicochemical characteristics, digestion behaviors, and nutraceutical properties. The results revealed that LMO has a high oil content of 40.84% and is particularly rich in linoleic acid (53.37-56.30%), oleic acid (22.04-25.08%) and triacylglycerol (TAG) of linoleic acid -palmitoleic acid- oleic acid (10.57-12.70%). The quality characteristics and phytochemical composition of LMO were found to be influenced by variety and extraction methods used. In simulated in vitro digestion tests, LMO showed a better lipid release rate and degree. Animal studies further demonstrated that LMO led to better TAG and cholesterol excretion compared to soybean oil and camellia oleifera oil. Overall, this study highlights the potential of LMO as a high-quality edible oil.

Widely Targeted Metabolomics Analysis of the Roots, Stems, Leaves, Flowers, and Fruits of Camellia luteoflora, a Species with an Extremely Small Population

Camellia luteoflora is a rare and endangered plant endemic to China. It has high ornamental and potential economic and medicinal value, and is an important germplasm resource of Camellia. To understand the distributions and differences in metabolites from different parts of C. luteoflora, in this study, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to examine the types and contents of chemical constituents in five organs of C. luteoflora: roots, stems, leaves, flowers, and fruits. The results showed that a total of 815 metabolites were identified in the five organs and were classified into 18 main categories, including terpenoids (17.1%), amino acids (10.4%), flavonoids (10.3%), sugars and alcohols (9.8%), organic acids (9.0%), lipids (7.1%), polyphenols (4.8%), alkaloids (4.8%), etc. A total of 684 differentially expressed metabolites (DEMs) in five organs were obtained and annotated into 217 KEGG metabolic pathways, among which metabolic pathways, ABC transporters, the biosynthesis of cofactors, and the biosynthesis of amino acids were significantly enriched. In DEMs, flowers are rich in flavonoids, polyphenols, organic acids, and steroids; fruits are rich in amino acids, alkaloids, vitamins, and xanthones; stems are rich in lignans; and leaves have the highest relative content of phenylpropanoids, ketoaldehydic acids, quinones, sugars and alcohols, terpenoids, coumarins, lipids, and others; meanwhile, the metabolite content is lower in roots. Among the dominant DEMs, 58 were in roots, including arachidonic acid, lucidone, isoliquiritigenin, etc.; 75 were in flowers, including mannose, shikimic acid, d-gluconic acid, kaempferol, etc.; 45 were in the fruit, including pterostilbene, l-ascorbic acid, riboflavin, etc.; 27 were in the stems, including salicylic acid, d-(-)-quinic acid, mannitol, (-)-catechin gallate, etc.; there was a maximum number of 119 dominant metabolites in the leaves, including oleanolic acid, l-glucose, d-arabitol, eugenol, etc. In sum, the rich chemical composition of C. luteoflora and the significant differences in the relative contents of metabolites in different organs will provide theoretical references for the study of tea, flower tea, edible oil, nutraceuticals, and the medicinal components of C. luteoflora.

Methyl Jasmonate (MeJA) Promotes the Self-Pollen Tube Growth of Camellia oleifera by Regulating Lignin Biosynthesis

Self-incompatibility (SI) poses a significant reproductive barrier, severely impacting the yield, quality, and economic value of Camellia oleifera. In this study, methyl jasmonate (MeJA) was employed as an exogenous stimulus to alleviate SI in C. oleifera. The research findings revealed that an exogenous dose of 1000 μmol·L-1 MeJA enhanced the germination and tube growth of C. oleifera self-pollen and greatly improved ovule penetration (18.75%) and fertilization (15.81%), ultimately increasing fruit setting (18.67%). It was discovered by transcriptome analysis that the key genes (CAD, C4H) involved in the lignin production process exhibited elevated expression levels in self-pistils treated with MeJA. Further analysis showed that the lignin concentration in the MeJA-treated pistils was 31.70% higher compared with the control group. As verified by pollen germination assays in vitro, lignin in the appropriate concentration range could promote pollen tube growth. Gene expression network analysis indicated that transcription factor bHLH may be pivotal in regulating lignin biosynthesis in response to MeJA, which in turn affects pollen tubes. Further transient knockdown of bHLH (Co_33962) confirmed its important role in C. oleifera pollen tube growth. In summary, the application of MeJA resulted in the stimulation of self-pollen tube elongation and enhanced fruit setting in C. oleifera, which could be associated with the differential change in genes related to lignin synthesis and the increased lignin content.

Integrated transcriptome and endogenous hormone analyses reveal the factors affecting the yield of Camellia oleifera

Camellia oleifera is an important woody oil tree in China, in which the flowers and fruits appear during the same period. The endogenous hormone changes and transcription expression levels in different parts of the flower tissue (sepals, petals, stamens, and pistils), flower buds, leaves, and seeds of Changlin 23 high-yield (H), Changlin low-yield (L), and control (CK) C. oleifera groups were studied. The abscisic acid (ABA) content in the petals and stamens in the L group was significantly higher than that in the H and CK groups, which may be related to flower and fruit drops. The high N6-isopentenyladenine (iP) and indole acetic acid (IAA) contents in the flower buds may be associated with a high yield. Comparative transcriptome analysis showed that the protein phosphatase 2C (PP2C), jasmonate-zim-domain protein (JAZ), and WRKY-related differentially expressed genes (DEGs) may play an important role in determining leaf color. Gene set enrichment analysis (GSEA) comparison showed that jasmonic acid (JA) and cytokinin play an important role in determining the pistil of the H group. In this study, endogenous hormone and transcriptome analyses were carried out to identify the factors influencing the large yield difference in C. oleifera in the same year, which provides a theoretical basis for C. oleifera in the future.

A Comparative Study on the Characteristics of Different Types of Camellia Oils Based on Triacylglycerol Species, Bioactive Components, Volatile Compounds, and Antioxidant Activity

This study aimed to investigate the characteristics of different varieties of camellia oils and their diacylglycerol (DAG)-enriched derivatives in terms of triacylglycerol (TAG) species, bioactive components, volatile compounds, and antioxidant activity. Six types of camellia oils, including C. oleifera (C.O), C. semiserrata (C.S), C. gauchowensis (C.G), along with commercially refined C. oleifera oil (C-C.O) and its DAG-enriched counterparts (at 40% and 80% enrichment), were analyzed and compared. Unique patterns of TAG profiles, fatty acid distributions on different glycerol backbones, tocopherol, squalene, total polyphenols, and volatile compounds were observed, suggesting that these characteristics can be utilized as a criterion to differentiate them. DAG-enriched oils exhibited increased levels of unsaturated fatty acids (UFAs) compared to C-C.O, albeit with decreased contents of tocopherol, squalene, and total polyphenols. Moreover, diverse volatile compounds were identified across all types of camellia oils, among which the DAG-enriched oils had distinct distribution characteristics compared with their crude oils, indicating the influence of the enrichment process on volatile compounds. Furthermore, DAG-enriched oils demonstrated reduced antioxidant activity abilities compared to their counterparts, with the highest activity observed in C.O, followed by C.G. Additionally, strong correlations were observed between antioxidant activity and tocopherol, as well as squalene content.

Comparative Transcriptomic and Lipidomic Analysis of Fatty Acid Accumulation in Three Camellia oleifera Varieties During Seed Maturing

Camellia oleifera, a major woody oil crop in China, produces tea oil rich in unsaturated fatty acids, earning it names like liquid gold and eastern olive oil. This study provides an integrated investigation of the transcriptome and lipidome within seeds at the maturing process across three C. oleifera varieties, revealing a significant relationship between fatty acid production and genes involved in lipid synthesis. Through transcriptomic analysis, 26,344 genes with varied expression were found. Functional enrichment analysis highlighted that pathways related to starch and sucrose metabolism, plant hormone signal transduction, and lipid accumulation were highly enriched among the differentially expressed genes. Coordinated high expression of key genes (ACCase, KAS I, KAS II, KAS III, KAR, HAD, EAR, SAD, LPAAT, LACS, DGAT, PDAT) during the late maturation stage contributes largely to high oil content. Additionally, expression variations of SAD and FADs among different varieties were explored. The analysis suggests that high expression of genes such as FAD3, FAD7, and FAD8 notably increased linolenic acid content. This research provides new insights into the molecular mechanisms of oil biosynthesis in C. oleifera, offering valuable references for improving yield and quality.

ABA and MeJA Induced Catechin and Epicatechin Biosynthesis and Accumulation in Camellia oleifera Fruit Shells

Camellia oleifera Abel, one of the most valuable woody oil plants, has been widely cultivated for extracting edible oil. The shell of C. oleifera is a by-product generated in the processing of edible oil extraction. However, there is still limited research on the maturity and high-value resource utilization of shell by-products. We found that the C. oleifera 'Huashuo' (HS) fruit shells contained a high content of catechins. Abscisic acid (ABA) and methyl jasmonate (MeJA) enhanced the accumulation of catechins in C. oleifera fruit shells, providing a basis for production and application of the catechins in fruit shells of C. oleifera. We further found that 500 μM ABA and 900 μM MeJA significantly promoted the accumulation of catechin (C) and epicatechin (EC) in fruit shells. Following treatment with 900 μM MeJA, the expressions of CoPAL1, CoC4H1, CoC4H2, CoC4H3, Co4CL1, Co4CL2, CoF3'H1, CoLAR1, CoLAR2, CoLAR3, CoANR2, and CoANRL2 were significantly upregulated, while after 500 μM ABA treatment the expressions of CoPAL3, CoCHS1, CoCHS4, CoF3'H1, CoDFR, CoLAR1, CoLAR2, CoLAR3, CoANS1, CoANR1, and CoANR2 increased dramatically. These results indicate that appropriate concentrations of ABA and MeJA activate C and EC biosynthesis and promote their accumulation in fruit shells. Our results provide new ideas and guidance for promoting the resource utilization of C. oleifera fruit shells.

The effect of extraction methods on the components and quality of Camellia oleifera oil: Focusing on the flavor and lipidomics

The objective of this study was to systematically elucidate the effects of conventional (Cold Pressing, CP; Hot Pressing, HP; Soxhlet Extraction; SE) and novel methods (Microwave-Assisted Extraction, MAE) on the physicochemical properties, bio-active substances, flavor and lipidomics of Camellia oleifera oil (COO). The cold-pressed COO contained the highest contents of squalene (176.38 mg/kg), α-tocopherol (330.52 mg/kg), polyphenols (68.33 mg/kg) and phytosterols (2782.55 mg/kg). Oleic acid was observed as the predominant fatty acid with the content of approximately 80%. HS-GC-IMS identified 47 volatile compounds, including 11 aldehydes, 11 ketones, 11 alcohols, 2 acids, 8 esters, 2 pyrazines, 1 furan, and 1 thiophene. A total of 5 lipid classes and 30 lipid subclasses of 339 lipids were identifed, among which TGs and DGs were observed as the major lipids. In summary, both cold-pressed and microwave-assisted technologies provided high-quality COO with high content of bio-active substances and diglycerides/triglycerides.

Extraction and identification of polyphenol from Camellia oleifera leaves using tailor-made deep eutectic solvents based on COSMO-RS design

Camellia oleifera leaf is a rich source of polyphenols. In this study, 50 polyphenolic compounds from C. oleifera leaves was identified by UHPLC-Q-TOF-MS/MS. Accordingly, COSMO-RS was used in the design of deep eutectic solvents (DESs) to extract those polyphenols. 17 types of choline chloride (ChCl)-based DESs molecules (ChCl-acid, ChCl-sugar, ChCl-alcohol, ChCl-amine and amide) were synthetized into virtual cluster molecules with Materials Studio software. They were used to determine the activity coefficients with the standard compounds. The results showed that the amine and amide-based DESs exhibited outstanding dissolution effects. Additionally, ChCl-acetamide was selected as the solvent in response surface methodology to optimize the ultrasound-assisted DES extraction process parameters, including ultrasonic power, ultrasonic time, and liquid-solid ratio, resulting in an improved total phenolic content of 131.63 ± 0.85 mg GAE/g. This study developed a system utilizing UHPLC-Q-TOF-MS/MS to acquire specific substances required for COSMO-RS calculations.

Natural products from Camellia oleifera fruit and its comprehensive utilisation

Camellia oleifera (C. oleifera) is a woody oil plant with a good reputation of 'Oriental Olive Oil' in China. The national understanding of the health-care benefits of Camellia oil are already widespread, but the production of C. oleifera fruit has not been achieved large-scale industrialisation. In this review, we focus on the properties and commercial value of its natural products, and processing technology, performance characterisation, and novel modification strategies of its processed products. In addition, we briefly summarised the research progress of breeding and put forward the comprehensive utilisation of C. oleifera fruit based on the tandem of extraction and processing. This review might attract more researchers to make profound study regarding it as an alternative of olive oil.

A serine carboxypeptidase-like acyltransferase catalyzes consecutive four-step reactions of hydrolyzable tannin biosynthesis in Camellia oleifera

Hydrolyzable tannins (HTs), a class of polyphenolic compounds found in dicotyledonous plants, are widely used in food and pharmaceutical industries because of their beneficial effects on human health. Although the biosynthesis of simple HTs has been verified at the enzymatic level, relevant genes have not yet been identified. Here, based on the parent ion-fragment ion pairs in the feature fragment data obtained using UPLC-Q-TOF-/MS/MS, galloyl phenolic compounds in the leaves of Camellia sinensis and C. oleifera were analyzed qualitatively and quantitatively. Correlation analysis between the transcript abundance of serine carboxypeptidase-like acyltransferases (SCPL-ATs) and the peak area of galloyl products in Camellia species showed that SCPL3 expression was highly correlated with HT biosynthesis. Enzymatic verification of the recombinant protein showed that CoSCPL3 from C. oleifera catalyzed the four consecutive steps involved in the conversion of digalloylglucose to pentagalloylglucose. We also identified the residues affecting the enzymatic activity of CoSCPL3 and determined that SCPL-AT catalyzes the synthesis of galloyl glycosides. The findings of this study provide a target gene for germplasm innovation of important cash crops that are rich in HTs, such as C. oleifera, strawberry, and walnut.

A critical review of the bioactive ingredients and biological functions of camellia oleifera oil

Camellia oleifera oil is a pure and natural high-grade oil prevalent in South China. Camellia oleifera oil is known for its richness in unsaturated fatty acids and high nutritional value. There is increasing evidence indicating that a diet rich in unsaturated fatty acids is beneficial to health. Despite the widespread production of Camellia oleifera oil and its bioactive components, reports on its nutritional components are scarce, especially regarding systematic reviews of extraction methods and biological functions. This review systematically summarized the latest research on the bioactive components and biological functions of Camellia oleifera oil reported over the past decade. In addition to unsaturated fatty acids, Camellia oleifera oil contains six main functional components contributing to its antioxidant, antibacterial, anti-inflammatory, antidiabetic, anticancer, neuroprotective, and cardiovascular protective properties. These functional components are vitamin E, saponins, polyphenols, sterols, squalene, and flavonoids. This paper reviewed the biological activity of Camellia oleifera oil and its extraction methods, laying a foundation for further development of its bioactive components.

Rapid quantitative authentication and analysis of camellia oil adulterated with edible oils by electronic nose and FTIR spectroscopy

Camellia oil, recognized as a high-quality edible oil endorsed by the Food and Agriculture Organization, is confronted with authenticity issues arising from fraudulent adulteration practices. These practices not only pose health risks but also lead to economic losses. This study proposes a novel machine learning framework, referred to as a transformer encoder backbone with a support vector machine regressor (TES), coupled with an electronic nose (E-nose), for detecting varying adulteration levels in camellia oil. Experimental results indicate that the proposed TES model exhibits the best performance in identifying the adulterated concentration of camellia oi, compared with five other machine learning models (the support vector machine, random forest, XGBoost, K-nearest neighbors, and backpropagation neural network). The results obtained by E-nose detection are verified by complementary Fourier transform infrared (FTIR) spectroscopy analysis for identifying functional groups, ensuring accuracy and providing a comprehensive assessment of the types of adulterants. The proposed TES model combined with E-nose offers a rapid, effective, and practical tool for detecting camellia oil adulteration. This technique not only safeguards consumer health and economic interests but also promotes the application of E-nose in market supervision.

A novel strategy by combining foam fractionation with high-speed countercurrent chromatography for the rapid and efficient isolation of antioxidants and cytostatics from Camellia oleifera cake

Camellia oleifera cake is a by-product, which is rich in functional chemical components. However, it is typically used as animal feed with no commercial value. The purpose of this study was to isolate and identify compounds from Camellia oleifera cake using a combination of foam fractionation and high-speed countercurrent chromatography (HSCCC) and to investigate their biological activities. Foam fractionation with enhanced drainage through a hollow regular decahedron (HRD) was first established for simultaneously enriching flavonoid glycosides and saponins for further separation of target compounds. Under suitable operating conditions, the introduction of HRD resulted in a threefold increase in enrichment ratio with no negative effect on recovery. A novel elution-extrusion countercurrent chromatography (EECCC) coupled with the consecutive injection mode was established for the successful simultaneous isolation of flavonoid glycosides and saponins. As a result, 38.7 mg of kaemferol-3-O-[2-O-D-glucopyranosyl-6-O-α-L-rhamnopyranosyl]-β-D-glucopyranoside (purity of 98.17%, FI), 70.8 mg of kaemferol-3-O-[2-O-β-D-xylopyranosyl-6-O-α-L-rhamnopyranosyl]-β-D-glucopyranoside (purity of 97.52%, FII), and 560 mg of an oleanane-type saponin (purity of 92.32%, FIII) were separated from the sample (900 mg). The present study clearly showed that FI and II were natural antioxidants (IC50 < 35 μg/mL) without hemolytic effect. FIII displayed the effect of inhibiting Hela cell proliferation (IC50 < 30 μg/mL). Further erythrocyte experiments showed that this correlated with the extremely strong hemolytic effect of FIII. Overall, this study offers a potential strategy for efficient and green isolation of natural products, and is beneficial to further expanding the application of by-products (Camellia oleifera cake) in food, cosmetics, and pharmacy.

Recent Progress on Green New Phase Extraction and Preparation of Polyphenols in Edible Oil

With the proposal of replacing toxic solvents with non-toxic solvents in the concept of green chemistry, the development and utilization of new green extraction techniques have become a research hotspot. Phenolic compounds in edible oils have good antioxidant activity, but due to their low content and complex matrix, it is difficult to achieve a high extraction rate in a green and efficient way. This paper reviews the current research status of novel extraction materials in solid-phase extraction, including carbon nanotubes, graphene and metal-organic frameworks, as well as the application of green chemical materials in liquid-phase extraction, including deep eutectic solvents, ionic liquids, supercritical fluids and supramolecular solvents. The aim is to provide a more specific reference for realizing the green and efficient extraction of polyphenolic compounds from edible oils, as well as another possibility for the future research trend of green extraction technology.

Virgin Camellia Seed Oil Improves Glycolipid Metabolism in the Kidney of High Fat-Fed Rats through AMPK-SREBP Pathway

Camellia seed oil (CO) is used as edible oil in southern China because of its excellent fatty acid composition and abundant bioactive compounds. Chronic kidney disease (CKD) is one of the most common chronic degenerative diseases in China, and active compounds in vegetable oil, like virgin olive oil, have been demonstrated to be efficacious in the management of CKD. In this study, virgin CO was refined using a standard process. The refining had minimal impact on the fatty acid composition, but significantly reduced the presence of bioactive compounds like polyphenols in CO. Sprague-Dawley (SD) rats fed with high fat diet (Group G) were treated with either virgin (Group Z) or refined CO (Group R). The oral administration of CO alleviated lipid accumulation and decreased body and kidney weight gain. Furthermore, treatment with virgin CO increased the renal ATP content. The renal expression levels of AMPK and key enzymes involved in fatty acid oxidation (CPT-1 and ACOX1) and glycolysis (HK, PFK, PK and GAPDH) were up-regulated in Group Z, thereby enhancing the ATP production. Virgin CO treatment downregulated the expression level of SREBP2 and its downstream target genes, such as ACC, FAS, and HMGCR, which reduced lipid synthesis. These findings indicate that virgin CO improves glycolipid metabolism and restores energy homeostasis in the kidneys of rats fed with a high-fat diet by modulating the AMPK-SREBP-signaling pathway, suggesting the potential of active compounds in virgin CO for managing the renal failure associated with glycolipid dysmetabolism.

Tiger nut (Cyperus esculentus L.) oil: A review of bioactive compounds, extraction technologies, potential hazards and applications

Tiger nut is a tuber of a plant native in the Mediterranean coastal countries, which is of great interest in food industry due to its richness in carbohydrates, lipids, starches, minerals, etc. Recent studies have focused on the analysis of the phytochemical composition of tiger nut, including six essential nutrients, polyphenols, and the extraction of proteins, starches, and phenolic compounds from the by-products of tiger nut milk 'horchata'. Few works were focused on the possibility of using tiger nut oil, a nutritious oil comparable to olive oil, as an edible oil. Therefore, this review discussed some extraction technologies of tiger nut oil, and their effects on the properties of oil, such as bioactive compounds, oxidative stability and potential hazards. The information on the emerging applications of tiger nut oil was summarized and an outlook on the utilization of tiger nut oil by-products were also reviewed.

UPLC-Q-TOF-MS, network analysis, and molecular docking to investigate the effect and active ingredients of tea-seed oil against bacterial pathogens

Object: This research intended to probe the antibacterial effect and pharmacodynamic substances of Tea-Seed Oil (TSO) through the use of ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) analysis, network analysis, and molecular docking. Methods: The major chemical components in the methanol-extracted fractions of TSO were subjected to UPLC-Q-TOF-MS. Network pharmacology and molecular docking techniques were integrated to investigate the core components, targets, and potential mechanisms of action through which the TSO exert their antibacterial properties. To evaluate the inhibitory effects, the minimum inhibitory concentration and diameter of the bacteriostatic circle were calculated for the potential active ingredients and their equal ratios of combinatorial components (ERCC) against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Moreover, the quantification of the active constituents within TSO was achieved through the utilization of high-performance liquid chromatography (HPLC). Results: The methanol-extracted fractions contained a total of 47 chemical components, predominantly consisting of unsaturated fatty acids and phenolic compounds. The network pharmacology analysis and molecular docking analysis revealed that various components, including gallocatechin, gallic acid, epigallocatechin, theophylline, chlorogenic acid, puerarin, and phlorizin, have the ability to interact with critical core targets such as serine/threonine protein kinase 1 (AKT1), epidermal growth factor receptor (EGFR), a monoclonal antibody to mitogen-activated protein kinase 14 (MAPK14), HSP90AA1, and estrogen receptor 1 (ESR1). Furthermore, these components can modulate the phosphatidylinositol-3-kinase protein kinase B (PI3K-AKT), estrogen, MAPK and interleukin 17 (IL-17) signaling pathways, hereby exerting antibacterial effects. In vitro validation trials have found that seven components, namely gallocatechin, gallic acid, epigallocatechin, theophylline, chlorogenic acid, puerarin, and phloretin, displayed substantial inhibitory effects on E. coli, S. aureus, P. aeruginosa, and C. albicans, and are typically present in tea oil, with a total content ranging from 15.87∼24.91 μg·g-1. Conclusion: The outcomes of this investigation possess the possibility to expand our knowledge base concerning the utilization of TSO, furnish a theoretical framework for the exploration of antibacterial drugs and cosmetics derived from inherently occurring TSO, and establish a robust groundwork for the advancement and implementations of TOS products within clinical settings.

Application of Multi-Perspectives in Tea Breeding and the Main Directions

Tea plants are an economically important crop and conducting research on tea breeding contributes to enhancing the yield and quality of tea leaves as well as breeding traits that satisfy the requirements of the public. This study reviews the current status of tea plants germplasm resources and their utilization, which has provided genetic material for the application of multi-omics, including genomics and transcriptomics in breeding. Various molecular markers for breeding were designed based on multi-omics, and available approaches in the direction of high yield, quality and resistance in tea plants breeding are proposed. Additionally, future breeding of tea plants based on single-cellomics, pangenomics, plant-microbe interactions and epigenetics are proposed and provided as references. This study aims to provide inspiration and guidance for advancing the development of genetic breeding in tea plants, as well as providing implications for breeding research in other crops.

Classification of Camellia oleifera Diseases in Complex Environments by Attention and Multi-Dimensional Feature Fusion Neural Network

The use of neural networks for plant disease identification is a hot topic of current research. However, unlike the classification of ordinary objects, the features of plant diseases frequently vary, resulting in substantial intra-class variation; in addition, the complex environmental noise makes it more challenging for the model to categorize the diseases. In this paper, an attention and multidimensional feature fusion neural network (AMDFNet) is proposed for Camellia oleifera disease classification network based on multidimensional feature fusion and attentional mechanism, which improves the classification ability of the model by fusing features to each layer of the Inception structure and enhancing the fused features with attentional enhancement. The model was compared with the classical convolutional neural networks GoogLeNet, Inception V3, ResNet50, and DenseNet121 and the latest disease image classification network DICNN in a self-built camellia disease dataset. The experimental results show that the recognition accuracy of the new model reaches 86.78% under the same experimental conditions, which is 2.3% higher than that of GoogLeNet with a simple Inception structure, and the number of parameters is reduced to one-fourth compared to large models such as ResNet50. The method proposed in this paper can be run on mobile with higher identification accuracy and a smaller model parameter number.

Genome-Wide Detection of SPX Family and Profiling of CoSPX-MFS3 in Regulating Low-Phosphate Stress in Tea-Oil Camellia

Camellia oleifera a member of the family Theaceae, is a phosphorus (P) tolerator native to southern China. The SPX gene family critically regulates plant growth and development and maintains phosphate (Pi) homeostasis. However, the involvement of SPX genes in Pi signaling in Tea-Oil Camellia remains unknown. In this work, 20 SPX genes were identified and categorized into four subgroups. Conserved domains, motifs, gene structure, chromosomal location and gene duplication events were also investigated in the SPX gene family. Defense and stress responsiveness cis-elements were identified in the SPX gene promoters, which participated in low-Pi stress responses. Based on transcriptome data and qRT-PCR results, nine CoSPX genes had similar expression patterns and eight genes (except CoPHO1H3) were up-regulated at 30 days after exposure to low-Pi stress. CoSPX-MFS3 was selected as a key candidate gene by WGCNA analysis. CoSPX-MFS3 was a tonoplast protein. Overexpression of CoSPX-MFS3 in Arabidopsis promoted the accumulation of total P content and decreased the anthocyanin content. Overexpression of CoSPX-MFS3 could enhance low-Pi tolerance by increased biomass and organic acid contents in transgenic Arabidopsis lines. Furthermore, the expression patterns of seven phosphate starvation genes were higher in transgenic Arabidopsis than those in the wild type. These results highlight novel physiological roles of the SPX family genes in C. oleifera under low-Pi stress, and lays the foundation for a deeper knowledge of the response mechanism of C. oleifera to low-Pi stress.

Mechanism of synergistic stabilization of emulsions by amorphous taro starch and protein and emulsion stability

Amorphous taro starch (TS)/whey protein isolate (WPI) mixtures were prepared using pasting treatment. The TS/WPI mixtures and their stabilized emulsions were characterized to determine the emulsion stability and the mechanism of synergistic stabilization of emulsions. As WPI content increased from 0% to 13%, the paste final viscosity and retrogradation ratio of the TS/WPI mixture gradually decreased from 3683 cP to 2532 cP and from 80.65% to 30.51%, respectively. As the WPI content increased from 0% to 10%, the emulsion droplet size decreased gradually from 96.81 μm to 10.32 μm, and the storage modulus G' and stabilities of freeze-thaw, centrifugal, and storage increased gradually. Confocal laser scanning microscopy revealed that WPI and TS were mainly distributed at the oil-water interface and droplet interstice, respectively. Thermal treatment, pH, and ionic strength had little influence on the appearance but had different influences on the droplet size and G', and the rates of droplet size and G' increase under storage varied with different environmental factors.

Microbiota-gut-brain axis and related therapeutics in Alzheimer's disease: prospects for multitherapy and inflammation control

Alzheimer's disease (AD) is the most common type of dementia in the elderly and causes neurodegeneration, leading to memory loss, behavioral disorder, and psychiatric impairment. One potential mechanism contributing to the pathogenesis of AD may be the imbalance in gut microbiota, local and systemic inflammation, and dysregulation of the microbiota-gut-brain axis (MGBA). Most of the AD drugs approved for clinical use today are symptomatic treatments that do not improve AD pathologic changes. As a result, researchers are exploring novel therapeutic modalities. Treatments involving the MGBA include antibiotics, probiotics, transplantation of fecal microbiota, botanical products, and others. However, single-treatment modalities are not as effective as expected, and a combination therapy is gaining momentum. The purpose of this review is to summarize recent advances in MGBA-related pathological mechanisms and treatment modalities in AD and to propose a new concept of combination therapy. "MGBA-based multitherapy" is an emerging view of treatment in which classic symptomatic treatments and MGBA-based therapeutic modalities are used in combination. Donepezil and memantine are two commonly used drugs in AD treatment. On the basis of the single/combined use of these two drugs, two/more additional drugs and treatment modalities that target the MGBA are chosen based on the characteristics of the patient's condition as an adjuvant treatment, as well as the maintenance of good lifestyle habits. "MGBA-based multitherapy" offers new insights for the treatment of cognitive impairment in AD patients and is expected to show good therapeutic results.

Transcriptomic and metabolomic insights on the molecular mechanisms of flower buds in responses to cold stress in two Camellia oleifera cultivars

INTRODUCTION

The Camellia oleifera (C. oleifera) cultivars 'Huashuo' (HS) and 'Huaxin' (HX) are new high-yielding and economically valuable cultivars that frequently encounter prolonged cold weather during the flowering period, resulting in decreased yields and quality. The flower buds of HS sometimes fail to open or open incompletely under cold stress, whereas the flower buds of HX exhibit delayed opening but the flowers and fruits rarely drop.

METHODS

In this study, flower buds at the same development stage of two C. oleifera cultivars were used as test materials for a combination of physiological, transcriptomic and metabolomic analyses, to unravel the different cold regulatory mechanisms between two cultivars of C. oleifera.

RESULTS AND DISCUSSION

Key differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) involved in sugar metabolism, phenylpropanoid biosynthesis, and hormone signal transduction were significantly higher in HX than in HS, which is consistent with phenotypic observations from a previous study. The results indicate that the flower buds of HX are less affected by long-term cold stress than those of HS, and that cold resistance in C. oleifera cultivars varies among tissues or organs.This study will provide a basis for molecular markers and molecular breeding of C. oleifera.

Bioactivities and green advanced extraction technologies of ginger oleoresin extracts: A review

Zingiber officinale Roscoe is an excellent source of bioactive compounds, mainly gingerols and shogaols compounds, that associated with various bioactivities including antioxidant, anticancer, anti-inflammatory, antimicrobial, and antibiofilm. Zingiber officinale Roscoe found its application in the food, pharmaceutical, and cosmeceutical industries. The demand for a high quality of ginger oleoresin extracts based on the contents of gingerols and shogaols compounds for a health-benefit has dramatically increased. Various extraction techniques, including the conventional and advanced extraction techniques for gingerols and shogaols have been reported based on the literature data from 2012 to 2022. The present review examines the functional composition and bioactivities of Zingiber officinale Roscoe and the advanced green extraction technologies. Some variations in the quantity and quality of gingerols and shogaols compounds are because of the extraction method employed. This review provides a depth discussion of the various green advanced extraction technologies and the influences of process variables on the performance of the extraction process. Lower temperature with a short exposure time such as ultrasound-assisted and enzyme-assisted extraction, will lead to high quality of extracts with high content of 6-gingerol. High thermal processing, such as microwave-assisted and pressurized liquid extraction, will produce higher 6-shogaol. Meanwhile, supercritical fluid extraction promotes high quality and the safety of extracts by using non-toxic CO2. In addition, challenges and future prospects of the extraction of ginger oleoresin have been identified and discussed. The emerging green extraction methods and technologies show promising results with less energy input and higher quality extracts than conventional extraction methods.

Isolation of Cherry Seed Oil Using Conventional Techniques and Supercritical Fluid Extraction

This study aims to compare the suitability of three extraction techniques (cold pressing, Soxhlet and supercritical fluid extraction (SFE)) to isolate oil from cherry seeds. Oils were examined in terms of extraction yield, fatty acids profile, tocopherols yield and antioxidant activity. Additionally, influence of SFE parameters was evaluated using one-factor-at-a-time design with pressure (200−350 bar), temperature (40−70 °C), flow rate (0.2−0.4 kg/h) and particle size (<800 µm and >800 µm). Oil yields ranged from 2.50% to 13.02%, whereas the highest yield was achieved with SFE. Samples were rich in polyunsaturated fatty acids, regardless of the applied extraction technique. The main fatty acids were linoleic (46.32−47.29%), oleic (40.89−41.65%), palmitic (6.56−8.00%) and stearic (2.21−2.30%) acid. Total tocopherols yield was between 16.63 mg/100 g oil and 60.61 mg/100 g oil, and highest yield was achieved with SFE. Among the tocopherols, γ-tocopherol was the most abundant, followed by α-, δ- and β-tocopherol. Antioxidant activity was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic) cation (ABTS) assays, and the results indicated that SFE extracts exhibited better or comparable antioxidant potential compared to traditional techniques. The comparison between modern and conventional extractions for oil recovery demonstrates pros and cons for the possibility of industrial application.

Maturity Grading and Identification of Camellia oleifera Fruit Based on Unsupervised Image Clustering

Maturity grading and identification of Camellia oleifera are prerequisites to determining proper harvest maturity windows and safeguarding the yield and quality of Camellia oil. One problem in Camellia oleifera production and research is the worldwide confusion regarding the grading and identification of Camellia oleifera fruit maturity. To solve this problem, a Camellia oleifera fruit maturity grading and identification model based on the unsupervised image clustering model DeepCluster has been developed in the current study. The proposed model includes the following two branches: a maturity grading branch and a maturity identification branch. The proposed model jointly learns the parameters of the maturity grading branch and maturity identification branch and used the maturity clustering assigned from the maturity grading branch as pseudo-labels to update the parameters of the maturity identification branch. The maturity grading experiment was conducted using a training set consisting of 160 Camellia oleifera fruit samples and 2628 Camellia oleifera fruit digital images collected using a smartphone. The proposed model for grading Camellia oleifera fruit samples and images in training set into the following three maturity levels: unripe (47 samples and 883 images), ripe (62 samples and 1005 images), and overripe (51 samples and 740 images). Results suggest that there was a significant difference among the maturity stages graded by the proposed method with respect to seed oil content, seed soluble protein content, seed soluble sugar content, seed starch content, dry seed weight, and moisture content. The maturity identification experiment was conducted using a testing set consisting of 160 Camellia oleifera fruit digital images (50 unripe, 60 ripe, and 50 overripe) collected using a smartphone. According to the results, the overall accuracy of maturity identification for Camellia oleifera fruit was 91.25%. Moreover, a Gradient-weighted Class Activation Mapping (Grad-CAM) visualization analysis reveals that the peel regions, crack regions, and seed regions were the critical regions for Camellia oleifera fruit maturity identification. Our results corroborate a maturity grading and identification application of unsupervised image clustering techniques and are supported by additional physical and quality properties of maturity. The current findings may facilitate the harvesting process of Camellia oleifera fruits, which is especially critical for the improvement of Camellia oil production and quality.

Combining effect of camellia oil and squalene on hyperlipidemia-induced reproductive damage in male rats

Introduction

Camellia oil (CO), a common edible oil in China, contains a variety of active ingredients. In this study, we explored the combining effect and optimal feeding time of CO and squalene on hyperlipemia-induced reproductive damage rats and probably provided supportive data for use of CO for health benefits.

Methods

We established the hyperlipidaemia-induced reproductive damage model, and then the successfully modeled rats were randomly classified into four groups including a model control (MC) group, a camellia oil (CO) group, a camellia oil + squalene (COS) group, and a sildenafil (SN) group, which were feeding with different subjects during days 30 and 60. The normal (NC) group was fed under the same conditions.

Results

Our results showed that compared with the MC group, the CO, COS, and SN groups could significantly decline the serum TG, TC and LDL-C levels, increase the serum testosterone levels, the sperm counts in epididymidis and organ coefficients of penises, and no pathological change in penis and testis at days 30 and 60. Compared with the pure CO, the mixture of CO and squalene could significantly enhance the effect of decreasing the concentrations of TG, TC, and LDL-C and increasing the serum testosterone level and sperm count of epididymal tail, and the results of day 30 were better than those of day 60.

Discussion

CO and squalene have a combining effect on lowering blood lipid, improving the level of testosterone and the number of epididymal tail sperm, and promoting the recovery of erectile and sexual function on hyperlipidemia-induced reproductive damage rats on day 30.

Typical Characterization of Commercial Camellia Oil Products Using Different Processing Techniques: Triacylglycerol Profile, Bioactive Compounds, Oxidative Stability, Antioxidant Activity and Volatile Compounds

The processing technique is one of the key factors affecting the quality of camellia oil. In this study, camellia oils were obtained using four different processing techniques (cold-pressed, roast-pressed, fresh-pressed, and refined), and their triacylglycerols (TAGs) profile, bioactive compound (tocopherols, sterols, squalene, and polyphenols) level, oxidative stability, and volatile compounds were analyzed and compared. To further identify characteristic components in four camellia oil products, the TAG profile was analyzed using UPLC-QTOF-MSE. Five characteristic markers were identified, including OOO (m/z 902.8151), POL (m/z 874.7850), SOO (m/z 904.8296), PPL (m/z 848.7693), PPS (m/z 852.7987). Regarding the bioactive compound level and antioxidant capacity, the fresh-pressed technique provided higher α-tocopherols (143.15 mg/kg), β-sitosterol (93.20 mg/kg), squalene (102.08 mg/kg), and polyphenols (35.38 mg/kg) and showed stronger overall oxidation stability and antioxidant capacity. Moreover, a total of 65 volatile compounds were detected and identified in four camellia oil products, namely esters (23), aldehydes (19), acids (8), hydrocarbons (3), ketones (3), and others (9), among which pressed oil was dominated by aldehydes, acid, and esters, while refined oil had few aroma components. This study provided a comprehensive comparative perspective for revealing the significant influence of the processing technique on the camellia oil quality and its significance for producing camellia oil of high quality and with high nutritional value.

Effect of pretreatments of camellia seeds on the quality, phenolic profile, and antioxidant capacity of camellia oil

Camellia oil is one of the four major woody oils in the world and has high nutritional value due to its richness in monounsaturated fatty acids (MUFAs) and bioactive substances. In order to compare the effects of pretreatments of camellia seeds on the quality, phenolic profile, and antioxidant capacity of camellia oil, three different pretreatment methods, i.e., hot air (HA), steam (ST) and puffing (PU), were used to treat the seed powder in the present study. All three pretreatments changed the internal structure of the camellia seeds. The oil yield was increased after all three pretreatments, with the highest oil yield increased by PU pretreatment (Based on the oil yield, we screened out the best conditions of the three pretreatments, HA pretreatment is 60°C for 40 min, ST pretreatment is 100°C for 15 min, PU pretreatment is 800 rpm). The fatty acids (FAs) of the oil were relatively stable, with no significant changes after three pretreatments. However, all three pretreatments had a significant effect on the acid value (AV), peroxide value (PV), and benzo(a)pyrene (Ba P) of the camellia oil. The PU and HA pretreatments could increase the tocopherol content and the total sterols content in the camellia oil. The ST and PU pretreatments significantly increased the free phenolics (FP) content, all three pretreatments reduced the contents of conjugated phenolics (CP) and insoluble-bound phenolics (IBP) in the camellia oil. The IBP made the most significant contribution to the antioxidant capacities of camellia oil. ST and PU prtreatments increased the antioxidant capacities of the total phenolics in the camellia oil. Eight phenolics in FP, CP, and IBP were significantly correlated with the antioxidant capacities of camellia oil. The results of the present study could provide some theoretical guidance for the pretreatment of camellia seeds for higher oil yield, phenolic content and enhanced antioxidant capacities of camellia oil.

Peppermint essential oil: its phytochemistry, biological activity, pharmacological effect and application

Mentha (also known as peppermint), a genus of plants in the taxonomic family Lamiaceae (mint family), is widely distributed throughout temperate regions of the world. Mentha contains various constituents that are classified as peppermint essential oil (PEO) and non-essential components. PEO, consisting mainly of menthol, menthone, neomenthol and iso-menthone, is a mixture of volatile metabolites with anti-inflammatory, antibacterial, antiviral, scolicidal, immunomodulatory, antitumor, neuroprotective, antifatigue and antioxidant activities. Mounting evidence indicates that PEO may pharmacologically protect gastrointestinal, liver, kidney, skin, respiratory, brain and nervous systems, and exert hypoglycemic and hypolipidemic effects. Clinically, PEO is used for gastrointestinal and dermatological diseases, postoperative adjuvant therapy and other fields. This review aims to address the advances in the extraction and isolation of PEO, its biological activities, pharmacological effects, toxicity and applications, with an emphasis on the efficacy of PEO on burn wounds and psoriasis, providing a comprehensive foundation for research, development and application of PEO in future.

Extraction of Oils and Phytochemicals from Camellia oleifera Seeds: Trends, Challenges, and Innovations

Camellia seed oil, extracted from the seeds of Camellia oleifera Abel., is popular in South China because of its high nutritive value and unique flavor. Nowadays, the traditional extraction methods of hot pressing extraction (HPE) and solvent extraction (SE) are contentious due to low product quality and high environmental impact. Innovative methods such as supercritical fluid extraction (SCFE) and aqueous extraction (AE) are proposed to overcome the pitfalls of the traditional methods. However, they are often limited to the laboratory or pilot scale due to economic or technical bottlenecks. Optimization of extraction processes indicates the challenges in finding the optimal balance between the yield and quality of oils and phytochemicals, as well as the environmental and economic impacts. This article aims to explore recent advances and innovations related to the extraction of oils and phytochemicals from camellia seeds, and it focuses on the pretreatment and extraction processes, as well as their complex effects on nutritional and sensory qualities. We hope this review will help readers to better understand the trends, challenges, and innovations associated with the camellia industry.