Effect of hot air drying on the polyphenol profile of Hongjv (Citrus reticulata Blanco, CV. Hongjv) peel: A multivariate analysis

Chemometric analysis illuminates the relationship among browning, polyphenol degradation, Maillard reaction and flavor variation of 5 jujube fruits during air-impingement jet drying

This study was designed to reveal the relationship among browning, polyphenol degradation, Maillard reaction (MR) and flavor variation in jujube fruit (JF) during air-impingement jet drying (AIJD). Five kinds of JFs were dried by AIJD at 60 °C and vacuum freeze drying. Colorimeter and chemometric analysis found that AIJD induced color changes of JF pulp and peel. AIJD also reduced the total polyphenols content and total flavonoids levels in JF. The Fe3+ reducing capacity and 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulphonate) cationic radical scavenging capacity of JF were reduced by 31.6% and 8.2%, respectively. Seven polyphenols were identified in JF, and epicatechin was found related to change of JF pulp color by sparse partial least square (sPLS). sPLS revealed that 3-deoxy glucosone, N-ε-carboxymethyl-l-lysine and 5-hydroxymethylfurfural associated with JF color. sPLS found that MR generated 3-methyl-butanoic acid and cyclobutanone during AIJD of JF. Chemometrics is an effective tool to disclose mechanism of color changes in food.

Advancements in Litchi chinensis Peel Processing: A Scientific Review of Drying, Extraction, and Isolation of Its Bioactive Compounds

This article systematically reviews the advancements in processing litchi peel (Litchi chinensis), emphasizing drying, extraction, purification methods, and the potential of bioactive compounds obtained from litchi peel. This work also highlights the impact of various drying techniques on phytochemical profiles, focusing on how methods such as hot air and freeze-drying affect the preservation of bioactive compounds. The study delves into extraction methods, detailing how different solvents and techniques influence the efficiency of extracting bioactive compounds from litchi peel. Furthermore, the purification and characterization of active compounds, showcasing the role of chromatographic techniques in isolating specific bioactive molecules, is discussed. Biological properties and mechanisms of action, such as antioxidant, antihyperglycemic, cardioprotective, hepatoprotective, anti-atherosclerotic, and anticancer activities, are reviewed, providing insight into the potential health benefits of litchi peel compounds. This review highlights the importance of optimizing and selecting accurate drying and extraction methods to maximize the therapeutic effects of litchi peel and its bioactive compounds. This review also reveals the broad pharmacological potential of the isolated compounds, underscoring the need for further research to discover their specific actions and health benefits.

An integrated strategy for anti-inflammatory quality markers screening of traditional Chinese herbal medicine Mume Fructus based on phytochemical analysis and anti-colitis activity

BACKGROUND

Mume Fructus (MF) is used in traditional Chinese herbal medicine (TCM) to treat chronic cough, prolonged diarrhea, and other inflammation-related diseases. It is processed from Prunus mume fruit (PM) by drying at low temperature according to the Chinese Pharmacopoeia. The standard quality control method includes measurement of citric acid content, which is not sufficient to determine its clinical efficacy. In addition, the quality markers, that would ensure consistent drug composition and stability during extraction and processing of the drug, are currently not available.

PURPOSE

This study sought to determine and analyze the bioactive compounds in MF and to establish the quality maker evaluation system, which would enable accurate assessment of different processing and extraction approaches for MF preparation.

STUDY DESIGN AND METHODS

First, a UPLC-QTOF-MS/MS method was established to identify the chemical constituents of PM and MF. Second, the 2,4,6-trinitrobenzenesulfonic acid (TNBS)-treated rats were used to assess anti-inflammatory activity of water and ethanol extracts of PM and MF. Third, correlation analysis and multivariate statistical analysis was used to seek the candidate quality markers of MF. Fourth, molecular docking was used to predict the potential mechanism of identified compounds for the anti-inflammatory activity. Finally, a UPLC method was established to quantify the selected quality markers in MF products, that were prepared by different drying processes.

RESULTS

99 components (28 newly reported) were identified from PM and MF. During the drying process several changes in the composition were observed; caffeoylquinic acids were degraded to p-coumaric acid, caffeic acid, protocatechuic acid, or p-hydroxybenzoic acid; multi-acetyl p-coumaroyl sucroses were degraded to mumeose R and p-coumaroyl-3-O-sucrose. On the other hand, contents of mumefural and amygdalin increased after drying process. In colitis rats, MF reduced more NO levels to greater extent in comparison to PM, which could be attributed to the presence of caffeic acid, p-coumaric acid, protocatechuic acid, p-hydroxybenzoic acid, mumefural, p-coumaroyl-3-O-sucrose, mumeose R, and amygdalin in MF. Moreover, water extracts were better than ethanol extracts in alleviating the IL-1β, IL-6, and IL-17 levels, possibly on account of citric acid and caffeoylquinic acids. The predicted mechanism of action could be through inhibition of the production of NLRP3, TLR4, and NF-κB proteins. Finally, 7 compounds (citric acid, 3-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, caffeic acid, protocatechuic acid, and p-coumaric acid) were selected as quality markers of MF that could be used for the process quality control.

CONCLUSION

This study revealed the material basis of PM and MF for anti-colitis activity and discovered the quality markers of MF which could reflect the anti-inflammatory activity and the processing process of MF.

Dynamic variation of the phytochemical and volatile compounds in the pericarp of Citrus reticulata ''Chachi'' (Rutaceae) during 2 years of storage

The pericarp of Citrus reticulata "Chachi" (CRCP) is used as nutritional food and traditional medicine in China, usually harvested at three periods, namely, immature (CRCP-G1), semi-mature (CRCP-G2), and fully mature (CRCP-G3). Traditionally, if the CRCP is stored for a longer period, then the quality will be better. In this study, the dynamic variation of phytochemical and volatile compounds was profiled in the same batches of CRCP during 2 years of storage. Results illustrated that most of the phytochemical compounds showed a decreasing trend during storage, that is, total flavonoids, total phenolic acids, hesperidin, 3,5,6,7,8,3',4'-heptamethoxyflavone, 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone, synephrine, and limonin. The ferulic acid increased significantly, whereas no significant changes were observed in the total polymethoxyflavones, nobiletin, and tangeretin after 2 years of storage. In addition, we found that the extraction yield of volatile oil decreased significantly in CRCP-G1 during storage, and the herb odors were enhanced with the increase of phenols and esters. No significant difference in the extraction yield of volatile oil of CRCP-G2 and CRCP-G3 was found after 2 years of storage, but the citrus-like notes were increased with the promoted generation of alkenes. In particular, the multivariate statistical analysis indicated that 7 volatiles showed a higher level after 1 year of storage, whereas 11 volatiles decreased and 4 volatiles increased after 2 years of storage, respectively. This study could show the early aging mechanism of CRCP harvested at different periods and provide a scientific guidance in the storage of CRCP. PRACTICAL APPLICATION: This study indicated a comprehensive method for rapid analysis of phytochemical and volatile compounds in pericarp of Citrus reticulata ''Chachi'' (Rutaceae) (CRCP) harvested at different periods during 2 years of storage. The results obtained from this study would be valuable for revealing the early aging mechanism and sustainable storage of CRCP.

Effects of Different Drying Methods and Temperature on the Drying Behavior and Quality Attributes of Cherry Laurel Fruit

This study aimed to investigate the effect of different drying methods and drying temperature on the drying kinetics, total bioactive compounds, phenolic profile, microstructural properties, rehydration kinetics, and color change of cherry laurel fruit. For this aim, hot air drying (HAD), ultrasound-assisted vacuum drying (USV), and freeze-drying (FD) were conducted on drying of cherry laurel. HAD and USV were conducted at 50, 60, and 70 °C. Drying times of the samples were 1980, 1220, and 770 min for HAD at 50, 60 and 70 °C, and 950, 615, and 445 min at 50, 60, and 70 °C, respectively, for USV. The total bioactive compound was significantly affected by both drying methods and temperature (p < 0.05). FD exhibited the highest total phenolic (TPC), total flavonoid (TFC), total anthocyanin (TAC), and antioxidant capacity value USV showed a higher amount of bioactive compounds than those of HAD at the same drying temperature. The content of total bioactive compounds significantly increased as the temperature increased for both HAD and USV (p < 0.05). The chlorogenic acid was identified as a major phenolic, and its amount significantly depended on drying methods (p < 0.05). SEM images described the surface characteristic of dried samples. HAD dried products showed higher shrinkage compared to FD and USV. All drying methods significantly affected the total color difference (ΔE) values (p < 0.05). This study proposed that USV could be as an alternative method to HAD due to higher bioactive compounds retention and rehydration ratio, shorter drying time, less color change, and shrinkage formation.