Polyphenolic composition, antioxidant and antiproliferative effects of wild and cultivated blackberries(Rubus fruticosus L.)pomace

Exploring the Multifaceted Biological Activities of Anthocyanins Isolated from Two Andean Berries

Natural pigments extracted from plant species are used in foods, cosmetics, and pharmaceuticals. This study evaluates the comprehensive biological activities of anthocyanins isolated from Andean blueberry (Vaccinium floribundum Kunth) and Andean blackberry (Rubus glaucus Benth), focusing on their antimicrobial, antioxidant, antitumoral, anti-inflammatory, and hemolytic properties. Chemical characterization revealed significant anthocyanin content with complex mass spectrometric profiles indicating diverse glycosylation patterns that may influence their bioactivity. The antimicrobial assays showed that the extracts were particularly effective against Gram-positive bacteria, with minimal inhibitory concentrations (MICs) as low as 1 mg/mL for Rubus glaucus, indicating strong potential for therapeutic use. The antioxidant capacity of the berries was substantial, albeit slightly lower than that of ascorbic acid. The extracts also exhibited notable antitumoral activity in various cancer cell lines, showing promise as adjunctive or preventive treatments. The anti-inflammatory effects were confirmed by inhibiting nitric oxide production in macrophage cells, highlighting their potential in managing inflammatory diseases. In terms of hemolytic activity, Rubus glaucus exhibited dose-dependent effects, potentially attributable to anthocyanins and phenolics, while Vaccinium floribundum demonstrated no significant hemolytic activity, underscoring its safety. These findings suggest that anthocyanins from Andean berries possess potent biological activities, which could be leveraged for health benefits in pharmaceutical and nutraceutical applications. Further studies are needed to isolate specific bioactive compounds and investigate their synergistic effects in clinical and real-world contexts.

Optimization and component identification of ultrasound-assisted extraction of functional compounds from waste blackberry (Rubus fruticosus Pollich) seeds

BACKGROUND

Blackberry seeds, as a by-product of processing, have potential bioactive substances and activities. A response surface method was used to determine the optimal conditions of blackberry seed extracts (BSEs) with high 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity by ultrasound-assisted extraction (UAE). The composition and antioxidant capacity of BSEs were further analyzed.

RESULTS

The optimal conditions were material-to-liquid ratio of 0.07 g mL-1, ethanol concentration of 56%, extraction temperature of 39 °C and ultrasonic power of 260 W. Using these conditions, the extraction yield and total polysaccharide, phenolic and anthocyanin contents in BSEs were 0.062 g g-1 and 633.91, 36.21 and 3.07 mg g-1, respectively. The Fourier transform infrared spectra of BSEs exhibited characteristic peaks associated with polysaccharide absorption. The antioxidant capacity, DPPH and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, and ferric reducing antioxidant power of BSEs were 1533.19, 1021.93 and 1093.38 mmol Trolox equivalent g-1, respectively. The delphinidin-3-O-glucoside, paeoniflorin-3-O-glucoside and cyanidin-3-O-arabinoside contents in BSEs were 3.05,12.76 and 1895.90 ± 3.45 μg g-1. Five polyphenols including gallic acid, coumaric acid, ferulic acid, catechin and caffeic acid were identified and quantified in BSEs with its contents at 8850.43, 5053.26, 4984.65, 1846.91 and 192.40 μg g-1.

CONCLUSION

These results provide a method for preparing BSE containing functional components such as polysaccharides, phenols and anthocyanins through UAE, and BSEs have potential application in food industries. © 2024 Society of Chemical Industry.

Untapped potential of non-conventional rubus species: bioactivity, nutrition, and livelihood opportunities

Rubus species holds promise as a valuable source of polyphenols and bioactive compounds, offering significant potential as functional food ingredients with both nutraceutical and pharmaceutical benefits. However, many edible species within this genus remain under-explored and their importance is largely unrecognized. This review aims to provide an overview of the nutritional and bioactive components of both explored and under-explored Rubus species, highlighting their potential health advantages, value addition, and recent advancements. The economic exploitation of Rubus is currently limited to a few cultivated species, while numerous non-conventional and wild edible species are overlooked. Recognizing the economic and nutritional significance of exploited Rubus species, it is imperative to explore the untapped potential of these underutilized plants. By doing so, these species can be preserved from endangerment and contribute to nutritional and livelihood security for communities having access to them. This review emphasizes the importance of understanding the exceptional characteristics of Rubus species as "superfoods" and encourages the promotion and cultivation of these unexplored species. By expanding the cultivation and utilization of under-explored Rubus species, we can unlock their full potential and support sustainable nutritional and economic benefits.

Proteins from Blackberry Seeds: Extraction, Osborne Isolate, Characteristics, Functional Properties, and Bioactivities

Blackberry fruit contains high levels of nutrients and phenolic compounds. Blackberry pomace accounts for 20~30% of its whole fruit during processing and is generally treated as fertilizer. Blackberry pomace has many seeds that contain carbohydrates, polyphenols, flavonoids, pectin, protein, and other bioactive nutrients. However, its functional properties and seed protein compositions have not been reported. We used a single-factor experiment, response surface, and Osborne isolate method to extract protein isolate, albumin, globulin, glutelin, and prolamin from blackberry seeds for the first time and evaluated their characteristics and functional properties. Glutelin and protein isolate showed good water-holding capacity, emulsification, and foaming capacity, while albumin and globulin showed good oil-holding capacity and thermal stability. They were found to have good antioxidant activities that might be good DPPH free radical scavengers, especially prolamin, which has the lowest IC50 value (15.76 μg/mL). Moreover, globulin had the lowest IC50 value of 5.03 μg/mL against Hela cells, 31.82 μg/mL against HepG2 cells, and 77.81 μg/mL against MCF-7 cells and a high selectivity index (SI), which suggested globulin had better anti-cervical, antihepatoma, and anti-breast activity but relatively low cytotoxicity. These seed proteins may have great prospects for the development and application of food and drugs in the future.

Phytochemicals Determination, and Antioxidant, Antimicrobial, Anti-Inflammatory and Anticancer Activities of Blackberry Fruits

A comprehensive characterization of the phytochemicals present in a blackberry fruit extract by HPLC-TOF-MS has been carried out. The main compounds in the extract were ursane-type terpenoids which, along with phenolic compounds, may be responsible for the bioactivity of the extract. In vitro antioxidant capacity was assessed through Folin–Ciocalteu (31.05 ± 4.9 mg GAE/g d.w.), FRAP (637.8 ± 3.2 μmol Fe2+/g d.w.), DPPH (IC50 97.1 ± 2.4 μg d.w./mL) and TEAC (576.6 ± 8.3 μmol TE/g d.w.) assays. Furthermore, the extract exerted remarkable effects on in vitro cellular antioxidant activity in HUVEC cells at a concentration of 5 mg/mL. Antimicrobial activity of the extract was also tested. Most sensible microorganisms were Gram-positive bacteria, such as E. faecalis, B. cereus and Gram-negative E. coli (MBC of 12.5 mg/mL). IC50 values against colon tumoral cells HT-29 (4.9 ± 0.2 mg/mL), T-84 (5.9 ± 0.3 mg/mL) and SW-837 (5.9 ± 0.2 mg/mL) were also obtained. Furthermore, blackberry extract demonstrated anti-inflammatory activity inhibiting the secretion of pro-inflammatory IL-8 cytokines in two cellular models (HT-29 and T-84) in a concentration-dependent manner. These results support that blackberry fruits are an interesting source of bioactive compounds that may be useful in the prevention and treatment of different diseases, mainly related to oxidative stress.

Ultrasound-Assisted Extraction of Blackberry Seed Oil: Optimization and Oil Characterization

Ultrasound-assisted extraction (UAE) was applied to extract oil from blackberry (BB) seeds. The effect of UAE conditions on oil recovery and quality was investigated. Favorable experimental conditions (ultrasound intensity (UI), extraction temperature, and time) were investigated using response surface methodology (RSM). A Box–Behnken design was used to predict optimized conditions for BB seed oil extraction. These conditions were as follows: 13.77 W/cm2 UI, 45 °C extraction temperature, and 15 min extraction time. The experimental value obtained for extraction efficiency under optimal conditions was 87 ± 0.34%, in good agreement with the optimized predicted value. UAE does not affect the oil composition and confers higher antioxidant values in BB seed oil in comparison with Soxhlet extraction.

Effect of Beetroot Powder Incorporation on Functional Properties and Shelf Life of Biscuits

The demand for ready-to-use functional foods is high, which encourages manufacturers to develop new, nutritionally valuable products. As an excellent source of biologically active compounds, beetroot (Beta vulgaris L.) is considered to have highly beneficial effects on health. This research aimed to evaluate the impact of replacing spelt flour (SF) with 15%, 20% and 25% beetroot powder (BP). The physicochemical and functional properties of biscuits baked at different temperatures (150 and 170 °C) were followed at the beginning, and after 3 and 6 months of storage as standard conditions. Moisture content and water activity (aw) gave insight into the biscuits' shelf life. The value of aw from 0.35 to 0.56 indicated appropriate storability. Dietary fiber content in fresh biscuits ranged from 6.1% to 7.6%, protein from 9.2% to 8.9% and sugar from 30.6% to 35.9%. The content of betalain, total polyphenols and flavonoids, and antioxidant activity (DPPH, FRAP) increased with beetroot powder content incorporated. A slight decrease of all the mentioned parameters during the storage indicated satisfied retention of bioactive molecules. The content of prevalent phenolic compounds gallic and protocatechuic acid, identified by HPLC, decreased from 22.2-32.0 and 21.1-24.9 in fresh biscuits to 18.3-23.4 and 17.3-20.3 mg/100 g upon six months of storage, respectively. An increase of the L* and a* and a decrease of the b* coordinate values, compared with the control sample without beetroot values, was noticed as well as the expected level of their change during the storage. The obtained results indicated that biscuits enriched with beetroot powder showed a significantly improved functional, nutritional and antioxidant potential during storage.

Identification of anthocyanic profile and determination of antioxidant activity of Dahlia pinnata petals: A potential source of anthocyanins

In recent decades, the food industry has focused on the search for potential sources of anthocyanins that are able to provide color to replace synthetic dyes and at the same time provide health benefits through food products. Thus, in the present work, we propose the Dahlia pinnata flower as a potential source of anthocyanins. The dahlia is a native, annual flower from Mexico with a wide diversity of shapes and colors. The ancestral use of the flower in several dishes, its abundance, and the intense color of the flowers known as black make the D. pinnata flower a suitable candidate to be considered as a potential source of anthocyanins. Thus, the aim of this research is the determination of its nutritional composition, anthocyanin profile, and antioxidant activity. For this purpose, proximate composition of petals was determined by the AOAC standard methods. Anthocyanins were extracted from the dried petals of the flower with 0.1% HCl in methanol and 70% aqueous acetone solution and purified through Amberlite-XAD7-HP resin. Then, the purified extracts were analyzed for antioxidant activity by the DPPH method and the anthocyanin profile was characterized by HPLC and UPLC-MS/MS. Results showed that D. pinnata flowers have a proximate composition similar to other important edible flowers with a high level of moisture (87%-92%) and fiber (6%-7%). The antioxidant activity of both purified extracts was considerable (2.6-12 g/ml) compared to other sources of anthocyanins. The anthocyanin profile of the purified extracts contains four main anthocyanins: delphinidin-3-glucoside, delphinidin-3-rutinoside, pelargonidin-3-sambubioside-5-glucoside, and peonidin-3-sambubioside-5-glucoside, the last two being uncommon as major anthocyanin components in other plant sources. PRACTICAL APPLICATION: We present a potential and novel source of anthocyanins based on anthocyanin content and antioxidant activity of Dahlia pinnata petals. On the basis of UPLC-MS/MS studies, we identified four main anthocyanins, so this information provides the opportunity to study the source in many areas such as natural pigment stabilization, food additives, and antioxidants.

Alternative Methods of Bioactive Compounds and Oils Extraction from Berry Fruit By-Products—A Review

Berry fruit by-products are a source of polyphenol compounds and highly nutritious oils and can be reused to fulfill the requirements of the circular economy model. One of the methods of obtaining polyphenol-rich extracts or oils is extraction. Applying conventional solvent extraction techniques may be insufficient to reach high polyphenol or lipid fraction yields and selectivity of specific compounds. Alternative extraction methods, mainly ultrasound-assisted extraction, pulsed electric field-assisted extraction, microwave-assisted extraction and supercritical fluid extraction, are ways to improve the efficiency of the isolation of bioactive compounds or oils from berry fruit by-products. Additionally, non-conventional techniques are considered as green extraction methods, as they consume less energy, solvent volume and time. The aim of this review is to summarize the studies on alternative extraction methods and their relationship to the composition of extracts or oils obtained from berry waste products.

Blackberry Leaves as New Functional Food? Screening Antioxidant, Anti-Inflammatory and Microbiological Activities in Correlation with Phytochemical Analysis

Blackberry fruits are recognized as functional foods while blackberry leaves are outside this classification and they also contain active compounds with health-promoting potential. Therefore, the aim of this study was the phytochemical analysis of blackberry leaves of varieties (Chester, Loch Ness, Loch Tay and Ruczaj) and screening of their biological activity (antioxidant potential, possibility of inhibition of enzymes, anti-inflammatory and microbial activity). The following compounds from selected groups: phenolic acids (caffeic acid, ellagic acid, gallic acid, syringic acid), flavonols (quercetin, kaempferol) and their glycosides (rutin, isoquercetin, hyperoside) and flavon-3-ols (catechin, epicatechin) were chromatographically determined in the aqueous and hydroalcoholic leaves extracts. All tested blackberry leaves extracts showed antioxidant effects, but the highest compounds content (TPC = 101.31 mg GAE/g) and antioxidant activity (e.g., DPPH IC₅₀ = 57.37 μg/mL; ABTS IC₅₀ = 24.83 μg/mL; CUPRAC IC₅₀ = 62.73 μg/mL; FRAP IC₅₀ = 39.99 μg/mL for hydroalcoholic extracts) was indicated for the Loch Tay variety. Blackberry leaf extracts’ anti-inflammatory effect was also exceptionally high for the Loch Tay variety (IC₅₀ = 129.30 μg/mL), while leaves extracts of the Loch Ness variety showed a significant potential for microbial activity against Lactobacillus spp. and Candida spp. Summarizing, the best multidirectional pro-health effect was noted for leaves extracts of Loch Tay variety.

Phytochemical analysis, antioxidant, antibacterial, and cytotoxic activities of leaves and roots of Rubus hyrcanus Juz

Rubus hyrcanus Juz. (Rosaceae), known as Caspian blackberry, is wildly distributed around the Caspian Sea. This study focused on antioxidant, cytotoxic, and antibacterial activities of total extracts and different fractions from the roots and leaves of this species. The total phenolics and flavonoid contents were also evaluated. Finally, the phenolic profiles of selected fractions were determined using HPLC–DAD and LC–MS/MS. The results indicated that the total phenolics content (TPC) of root total extract (RTE) was 3.5 times that of leaves (340.4 and 102.7 mg GAE/g, respectively). The TPC of three root fractions ranged from 226.6 to 392.9 mg GAE/g, while in leaves fractions, it ranged between 68.3 and 101.8 mg GAE/g. The total extract of leaves had higher contents of total flavonoids than roots (70.5 and 8.9 mg QE/g, respectively). The methanol fractions of both parts had the highest amounts of flavonoids. The root methanol fraction (RMF) had the best antioxidant effect in both DPPH radical scavenging assay (IC50: 9.16 μg ml−1) and total antioxidant capacity test (1010.5 mg ɑTE/g). The RMF and RTE had potent antibacterial activities against Bacillus subtilis and Staphylococcus aureus (MIC 1.5 mg ml−1). In the MTT assay, ethyl acetate fractions of roots and leaves exhibited the best cytotoxicity (IC50 247 and 227 μg ml−1, respectively) and the highest selectivity indexes (4.73 and 5.31, respectively). Phytochemical analysis revealed the presence of gallic acid, p-coumaric acid, and chlorogenic acid in leaves ethyl acetate fraction, chlorogenic acid in leaves methanol fraction, and gallic acid in the root ethyl acetate fraction.

In vitro gastrointestinal digestion impact on stability, bioaccessibility and antioxidant activity of polyphenols from wild and commercial blackberries (Rubus spp.)

Gastrointestinal digestion (GID) is a physiological process that transforms the stability, bioaccessibility and antioxidant activity (AOX) of polyphenols from blackberries (Rubus spp.). This study aimed to investigate the effect of the INFOGEST® GID protocol on the phenolic stability, bioaccessibility and AOX of Mexican wild (WB) and commercial (CB) blackberries. After GID, the total phenolic and anthocyanin contents in blackberries decreased by ≥68% and ≥74%, respectively. More than 40 phenolics were identified during GID; most of them degraded completely during digestion. GID had a negative effect on the AOX of both fruits (>50%), but WB showed the highest antioxidant activities, as assessed by the ORAC, DPPH, reducing power and β-carotene bleaching methods. In Caco-2 cells, the cell-based antioxidant activity of digested blackberries (p < 0.05) decreased by 48% in WB and by 56% in CB. The capacity to inhibit intracellular ROS decreased by 50% in WB and by up to 86% in CB, after digestion. GID is a complex process that impacts on the bioactive properties of food nutrients, especially phenolics. In vitro and cellular AOX of WB polyphenols withstood the gastrointestinal environment better than CB phenolics. The in vitro assays results suggest that phenolics from underutilized WB have a higher bioaccessibility and antioxidant capacity than the polyphenols from the most frequently consumed CB. However, whether this corresponds to a better bioaccessibility in humans remains to be determined in future work.

Investigation on High-Value Bioactive Compounds and Antioxidant Properties of Blackberries and Their Fractions Obtained by Home-Scale Juice Processing

Blackberry pomace represents a valuable but underused byproduct of juice manufacturing. Its further applicability in various food systems is facilitated by detailed knowledge of its own bioactive potential. This study was focused on the investigation of the polyphenolic compound profile, total phenolic and ascorbic acid content, as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of blackberries (Rubus fruticosus L.) coming from spontaneous flora of two different areas of Romania, Paltinis (Sibiu County) and Zugau (Arad County) and their fractions, juice and pomace, resulting from home-scale processing. To ensure a satisfactory shelf life, the blackberry pomace was subjected to convective drying (60 °C for 12 hours) and the impact of this treatment on the antioxidant properties was evaluated. No significant differences in the investigated characteristics according to the place of origin were recorded. However, a slight increase in the antioxidant properties of fruits and fractions from the Zugau region, characterized by higher temperatures and a lower precipitation regime, was noticed compared with samples derived from the Paltinis area. The drying of blackberry byproducts led to losses of 10–23% in the content of the investigated bioactive compounds and DPPH radical scavenging activity. A significant correlation between DPPH radical scavenging activity and the total phenolic content has been recorded. Our findings are of interest in blackberry selection to enhance the level of bioactive compounds in the targeted products. The obtained results confirm that the blackberry processing byproducts may be regarded as a promising source of high-quality bioactive compounds and a proven radical scavenging capacity, representing a starting point for further analyses. This study responds to a global issue regarding fruit byproduct management in order to ensure the sustainable development of a circular economy.

Antioxidant and Potentially Anti-Inflammatory Activity of Anthocyanin Fractions from Pomace Obtained from Enzymatically Treated Raspberries

Raspberry pomace was obtained from raspberries subjected to enzymatic maceration using three commercial pectinolytic preparations (Pectinex Ultra SP-L, Pectinex Yield Mash, and Ultrazym AFP-L). Phenolic compounds were extracted and anthocyanin fractions were isolated using the SPE solid phase extraction technique. In the separated anthocyanin fractions, the content of individual compounds was determined by the HPLC technique and the antioxidant activity was assessed with four complementary methods (DPPH and ABTS radical scavenging activity, chelating Fe(II) power, and ferric reducing power). Potential anti-inflammatory properties were also identified as the ability to inhibit the activity of lipoxygenase and cyclooxygenase 2. For these enzymes, the type of inhibition was determined based on the Lineweaver–Burke plot.