Proanthocyanidin in the fruit of Japanese apricot (Prunus mume Sieb. et Zucc.) and their structural estimation by HPLC-ESI-MS/MS

Changes in polyphenolic compounds and antioxidant activity of Japanese pickled apricot with salted red perilla leaf during pickling and digestion process

Japanese pickled apricot, called "umeboshi", is a traditional food that has experientially been consumed as a folk medicine. The main variation of umeboshi is called "shiso-zuke umeboshi", meaning pickled with red perilla leaves to add a colorful appearance. This study investigated changes in phenolics and antioxidant potential of shiso-zuke umeboshi during pickling processes and simulated digestion. Results showed that the red perilla pickling (PP; 1338.12) had 13 times higher phenolics than salt pickling (SP; 101.99) in μg/g DW, and the formation of rosmarinic acid was enhanced. The simulated digestion showed a gradual increase in antioxidant content and activity from the stomach to small intestine, with TPC and TFC being rapidly released in the intestinal environment. The study concluded that shiso-zuke umeboshi provides higher health benefits due to the excellent antioxidant compounds produced through the perilla pickling process.

Phenolic acids from medicinal and edible homologous plants: a potential anti-inflammatory agent for inflammatory diseases

Inflammation has been shown to trigger a wide range of chronic diseases, particularly inflammatory diseases. As a result, the focus of research has been on anti-inflammatory drugs and foods. In recent years, the field of medicinal and edible homology (MEH) has developed rapidly in both medical and food sciences, with 95% of MEH being associated with plants. Phenolic acids are a crucial group of natural bioactive substances found in medicinal and edible homologous plants (MEHPs). Their anti-inflammatory activity is significant as they play a vital role in treating several inflammatory diseases. These compounds possess enormous potential for developing anti-inflammatory drugs and functional foods. However, their development is far from satisfactory due to their diverse structure and intricate anti-inflammatory mechanisms. In this review, we summarize the various types, structures, and distribution of MEHP phenolic acids that have been identified as of 2023. We also analyze their anti-inflammatory activity and molecular mechanisms in inflammatory diseases through NF-κB, MAPK, NLRP3, Nrf2, TLRs, and IL-17 pathways. Additionally, we investigate their impact on regulating the composition of the gut microbiota and immune responses. This analysis lays the groundwork for further exploration of the anti-inflammatory structure-activity relationship of MEHP phenolic acids, aiming to inspire structural optimization and deepen our understanding of their mechanism, and provides valuable insights for future research and development in this field.

Effect of water deficit stress during fruit cultivation on the carbon stable isotopes of organic acids in Japanese apricots and liqueur prepared from these fruits

ABSTRACTThe objective of this study was to assess the impact of water deficit stress during fruit cultivation on the δ13C values of citric acid and malic acid in Japanese apricots at different ripeness stages and their resulting liqueurs. Our experiments show that water deficit stress increases the δ13C values of citric acid and malic acid in tree-ripened fruits, counteracting the typical decrease during ripening. However, water deficit treatment has a minimal effect on the δ13C values of organic acids in green fruits. Regardless of fruit ripeness or water status, the δ13C values of organic acids in fruits are directly reflected in the resulting liqueurs. Overall, water deficit stress during fruit cultivation has the potential to promote similarity in the δ13C values of organic acids across fruits at different ripeness levels, reducing variations among liqueurs derived from fruits of varying ripeness levels.

Exploring separation patterns and mechanisms of proanthocyanidins in grape seeds and pomace with diverse molecular weights, compositions, and structures

The function of proanthocyanidins (PAs) relies on their structure and requires high-purity PAs. Though Sephadex LH-20 gel permeation chromatography (GPC) is expected to separate PAs based on structure, its usage rules and mechanisms remain unclear. This study delves into the PAs separation patterns on Sephadex LH-20, first confirming the purification mechanisms of PAs with various mean degrees of polymerization (DP) using the adsorption kinetic model. The study found that an increase in the molecular weight or mean DP of PAs results in decreased polarity, reduced hydrogen bonding actions, and intensified hydrophobic effect, causing delayed extraction of PAs on Sephadex LH-20, with galloylated PA as an exception, which was extracted first despite its high DP. Additionally, the principles for separating specific composition, such as monomers, dimers, etc., were evaluated. The study sheds light on enhancing the purification efficiency of PAs, thus advancing the precise separation technology of diverse proanthocyanidins.

Exploring the potential of ume-derived proanthocyanidins: novel applications for blueberry preservation

Proanthocyanidins (PCs) extracted from ume have many well-known functional properties. The aim of this study was to explore a novel natural food preservative using ume plum pulp proanthocyanidins (UPPP). The crude product of PCs from ume plum was obtained by using ethanol as extraction solvent and ultrasonic-assisted extraction, and then the pure product of UPPP was obtained by purification with AB-8 resin. The bacteriostatic ability of UPPP and the freshness preservation effect on blueberry were analyzed. The results showed that UPPP had a high inhibitory effect on Staphylococcus aureus (MIC of 1.563 mg/mL) and Escherichia coli (MIC of 3.125 mg/mL). Findings revealed that, in comparison to 0.02% potassium sorbate, blueberries treated with a high concentration of UPPP in a dipping treatment displayed superior quality maintenance after 7 days of storage at 4°C. Importantly, analysis of the various metrics showed that treatment with UPPP was significantly better compared to blueberries treated with 0.02% potassium sorbate. For example, the decay rate, weight loss, and total number of colonies of blueberries treated with 0.02% potassium sorbate were 55.56, 3.48%, and 4.24 ± 0.07 log CFU/mL, whereas the values of the above indexes for blueberries treated with 25 mg/mL of UPPP were 22.22, 3.09%, and 3.10 ± 0.17 log CFU/mL, respectively. Conversely, blueberries that were not dipped in any preservative displayed signs of deterioration as early as the 3rd day of the storage period, highlighting the potential of UPPP as a valuable method for preserving fruits and vegetables. Therefore, UPPP holds great promise as an innovative natural food preservative, effectively enhancing food safety, quality, and extending shelf-life.

Identification of a novel α-glucosidase inhibitor from Melastoma dodecandrum Lour. fruits and its effect on regulating postprandial blood glucose

Melastoma dodecandrum Lour. (MDL) extracts have shown potent α-glucosidase inhibitory activity, suggesting MDL might be a good source of α-glucosidase inhibitors. The aim of the study was to identify compounds in MDL extracts with α-glucosidase inhibitory activities and evaluate their effect on postprandial blood glucose as well as elucidating the underlying mechanisms of inhibition. A total of 34 polyphenols were identified in MDL fruits, among which 10 anthocyanins and three proanthocyanidin derivatives were discovered for the first time. Dosing mice with MDL extracts (100 mg/kg body weight, by gavage) was associated with a significantly decrease in postprandial blood glucose concentrations after oral administration of maltose. The most potent α-glucosidase inhibitor was identified as casuarictin (IC₅₀ of 0.21 μg/mL). Casuarictin bound competitively to α-glucosidase, occupying not only the catalytic site but also forming strong hydrogen bonds with α-glucosidase residues. Therefore, casuarictin derived from MDL fruits might be used as novel α-glucosidase inhibitor in functional foods or other dietary products.

Influence of ripening stage and meteorological parameters on the accumulation pattern of polyphenols in greengages (Prunus mume Sieb. Et Zucc) by widely targeted metabolomic

Greengage is a Chinese traditional medicine food homology plant that contains abundant polyphenols. Greengages with different levels of maturity have different medicinal functions and applications. Therefore, this study comprehensively analysed the phenolic compounds in greengage of whole mature stage. Notably, the influence of climate conditions on greengage polyphenol synthesis was deeply explored. The polyphenols of greengages were profiled based on the widely targeted metabolomic technology using ultra-performance liquid chromatography-electrospray ionisation triple quadrupole mass spectrometry (UPLC-QTRAP-MS/MS). A total of 214 polyphenols were detected, covering 11 subclasses. During the ripening of greengages, these polyphenols first increased and then decreased, peaking during the swell stage. Multivariate statistical methods, including redundancy analysis (RDA), random forest analysis, Mantel test, and Spearman's correlation indicated that temperature, sunshine hours, humidity, and radiation were important factors driving the formation and changes in the polyphenols of greengages. In particular, flavanones and flavonols, showed a structure-dependent response to temperature and radiation.

Prunus lusitanica L. Fruits as a Novel Source of Bioactive Compounds with Antioxidant Potential: Exploring the Unknown

Prunus lusitanica L., also known as Portuguese laurel or locally known as ‘azereiro’, is a rare species with ornamental and ecological value. Only two studies regarding the bioactivity and chemical composition of its leaves were reported to date. Thus, the present study aims to qualitatively and quantitatively evaluate the phenolic profile, through HPLC-PAD-ESI-MS/MS (high-performance liquid chromatography–photodiode array detection–electrospray ionization tandem mass spectrometry), as well as the radical scavenging capacity, through ABTS (2,2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1 picrylhydrazyl), and the reducing power (FRAP, ferric reducing antioxidant power) assays, of P. lusitanica fruits during a 4-year study. In total, 28 compounds were identified and quantified in the fruits, including 21 hydroxycinnamic acids (60.3%); 2 flavan-3-ols (27.9%), 2 anthocyanins (10.5%), 2 flavonols (1.0%), and 1 secoiridoid (0.3%). High antioxidant capacity was observed, with ABTS values ranging from 7.88 to 10.69 mmol TE (Trolox equivalents)/100 g fw (fresh weight), DPPH values from 5.18 to 8.17 mmol TE/100 g fw, and FRAP values from 8.76 to 11.76 mmol TE/100 g fw. According to these results, it can be concluded that these are rich sources of phenolic compounds with very promising antioxidant capacity and, therefore, with potential applications in the food and/or phytopharmaceutical sectors.

Current and potential trends in the bioactive properties and health benefits of Prunus mume Sieb. Et Zucc: a comprehensive review for value maximization

Prunus mume Sieb. Et Zucc (P. mume) is an acidic fruit native to China (named Chinese Mei or greengage plum). It is currently cultivated in several Asian countries, including Japan ("Ume"), Korea (Maesil), and Vietnam (Mai or Mo). Due to its myriad nutritional and functional properties, it is accepted in different countries, and its characteristics account for its commercialization. In this review, we summarize the information on the bioactive compounds from the fruit of P. mume and their structure-activity relationships (SAR); the pulp has the highest enrichment of bioactive chemicals. The nutritional properties of P. mume and the numerous uses of its by-products make it a potential functional food. P. mume extracts exhibit antioxidant, anticancer, antimicrobial, and anti-hyperuricaemic properties, cardiovascular protective effects, and hormone regulatory properties in various in vitro and in vivo assays. SAR shows that the water solubility, molecular weight, and chemical conformation of P. mume extracts are closely related to their biological activity. However, further studies are needed to evaluate the fruit's potential nutritional and functional therapeutic mechanisms. The industrial process of large-scale production of P. mume and its extracts as functional foods or nutraceuticals needs to be further optimized.