The main goal of this study was to chemically characterize an aqueous S. nigra flower extract and validate it as a bioactive agent. The elderflower aqueous extraction was performed at different temperatures (50, 70 and 90 °C). The extract obtained at 90 °C exhibited the highest phenolic content and antiradical activity. Therefore, this extract was analyzed by GC-MS and HPLC-MS, which allowed the identification of 46 compounds, being quercetin and chlorogenic acid derivatives representative of 86% of the total of phenolic compounds identified in hydrophilic fraction of the aqueous extract. Naringenin (27.2%) was the major compound present in the lipophilic fraction. The antiproliferative effects of the S. nigra extract were evaluated using the colon cancer cell lines RKO, HCT-116, Caco-2 and the extract’s antigenotoxic potential was evaluated by the Comet assay in RKO cells. The RKO cells were the most susceptible to S. nigra flower extract (IC₅₀ = 1250 µg mL⁻¹). Moreover, the extract showed antimicrobial activity against Gram-positive bacteria, particularly Staphylococcus aureus and S. epidermidis. These results show that S. nigra-based extracts can be an important dietary source of bioactive phenolic compounds that contribute to health-span improving life quality, demonstrating their potential as nutraceutical, functional foods and/or cosmetic components for therapeutic purposes.

Horticultural crops are vulnerable to several disorders, which affect their physiological and organoleptic quality. For about forty years, the control of physiological disorders (such as superficial scald) in horticultural crops, particularly in fruit, was achieved through the application of the antioxidant diphenylamine (DPA), usually combined with controlled atmosphere (CA) conditions. However, identification of DPA residues and metabolites in treated fruits, associated with their toxicity, banned the use of this antioxidant in Europe. This triggered the urgent need for novel and, ideally, natural and sustainable alternatives, combined with adequate storage conditions to protect cultivars from harmful agents. This review systematizes the state-of-the-art DPA application on several fresh cultivars, such as apples, pears, and vegetables (potatoes, spinach, etc.), as well as the possible mechanisms of the action and effects of DPA, emphasizing its antioxidant properties. Alternative methods to DPA are also discussed, as well as respective effects and limitations. Recent research on scald development molecular pathways are highlighted to open new non-chemical strategies opportunities. This appraisal shows that most of the current solutions have not lead to satisfactory commercial results; thus, further research aimed to understand the mechanisms underlying postharvest disorders and to design sustainable and safe solutions to improve horticultural products storage is needed.

Substantial amounts of vine wastes are produced during vineyard management, and the chemical profiling of high-value lipophilic phytochemicals is becoming crucial in order to find a complementary route towards their integrated valorisation. The prospection of bioactive phytochemicals from unripe grape, vine shoot, vine cane, stalk and leaf dichloromethane extracts was carried out by gas chromatography–mass spectrometry (GC–MS), analysing samples from a mixture of four red Vitis vinifera L. varieties (Baga, Aragonez, Água Santa and Shiraz), collected at Bairrada Appellation, as a representative case study of typical multi-variety Portuguese vineyards. Vine wastes showed distinct amounts of lipophilic extract, ranging from 0.68% (vine canes) to 13.35% (vine leaves) at dry weight (dw). Thirty-three components were identified, including fatty acids and alcohols, sterols and triterpenoids accounting for amounts from 118.9 mg/100 g dw to 1512.0 mg/100 g dw. The integrated study revealed that unripe grape, stalk and leaf dichloromethane extracts stood out as possible sources of triterpenic compounds (103.2 to 653.5 mg/100 g dw), with lupeol, ursolic and oleanolic acids prevailing. Leaf extract is also reported as an undervalued source of α-tocopherol, as the major component detected in this matrix (300.5 mg/100 g dw). These exploratory results are a relevant contribution for the exploitation of undervalued vine residues as a source of health-promoting components with the potential to be used as supplements or nutraceutical ingredients.

Elderberry (Sambucus nigra L.) consumption has been growing in the last years, generating a large number of stalks (~10% of the berries bunch) that are still under-valorized. This study focused on the evaluation of elderberry stalks as a source of high-value phytochemicals. In this vein, the essential mineral content and lipophilic composition were analyzed for the first time. In addition, the polar fraction was evaluated regarding its total phenolic content (TPC) and antioxidant activity by both 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2-diphenyl-1-picrylhydrazyl hydrate (DPPH) assays. The lipophilic fraction was mainly composed of triterpenic acids (2902.20 mg kg⁻¹ of dry weight (dw)), fatty acids (711.73 mg kg⁻¹ dw) and sterols (288.56 mg kg⁻¹ dw). Minor amounts of long-chain aliphatic alcohols and other components were also detected. Ursolic acid (2265.83 mg kg⁻¹ dw), hexadecanoic acid (219.85 mg kg⁻¹ dw) and β-sitosterol (202.74 mg kg⁻¹ dw) were the major lipophilic components verified. The results of this study also indicated that elderberry stalks might be used as a natural source of essential minerals, particularly calcium, iron and potassium, which are known to play important roles in various body functions. The analysis of the polar fraction also showed that elderberry stalks present TPC as high as elderberry themselves as well as considerable antioxidant activity (1.04 and 0.37 mmol TE g⁻¹ of extract, against respectively ABTS and DPPH radicals). These results highlight the potential of elderberry stalks as a natural source of high-value phytochemicals that may be explored in several fields.

Diabetes mellitus (DM) is one of the most prevalent lifestyle diseases with an increasing impact on human health. Chronic hyperglycaemia in diabetes leads to various metabolic disorders such as protein glycation, fluid and mineral imbalance, and deterioration of tissues. Currently available pharmacological treatments of DM help control glycaemia and slow down diabetic complications. On the other hand, they can also cause various side effects. Medicinal plants can contribute to controlling hyperglycemia and reducing diabetic complications. One such plant is the elderberry (Sambucus nigra L.) which contains several biologically active phytochemicals and minerals that can support in the therapy of DM. The objective of this study was to evaluate the effect of elderberry fruit extract (lipophilic (LFSn) and phenolic (PhFSn) fractions) supplementation on the calcium and magnesium status in diabetic rats. The experiment was performed on 32 male Wistar rats which were divided into four groups: healthy control, diabetic control, diabetic treated with LFSn (1.5 g/kg b.w./day) and diabetic group treated with PhFSn (5 g/kg b.w./day) for 4 weeks. Hyperglycaemia (diabetes) was induced by feeding rats with a high-fat diet and STZ injections (55 mg/kg b.w). After a four-week test period, animals were sacrificed to collect blood, internal organs and femoral bones for biochemical assays. The Ca and Mg status was evaluated on the basis of the contents of these minerals in the blood serum, liver, kidneys and femoral bones, using the AAS method. The tissue samples were mineralized in 65% nitric acid (MW oven). The results were evaluated statistically using software Statistics ver. 13.0, at p < 0.05. It was found that chronic hyperglycaemia disturbed Ca and Mg status which was evidenced by a significant loss of tissular Mg content and calcification of kidneys in diabetic rats. Treatment with both types of Sambucus nigra fruit extracts normalized the kidney Ca content, while PhFSn extract decreased the liver Mg content in diabetic rats. The results demonstrated an appreciable potential of Sambucus nigra fruit extracts in ameliorating the Ca and Mg imbalance in diabetic rats.

Plant secondary metabolites are synthesized for their protection and regulation purposes. Quite often, due to their properties, these metabolites have relevant organoleptic and biological properties and can play important roles in human health and general well-being. A relevant case study in this context is berries and flowers from Sambucus nigra L., which have been used for generations in folk medicine. Although those effects are mainly linked to phenolic compounds, mono and sesquiterpenic secondary metabolites may also play a key role. Despite their potential, S. nigra mono and sesquiterpenic compounds are yet largely unexplored. Complex and dynamic external and internal plant-related phenomena deeply affect terpenes profile, as metabolism, abiotic and biotic stresses, and understanding these phenomena is the first step for S. nigra berries and flowers’ valuation. This chapter will cover aspects linked to elder plant uses, mono and sesquiterpenic composition, and the influence of preharvest and postharvest effects over these metabolites. This knowledge is crucial for scientists and industries to understand and improve the quality of S. nigra-based products.