Carotenoid composition of strawberry tree (Arbutus unedo L.) fruits

Lebanese Medicinal Plants with Ophthalmic Properties

Lebanon benefits from a rich biodiversity, with medicinal and aromatic plants (MAPs) representing an important part of the country's natural wealth; however, limited data are available documenting medicinal plants being employed in eye health. This review is the first to document Lebanese medicinal plants with ophthalmic characteristics and phytochemistry that might be beneficial in the development of new, accessible, and efficient ocular medications. In this study, we searched for studies on ocular therapeutic plants using known resources, including PubMed, ScienceDirect, and Google Scholar, and confirmed these plants' presence within the Lebanese flora. The efficacy of 52 species from 28 families, including two endemic species (Crepis libanotica and Salvia libanotica), has been documented. Their Latin names, regional names, ocular medical applications, the plant parts used, and preparation forms are detailed below. The largest number of species belongs to the Lamiaceae family (21%), followed by Asteraceae (14%) and Solanaceae (7%). The most commonly used plant parts are the stems, leaves, and seeds. Ocular treatments fall into several categories: inflammation, infection, irritation, dry-eye, eyewash, the prevention or delay of cataracts, and general eye problems. A significant percentage (68%) of the medicinal plants target the anterior part of the eye. Some of the reported plants can be harmful to the eyes and should be handled with caution. The Lebanese medicinal plants listed, constituting a local heritage with global importance, could be used for treating ophthalmic ailments and require special screening and preservation.

Exosome-like nanoparticles from Arbutus unedo L. mitigate LPS-induced inflammation via JAK-STAT inactivation

Exosomes have garnered attention as a potential cell-free therapy for inflammatory diseases due to their immunomodulatory and anti-inflammatory properties. Exosome-like nanoparticles isolated from Arbutus unedo were characterized and analyzed for their anti-inflammatory potential. The results revealed that the isolated exosomes exhibited a spheroid morphology, with an approximate modal size of 190 nm. Exposure to these exosomes significantly reduced the mRNA expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), the glycoprotein CD80, the transcription factor STAT1, and pro-inflammatory cytokine genes like IL-1b and IL-6, in lipopolysaccharide (LPS)-induced protein RAW264.7 cells. In addition, exosomes reduced the LPS-induced protein levels of PSTAT1 and STAT1, IRF1 and RelB, which are key transcription factors in the control of proinflammatory gene expression. LC-MS analysis identified the presence of carotenoids, mainly β-carotene, with known anti-inflammatory activity, related to its ROS-scavenging activity, suggesting its potential contribution to the anti-inflammatory activity of the exosomes isolated from A. unedo fruits.

Lutein esterification increases carotenoid retention in durum wheat grain. A step further in breeding and improving the commercial and nutritional quality during grain storage

Carotenoid esterification is a common mechanism for carotenoid sequestration, accumulation and storage in plants. Carotenoids are responsible for the bright yellow colour of pasta. Therefore, carotenoid retention during storage is of great importance in the durum wheat food chain. In this work, we investigated the role of carotenoid esterification on carotenoid retention in durum wheat using two consecutive storage experiments. Firstly, we compared two landraces and two durum wheat varieties as a preliminary work. We then compared individuals derived from the BGE047535×'Athoris' cross contrasting for esterification ability. Our results show that carotenoid esterification leads to a higher carotenoid retention during storage in durum wheat. Thus, the use of the carotenoid esterification would be useful as an extra strategy to ongoing efforts to improve carotenoid retention in the durum wheat food chain.

Effect of Apple Juice Enrichment with Selected Plant Materials: Focus on Bioactive Compounds and Antioxidant Activity

Using a multi-analytical approach, this paper aimed to investigate the effect of apple juice enrichment with Arbutus unedo and Diospyros kaki fruits, Myrtus communis berry extract, Acca sellowiana, or Crocus sativus flower by-products on both bioactive compounds content and antioxidant activity. Physico-chemical parameters, vitamin C, sugars, organic acids, total polyphenol content, antioxidant activity, and sensory attributes were evaluated. An LC-PDA/MS QTof analysis allowed for the identification of 80 different phenolic compounds. The highest polyphenol content (179.84 and 194.06 mg of GAE/100 g fw) and antioxidant activity (CUPRAC, 6.01 and 7.04 mmol of Fe²⁺/100 g fw) were observed in products with added A. sellowiana and D. kaki, respectively. Furthermore, the study showed a positive correlation between polymeric procyanidins and antioxidant activity (0.7646-0.8539). The addition of A. unedo fruits had a positively significant influence on the increment of vitamin C (23.68 ± 0.23 mg/100 g fw). The obtained products were attractive to consumers, especially those with 0.1% C. sativus flower juice, M. communis berry extract, and persimmon D. kaki fruits. The synergy among the different analytical techniques allowed us to obtain a complete set of information, demonstrating that the new apple smoothies were enriched in both different beneficial molecules for human health and in antioxidant activity.

Zostera marina L.: Supercritical CO2-Extraction and Mass Spectrometric Characterization of Chemical Constituents Recovered from Seagrass

Three types of Zostera marina L. collection were extracted using the supercritical CO2-extraction method. For the purposes of supercritical CO2-extraction, old seagrass ejection on the surf edge, fresh seagrass ejection on the surf edge and seagrass collected in water were used. Several experimental conditions were investigated in the pressure range 50–350 bar, with the used volume of co-solvent ethanol in the amount of 1% in the liquid phase at a temperature in the range of 31–70 °C. The most effective extraction conditions are: pressure 250 Bar and temperature 60 °C for Z. marina collected in sea water. Z. marina contain various phenolic compounds and sulfated polyphenols with valuable biological activity. Tandem mass-spectrometry (HPLC-ESI–ion trap) was applied to detect target analytes. 77 different biologically active components have been identified in Z. marina supercritical CO2-extracts. 38 polyphenols were identified for the first time in Z. marina.

An Insight into Phytochemical, Pharmacological, and Nutritional Properties of Arbutus unedo L. from Morocco

Arbutus unedo L. (Ericaceae) is an evergreen shrub widely distributed in the Mediterranean region, particularly through the Moroccan forests. It is an important medicinal plant of great scientific interest due to its nutritional, pharmacological, and chemical properties. The objective of this review is to provide insights into traditional medicinal uses and phytochemical and pharmacological properties of A. unedo from Morocco. In Morocco, the plant has been used as a traditional medicine to treat several pathological conditions. Many phytochemical compounds have been reported in the plant, of which vitamins, carotenoids, flavonoids, polyphenols, tannins, and their derivatives are the most prevalent. Leaves and fruits of A. unedo contain the most significant number of phytochemicals among the species. Furthermore, researchers have demonstrated that A. unedo exhibited antioxidant, anticancer, antibacterial, antidiabetic, antiaggregant, and antihypertensive activities due to the presence of many biochemical compounds with health-promoting properties. According to different toxicity tests, the use of A. unedo is devoid of any significant side effects and/or toxicity. Despite its nutraceutical and health-promoting properties, Moroccan A. unedo remains underexploited mainly, and most of its traditional uses have not yet undergone scientific evidence-based research; therefore, improved knowledge about the potential value of the plant would allow understanding of its biological activity based on its phytochemical compounds that may contribute to the species preservation and valorization.

Moroccan Strawberry Tree (Arbutus unedo L.) Fruits: Nutritional Value and Mineral Composition

The strawberry tree (Arbutus unedo L.), grown throughout the Mediterranean, produces edible fruit; as it is easily bruised, the sweet, reddish fruit is used mostly to prepare jams, marmalades and alcoholic beverages. As the genus is paraphyletic, phytochemical analysis can assist in defining the fruit composition with the species Arbutus unedo L. (A. unedo). Here we report on the carbohydrate, total sugar, protein, fat, fiber, ash, and mineral content of wild fruit, harvested from 45 specimens from five locations. The dominant nutrients were carbohydrates (78.2–84.8 g/100 g), total sugars (52.1–67.2 g/100 g) and dietary fiber (11.0–20.1 g/100 g). Other important nutrients supplied by A. unedo fruit include P, K, and Fe. The fruit was observed to contain health-promoting components providing 42 and 36%, of recommended daily allowance (RDA) for fiber and zinc, respectively, as well as iron and manganese, at levels exceeding minimum RDA. The free-sugar profile revealed high glucose followed by fructose content with minor amounts of sucrose (14, 11, and 6 g/100 g, respectively). Significant differences both between regions and within individuals were observed for several traits. The richness of fruit nutrients in A. unedo confers nutritional value and as such, a promising alternative fruit source.

Evaluation of the antioxidant and cytotoxic potency of Euphorbia rigida and Arbutus andrachne methanol extracts in human hepatocellular carcinoma cell lines in vitro

Background

Ethnobotanical studies on plants and their active compounds take a great interest in traditional medicine. After pharmacological and toxicological studies, there will be a possibility to be used in therapy. This study aimed to examine the in vitro antioxidant and cytotoxic activity of the methanol extracts of Arbutus andrachne L. and Euphorbia rigida M.Bieb. 10, 25, 50, 75, 100 and 150 µg mL−1 concentrations of A. andrachne and E. rigida were tested for antioxidant activity by using DPPH radical scavenging assays, total antioxidant capacity (phosphomolybdate assay) and and metal ion chelating activity. In addition, in vitro cytotoxic effects of this plants methanol extracts on Hep3B and HepG2 human hepatocellular carcinoma cell lines were evaluated at 24, 48 and 72 h. The cytotoxicity test was carried using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay.

Results

Methanol extract obtained from both plants showed increased antioxidant activity depending on the increase in concentration. When A. andrachne and E. rigida methanol extracts were compared in free DPPH scavenging activity, total antioxidant capacity and metal ion chelating activity, A. andrachne methanol extract was found more effective than E. rigida. Results from MTT assay revealed that except for 72 h treatment of HepG2 cells with 400 and 500 µgmL−1 extract concentrations, A. andrachne methanol extract did not show significant cytotoxic effects on either Hep3B or HepG2 cells at any concentration and treatment time. On the contrary, it significantly increased proliferation in Hep3B cells from 48 h and at a concentration of 100 µg mL−1. E. rigida methanol extract exhibited statistically significant cytotoxic activity on HepG2 cells after 48 and 72 h treatment. However, the treatment concentrations of E. rigida methanol extract were not as effective on Hep3B cells as on HepG2 cells.

Conclusions

According to our findings, it was determined that A. andrachne methanol extract did not have cytotoxic activity on neither Hep3B nor HepG2 cells, while E. rigida methanol extract had cytotoxic activity especially on HepG2 hepatocellular carcinoma cells. Further research is needed to identify and purify the active ingredients in E. rigida extracts.

Stability of carotenoids and carotenoid esters in pumpkin (Cucurbita maxima) slices during hot air drying

The levels of carotenoids and carotenoid esters in pumpkin (C. maxima) slices as affected by hot air drying (60-100 °C, 6-17 h) were assessed via an HPLC-MS/MS method. Among the 25 carotenoids and carotenoid esters identified in pumpkin flesh, xanthophyll diesters (including (all-E)-violaxanthin dipalmitate, lutein 3-O-myristate-3'-O-laurate, lutein 3-O-palmitate-3'-O-laurate, lutein 3-O-myristate-3'-O-palmitate, lutein 3-O-stearate-3'-O-myristate and lutein 3-O-stearate-3'-O-palmitate) accounted for 43% of the total carotenoids (853.6 ± 18.5 μg/g, dried weight). Dihydroxy xanthophylls, especially those containing 5,6-epoxy group, were more heat-labile than carotenes, while xanthophylls were less heat stable than their diester counterparts. The degradation rates (first-order reactions, R² = 0.983-0.992) for lutein diesters (rate constant: 0.002-0.049 h^-1) in pumpkin slices were only 10-20% of that for lutein (rate constant: 0.020-0.243 h^-1) during hot air drying, and 76-98% of lutein diesters could be retained in the final dried products.

European Database of Carotenoid Levels in Foods. Factors Affecting Carotenoid Content

Many studies indicate that diets including carotenoid-rich foods have positive effects on human health. Some of these compounds are precursors of the essential nutrient vitamin A. The present work is aimed at implementing a database of carotenoid contents of foods available in the European market. Factors affecting carotenoid content were also discussed. Analytical data available in peer-reviewed scientific literature from 1990 to 2018 and obtained by HPLC/UHPLC were considered. The database includes foods classified according to the FoodEx2 system and will benefit compilers, nutritionists and other professionals in areas related to food and human health. The results show the importance of food characterization to ensure its intercomparability, as large variations in carotenoid levels are observed between species and among varieties/cultivars/landraces. This highlights the significance of integrating nutritional criteria into agricultural choices and of promoting biodiversity. The uncertainty quantification associated with the measurements of the carotenoid content was very rarely evaluated in the literature consulted. According to the EuroFIR data quality evaluation system for food composition tables, the total data quality index mean was 24 in 35, reflecting efforts by researchers in the analytical methods, and less resources in the sampling plan documentation.

A comprehensive review on carotenoids in foods and feeds: status quo, applications, patents, and research needs

Carotenoids are isoprenoids widely distributed in foods that have been always part of the diet of humans. Unlike the other so-called food bioactives, some carotenoids can be converted into retinoids exhibiting vitamin A activity, which is essential for humans. Furthermore, they are much more versatile as they are relevant in foods not only as sources of vitamin A, but also as natural pigments, antioxidants, and health-promoting compounds. Lately, they are also attracting interest in the context of nutricosmetics, as they have been shown to provide cosmetic benefits when ingested in appropriate amounts. In this work, resulting from the collaborative work of participants of the COST Action European network to advance carotenoid research and applications in agro-food and health (EUROCAROTEN, www.eurocaroten.eu, https://www.cost.eu/actions/CA15136/#tabs|Name:overview) research on carotenoids in foods and feeds is thoroughly reviewed covering aspects such as analysis, carotenoid food sources, carotenoid databases, effect of processing and storage conditions, new trends in carotenoid extraction, daily intakes, use as human, and feed additives are addressed. Furthermore, classical and recent patents regarding the obtaining and formulation of carotenoids for several purposes are pinpointed and briefly discussed. Lastly, emerging research lines as well as research needs are highlighted.

Insights into the stability of carotenoids and capsaicinoids in water-based or oil-based chili systems at different processing treatments

Ultrasonication, microwave, heat, and light treatments, as well as storage conditions, were investigated for their effects on the stability of carotenoids and capsaicinoids in water/oil chili systems. The stability of carotenoids and capsaicinoids were found to vary in response to different processing treatments. Carotenoid and capsaicinoid contents in chili juice (CJ, water system) were increased by low-power ultrasonic and microwave treatments, but decreased by high-power treatments. The thermal stability of carotenoids and capsaicinoids in hot pot bottom (HPB, oil system) were superior to those in CJ. Moreover, ultraviolet light significantly reduced the contents of carotenoids and capsaicinoids in both CJ and HPB. It was also demonstrated that low temperature conditions (4 °C) significantly delayed the degradation of carotenoids and capsaicinoids in chili-based food. In conclusion, our findings suggest that the stability of carotenoids and capsaicinoids can be tuned using different processing and storage techniques appropriate to different systems.

A Brief Overview of Dietary Zeaxanthin Occurrence and Bioaccessibility

As it exhibits no provitamin A activity, the dietary intake of zeaxanthin is not considered essential. However, its contribution to ocular health has long been acknowledged. Numerous publications emphasize the importance of zeaxanthin alongside lutein in ocular diseases such as cataracts and age-related macular degeneration which constitute an important health concern, especially among the elderly. Considering that the average dietary ratio of lutein to zeaxanthin favors the first, more bioaccessible food sources of zeaxanthin that can hinder the development and progression of the above-mentioned disorders are of great interest. In this paper, a brief overview of the more recent state of knowledge as regards dietary sources together with their respective zeaxanthin bioaccessibility assessed through a standardized in vitro digestion method was provided.

Impact of Aqueous Extract of Arbutus unedo Fruits on Limpets (Patella spp.) Pâté during Storage: Proximate Composition, Physicochemical Quality, Oxidative Stability, and Microbial Development

Limpets are molluscs widely used in food diet and much appreciated in many regions. The consumption of fishery products rich in polyunsaturated fatty acids has been increasing through filleted products and restructured products. Since food oxidation is the major cause of nutritional quality deterioration in fish products, the interest in the replacement of synthetic antioxidants with natural sources, namely in the preparation of restructured animal products such as burgers, sausages and pâtés, has been increasing. Phenolic compounds from fruits and vegetables have recognised antioxidant properties and are therefore currently considered as good alternatives to synthetic antioxidants in the food industry. In this study, the effects of the extracts of Arbutus unedo fruits, at two concentration levels (3% and 6%), on proximate composition, physicochemical properties, oxidative stability and safety of limpets pâté, during 90 days at refrigerated storage, were investigated. After processing, the addition of 3% and 6% of A. unedo extracts into limpets pâté contributed to an increase of 18% and 36% in the total phenolic content and 5% and 36% in the antioxidant capacity, respectively. During storage, the enriched limpets pâté with A. unedo fruit extracts at 6% was more efficient as an enhancer of oxidative stability, with 34% inhibition of lipid oxidation, highlighting the potential use of A. unedo fruits as a functional ingredient in the fish industry. Overall, the limpets pâté with 6% of A. unedo fruit extracts proved to be more efficient regarding microbial control, and had the lowest changes in the quality parameters such as in colour, texture and pH during 90 days at refrigerated storage.

Carotenogenesis and chromoplast development during ripening of yellow, orange and red colored Physalis fruit

Formation of specific ultrastructural chromoplastidal elements during ripening of fruits of three different colored Physalis spp. is closely related to their distinct carotenoid profiles. The accumulation of color-determining carotenoids within the chromoplasts of ripening yellow, orange, and red fruit of Physalis pubescens L., Physalis peruviana L., and Physalis alkekengi L., respectively, was monitored by high-performance liquid chromatography/diode array detector/tandem mass spectrometry (HPLC-DAD-MS/MS) as well as light and transmission electron microscopy. Both yellow and orange fruit gradually accumulated mainly β-carotene and lutein esters at variable levels, explaining their different colors at full ripeness. Upon commencing β-carotene biosynthesis, large crystals appeared in their chromoplasts, while large filaments protruding from plastoglobules were characteristic elements of chromoplasts of orange fruit. In contrast to yellow and orange fruit, fully ripe red fruit contained almost no β-carotene, but esters of both β-cryptoxanthin and zeaxanthin at very high levels. Tubule bundles and unusual disc-like crystallites were predominant carotenoid-bearing elements in red fruit. Our study supports the earlier hypothesis that the predominant carotenoid type might shape the ultrastructural carotenoid deposition form, which is considered important for color, stability and bioavailability of the contained carotenoids.

Phenolic Compounds Extraction of Arbutus unedo L.: Process Intensification by Microwave Pretreatment

Arbutus unedo L., commonly known as the strawberry-tree fruit, is an endemic species of the Mediterranean flora. Microwave extraction technology has been considered as a fast and “green” method for the production of extracts rich in bioactive compounds, although the energy consumption is high. To overcome this bottleneck, microwave was used as a pretreatment procedure in short time periods. This technique promotes the burst of intracellular vacuoles leading to an increase in the lixiviation of phenolic compounds. Different approaches were tested, namely a solvent-free irradiation (SFI), a solvent-assisted irradiation (SAI) and a pressurized solvent-assisted irradiation (PSAI). After irradiation, a solid–liquid extraction procedure was performed using a mixture of water and ethanol. A kinetic evaluation of the total phenolic content (TPC) was performed using the Folin–Ciocalteu method. For the total anthocyanin content, a UV-spectrophotometric method was used. HPLC-UV and LC-MS were used for TPC and identification of present compounds. Microwave irradiation led to an increase in TPC of extracts after SAI (52%) and PSAI (66%) along with a reduction in time of extraction from 30 min to less than 2 min. The anthocyanin content also increased by 66% for the SAI and PSAI extractions.

Green Extraction Approaches for Carotenoids and Esters: Characterization of Native Composition from Orange Peel

Orange peel is a by-product produced in large amounts that acts as a source of natural pigments such as carotenoids. Xanthophylls, the main carotenoid class found in citrus fruit, can be present in its free form or esterified with fatty acids, forming esters. This esterification modifies the compound’s chemical properties, affecting their bioavailability in the human body, and making it important to characterize the native carotenoid composition of food matrices. We aimed to evaluate the non-saponified carotenoid extracts of orange peel (cv. Pera) obtained using alternative green approaches: extraction with ionic liquid (IL), analyzed by high performance liquid chromatography coupled to a diode array detector with atmospheric pressure chemical ionization and mass spectrometry HPLC-DAD-APCI-MS, and supercritical fluid extraction (SFE), followed by supercritical fluid chromatography with atmospheric pressure chemical ionization and triple quadrupole mass spectrometry detection (SFC-APCI/QqQ/MS) in an online system. Both alternative green methods were successfully applied, allowing the total identification of five free carotenoids, one apocarotenoid, seven monoesters, and 11 diesters in the extract obtained with IL and analyzed by HPLC-DAD-APCI-MS, and nine free carotenoids, six carotenoids esters, 19 apocarotenoids, and eight apo-esters with the SFE-SFC-APCI/QqQ/MS approach, including several free apocarotenoids and apocarotenoid esters identified for the first time in oranges, and particularly in the Pera variety, which could be used as a fruit authenticity parameter.

A Routine Method for the Extraction and HPLC-DAD Profiling of Major Plant and Food Carotenoids

Carotenoids are ubiquitously present in Nature, and especially in plants and derived foods. The carotenoid profiling is necessary to understand relevant aspects in relation to their biochemistry and genetics, as well as their important roles on human health and animal ecophysiology. Here we propose a simple methodology for the routine extraction and efficient HPLC separation of the most common plant and food carotenoids from plant and animal origins.

Chemical compounds as well as antioxidant and litholytic activities of Arbutus unedo L. leaves against calcium oxalate stones

OBJECTIVE

The present study aimed to quantify and identify the bioactive compounds of the Arbutus unedo L. leaves in order to evaluate both their antioxidant properties and litholytic activities against calcium oxalate stones.

METHODS

This survey was carried out using hydroalcoholic extract (E.FA) and infusion (I.FA) of A. unedo leaves. The quantification of phenolic compounds, flavonoids, flavonols and anthocyanins was done by spectrophotometric methods and identification of chemical components was performed by ultra-performance liquid chromatography with photodiode array and electrospray ionization tandem mass spectrometry. Antioxidant activity was measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and by the ferric reducing/antioxidant power (FRAP) assay. Litholytic activity of E.FA and I.FA was studied using a special model that resembles circuitry of the urinary system.

RESULTS

E.FA showed greater antioxidant efficacy than I.FA (P < 0.05). Its higher efficiency was shown via the values of median inhibitory concentration, which was close to (76.14 ± 0.91) µg/mL for E.FA versus (202.64 ± 5.77) μg/mL for I.FA using the DPPH method, and (53.77 ± 0.81) μg/mL for E.FA versus (236.86 ± 31.90) μg/mL for I.FA, using FRAP method. I.FA exhibited significantly higher litholytic activity compared to E.FA (P < 0.05), with dissolution values of 31.03% ± 0.63% versus 14.55% ± 0.65%, respectively.

CONCLUSION

Overall, the results suggest that the A. unedo is rich in bioactive compounds, and possesses antioxidant and litholitic abilities that are worthy of further study.

Production and extraction of carotenoids produced by microorganisms

Carotenoids are a group of isoprenoid pigments naturally synthesized by plants and microorganisms, which are applied industrially in food, cosmetic, and pharmaceutical product formulations. In addition to their use as coloring agents, carotenoids have been proposed as health additives, being able to prevent cancer, macular degradation, and cataracts. Moreover, carotenoids may also protect cells against oxidative damage, acting as an antioxidant agent. Considering the interest in greener and sustainable industrial processing, the search for natural carotenoids has increased over the last few decades. In particular, it has been suggested that the use of bioprocessing technologies can improve carotenoid production yields or, as a minimum, increase the efficiency of currently used production processes. Thus, this review provides a short but comprehensive overview of the recent biotechnological developments in carotenoid production using microorganisms. The hot topics in the field are properly addressed, from carotenoid biosynthesis to the current technologies involved in their extraction, and even highlighting the recent advances in the marketing and application of "microbial" carotenoids. It is expected that this review will improve the knowledge and understanding of the most appropriate and economic strategies for a biotechnological production of carotenoids.

Arbutus unedo L.: From traditional medicine to potential uses in modern pharmacotherapy

ETHNOPHARMACOLOGICAL RELEVANCE

Arbutus unedo L., the strawberry tree (Ericaceae family) is of increasing interest because of its common traditional, industrial, chemical and pharmaceutical uses. The plant is a typical evergreen plant of the Mediterranean basin, as well as of other regions with hot summers and mild rainy winters. This review covers the studies relevant to Arbutus unedo L. utilization in the current pharmacological therapy.

MATERIALS AND METHODS

The available information on traditional uses, phytochemistry and biological activities of Arbutus unedo L. was collected from scientific databases through a search using the keywords 'Arbutus unedo L.' and/or 'strawberry tree' in 'Google Scholar', 'Pubmed', 'Sciencedirect', 'SpringerLink', 'Web of Science - Clarivate Analytics' and 'Wiley'. Unpublished Ph.D. and M.Sc. dissertations were also consulted for chemical composition, biological activities and traditional uses of Arbutus unedo L. and for manual search of additional references.

RESULTS

The fruits of the plant have been traditionally used as antiseptics, diuretics and laxatives in folk medicine, while the leaves have been used due to their diuretic, urinary antiseptic, antidiarrheal, astringent, depurative and antihypertensive properties. According to the scientific literature survey, different extracts obtained from Arbutus unedo L. have demonstrated a high pharmacological potential due to their in vitro and preclinical antibiotic, antifungal, antiparasitic, antiaggregant, antidiabetic, antihypertensive, anti-inflammatory, antitumoral, antioxidant, and spasmolytic properties.

CONCLUSION

This review suggests that A. unedo is a promising source of phytopharmaceutical products. The potential advantages of Arbutus unedo are related with the presence of polyphenolic compounds in its composition. However, further studies are needed to ascertain some profitable effects in humans. The beneficial effects associated with this shrub suggest that Arbutus unedo can be used for the development of new drugs to treat diseases such diabetes, hypertension, among others. Nonetheless, the safety of the Arbutus unedo compounds should also be examined.

Impact of in vitro digestion phases on the stability and bioaccessibility of carotenoids and their esters in mandarin pulps

The composition of carotenoids (carotenes and free and acylated xanthophylls) and their bioaccessibilities were determined for the first time in pulps of mandarins cultivated in Brazil. Two cultivars of mandarin, Citrus reticulata Blanco cv. 'Ponkan' and Citrus reticulata × C. sinensis cv. 'Murcott', showed higher contents of most carotenoids compared to those found in C. deliciosa Tenore cv. 'Rio'. The major carotenoids in mandarin cv. 'Ponkan' and 'Murcott' were (all-E)-β-cryptoxanthin laurate (19-21%), (all-E)-β-cryptoxanthin myristate (15-17%) and (Z)-ζ-carotene (7-12%), followed by (all-E)-β-cryptoxanthin palmitate (4-7%), free (all-E)-β-cryptoxanthin (5-6%) and (all-E)-β-carotene (4-5%), while in mandarin cv. 'Rio' (all-E)-β-cryptoxanthin myristate (22%) was the major compound, followed by (all-E)-β-cryptoxanthin laurate (16%), (all-E)-β-cryptoxanthin palmitate (11%), (all-E)-β-cryptoxanthin (9%) and (all-E)-β-carotene (6%). After in vitro digestion, the qualitative carotenoid profile of the supernatant containing the micellarized carotenoids was similar to that of fresh fruits, but the contents were significantly lower. Carotenoid and mandarin physico-chemical properties influenced the bioaccessibility of carotenoids. Free (all-E)-β-cryptoxanthin showed the highest bioaccessibility in all mandarin cultivars (33-42%), while the bioaccessibilities of β-carotene (16-36%) and the major carotenoid esters (18-33%) were lower. The overall recovery of carotenoids during in vitro digestion was around 98% after the oral phase, 79% after oral + gastric phases and 77% after oral + gastric + duodenal phases, with free (all-E)-β-cryptoxanthin and (all-E)-β-carotene being the most stable ones. Besides possible E-Z isomerization and ester hydrolysis, evident losses occurred in total carotenoid contents and also in the most individual carotenoids and they were not compensated for by the former reactions.

A global perspective on carotenoids: Metabolism, biotechnology, and benefits for nutrition and health

Carotenoids are lipophilic isoprenoid compounds synthesized by all photosynthetic organisms and some non-photosynthetic prokaryotes and fungi. With some notable exceptions, animals (including humans) do not produce carotenoids de novo but take them in their diets. In photosynthetic systems carotenoids are essential for photoprotection against excess light and contribute to light harvesting, but perhaps they are best known for their properties as natural pigments in the yellow to red range. Carotenoids can be associated to fatty acids, sugars, proteins, or other compounds that can change their physical and chemical properties and influence their biological roles. Furthermore, oxidative cleavage of carotenoids produces smaller molecules such as apocarotenoids, some of which are important pigments and volatile (aroma) compounds. Enzymatic breakage of carotenoids can also produce biologically active molecules in both plants (hormones, retrograde signals) and animals (retinoids). Both carotenoids and their enzymatic cleavage products are associated with other processes positively impacting human health. Carotenoids are widely used in the industry as food ingredients, feed additives, and supplements. This review, contributed by scientists of complementary disciplines related to carotenoid research, covers recent advances and provides a perspective on future directions on the subjects of carotenoid metabolism, biotechnology, and nutritional and health benefits.

Carotenoids and Carotenoid Esters of Red and Yellow Physalis (Physalis alkekengi L. and P. pubescens L.) Fruits and Calyces

Carotenoid profiles of fruits and calyces of red (Physalis alkekengi L.) and yellow (P. pubescens L.) Physalis were characterized by HPLC-DAD-APCI-MSⁿ. Altogether 69 carotenoids were detected in red Physalis, thereof, 45 were identified. In yellow Physalis, 40 carotenoids were detected and 33 were identified. Zeaxanthin esters with various fatty acids were found to be the most abundant carotenoids in red Physalis, accounting for 51-63% of total carotenoids, followed by β-cryptoxanthin esters (16-24%). In yellow Physalis, mainly free carotenoids such as lutein and β-carotene were found. Total carotenoid contents ranged between 19.8 and 21.6 mg/100 g fresh red Physalis fruits and 1.28-1.38 mg/100 g fresh yellow Physalis fruits, demonstrating that Physalis fruits are rich sources of dietary carotenoids. Yellow Physalis calyces contained only 153-306 μg carotenoids/g dry weight, while those of red Physalis contained substantially higher amounts (14.6-17.6 mg/g dry weight), thus possibly exhibiting great potential as a natural source for commercial zeaxanthin extraction.

Characterization of carotenoid profile of Spanish Sanguinos and Verdal prickly pear (Opuntia ficus-indica, spp.) tissues

Carotenoid profiles of different tissues (peel, pulp and whole fruit) of Spanish Sanguinos (red) and Verdal (orange) prickly pears (Opuntia ficus-indica spp.) have been characterized in detail and quantified for the first time. Carotenoids were determined by HPLC-PDA-MS (APCI⁺), using a reverse phase C₃₀ column. A total of 9 xantophylls and 4 hydrocarbon carotenes were identified. Also, minor amounts of chlorophyll a, a' and b can be observed in Opuntia peel extracts. All carotenoids were found to be present in their free form (no carotenoid esters were detected). The RAE was highest in Opuntia peels, showing values from 19.20 to 16.48µg/100g fresh weigth, for Sanguinos and Verdal Opuntia fruits, respectively. The main carotenoid in Opuntia peel extracts was (all-E)-lutein with 1132.51 and 767.98µg/100g fresh weigth, followed by (all-E)-β-carotene with 200.40 and 173.50µg/100g fresh weigth for Sanguinos and Verdal varieties of Opuntia fruits, respectively.

Carotenoid esters in foods - A review and practical directions on analysis and occurrence

Carotenoids are naturally found in both free form and esterified with fatty acids in most fruits and some vegetables; however, up to now the great majority of studies presents data on carotenoid composition only after saponification. The reasons for this approach are that a single xanthophyll can be esterified with several different fatty acids, generating a great number of different compounds with similar chemical and structural characteristics, thus, increasing the complexity of analysis compared to the respective saponified extract. This means that since UV/Vis spectrum does not change due to esterification, differentiation between free and acylated xanthophylls is dependent at least on elution order and mass spectrometry (MS) features. The presence of interfering compounds, especially triacylglycerides (TAGs), in the non-saponified extract of carotenoids can also impair carotenoid ester analyses by MS due to high background noise and ionization suppression since TAGs can be present in much higher concentrations than the carotenoid esters. This leads to the need of development of new and effective clean-up procedures to remove the potential interferents. In addition, only few standards of xanthophyll esters are commercially available, making identification and quantification of such compounds even more difficult. Xanthophyll esterification may also alter some properties of these compounds, including solubility, thermostability and bioavailability. Considering that commonly consumed foods are dietary sources of xanthophyll esters and that it is the actual form of ingestion of such compounds, an increasing interest on the native carotenoid composition of foods is observed nowadays. This review presents a compilation of the current available information about xanthophyll ester analyses and occurrence and a practical guide for extraction, pre-chromatographic procedures, separation and identification by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Composition by LC-MS/MS of New Carotenoid Esters in Mango and Citrus

Interest in the composition of carotenoid esters of fruits is growing because esterification may affect their bioavailability. Thus, the aim was to provide a detailed identification of carotenoid esters in citrus and mango. Orange cv. 'Valencia' and cv. 'Pera' presented 9 free carotenoids, 38 monoesters, and 60 diesters. Violaxanthin and luteoxanthin derivatives were the major ones, followed by antheraxanthin, lutein, zeaxanthin, β-cryptoxanthin, and zeinoxanthin esters, many of them reported for the first time in orange pulp. The carotenoid ester composition of tangor cv. 'Murcott', reported for the first time, showed 8 free carotenoids, 34 monoesters, and 33 diesters, with β-cryptoxanthin esters as major compounds, followed by violaxanthin and zeaxanthin esters. In citrus, carotenoids were acylated mainly with capric, lauric, myristic, myristoleic, palmitic, palmitoleic, and oleic acids. In mango, 5 free carotenoids, 2 monoesters, and 19 diesters were identified, from which many violaxanthin and neoxanthin esters were reported for the first time.

Lutein ester profile in wheat and tritordeum can be modulated by temperature: Evidences for regioselectivity and fatty acid preferential of enzymes encoded by genes on chromosomes 7D and 7Hch

The increase of lutein retention through the food chain is desirable for wheat breeding. Lutein esters are more stable than free lutein during post-harvest storage and two loci on chromosomes 7D and 7H^ch are important for esterification. We investigated the effect of temperature during grain filling on carotenoid accumulation and lutein ester profile including fatty acid selectivity (palmitic vs. linoleic) and regioselectivity (esterification at positions 3 vs. 3'). Three different temperature regimes were assayed (controlled, semi-controlled and non-controlled). Lutein esters were more stable than free carotenoids in vivo and the enzymes encoded by chromosomes 7H^ch and 7D are complementary. Indeed, they show differential preferences for the fatty acid (palmitic and linoleic, respectively) and regioselectivity (3 and 3', respectively). Besides, H. chilense has additional genes for esterification. Finally, the increase of temperature favoured the accumulation of lutein esters with linoleic acid and the synthesis of regioisomers at position 3'.

Two-step cleanup procedure for the identification of carotenoid esters by liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry

Carotenoids are naturally found in both free form and esterified with fatty acids in most fruits; however, up to now the great majority of studies only evaluated their composition after saponification. This fact is easily explained by the difficult to analyze carotenoid esters. Preliminary studies showed that cleanup procedures in the extract are necessary for further analysis by LC-MS/MS since triacylglycerols (TAGs) impair the MS detection. Considering these facts, we developed a new cleanup procedure to remove TAGs and other lipids from carotenoid fruit extracts. This procedure is based on physical removal of solid lipids at low temperature followed by open column chromatography on MgO and diatomaceous earth. Before cleanup, four carotenoid diesters and two free xanthophylls were identified in murici (Byrsonyma crassifolia), corresponding to about 65% of the total chromatogram area. After carrying out the two-step cleanup procedure, 35 carotenoids were identified, being 14 monoesters, six free carotenoids and 15 carotenoid diesters. We can conclude that this two-step procedure was successfully applied to murici, an Amazonian fruit, which contains high amounts of lipids.