Antioxidant Activity and Total Polyphenols Content of Camellia Oil Extracted by Optimized Supercritical Carbon Dioxide

The potential application of fermented tea as a drink for regulating bone mass

Currently, there is evidence to suggest the benefits of drinking fermented tea for people with osteoporosis, and based on this, many studies have been conducted on the dosage, exact ingredients, mechanisms, and industrial applications of fermented tea for protecting against osteoporosis. A summary and analysis of studies on the regulation of bone mass by oolong tea, black tea, and their active ingredients (including 39 known catechin compounds) was conducted. It was found that the regulation of bone mass by fermented tea is backed by evidence from epidemiology, animal experiments, and cell experiments. The main active components of fermented tea are tea polyphenols, tea pigments, and trace amino acids. The specific mechanisms involved include regulating bone marrow mesenchymal stem cell osteogenesis, inhibiting osteoclast activity, promoting calcium and phosphorus absorption, reducing inflammation levels, regulating gut microbiota, regulating endocrine function, and inhibiting oxidative stress. In terms of its application, extraction, precipitation, biosynthesis and membrane separation method are mainly used to separate the active ingredients of anti osteoporosis from fermented tea. In conclusion, fermented tea has sufficient theoretical and practical support for regulating bone mass and preventing osteoporosis, and is suitable for development as a health supplement. At the same time, a large amount of epidemiological evidence is needed to prove the specific dosage of tea consumption.

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.

Comprehensive Evaluation of Quality of Camellia semiserrata Seed Oils from Various Harvest Dates

The ripening degree of camellia fruit is one of the key factors affecting the quality of camellia seed oil. In this study, taking Camellia semiserrata as the research object, the oil content, physicochemical indexes, nutritional indexes, fatty acid composition, and volatile compounds of camellia seed oils from various harvest dates (from September to October) were determined. The results showed that with the increase of the ripening degree of camellia fruit, the oil content of camellia seed increased at first and then decreased and reached the highest (58.74%) on September 30, while the acid value, peroxide value, β-sitosterol, α-tocopherol, and polyphenols of camellia seed oil showed a downward trend. Among them, the highest contents of β-sitosterol, α-tocopherol, and polyphenols were observed on September 2, which were 6881.60, 311.34, and 78.08 mg/kg, respectively. In terms of the fatty acid composition of camellia seed oils, the content of oleic acid increased at first and then decreased, the content of linoleic acid and palmitic acid decreased gradually, while the content of stearic acid increased gradually. A total of 37 volatile compounds were identified in different samples, including 12 aldehydes, 5 ketones, 12 alcohols, 2 acids, 5 esters, and 1 other. With the increase of the ripening degree, the concentration of aldehydes and alcohols increased at first and then decreased, the concentration of ketones and esters decreased gradually, but the concentration of acid compounds had no obvious rule. In addition, the camellia seed oils from various harvest dates were classified and comprehensively evaluated by principal component analysis and grey relation analysis. The results showed that different camellia seed oils could be divided into three groups, and the comprehensive score of camellia seed oils on September 30 was the highest. In general, this work can provide theoretical guidance for the harvest date of Camellia semiserrata.

Response surface methodology to optimize supercritical carbon dioxide extraction of Polygonum cuspidatum

BACKGROUND

Resveratrol and emodin are abundant polyhydroxy compounds that are found in the Chinese traditional medicinal herb Polygonum cuspidatum and widely used due to their excellent antioxidant properties.

OBJECTIVE

This study aimed to obtain the maximum extraction yields of resveratrol and emodin from the P. cuspidatum via green extraction.

METHODS

The extracts were acquired through supercritical carbon dioxide (SC-CO2) extraction with ethanol as cosolvent. The independent variables of the extraction process, namely, temperature (45-55 °C), the pressure (20-30 MPa), and the ethanol content (80 -120 mL/L), were optimized by response surface methodology (RSM).

RESULTS

These variables extremely affected the yields of resveratrol and emodin. Second-order polynomial mathematical models were developed and applied to predict the optimal extraction conditions (i.e., temperature of 51.8 °C, pressure of 25.34 MPa, and ethanol content of 110.83 mL/L). Under these conditions, confirmatory experiment displayed that the yields of resveratrol and emodin were 2.564 ± 0.121 and 2.804 ± 0.108 mg/g, respectively. High antioxidant properties, strong free radical scavenging ability, and good reducing ability were observed for the extracts.

CONCLUSION

Resveratrol and emodin could be successfully extracted from P. cuspidatum by SC-CO2, and RSM can effective optimize the process.

HIGHLIGHTS

The SC-CO2 extraction of resveratrol and emodin from P. cuspidatum was developed, and RSM was successfully used to optimize the extraction parameters and predict the optimal conditions.

Comparison of Antioxidant and Antibacterial Activities of Camellia Oil From Hainan With Camellia Oil From Guangxi, Olive Oil, and Peanut Oil

Background/Aim: Camellia oil from Hainan (SY) is a unique vegetable oil in Hainan, China, due to the geographical environment and oil extraction only through simple physical treatments. To compare SY with camellia oil from Guangxi (SC), olive oil (GL), and peanut oil (HS), this study analyzed the antioxidant and antibacterial activity of four vegetable oils.

Methods: Using Gallic acid, BHT as the control, Saccharomyces cerevisiae as the model organism, the antioxidant activities of vegetable oils were measured in vitro and in vivo, and the antibacterial activity was measured with the minimum inhibitory concentration (MIC) method.

Results: The major contents of SY, SC, and HS were oleic Acid; the major content of GL was squalene. The highest total flavonoids content of SY was 39.50 ± 0.41 mg RE/g DW; and the highest total phenolic content of SC was 47.05 ± 0.72 mg GAE/g DW. SY exhibited the strongest scavenging activity of hydroxyl radical (HO·) and superoxide anions (O2-·), the IC₅₀ value were 2.06 mg/mL, 0.62 mg/mL, respectively; and SC showed the strongest DPPH· and ABTS· scavenging activity and the reducing abilities. SY showed excellent effect on survival rate, protection rate, flavonoids uptake of S. cerevisiae cells, decreased MDA content and ROS level, inhibited CAT, POD, and GR enzyme activity. The absorption of SC total phenols was the highest by cells. The activity showed GL had a broad-spectrum antibacterial activity.

Conclusion: Thus, SY shows potential antioxidant activity and provides an important reference value for people to choose edible vegetable oils.