Magnesium and manganese induced changes on chemical, nutritional, antioxidant and antimicrobial properties of the pansy and Viola edible flowers.

Pansy and viola edible flowers were grown hydroponically with different levels of Mg and Mn. The nutritional composition was determined using standard methods. Free sugars, fatty acids, organic acids, tocopherols, and phenolic compounds were analyzed using various HPLC and GC devises. The extract's antimicrobial, antioxidant, cytotoxicity, and anti-inflammatory activity were assessed. The results indicated that Mg enrichment negatively affected plant growth and mineral accumulation but improved photosynthetic performance. The edible flowers contained significant amounts of protein, low levels of fat, and varying sugar contents, such as glucose and fructose. Various fatty acids and phenolic compounds were identified, with different concentrations depending on the treatment. The flowers exhibited antioxidant potential, antimicrobial activity, cytotoxic effects, and anti-inflammatory properties. The correlations between the investigated parameters not only expand knowledge on Mg and Mn interaction but also catalyze significant advancements in sustainable agriculture and food health, fostering a healthier and more conscious future.

Betacyanins obtained from alternative novel sources as natural food colorant additives: incorporated in savory and sweet food products.

The aim of this study was to assess the performance and stability of betacyanin compounds present in enriched extracts of red-fleshed pitaya peels (Hylocereus costaricensis) and the flowers of Amaranthus caudatus; they were evaluated as natural food colorants in tagliatelle pasta and meringue cookies. The recovered natural extracts showed promising stability, maintaining a deep pink color over a storage time of 14 days, without deeply changing the chemical composition. A number of factors were assessed, including the microbial load, texture, color, nutritional value, and contents of organic acids, fatty acids, and even free sugars of the products. Some significant interactions between the type of colorant and storage time contributed to the changes in some analyzed parameters, as can be observed from the results for organic and fatty acids in the tagliatelle pasta and meringue cookies. Another significant achievement was the reduction in the microbial load during the storage time, which strengthens the antibacterial power of these natural extracts.

Effects of the extraction techniques on the chemical composition and bioactive properties of lemon balm (Melissa officinalis L.) plants grown under different cropping and irrigation regimes.

The present study aims to determine the combined effect of cropping system and irrigation regime on the chemical composition and bioactive properties of lemon balm aerial parts. For this purpose, lemon balm plants were grown under two farming systems (conventional farming vs organic farming) and two irrigation levels (full irrigation vs deficit irrigation) and harvested twice throughout the growing period. The collected aerial parts were subjected to three different methods of extractions, namely infusion, maceration and ultrasound-assisted extraction and the obtained extracts were evaluated in terms of chemical profile and bioactivities. Five organic acids with varied composition among the tested treatments were identified in all the tested samples for both harvests, namely, citric, malic, oxalic, shikimic and quinic acid. Regarding phenolic compounds composition, the most abundant ones were rosmarinic acid, lithospermic acid A isomer I and hydroxylsalvianolic E, especially for the maceration and infusion extraction methods. Full irrigation resulted in lower EC50 values than deficit irrigation only in the treatments of the second harvest, while variable cytotoxic and anti-inflammatory effects were recorded in both harvests. Finally, in most cases the lemon balm extracts has similar or better activity than the positive controls, while the antifungal activity of lemon balm extracts was stronger than the antibacterial effects. In conclusion, the results of the present study showed that the implemented agronomic practices, as well as the extraction protocol may significantly affect the chemical profile and bioactivities of lemon balm extracts, suggesting that both the farming system and the irrigation schedule may improve the quality of the extracts depending on the implemented extraction protocol.

Valorization of Pumpkin Peel as a Source of Bioactive Compounds: Optimization of Heat- and Ultrasound-Assisted Extraction.

The peels from three pumpkin genotypes cultivated in Greece were assessed for their phenolic content and bioactive properties to obtain extracts with a high preservative capacity. The optimization of the extraction was performed through response surface methodology (RSM) based on a Box-Behnken experimental design after applying two extraction techniques: heat-assisted (HAE) and ultrasound-assisted (UAE) extraction. The implemented independent variables were time, solvent concentration, and temperature/power (for HAE/UAE), while as dependent variables the dry residue (DR), reducing power (RP), and total phenolic content (TP) were considered. In general, HAE was the most effective technique for 'TL' (75 min; 30 °C; 24% ethanol) and 'Voutirato' (15 min; 30 °C; 10% ethanol), while UAE was more effective for 'Leuka Melitis' (5 min; 400 W; 0% ethanol). The extracts obtained in the global optimum conditions for each genotype peel were then assessed for their phenolic profile, by HPLC-DAD-ESI/MS, and bioactive potential. Seven phenolic compounds were detected, including four flavonoids, two phenolic acids, and one flavan-3-ol. The extracts presented high antioxidant, antibacterial, and antifungal potential, with no cytotoxicity for non-tumor cells. The optimized conditions for the extraction of preservative compounds from bioresidues were defined, allowing the acquisition of antioxidant and antimicrobial extracts and proving their potential for food application.

Plant Extracts and SARS-CoV-2: Research and Applications.

The recent pandemic of COVID-19 caused by the SARS-CoV-2 virus has brought upon the world an unprecedented challenge. During its acute dissemination, a rush for vaccines started, making the scientific community come together and contribute to the development of efficient therapeutic agents and vaccines. Natural products have been used as sources of individual molecules and extracts capable of inhibiting/neutralizing several microorganisms, including viruses. Natural extracts have shown effective results against the coronavirus family, when first tested in the outbreak of SARS-CoV-1, back in 2002. In this review, the relationship between natural extracts and SARS-CoV is discussed, while also providing insight into misinformation regarding the use of plants as possible therapeutic agents. Studies with plant extracts on coronaviruses are presented, as well as the main inhibition assays and trends for the future regarding the yet unknown long-lasting effects post-infection with SARS-CoV-2.

Pineapple by-products as a source of bioactive compounds with potential for industrial food application.

Pineapple is a tropical fruit consumed fresh or processed into various food products. However, the peel and crown of this fruit are not industrially exploited, thus generating tons of by-products that represent an economic and environmental concern. In order to promote the upcycling of these by-products, this work aimed to characterize the phenolic profile of its hydroethanolic extracts obtained from pineapple peel and crown leaves and to evaluate their in vitro bioactivity. The HPLC-DAD-ESI/MS analysis allowed the identification of 25 phenolic compounds, including phenolic acids and flavonoids. The antioxidant, cytotoxic, and antimicrobial activity assays highlighted the peel extract as the most promising and, therefore, it was incorporated into a traditional Portuguese pastry cake as a functional ingredient. The nutritional parameters of the developed food were not affected by the incorporation of the extract, but it promoted the antioxidant activity during its shelf-life. Overall, pineapple peel and crown appeared as promising by-products to be exploited by the food industry, which can be achieved through a circular economy approach.

Arbutus unedo leaf extracts as potential dairy preservatives: case study on quark cheese.

The plant kingdom is an endless source of molecules that can be applied in almost all realms of society. The food industry has profited from the use of plants and their derived materials for many decades. Recently, the food industry has been looking into plants to find different ways of either preserving, coloring or sweetening foods. In this work, leaf extracts of Arbutus unedo L. obtained by dynamic maceration and ultrasound assisted extraction with prior optimization of their extraction conditions through the response-surface methodology, were incorporated in quark cheese as natural preservatives and analyzed over 8 days of shelf-life. Both extracts showed antioxidant activity with no toxicity towards primary cell lines at the maximum tested concentration, as well as antibacterial activity, especially against Gram-positive strains. After their incorporation in quark cheese, no significant changes were observed in the nutritional profile and physical traits of the quark cheeses, while the microbial load was highly reduced in the cheese, especially using the extracts obtained from dynamic maceration. Thus, leaf extracts of A. unedo can be promising candidates for use in the food industry as natural preservatives.

Study on the Potential Application of Impatiens balsamina L. Flowers Extract as a Natural Colouring Ingredient in a Pastry Product.

Flowers of the genus Impatiens are classified as edible; however, their inclusion in the human diet is not yet a common practice. Its attractive colours have stirred great interest by the food industry. In this sense, rose (BP) and orange (BO) I. balsamina flowers were nutritionally studied, followed by an in-depth chemical study profile. The non-anthocyanin and anthocyanin profiles of extracts of both flower varieties were also determined by high-performance liquid chromatography coupled to a diode array and mass spectrometry detector (HPLC-DAD-ESI/MS). The results demonstrated that both varieties presented significant amounts of phenolic compounds, having identified nine non-anthocyanin compounds and 14 anthocyanin compounds. BP extract stood out in its bioactive properties (antioxidant and antimicrobial potential) and was selected for incorporation in "bombocas" filling. Its performance as a colouring ingredient was compared with the control formulations (white filling) and with E163 (anthocyanins) colorant. The incorporation of the natural ingredient did not cause changes in the chemical and nutritional composition of the product; and although the colour conferred was lighter than presented by the formulation with E163 (suggesting a more natural aspect), the higher antioxidant activity could meet the expectations of the current high-demand consumer.

Promising Preserving Agents from Sage and Basil: A Case Study with Yogurts.

In the present work, sage (Salvia officinalis L.) and basil (Ocimum basilicum L.) were exploited for their preservative purposes, as viable alternatives to artificial ones. The ultrasound-assisted extraction (UAE) of bioactive compounds was pre-optimized using factorial screening analysis, prior to applying response surface methodology (RSM). The obtained extracts were characterized in terms of phenolic compounds by high-performance liquid chromatography coupled to photodiode array detector and mass spectrometer HPLC-DAD-ESI/MS and bioactivities, namely the antioxidant, antimicrobial and cytotoxic potential. In addition, the most promising extracts were incorporated into yogurts, that were further screened for nutritional and physico-chemical properties and microbial load, over a shelf life of 14 days. According to the obtained results, the solvent percentage is the most relevant factor for obtaining rosmarinic acid-rich extract, followed by the extraction time and ultrasonic power. For the antioxidant and antimicrobial activity, sage showed the best result for both analysis and none of the two plant extracts were hepatotoxic. Finally, both extracts did not show changes in the physicochemical and nutritional characteristics of the yogurts and did not interfere with the growth of lactic acid bacteria, an important microorganism during yogurt fermentation. These results highlight the high potential of sage and basil as natural preservatives.

Influence of Calcium Silicate on the Chemical Properties of Pleurotus ostreatus var. florida (Jacq.) P. Kumm.

Supplementation of mushroom substrates has been linked to a higher resistance against insect pests, although few studies show the impact of this supplementation on the different agronomical parameters of mushrooms or even their chemical composition. In this work, the variation in the biological and chemical composition of oyster mushroom (Pleurotus ostreatus var. florida (Jacq.) P. Kumm) was analysed after varying the substrate supplementation of calcium silicate (0, 0.5, 1, 2, and 4% (w/w%)) during two harvest flushes. Overall, supplementation did not change the weight, the number of fruiting bodies, biological efficiency, yield ratio, and productivity rate of the mushrooms, although the harvest flushes did show significant differences. Furthermore, slight changes were found in the chemical composition with an increase in vitamin D2 and tocopherols for the mushrooms with higher amounts of calcium silicate. Overall, the substrate supplementation did not seem to induce expressive changes or decrease production yields, and can, therefore, continue to be researched as a potential application to fight agronomical pests.

Ficus carica L. and Prunus spinosa L. extracts as new anthocyanin-based food colorants: A thorough study in confectionery products.

The present work describes the evaluation of fig peels and blackthorn fruit extracts as natural purple colorants in doughnuts (icing) and in a typical Brazilian pastry called "beijinho". The extracts were screened for their antioxidant activity as well as their antibacterial capacity. Nutritionally, the employed extracts did not induce significant changes, contrarily to the observed for the rheological features, mainly the darker purple tone observed when blackthorn extract was used in the icing solution. After 24 h, both prepared formulations showed a decrease in color intensity, with no significant differences between fig and blackthorn extracts. In turn, the firmness and consistency of the doughnuts benefited from using natural colorants in the icing solution, while "beijinhos" became softer and chewier, which are valued attributes. A significant increase in the antioxidant and antimicrobial activities was also observed for both natural extracts. Accordingly, the evaluated extracts are promising candidates as natural food colorants.

Betacyanins from Gomphrena globosa L. flowers: Incorporation in cookies as natural colouring agents.

A betacyanin rich extract was obtained from the flowers of Gomphrena globosa L. by ultrasound-assisted extraction and dried either by lyophilization or spray-drying, was tested as a natural colourant in cookies and compared to a commercial colourant. The extracts were characterized in terms of betacyanin content and antioxidant potential. The effects of the colourants incorporation in the cookies were assessed through proximate composition, soluble sugars, fatty acids, color, texture and microbial load, over a shelf life of 30 days. Considering all the assays and analyzing the results through a 2-way analysis of variance, the cookies incorporated with spray-dried colourant showed the most intense pink coloration while cookies incorporated with lyophilized extract lost less color intensity over time. Thus, betacyanin extracts have potential as pink natural alternatives to synthetic colourants in the food industry.

Effect of Natural Preservatives on the Nutritional Profile, Chemical Composition, Bioactivity and Stability of a Nutraceutical Preparation of Aloe arborescens.

Citric acid, quercetin, dried chestnut flowers and an aqueous extract of chestnut flowers were screened as candidates for preserving a drinkable nutraceutical preparation for 45 days. The assays encompassed antioxidant and antimicrobial activities, nutritional and chemical profiles, and individual profiles of fatty acids and mineral composition, all of which in comparison with a sodium benzoate, a synthetic preservative. The centesimal composition of the nutraceutical formulation was mainly composed of carbohydrates, followed by proteins and fat, with moisture levels between 66% and 71%. Palmitic and stearic acid were the most abundant fatty acids, while calcium and magnesium where the minerals in higher amount. Anthroquinones, followed by flavonoids where the most abundant groups of phenolic compounds. In terms of the preserving effects of the extracts, the chestnut flowers and the citric acid were the most effective natural preservatives, which better preserved phenolic compounds. Furthermore, these two ingredients also revealed the strongest capacity to control the microbial growth in the formulation by inhibiting the growth of food contaminants. In general, these ingredients revealed higher preservation capacity than sodium benzoate, while not altering the nutritional and fatty acid profile. The chestnut flowers and citric acid could be used to preserve foods, food supplements, and nutraceutical formulations after passing the required regulatory procedures for food additives.

Extracts from Vaccinium myrtillus L. fruits as a source of natural colorants: chemical characterization and incorporation in yogurts.

The food industry is always seeking innovative approaches to maintain consumers' interest and increase their awareness towards the healthiness of diets. Therefore, much interest has been given to natural food additives, namely colourants. In this work, a bilberry extract was primarily characterized in terms of anthocyanin compounds by UPLC-DAD-ESI/MSn, and its colouring capacity was further compared with a synthetic anthocyanin colourant (E163) in different yogurt formulations. The prepared samples were evaluated in different periods (0 and 7 days) for nutritional profile, individual fatty acids, soluble sugars and external colour to determine the effects of each additive. Overall, the major anthocyanin compounds in bilberry were malvidin glycoside and delphinidin glycoside derivatives. With regard to the prepared yogurts, all samples maintained the nutritional profile, individual fatty acids and soluble sugars, independent of storage time. Nonetheless, bilberry extracts showed lower colouring capacity when compared to that of E163, despite the higher stability of bilberry extract throughout the storage time, when compared to that of E163. Furthermore, another advantage of this natural extract is that it has potential bioactive properties that can be conferred to foods, due to their high content of bioactive compounds, such as anthocyanins.

Development of dairy beverages functionalized with pure ergosterol and mycosterol extracts: an alternative to phytosterol-based beverages.

In the present work, Agaricus bisporus extracts obtained by ultrasound-assisted extraction (UAE), and ergosterol, were incorporated into dairy beverages at concentrations mimicking commercial phytosterol-added yogurts, to work as alternatives. The samples were analysed for nutritional and bioactive properties, and compared with controls (yogurts with no additives or phytosterols), at two storage times (right after incorporation (ST = 0) and after seven days at 4 °C (ST = 7)). The ones incorporated with the extract (YAb) and with ergosterol at the same concentration as in the extract (YPEAb) showed similar antioxidant properties as the ones with phytosterols (YPhy), but a higher cytotoxicity against tumor cells. YPEPhy, the sample with ergosterol at the same amount as phytosterols in YPhy, was the strongest in both bioactivities. For YAb, YPEAb and YPEPhy the antioxidant capacity increased from ST = 0 to ST = 7, meaning that the extract and ergosterol protected the yogurt from oxidation, improving the shelf life. Nutritional parameters were identical for all samples.

Fortification of yogurts with different antioxidant preservatives: A comparative study between natural and synthetic additives.

Consumers demand more and more so-called "natural" products and, therefore, the aim of this work was to compare the effects of natural versus synthetic antioxidant preservatives in yogurts. Matricaria recutita L. (chamomile) and Foeniculum vulgare Mill. (fennel) decoctions were tested as natural additives, while potassium sorbate (E202) was used as a synthetic additive. The fortification of yogurts with natural and synthetic antioxidants did not cause significant changes in the yoghurt pH and nutritional value, in comparison with control samples (yogurt without any additive). However, the fortified yogurts showed higher antioxidant activity, mainly the yogurts with natural additives (and among these, the ones with chamomile decoction). Overall, it can be concluded that plant decoctions can be used to develop novel yogurts, by replacing synthetic preservatives and improving the antioxidant properties of the final product, without changing the nutritional profile.

Chestnut and lemon balm based ingredients as natural preserving agents of the nutritional profile in matured "Serra da Estrela" cheese.

Chestnut flowers, lemon balm plants and their decoctions were incorporated into "Serra da Estrela" cheese, to assess their potential to preserve its nutritional properties and provide new foodstuffs. The analyses were carried out after the normal ripening period of 1month and after 6months of storage. The most abundant nutrients were proteins and fats. The most abundant minerals were Ca and Na, while C16:0 and C18:1 were the main fatty acids. Saturated fatty acids were the most abundant, followed by the monounsaturated. Moisture seemed to be lower in the samples with the plants incorporated. The dried plants, when incorporated, seemed to be more efficient as preservers then the decoctions, although these better preserved the proteins. These plants can be regarded as promising natural preservers in foodstuffs cheese, given the preservation of key parameters and the slight impact on the nutritional value.

Melissa officinalis L. decoctions as functional beverages: a bioactive approach and chemical characterization.

Lemon balm (Melissa officinalis L.) is a member of the Lamiaceae family with a long story of human consumption. It has been consumed for decades, directly in food and as a decoction or an infusion for its medicinal purposes. In this manuscript, a detailed chemical characterization of the decoction of this plant is described, encompassing antimicrobial, antioxidant and antitumor activities. Rosmarinic acid and lithospermic acid A were the most abundant phenolic compounds. Quinic acid, fructose, glucose and γ-tocopherol were the most abundant within their groups of molecules. M. officinalis decoctions were active against a wide range of microorganisms, Pseudomonas aeruginosa and Salmonella typhimurium, and Penicillium funiculosum being the most sensitive bacteria and fungi, respectively. The growth inhibition of different human tumor cell lines (mainly MCF-7 and HepG2) was also observed, as also high free radical scavenging activity and reducing power. This manuscript highlights some beneficial effects of these functional beverages.

Chestnut flowers as functionalizing agents to enhance the antioxidant properties of highly appreciated traditional pastry.

Some studies have proven the antioxidant and antimicrobial potency of chestnut flowers both in the raw matrix and after extraction, and the consumption of their decoctions has been related to beneficial effects towards health. In recent years, due to controversy and ambiguous legislation of chemical conservatives, plant extracts have been successfully used as functionalizing agents in different matrixes by displaying their various beneficial effects towards the foodstuff and/or the consumer. In this paper, decoctions of chestnut flowers as well as the dried flower were added to Portuguese traditional cakes that were then stored for 15 and 30 days, after which they were analysed for their antioxidant potential. The results were analysed by means of a 2 way ANOVA and a linear discriminant analysis, concluding that storage time had a slightly higher influence on alteration of the antioxidant activity. DPPH and TBARS were the most improved parameters, regardless of the concentration added.

Castanea sativa Mill. Flowers amongst the most powerful antioxidant matrices: a phytochemical approach in decoctions and infusions.

Infusions and decoction of chestnut tree flowers have been used for different medical purposes, but their phytochemical profile and antioxidant activity are still mostly unknown. Herein, decoctions and infusions of flowers from the two most appreciated chestnut cultivars (longal and judia) in Trás-os-Montes, Portugal, were prepared and characterized with regard to their content in free sugars, organic acids, and phenolic compounds, such as flavonoids and hydrolyzable tannins, and their antioxidant activity. Overall, the decoction of the cultivar judia was the sample with both the highest quantity of flavonoids and antioxidant activity. The phenolic compound with the highest abundance in all samples was trigalloyl-HHDP-glucoside, followed by pentagalloyl glucoside. The sample with the highest quantity of total phenolic compounds was judia infusion, closely followed by longal decoction, which also gave the highest quantities of ellagitannins. Regarding sugars and organic acids, the profiles were more similar. These results corroborate ancestral claims of the health benefits of infusions and decoctions of chestnut flowers.