Integrated Profiling of Fatty Acids, Sterols and Phenolic Compounds in Tree and Herbaceous Peony Seed Oils: Marker Screening for New Resources of Vegetable Oil

Nutritional composition, health-promoting effects, bioavailability, and encapsulation of tree peony seed oil: a review

Tree peony is cultivated worldwide in large quantities due to its exceptional ornamental and medicinal value. In recent years, the edible value of tree peony seed oil (TPSO) has garnered significant attention for its high content of alpha-linolenic acid (ALA, >40%) and other beneficial minor components, including phytosterols, tocopherols, squalene, and phenolics. This review provides a systematic summary of the nutritional composition and health-promoting effects of TPSO, with a specific focus on its digestion, absorption, bioavailability, and encapsulation status. Additionally, information on techniques for extracting and identifying adulteration of TPSO, as well as its commercial applications and regulated policies, is included. Thanks to its unique nutrients, TPSO offers a wide range of health benefits, such as hypolipidemic, anti-obesity, cholesterol-lowering, antioxidant and hypoglycemic activities, and regulation of the intestinal microbiota. Consequently, TPSO shows promising potential in the food and cosmetic industries and should be cultivated in more countries. However, the application of TPSO is hindered by its low bioavailability, poor stability, and limited water dispersibility. Therefore, it is crucial to develop effective delivery strategies, such as microencapsulation and emulsion, to overcome these limitations. In conclusion, this review provides a comprehensive understanding of the nutritional value of TPSO and emphasizes the need for further research on its nutrition and product development.

Chlorogenic acid: a review on its mechanisms of anti-inflammation, disease treatment, and related delivery systems

Chlorogenic acid is a bioactive compound ubiquitously present in the natural realm, lauded for its salient anti-inflammatory and antioxidant attributes. It executes its anti-inflammatory function by moderating the synthesis and secretion of inflammatory mediators, namely, TNF-α, IL-1β, IL-6, IL-8, NO, and PGE2. Concurrently, it modulates key signaling pathways and associated factors, including NF-κB, MAPK, Nrf2, and others, bestowing protection upon cells and tissues against afflictions such as cardio-cerebrovascular and diabetes mellitus. Nevertheless, the inherent low bioavailability of chlorogenic acid poses challenges in practical deployments. To surmount this limitation, sophisticated delivery systems, encompassing liposomes, micelles, and nanoparticles, have been devised, accentuating their stability, release mechanisms, and bioactivity. Given its innate anti-inflammatory prowess and safety profile, chlorogenic acid stands as a promising contender for advanced biomedical investigations and translational clinical endeavors.

Characterization of Agronomic and Seed Oil Features for Different Cultivars of Tree Peony

Tree peony is a unique oil plant resource in China, and tree peony seed oil is one of the healthy edible oils with a very promising future. However, the main oil tree peony cultivars promoted in China are Paeonia ostii 'Fengdan' and Paeonia rockii. In order to explore new oil tree peony cultivars, 68 tree peony cultivars were investigated and cultivars with oil potential were selected by cluster analysis and grey relational analysis (GRA) in this study. The results demonstrated that the 68 cultivars varied significantly in terms of agronomic characteristics (p < 0.05), with the coefficient of variation in seed yield per plant reaching a high of 75.36%. The oil content of 46 cultivars was higher than 'Fengdan' (20.87 ± 0.26%) and 'Zibanbai' (21.24 ± 1.01%), while the alpha-linolenic acids and total unsaturated fatty acid contents of 26 cultivars were higher than 'Fengdan' (39.79 ± 1.13% and 88.99 ± 0.47%) and 'Zibanbai' (40.51 ± 0.09% and 93.59 ± 0.09%). Finally, three cultivars with better integrated traits were selected by cluster analysis and grey relational analysis (GRA), comprising of 'Changshoule', 'Xianchizhenghui', and 'Yupantuojin'. The contents of alpha-linolenic acids and total unsaturated fatty acids in 'Changshoule' (47.98 ± 0.17% and 93.60 ± 0.08%), 'Xianchizhenghui' (49.44 ± 0.63% and 93.80 ± 0.06%), and 'Yupantuojin' (40.46 ± 0.26% and 93.58 ± 0.06%) were higher than that of 'Fengdan' (39.79 ± 1.13% and 88.99 ± 0.47%). In general, these cultivars can be used as hybrid parental materials for breeding new excellent oil tree peony cultivars.

Qualitative and quantitative analyses of chemical constituents in vitro and in vivo and systematic evaluation of the pharmacological effects of Tibetan medicine Zhixue Zhentong capsules

Introduction: Zhixue Zhentong capsules (ZXZTCs) are a Tibetan medicine preparation solely composed of Lamiophlomis rotata (Benth.) Kudo. L. rotata is the only species of the genus Laniophlomis (family Lamiaceae) that has medicinal constituents derived from the grass or root and rhizome. L. rotata is one of the most extensively used folk medicines by Tibetan, Mongolian, Naxi, and other ethnic groups in China and has been listed as a first-class endangered Tibetan medicine. The biological effects of the plant include hemostasis, analgesia, and the removal of blood stasis and swelling. Purpose: This study aimed to profile the overall metabolites of ZXZTCs and those entering the blood. Moreover, the contents of six metabolites were measured and the hemostatic, analgesic, and anti-inflammatory effects of ZXZTCs were explored. Methods: Ultra-performance liquid chromatography-tandem quadrupole time-of-flight high-resolution mass spectrometry (UPLC-Q-TOF-MS) was employed for qualitative analysis of the metabolites of ZXZTCs and those entering the blood. Six metabolites of ZXZTCs were quantitatively determined via high-performance liquid chromatography The hemostatic, analgesic, and anti-inflammatory effects of ZXZTCs were evaluated in various animal models. Results: A total of 36 metabolites of ZXZTCs were identified, including 13 iridoid glycosides, 9 flavonoids, 9 phenylethanol glycosides, 4 phenylpropanoids, and 1 other metabolite. Overall, 11 metabolites of ZXZTCs entered the blood of normal rats. Quantitative analysis of the six main metabolites, shanzhiside methyl ester, chlorogenic acid, 8-O-acetyl shanzhiside methyl ester, forsythin B, luteoloside, and verbascoside, was extensively performed. ZXZTCs exerted hemostatic effects by reducing platelet aggregation and thrombosis and shortening bleeding time. Additionally, ZXZTCs clearly had an analgesic effect, as observed through the prolongation of the latency of writhing, reduction in writhing, and increase in the pain threshold of experimental rats. Furthermore, significant anti-inflammatory effects of ZXZTCs were observed, including a reduction in capillary permeability, the inhibition of foot swelling, and a reduction in the proliferation of granulation tissue. Conclusion: Speculative identification of the overall metabolites of ZXZTCs and those entering the blood can provide a foundation for determining its biologically active constituents. The established method is simple and reproducible and can help improve the quality control level of ZXZTCs as a medicinal product. Evaluating the hemostatic, analgesic, and anti-inflammatory activities of ZXZTCs can help reveal its mechanism.

Enhancing the Stability and Bioaccessibility of Tree Peony Seed Oil Using Layer-by-Layer Self-Assembling Bilayer Emulsions

Tree peony seed oil (TPSO) is an important plant source of n-3 polyunsaturated fatty acid (α-linolenic acid, ALA > 40%) that is receiving increasing attention for its excellent antioxidant and other activities. However, it has poor stability and bioavailability. In this study, a bilayer emulsion of TPSO was successfully prepared using a layer-by-layer self-assembly technique. Among the proteins and polysaccharides examined, whey protein isolate (WPI) and sodium alginate (SA) were found to be the most suitable wall materials. The prepared bilayer emulsion contained 5% TPSO, 0.45% whey protein isolate (WPI) and 0.5% sodium alginate (SA) under selected conditions and its zeta potential, droplet size, and polydispersity index were -31 mV, 1291 nm, and 27%, respectively. The loading capacity and encapsulation efficiency for TPSO were up to 84% and 90.2%, respectively. It was noteworthy that the bilayer emulsion showed significantly enhanced oxidative stability (peroxide value, thiobarbituric acid reactive substances content) compared to the monolayer emulsion, which was accompanied by a more ordered spatial structure caused by the electrostatic interaction of the WPI with the SA. This bilayer emulsion also exhibited markedly improved environmental stability (pH, metal ion), rheological properties, and physical stability during storage. Furthermore, the bilayer emulsion was more easily digested and absorbed, and had higher fatty acid release rate and ALA bioaccessibility than TPSO alone and the physical mixtures. These results suggest that bilayer emulsion containing WPI and SA is an effective TPSO encapsulation system and has significant potential for future functional food development.

Effect of Adsorption Deacidification on the Quality of Peony Seed Oil

To overcome the issues in the traditional deacidification processes of peony seed oil (PSO), such as losses of neutral oil and trace nutrients, waste discharge, and high energy consumption, adsorption deacidification was developed. The acid removal capacity of adsorbent-alkali microcrystalline cellulose was evaluated using the isothermal adsorption equilibrium and the pseudo-first-order rate equation. The optimized adsorption deacidification conditions included adsorbent-alkali microcrystalline cellulose at 3%, a heating temperature of 50 °C, and a holding time of 60 min. The physicochemical, bioactive properties, antioxidant capacities, and oxidative stabilities of PSO processed by alkali refining and oil-hexane miscella deacidification were compared under the same operating conditions. Fatty acid content was not significantly different across all three methods. The deacidification rates were 88.29%, 98.11%, and 97.76%, respectively, for adsorption deacidification, alkali refining, and oil-hexane miscella deacidification. Among the three deacidification samples, adsorption deacidification showed the highest retention of tocopherols (92.66%), phytosterols (91.96%), and polyphenols (70.64%). Additionally, the obtained extract preserved about 67.32% of the total antioxidant activity. The oil stability index was increased 1.35 times by adsorption deacidification. Overall, adsorption deacidification can be considered a promising extraction technology in terms of quality as compared to alkali refining and oil-hexane miscella deacidification.

Extraction Systems and Analytical Techniques for Food Phenolic Compounds: A Review

Phenolic compounds are highly valuable food components due to their potential utilisation as natural bioactive and antioxidant molecules for the food, cosmetic, chemical, and pharmaceutical industries. For this purpose, the development and optimisation of efficient extraction methods is crucial to obtain phenolic-rich extracts and, for some applications, free of interfering compounds. It should be accompanied with robust analytical tools that enable the standardisation of phenolic-rich extracts for industrial applications. New methodologies based on both novel extraction and/or analysis are also implemented to characterise and elucidate novel chemical structures and to face safety, pharmacology, and toxicity issues related to phenolic compounds at the molecular level. Moreover, in combination with multivariate analysis, the extraction and analysis of phenolic compounds offer tools for plant chemotyping, food traceability and marker selection in omics studies. Therefore, this study reviews extraction techniques applied to recover phenolic compounds from foods and agri-food by-products, including liquid-liquid extraction, solid-liquid extraction assisted by intensification technologies, solid-phase extraction, and combined methods. It also provides an overview of the characterisation techniques, including UV-Vis, infra-red, nuclear magnetic resonance, mass spectrometry and others used in minor applications such as Raman spectroscopy and ion mobility spectrometry, coupled or not to chromatography. Overall, a wide range of methodologies are now available, which can be applied individually and combined to provide complementary results in the roadmap around the study of phenolic compounds.

Effect of Different Solvents on the Extraction of Oil from Peony Seeds (Paeonia suffruticosa Andr.): Oil Yield, Fatty Acids Composition, Minor Components, and Antioxidant Capacity

Peony seed oil is full of nutrition and exert positive effects on human's health. The influences of seven solvents (isopropanol, acetone, Hx:Iso (n-hexane/isopropanol, 3:2 v/v), Chf:Me (chloroform/methanol, 1:1 v/v), ethyl acetate, n-hexane, and petroleum ether) on the oil yields, lipid composition, minor components and antioxidant capacity of peony seed oil were compared in this study. Results indicated that the highest oil yield (35.63%) was obtained using Hx:Iso, while Chf:Me showed the best extraction efficiency for linolenic acid (43.68%), trilinolenoyl-glycerol (15.00%), and dilinolenoyl-linoleoyl-glycerol (18.01%). For minor components, Chf:Me presented a significant advantage in the extraction of tocopherol (601.49 mg/kg), and the peony seed oil extracted with petroleum ether had the highest sterols (4089.82 mg/kg) and squalene contents (66.26 mg/kg). Although the use of isopropanol led to a lower sterol content, its extracts showed a significant higher polyphenol content (68.88 mg GAE/kg) than other solvents and exhibited the strongest antioxidant capacity. Additionally, correlation analysis revealed that polyphenols were the most important minor component for predicting the antioxidant capacity of peony seed oil. The above information is valuable for manufacturers to select suitable solvents to produce peony seed oil with the required levels of fatty acids and minor components for targeted end-use.

Effects of Radio Frequency Pretreatment on Quality of Tree Peony Seed Oils: Process Optimization and Comparison with Microwave and Roasting

In this study, we explored the technical parameters of tree peony seeds oil (TPSO) after their treatment with radio frequency (RF) at 0 °C-140 °C, and compared the results with microwave (MW) and roasted (RT) pretreatment in terms of their physicochemical properties, bioactivity (fatty acid tocopherols and phytosterols), volatile compounds and antioxidant activity of TPSO. RF (140 °C) pretreatment can effectively destroy the cell structure, substantially increasing oil yield by 15.23%. Tocopherols and phytosterols were enhanced in oil to 51.45 mg/kg and 341.35 mg/kg, respectively. In addition, antioxidant activities for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) were significantly improved by 33.26 μmol TE/100 g and 65.84 μmol TE/100 g, respectively (p < 0.05). The induction period (IP) value increased by 4.04 times. These results are similar to those of the MW pretreatment. The contents of aromatic compounds were significantly increased, resulting in improved flavors and aromas (roasted, nutty), by RF, MW and RT pretreatments. The three pretreatments significantly enhanced the antioxidant capacities and oxidative stabilities (p < 0.05). The current findings reveal RF to be a potential pretreatment for application in the industrial production of TPSO.

Dissection of Allelic Variation Underlying Floral and Fruit Traits in Flare Tree Peony (Paeonia rockii) Using Association Mapping

Allelic variation in floral quantitative traits, including the elements of flowers and fruits, is caused by extremely complex regulatory processes. In the genetic improvement of flare tree peony (Paeonia rockii), a unique ornamental and edible oil woody species in the genus Paeonia, a better understanding of the genetic composition of these complex traits related to flowers and fruits is needed. Therefore, we investigated the genetic diversity and population structure of 160 P. rockii accessions and conducted single-marker association analysis for 19 quantitative flower and fruit traits using 81 EST-SSR markers. The results showed that the population had a high phenotypic diversity (coefficients of variation, 11.87-110.64%) and a high level of genetic diversity (mean number of alleles, N _A = 6.09). These accessions were divided into three subgroups by STRUCTURE analysis and a neighbor-joining tree. Furthermore, we also found a low level of linkage disequilibrium between these EST-SSRs and, by single-marker association analysis, identified 134 significant associations, including four flower traits with 11 EST-SSRs and 10 fruit traits with 32 EST-SSRs. Finally, based on the sequence alignment of the associated markers, P280, PS2, PS12, PS27, PS118, PS131, and PS145 may be considered potential loci to increase the yield of flare tree peony. These results laid the foundation for further analysis of the genetic structure of some key traits in P. rockii and had an obvious potential application value in marker-assisted selection breeding.