Carotenoid content of wild edible young shoots traditionally consumed in Spain (Asparagus acutifolius L., Humulus lupulus L., Bryonia dioica Jacq. and Tamus communis L.)

An Updated Review of the Genus Humulus: A Valuable Source of Bioactive Compounds for Health and Disease Prevention

The medicinal potential of hop (Humulus lupulus L.) is widely cited in ancient literature and is also allowed in several official pharmacopoeias for the treatment of a variety of ailments, mainly related to anxiety states. This is due to the plethora of phytoconstituents (e.g., bitter acids, polyphenols, prenyl flavonoids) present in the female inflorescences, commonly known as cones or strobili, endowed with anti-inflammatory, antioxidant, antimicrobial, and phytoestrogen activities. Hop has recently attracted the interest of the scientific community due to the presence of xanthohumol, whose strong anti-cancer activity against various types of cancer cells has been well documented, and for the presence of 8-prenyl naringenin, the most potent known phytoestrogen. Studies in the literature have also shown that hop compounds can hinder numerous signalling pathways, including ERK1/2 phosphorylation, regulation of AP-1 activity, PI3K-Akt, and nuclear factor NF-κB, which are the main targets of the antiproliferative action of bitter acids and prenylflavonoids. In light of these considerations, the aim of this review was to provide an up-to-date overview of the main biologically active compounds found in hops, as well as their in vitro and in vivo applications for human health and disease prevention. To this end, a quantitative literature analysis approach was used, using VOSviewer software to extract and process Scopus bibliometric data. In addition, data on the pharmacokinetics of bioactive hop compounds and clinical studies in the literature were analysed. To make the information more complete, studies on the beneficial properties of the other two species belonging to the genus Humulus, H. japonicus and H. yunnanensis, were also reviewed for the first time.

Chemical Profile and In Vitro Evaluation of the Antibacterial Activity of Dioscorea communis Berry Juice

Within the large family of Dioscoreaceae, Dioscorea communis (L.) Caddick & Wilkin (syn. Tamus communis L.) is considered among the four most widespread representatives in Europe, and it is commonly known under the name black bryony or bryonia. To date, reports have revealed several chemical components from the leaves and tubers of this plant. Nevertheless, an extensive phytochemical investigation has not been performed on its berry juice. In the present study, metabolite profiling procedures, using LC-MS, GC-MS, and NMR approaches, were applied to investigate the chemical profile of the D. communis berries. This work reveals the presence of several metabolites belonging to different phytochemical groups, such as fatty acid esters, alkylamides, phenolic derivatives, and organic acids, with lactic acid being predominant. In parallel, based on orally transmitted traditional uses, the initial extract and selected fractions were tested in vitro for their antibacterial effects and exhibited good activity against two bacterial strains related to skin infections: methicillin-resistant Staphylococcus aureus and Cutibacterium acnes. The MIC and MBC values of the extract were determined at 1.56% w/v against both bacteria. The results of this study provide important information on the chemical characterization of the D. communis berry juice, unveiling the presence of 71 metabolites, which might contribute to and further explain its specific antibacterial activity and its occasional toxicity.

Biochemical and Immunological implications of Lutein and Zeaxanthin

Throughout history, nature has been acknowledged for being a primordial source of various bioactive molecules in which human macular carotenoids are gaining significant attention. Among 750 natural carotenoids, lutein, zeaxanthin and their oxidative metabolites are selectively accumulated in the macular region of living beings. Due to their vast applications in food, feed, pharmaceutical and nutraceuticals industries, the global market of lutein and zeaxanthin is continuously expanding but chemical synthesis, extraction and purification of these compounds from their natural repertoire e.g., plants, is somewhat costly and technically challenging. In this regard microbial as well as microalgal carotenoids are considered as an attractive alternative to aforementioned challenges. Through the techniques of genetic engineering and gene-editing tools like CRISPR/Cas9, the overproduction of lutein and zeaxanthin in microorganisms can be achieved but the commercial scale applications of such procedures needs to be done. Moreover, these carotenoids are highly unstable and susceptible to thermal and oxidative degradation. Therefore, esterification of these xanthophylls and microencapsulation with appropriate wall materials can increase their shelf-life and enhance their application in food industry. With their potent antioxidant activities, these carotenoids are emerging as molecules of vital importance in chronic degenerative, malignancies and antiviral diseases. Therefore, more research needs to be done to further expand the applications of lutein and zeaxanthin.

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.

Packaging Solutions to Extend the Shelf Life of Green Asparagus (Asparagus officinalis L.) 'Vegalim'

The aim of the study was to assess, through a comparative shelf-life test, the suitability of two packaging materials, namely macro-perforated polypropylene (PP MA) and micro-perforated coextruded polypropylene (PP C), for the quality preservation of green asparagus (Asparagus officinalis L. 'Vegalim'). Quality of spears was evaluated during 30 days at refrigerated storage by monitoring chemical, physical, and enzymatic parameters as well as sensory descriptors. PP C kept headspace composition close to suggested values for fresh green asparagus. Total color difference increased during the storage and it was highly correlated with chlorophyll-a and carotenoids, however, sensory color perception did not change significantly until 22 days of storage. PP C maintained ascorbic acid concentrations close to the initial levels, limited total phenolic compound loss to 24% (45% in PP MA), determined an increase of 72% in fiber content and small changes in lignin value; enzymatic changes were significantly inhibited. Significant sensorial differences were detected after 22 days of storage, with PP C performing better than PP MA. PP C film was confirmed as the best choice, limiting weight loss and maintaining a fresh-like appearance during 30 days of storage, thus allowing an extension in postharvest life.

Nutritional and Phytochemical Composition of Mediterranean Wild Vegetables after Culinary Treatment

Studies are scarce on the nutritional and phytochemical composition of wild edible Mediterranean plants after culinary processing. This work provides the nutritional composition after culinary treatment (including dietary fiber and mineral composition) and bioactive compounds (folates, vitamin C and organic acids) of wild Rumex pulcher L., Silene vulgaris (Moench) Garcke. leaves, and wild Asparagus acutifolius L., Bryonia dioica Jacq., Humulus lupulus L., Tamus communis L. young shoots. Shoots better preserved their nutrients than leaves, due to their different tissue structure. Fresh and cooked wild greens present high dietary fiber values, and remained at remarkable levels after boiling. Na, K, Mg and Zn were lost in about 50% due to culinary processing, while Ca, Cu, Fe and Mn were more stable. Boiled leaves of S. vulgaris remained as a good Mn source. A portion of 100 g of most of the cooked analyzed species could cover a relevant percentage of the daily requirement of folates (R. pulcher and A. acutifolius providing more than 80%) and vitamin C (T. communis and A. acutifolius providing more than 35%).

Effects of microwave blanching conditions on the quality of green asparagus (Asparagus officinalis L.) butt segment

Blanching is a pretreatment method that is often applied in fruit and vegetable processing to inhibit enzyme activity and reduce loss of food quality. It was recently discovered that well-controlled microwave volumetric heating could improve the blanching efficiency and retain nutritional and sensorial values of product. This study was conducted to investigate effects of microwave blanching conditions on the quality of green asparagus (Asparagus officinalis L.) butt segments, a rich source of fiber and antioxidants but are often discarded during processing. The experiments were designed by one-factor-at-a-time method with two varying factors including blanching time (2, 4, 6, and 8 min) and microwave power output (150, 300, 450, and 600 W). Quality of product was evaluated by sensory, retention of phenolics, and free-radical scavenging activity retention. The results showed that longer blanching time or higher microwave power was associated with reduced quality of green asparagus butt segment. Besides, the appropriate parameters for microwave blanching of the green asparagus butt segment was found at 300 W for 4 min.

Antiproliferative and pro-apoptotic activities of wild asparagus (Asparagus acutifolius L.), black bryony (Tamus communis L.) and butcher's broom (Ruscus aculeatus L.) aqueous extracts against T24 and A549 cancer cell lines

The aim of this study was to determine the phenolic profile, antiproliferative, and pro-apoptotic activities of Asparagus acutifolius, Tamus communis, and Ruscus aculeatus aqueous extracts against human bladder (T24) and lung cancer (A549) cell lines. Antiproliferative activity of the extracts at the concentration range from 0.5 to 4 mg/ml was measured by MTT test, after the incubation period of 4, 24, 48, or 72 hr. Pro-apoptotic activity of selected plant extracts against T24 and A549 cells was analyzed by flow cytometry at the concentrations of 0.5, 1, and 2 mg/ml. The highest antiproliferative activity against both cancer cell lines was detected by T. communis aqueous extract. The highest pro-apoptotic effect was achieved by A. acutifolius aqueous extract and its effect was similar against A549 and T24 cells. PRACTICAL APPLICATIONS: Wild edible plants, such as wild asparagus, black bryony, and butcher's broom represent important aspect of the Mediterranean diet. They are rich source of various natural bioactive compounds which express different biological activities (antioxidative, antiproliferative, antibacterial, anti-inflammatory…). The current trend for natural and healthy diet, such as the Mediterranean diet, is in relation to the rapidly growing problem of chronic diseases in a modern society. Wild edible plants have a high direct-use value using them in dishes containing mixed vegetables, in soup preparation, as natural additives in fermented natural products containing cheese or fish, in water infusions (natural drinks).

Mediterranean Wild Edible Plants: Weeds or "New Functional Crops"?

The Mediterranean basin is a biodiversity hotspot of wild edible species, and their therapeutic and culinary uses have long been documented. Owing to the growing demand for wild edible species, there are increasing concerns about the safety, standardization, quality, and availability of products derived from these species collected in the wild. An efficient cultivation method for the species having promising nutraceutical values is highly desirable. In this backdrop, a hydroponic system could be considered as a reproducible and efficient agronomic practice to maximize yield, and also to selectively stimulate the biosynthesis of targeted metabolites. The aim of this report is to review the phytochemical and toxic compounds of some potentially interesting Mediterranean wild edible species. Herein, after a deep analysis of the literature, information on the main bioactive compounds, and some possibly toxic molecules, from fifteen wild edible species have been compiled. The traditional recipes prepared with these species are also listed. In addition, preliminary data about the performance of some selected species are also reported. In particular, germination tests performed on six selected species revealed that there are differences among the species, but not with crop species. “Domestication” of wild species seems a promising approach for exploiting these “new functional foods”.

Comprehensive Database of Carotenoid Contents in Ibero-American Foods. A Valuable Tool in the Context of Functional Foods and the Establishment of Recommended Intakes of Bioactives

Foods that are commonly consumed in the diet are considered to provide more than 40 different carotenoids. However, the content in carotenoids varies considerably in both qualitative and quantitative terms as a consequence of different genotypes, climatic conditions of the production area, and agronomic factors, among others. In this paper, analytical data, obtained by HPLC or UHPLC, of carotenoids in fruits and vegetables produced in Ibero-America have been compiled from peer-reviewed journals, organized in food categories, and documented in relation to the sampling and analytical quality system used. In addition to common products of the diet of the Ibero-American countries, other wild or little used fruit and vegetables have been included with the aim of contributing to promote and to value species and local varieties. The importance of the commodities containing carotenoids in food, health, agriculture, and biodiversity, and the need of their preservation, was evidenced in this work namely by the large differences in carotenoid content related to the locals of production and varieties, and the high levels of carotenoids in native fruits and vegetables. The contribution of these compounds to meet the needs of vitamin A as well as the necessity of establishing recommendation for the daily intakes of theses bioactive compounds were also discussed.

Wild food plants used in traditional vegetable mixtures in Italy

ETHNOPHARMACOLOGICAL RELEVANCE

Mixtures of wild food plants, part of the Mediterranean diet, have potential benefits for their content in bioactive compounds, minerals and fibers. In Italy, wild plants are still consumed in various ways, for their taste, effects on health and nutritional value. In this paper, we provide a list of wild plants used in vegetable mixtures, indicating their phytochemical and nutritional profile, highlighting those not yet studied.

AIM OF THE STUDY

We provide a first complete review of traditional uses of wild food plants used as vegetables and their preparations (e.g., salads, soups, rustic pies). We also highlight their phytochemical constituents.

MATERIALS AND METHODS

We carried out an extensive literature review of ethnobotanical publications from 1894 to date for finding plants used in traditional vegetable mixtures. We also performed an online search for scientific papers providing the phytochemical profile of plants that were cited at least twice in recipes found in the literature.

RESULTS

We list a total of 276 wild taxa used in traditional vegetable mixtures, belonging to 40 families. Among these, the most represented are Asteraceae (88), Brassicaceae (33), Apiaceae (21), Amaranthaceae (12). Many plants are cited in many recipes across several Italian regions. Among the most cited plant we note: Reichardia picroides (L.) Roth, Sanguisorba minor Scop., Taraxacum campylodes G. E. Haglund, Urtica dioica L. Tuscany is the region with the highest number of food recipes that incorporate wild plants used as vegetables. We also list the phytochemical constituents and some pharmacological activities of the plants cited at least twice. Finally, we discuss topics such as the taste of plants used in the recipes.

CONCLUSIONS

Nineteen edible wild plants, such as Asparagus albus L., Campanula trachelium L., Hypochaeris laevigata (L.) Benth. & Hook f., Phyteuma spicatum L., Scolymus grandiflorus Desf., are not yet studied as regards their phytochemical and nutritional profile. Some plants should be avoided due to the presence of toxic compounds such as Adenostyles alliariae (Gouan) A. Kern or Ranunculus repens L.