Compositional Features of the "Kweli" Red Raspberry and Its Antioxidant and Antimicrobial Activities

The Effects of Raspberry Consumption on Glycemic Control and Inflammation Markers in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Despite observing the health benefits of raspberry consumption in some recent studies, there is still no consensus regarding this effectiveness on inflammatory markers and glycemic control. This study aimed to investigate this effectiveness by performing a meta-analysis. The PubMed, Web of Science, and Scopus databases were comprehensively searched until December 2023 to find relevant randomized controlled trials. Eligible studies were screened, and relevant information was extracted. The overall effect size of raspberry consumption on each of the outcomes was estimated by following the random-effects model in the form of a 95% confidence interval (CI) and a weighted mean difference (WMD). Raspberry consumption led to a significant increase in insulin concentrations (WMD: 1.89 μU/mL; 95%CI: 1.45, 2.34; P < 0.001) and a significant decrease in tumor necrosis factor-α (TNF-α) concentrations (WMD: -3.07 pg/mL; 95%CI: -5.17, -0.97; P = 0.004), compared with the control groups. Raspberry consumption did not have a significant effect on fasting blood glucose, insulin, hemoglobin A1C, glucose tolerance tests, homeostatic model assessment for insulin resistance, C-reactive protein, and interleukin-6 concentrations. This review revealed that raspberry consumption led to a significant increase and decrease in insulin and TNF-α concentrations, respectively. However, to draw a more accurate conclusion, it is necessary to conduct studies with a larger sample size in the future. The current study's protocol has been registered in the PROSPERO system as CRD42023477559.

Overview of the distinctive characteristics of strawberry, raspberry, and blueberry in berries, berry wines, and berry spirits

Red berries have gained popularity as functional and nutritious food due to their health benefits, leading to increased consumer demand and higher production, totaling over 11,000 ktons for strawberries, raspberries, and blueberries combined in 2021. Nutritionally, strawberries, raspberries, and blueberries present high levels of vitamin C (9.7-58.8 mg/100 g dry weight [dw]), folates (6-24 µg/100 g dw), and minerals (96-228 mg/100 g dw). Due to their perishable nature, producers have utilized alcoholic fermentation to extend their shelf life, not only increasing the lifespan of red berries but also attracting consumers through the production of novel beverages. Strawberry, blueberry, and raspberry wines possess low alcohol (5.5-11.1% v/v), high acidity (3.2-17.6 g/L), and interesting bioactive molecules such as phenolic compounds, carotenoids, polysaccharides, and melatonin. Distillation holds tremendous potential for reducing food waste by creating red berry spirits of exceptional quality. Although research on red berry spirits is still in the early stages, future studies should focus on their production and characterization. By incorporating these factors, the production chain would become more sustainable, profitable, and efficient by reducing food waste, capitalizing on consumer acceptance, and leveraging the natural health-promoting characteristics of these products. Therefore, this review aims to provide a comprehensive overview of the characteristics of strawberry, blueberry, and red raspberry in berries, wines, and spirits, with a focus on their chemical composition and production methods.

Nutritional and Phytochemical Characterization of Freeze-Dried Raspberry (Rubus idaeus): A Comprehensive Analysis

Several studies have highlighted the beneficial effects of consuming red raspberries on human health thanks to their high content of phytochemicals. However, the products used in these studies, both in the raw or freeze-dried form, were not fully characterized for nutrient and phytochemical composition. In this study, we aimed to determine the nutrient and non-nutrient compounds present in a freeze-dried red raspberry powder widely used by the food industry and consumers. The main sugars identified were fructose (12%), glucose (11%), and sucrose (11%). Twelve fatty acids were detected, with linoleic acid (46%), α-linolenic acid (20%), and oleic acid (15%) being the most abundant. Regarding micronutrients, vitamin C was the main hydro-soluble vitamin, while minerals, potassium, phosphorous, copper and magnesium were the most abundant, with concentrations ranging from 9 up to 96 mg/100 g, followed by manganese, iron and zinc, detected in the range 0.1-0.9 mg/100 g. Phytochemical analysis using UHPLC-DAD-HR-MS detection revealed the presence of Sanguiin H6 (0.4%), Lambertianin C (0.05%), and Sanguiin H-10 isomers (0.9%) as the main compounds. Among anthocyanins, the most representative compounds were cyanidin-3-sophoroside, cyanidin-3-glucoside and cyanidin-3-sambubioside. Our findings can serve as a reliable resource for the food industry, nutraceutical applications and for future investigations in the context of human health.

Nutritionally Important Pro-Health Active Ingredients and Antioxidant Properties of Fruits and Fruit Juice of Selected Biennial Fruiting Rubus idaeus L. Cultivars

Raspberry fruits are an important source of many biologically active chemical compounds exerting nutritional and pro-health effects. The study presents a comparative analysis of nutritionally important bioactive chemical compounds-polyphenols; flavonoids, including anthocyanins; vitamin C; amino acids; fatty acids; and primary metabolites-contained in the fruits of three biennial fruiting cultivars, R. idaeus 'Glen Ample', 'Laszka', and 'Radziejowa', i.e., common cultivars in Poland and Europe. The antioxidant activity of fresh fruits and juice was determined with five methods. The analyses revealed the strong free radical scavenging potential of the fruits and juice, confirmed by the high concentration of nutrients, e.g., polyphenols, anthocyanins, vitamin C, amino acids, and fatty acids. The antioxidant activity of the juice determined with the ferric reducing antioxidant power (FRAP) and OH radical methods was from 2.5 to 4.0 times higher than that of the fruits. The following orders of total polyphenol contents were established in the analyzed cultivars: 'Glen Ample' < 'Laszka' < 'Radziejowa' in the fruits and 'Glen Ample' < 'Radziejowa' < 'Laszka' in the juice. The highest antioxidant activity was exhibited by the 'Radziejowa' fruits. Given their high content of dietary fiber, the fruits of the analyzed raspberry cultivars can be consumed by dieting subjects. The concentrations of vitamin C (28-34 mg/100 g) and anthocyanins (20-34 mg/100 g) indicate the biological and pharmacological activity of these fruits. The main unsaturated fatty acids in the fruits were gamma-linoleic acid (C18:2n6c) and alpha-linolenic acid (C18:3n3), which neutralize excess free radicals. The amino acids nutritionally essential to humans were dominated by leucine, arginine, and phenylalanine. This is the first comparative analysis of the antioxidant activity of fruits and juice and the contents of selected active compounds in the fruits of biennial fruiting cultivars of R. idaeus, i.e., a highly commercialized crop in Europe.

Rubi idaei fructus as a Source of Bioactive Chemical Compounds with an Important Role in Human Health and Comparison of the Antioxidant Potential of Fruits and Juice of Three Repeat-Fruiting Rubus idaeus L. Cultivars

Rubi idaei fructus is a source of nutritionally important bioactive chemical compounds, mainly antioxidants, which strengthen the immune system and can be used in the prophylaxis and adjuvant therapies of many oxidative stress-induced diseases. There are no literature reports presenting a comprehensive comparative analysis of the antioxidant activity and nutritionally relevant metabolites contained in the fruits of repeat-fruiting raspberry cultivars, which are commonly grown in Europe. The aim of this study was to carry out a comparative analysis of the antioxidant potential (Folin-Ciocalteu, DPPH, FRAP), the content of selected primary and secondary metabolites, and the qualitative and quantitative composition of amino acids and fatty acids in the fruits of R. idaeus cv. 'Pokusa', 'Polana', and 'Polka'. The fruits of the analyzed cultivars have a low caloric value (171-219 kcal/100 g); low content of available carbohydrates (6-6.6%) and total carbohydrates (3.4-4.8%); and high levels of dietary fiber (4.7-5.8%), vitamin C (22.8-27 mg/100 g), anthocyanins (25.1-29.6 mg/100 g), and flavonoids (0.5-2.6 mg/100 g). The fruits were found to contain valuable unsaturated fatty acids (35-60%), especially MUFAs with dominant oleic, elaidic, palmitic, and erucic acids and PUFAs (α-linolenic, eicosapentaenoic, and linoleic acids). MUFAs from the ω-9 group accounted for 12-18%, whereas the content of PUFAs from the ω-3 and ω-6 groups was in the range of 15-23 and 6-21%, respectively. Exogenous amino acids, accounting for 56-62%, were dominated by leucine, phenylalanine, and lysine. The following order of the total polyphenolic content was established in the fresh fruit juice from the analyzed cultivars: 'Pokusa' < 'Polana' < 'Polka'. The different antioxidant capacity assays used in the study confirmed the high antioxidant potential of the fruits and fresh juice from the three R. idaeus cultivars. This indicates that raspberry fruits can serve as a source of nutrients and can be used as a valuable supplement in a healthy human diet and a raw material in the pharmaceutical and cosmetic industries.

Widely targeted metabolome profiling of different plateau raspberries and berry parts provides innovative insight into their antioxidant activities

Raspberries are highly nutritious and have powerful antioxidant properties, making them functional berries with positive effects on physiological functioning. However, there is limited information available on the diversity and variability of metabolites in raspberry and its parts, especially in plateau raspberries. To address this, commercial raspberries and their pulp and seeds from two plateaus in China were subjected to LC-MS/MS-based metabolomics analysis and evaluated for antioxidant activity using four assays. A metabolite-metabolite correlation network was established based on antioxidant activity and correlation analysis. The results showed that 1661 metabolites were identified and classified into 12 categories, with significant variations in composition between the whole berry and its parts from different plateaus. Flavonoids, amino acids and their derivatives, and phenolic acids were found to be up-regulated in Qinghai's raspberry compared to Yunnan's raspberry. The main differently regulated pathways were related to flavonoid, amino acid, and anthocyanin biosynthesis. The antioxidant activity of Qinghai's raspberry was stronger than Yunnan's raspberry, and the order of antioxidant capacity was seed > pulp > berry. The highest FRAP (420.31 µM TE/g DW) values was found in the seed of Qinghai's raspberry. Overall, these findings suggest that the environment in which the berries grow can affect their chemical composition, and comprehensive exploitation and cultivation of whole raspberry and its parts from different plateaus can lead to new opportunities for phytochemical compositions and antioxidant activity.

A discriminant analysis of plasma metabolomics for the assessment of metabolic responsiveness to red raspberry consumption

Background

Many studies show that the intake of raspberries is beneficial to immune-metabolic health, but the responses of individuals are heterogeneous and not fully understood.

Methods

In a two-arm parallel-group, randomized, controlled trial, immune-metabolic outcomes and plasma metabolite levels were analyzed before and after an 8-week red raspberry consumption. Based on partial least squares discriminant analysis (PLS-DA) on plasma xenobiotic levels, adherence to the intervention was first evaluated. A second PLS-DA followed by hierarchical clustering was used to classify individuals into response subgroups. Clinical immune and metabolic outcomes, including insulin resistance (HOMA-IR) and sensitivity (Matsuda, QUICKI) indices, during the intervention were assessed and compared between response subgroups.

Results

Two subgroups of participants, type 1 responders (n = 17) and type 2 responders (n = 5), were identified based on plasma metabolite levels measured during the intervention. Type 1 responders showed neutral to negative effects on immune-metabolic clinical parameters after raspberry consumption, and type 2 responders showed positive effects on the same parameters. Changes in waist circumference, waist-to-hip ratio, fasting plasma apolipoprotein B, C-reactive protein and insulin levels as well as Matsuda, HOMA-IR and QUICKI were significantly different between the two response subgroups. A deleterious effect of two carotenoid metabolites was also observed in type 1 responders but these variables were significantly associated with beneficial changes in the QUICKI index and in fasting insulin levels in type 2 responders. Increased 3-ureidopropionate levels were associated with a decrease in the Matsuda index in type 2 responders, suggesting that this metabolite is associated with a decrease in insulin sensitivity for those subjects, whereas the opposite was observed for type 1 responders.

Conclusion

The beneficial effects associated with red raspberry consumption are subject to inter-individual variability. Metabolomics-based clustering appears to be an effective way to assess adherence to a nutritional intervention and to classify individuals according to their immune-metabolic responsiveness to the intervention. This approach may be replicated in future studies to provide a better understanding of how interindividual variability impacts the effects of nutritional interventions on immune-metabolic health.

Comprehensive Evaluation of 24 Red Raspberry Varieties in Northeast China Based on Nutrition and Taste

Red raspberry is a kind of fruit with high nutritional values. To evaluate the comprehensive quality of 24 red raspberry varieties in Northeast China, physicochemical properties, bioactive compounds and sensory characteristics were measured, followed by principal component analysis (PCA) and cluster analysis (CA). Altogether, eight important property indexes for processing attributes were selected out using PCA, including titratable acidity (TAC), sugar-acid ratio (SAR), pH, length, diameter, weight, sucrose and citric acid. Six individual sugars, including l-rhamnose monohydrate, fructose, glucose, sucrose, maltose and d-trehalose anhydrous, as well as eight organic acids, including oxalic acid, tartaric acid, malic acid, α-ketoglutaric acid, lactic acid, citric acid, fumaric acid and succinic acid, were identified in red raspberry. The two main clusters according to individual sugar, organic acids and SAR indicated that varieties including ‘European red’, ‘DNS9’, ‘Bulgaskc’, ‘Canby’ and ‘Samodiva’ were suitable for fresh-eating or processing to juice or other products directly because they had suitable SAR; other varieties with relatively low SAR were unsuitable for fresh-eating and need to adjust their excessive sour taste during processing.

Impact of Gum Arabic Coating Pretreatment on Quality Attributes of Oven-Dried Red Raspberry (Rubus idaeus L.) Fruit

The present study evaluated the effect of gum arabic (GA) edible coating pretreatment on the quality of dried red raspberries. Red raspberries were independently pretreated with varied concentrations of GA (3, 5, and 10% (w/v) by dipping for 2 min before oven-drying at 60 °C until the moisture content was below 8% (18–24 h). Raspberries dipped in distilled water were used as the control samples. Quality attributes including colour, moisture content, water activity (aw), hardness, hygroscopicity, rehydration capacity, total soluble solids (TSS), titratable acidity (TA), pH, anthocyanin composition, ascorbic acid (AA) content, total phenolic content (TPC), antioxidant activity, peroxidase (POD), and polyphenol oxidase (PPO) enzyme activity were investigated. GA pretreatment of the raspberries improved the aw (lower), hardness (lower), TSS, TSS/TA ratio, BrimA, AA content, and TPC, whilst it significantly (p < 0.05) reduced the colour properties (redness, chroma, hue angle, and total colour differences) and the total anthocyanin content when compared with the control samples. The DPPH radical scavenging activity, POD, and PPO enzymes residual activities were not significantly (p > 0.05) affected by GA pretreatment. Five different types of anthocyanins, including cyanidin dihexoside, cyanidin 3-O-galactoside, cyanidin 3-O-glucosyl-rutinoside, and cyanidin 3-O-rutinoside were identified and quantified with cyanidin dihexoside being the primary anthocyanin, varying from 951.18–1053.70 µg/g DM. GA pretreatment of raspberries between 3 and 5% could result in improved physicochemical, antioxidant properties and minimum loss of anthocyanins.

Antiviral and Antibacterial Effect of Honey Enriched with Rubus spp. as a Functional Food with Enhanced Antioxidant Properties

The aim of this study was to investigate the effect of blackberry and raspberry fruits (1 and 4%) and leaves (0.5 and 1%) on the biological activities of rape honey. Honey and plant material extracts were analyzed regarding total phenolic, flavonoid, anthocyanin contents, HPTLC and HPLC polyphenol profiles, as well as antioxidant activity. The antiviral potential was analyzed against bacteriophage phi 6-a coronavirus surrogate-whereas antimicrobial was tested against S. aureus and E. coli. Blackberry extracts were more abundant in antioxidants than raspberry extracts, with better properties found for leaves than fruits and for cultivated rather than commercial plants. The addition of both Rubus plant additives significantly increased the antioxidant potential of honey by four-fold (for 4% fruits additive) to five-fold (for 1% of leaves). Honey with the addition of fruits possessed higher antiviral potential compared with raw rape honey (the highest for 4% of raspberry fruit and 1% of blackberry leaf additive). Honey enriched with Rubus materials showed higher antibacterial potential against S. aureus than rape honey and effectively inhibited S. aureus biofilm formation. To summarize, honey enriched with Rubus fruit or leaves are characterized by increased pro-health value and can be recommended as a novel functional food.

Berry By-Products in Combination with Antimicrobial Lactic Acid Bacteria Strains for the Sustainable Formulation of Chewing Candies

The purpose of this research was to develop formulations of chewing candies (CCs) in a sustainable manner by using berry by-products in combination with antimicrobial lactic acid bacteria (LAB) strains. To implement this aim, the optimal quantities of by-products from lyophilised raspberry (Rasp) and blackcurrant (Bcur) from the juice production industry were selected. Prior to use, Lactiplantibacillus plantarum LUHS135, Liquorilactobacillusuvarum LUHS245, Lacticaseibacillusparacasei LUHS244, and Pediococcus acidilactici LUHS29 strains were multiplied in a dairy industry by-product-milk permeate (MP). The antimicrobial activity of the selected ingredients (berry by-products and LAB) was evaluated. Two texture-forming agents were tested for the CC formulations: gelatin (Gl) and agar (Ag). In addition, sugar was replaced with xylitol. The most appropriate formulation of the developed CCs according to the product's texture, colour, total phenolic compound (TPC) content, antioxidant activity, viable LAB count during storage, overall acceptability (OA), and emotions (EMs) induced in consumers was selected. It was established that the tested LAB inhibited three pathogens out of the 11 tested, while the blackcurrant by-products inhibited all 11 tested pathogens. The highest OA was shown for the CC prepared with gelatin in addition to 5 g of Rasp and 5 g of Bcur by-products. The Rasp and LUHS135 formulation showed the highest TPC content (147.16 mg 100 g^-1 d.m.), antioxidant activity (88.2%), and LAB count after 24 days of storage (6.79 log₁₀ CFU g^-1). Finally, it was concluded that Gl, Rasp and Bcur by-products, and L. plantarum LUHS135 multiplied in MP are promising ingredients for preparing CCs in a sustainable manner; the best CC formula consisted of Gl, Rasp by-products, and LUHS135 and showed the highest OA (score 9.52) and induced the highest intensity of the EM 'happy' (0.231).

Effects of Dietary Red Raspberry Consumption on Pre-Diabetes and Type 2 Diabetes Mellitus Parameters

Type 2 diabetes mellitus (T2DM) is a chronic metabolic condition characterized by glucose clearance abnormalities and insufficient insulin response. Left uncontrolled, T2DM can result in serious complications and death. With no cure available currently and the prevalence of major risk factors such as pre-diabetes and the metabolic syndrome continuously increasing, there is an urgent need for effective treatments with limited or no side effects. Red raspberries (RR) contain various phytonutrients with potential for modulating insulin function, glucose, and lipid metabolism. The objective of this literature review was to investigate the potential metabolic benefits of dietary RR in individuals with T2DM and pre-diabetes. A search of major scientific databases was employed to identify peer-reviewed, in vivo, or human studies that utilized whole RR or its functional constituents as treatment. The studies examined provide evidence that RR may offer clinically beneficial effects for the prevention and management of chronic diseases through improvements in glucose handling and insulin sensitivity, adiposity, lipid profiles, ectopic lipid accumulation, inflammation, oxidative stress, and cardiac health. More human trials and in vivo studies are needed to confirm the benefits of dietary RR in T2DM and pre-diabetes and to explore the dose-dependent relationships, optimal duration, and treatment modality.

Anthocyanins from Rubus fruticosus L. and Morus nigra L. Applied as Food Colorants: A Natural Alternative

Given the importance of colour in the general acceptance or rejection of a product, the use of colorants is a widespread practice, particularly in the food industry. At the same time, with the increasing consumers' awareness of the health effects that some artificial colorants can exert, there is a growing tendency to prioritize foodstuffs containing natural additives. In this work, Morus nigra L. and Rubus fruticosus L. fruit juices were characterized in terms of anthocyanins, organic acids, free sugars, and tocopherols, as also regarding their bioactive properties. Given their richness in anthocyanins, this study also aimed to prepare different solid colouring formulations by the spray-drying technique, using as stabilizers maltodextrin and arabic gum. Six free sugars and two organic acids were detected in the fruit juices, as well as the four tocopherol isoforms. Two cyanidin derivatives were found in M. nigra (cyanidin-3-O-glucoside and cyanidin-O-rhamnoside) and other four in R. fruticosus (cyanidin-O-hexoside, cyanidin-3-O-glucoside, cyanidin-O-pentoside, and cyanidin-3-O-dioxaloilglucoside). The developed colouring formulations revealed a good stability over time, in terms of anthocyanin concentration and colour parameters, and revealed to be safe for consumption, either concerning their low microbial load and lack of cytotoxicity. Thus, they represent a promising natural alternative to the massively used artificial colorants.

Biowaste as a Potential Source of Bioactive Compounds-A Case Study of Raspberry Fruit Pomace

Raspberry fruit pomace, a byproduct of juice production, was studied as a potential source of antioxidant compounds. Target high-performance liquid chromatography analysis of important polyphenolic compounds (gallic, p-coumaric, caffeic, quercitrin, chlorogenic, and ellagic acid) was performed together with analysis of total phenolic content (TPC), total flavonoid content (TFC), total anthocyanins content (TAC), and antioxidant capacity (via ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays). The differences in polyphenolic content of Rubus idaeus L. pomace were evaluated following ultrasound-assisted extraction and conventional maceration with different organic solvents. Additionally, the yield of free phenolics was measured in hydrolyzed pomace extracts. The results obtained show that the ultrasound method maximizes the quantity of antioxidant compounds in terms of TPC (27.79 mg/L gallic acid equivalent (GAE)), TFC (8.02 mg/g quercetin equivalent (QE)), TAC (7.13 mg/L cyanidine-3-glucoside equivalent (C3G Eq)), caffeic (19.17 µg/g), chlorogenic (3.56 µg/g), ellagic (105.52 µg/g), and gallic acids (8.75 µg/g), as well as FRAP (1002.72 µmol/L) and DPPH assays (969.71 µmol/mL vitamin C equivalent (vit C Eq); 567.00 µmol/100 g Trolox equivalent (TE)). On the other hand, conventional maceration maximizes the yield of quercetin and p-coumaric acid. In terms of biowaste valorization, raspberry fruit pomace has a promising industrial potential and may prove to be useful in the development of antioxidant dietary supplements.