On the effect of flavonoids and dietary fibre in lingonberries on atherosclerotic plaques, lipid profiles and gut microbiota composition in Apoe-/- mice.

It has not been clarified whether the anti-atherosclerotic effect of lingonberry can be ascribed to its content of flavonoids or dietary fibre or both. The aim of this study was to evaluate the metabolic effects of whole lingonberries compared with isolated flavonoid and fibre fractions on atherosclerotic plaques, plasma lipid profiles, gut microbiota and microbiota-dependent metabolites in an Apoe-/- mouse model. Mice fed whole lingonberries showed the lowest amount of atherosclerotic plaques, while mice fed the fibre fraction had the highest formation of caecal butyric acid. Flavonoids, rather than dietary fibre, were suggested to be the components that favour proliferation of Akkermansia, as judged by the lowest abundance of this bacterium in mice fed the fibre fraction. All groups fed lingonberry diets had both, lower Firmicutes/Bacteroidetes ratios and creatinine concentrations, compared with the control. To conclude, different components in lingonberries are associated with different physiological effects in Apoe-/- mice.

Lingonberry (Vaccinium vitis-idaea L.) Fruit as a Source of Bioactive Compounds with Health-Promoting Effects-A Review.

Berries, especially members of the Ericaceae family, are among the best dietary sources of bioactive compounds with beneficial health effects. The most popular berries are in the genus Vaccinium, such as bilberry (Vaccinium myrtillus), cranberry (Vaccinium macrocarpon, V. oxycoccos), and blueberry (Vaccinium corymbosum). Lingonberry (Vaccinium vitis-idaea) is less prevalent in the daily human diet because they are collected from the wild, and plant breeding of lingonberry is still on a small scale. Lingonberries are classed as "superfruits" with the highest content of antioxidants among berries and a broad range of health-promoting effects. Many studies showed various beneficial effects of lingonberries, such as anti-inflammatory, antioxidant, and anticancer activities. Lingonberries have been shown to prevent low-grade inflammation and diet-induced obesity in diabetic animals. Moreover, lingonberry intake has been associated with a beneficial effect on preventing and treating brain aging and neurodegenerative disorders. The consumption of berries and their health-promoting activity is a subject receiving a great deal of attention. Many studies investigated the natural compounds found in berries to combat diseases and promote healthy aging. This article's scope is to indicate the potential beneficial effect of lingonberry consumption on health, to promote well-being and longevity.

Isolation, characterization and regulation of moonlighting proteases from Candida glabrata cell wall.

Candida glabrata (C. glabrata) cell wall proteins play a role in virulence and in initial host immune recognition and responses. We isolated and characterized C. glabrata cell wall proteases from a clinical hospital C. glabrata T-1638 blood isolate and estimated the enzymatic activities and their ability to degrade gelatin and processing proMMP-8 and assess the regulation of these proteases with salt treatment, mercaptoethanol and fermented lingonberry juice from Vaccinium vitis idaea L. The cell wall proteases were enzymatically released from the cell wall and beta- 1,3- bonded proteases were fractioned into 10-50 kDa and >50 kDa fractions with anionic DEAE-sepharose ion-exchange chromatography and gel filtration. Proteins were monitored and analyzed with MDPF- zymography, and five gelatinolytic bands were cut out from a parallel silver-stained gel for the LC- MS/MS analysis. The proteases lacked a signal sequence, indicating that they are moonlighting proteases. Human proMMP-8 activation assays were performed with both fractions and verified by western-immunoblot using aMMP-8 specific antibody. Inhibition of proMMP-8 conversion to the lower molecular active enzyme species were demonstrated with fermented lingonberry juice. The results indicate that moonlighting proteases may play a role in the virulence of C. glabrata.

Oral intake of lingonberry and amla fruit extract improves skin conditions in healthy female subjects: A randomized, double-blind, placebo-controlled clinical trial.

In this study, we examined the effect of ingestion of lingonberry and amla fruit extract (LAE) on several human skin conditions. To conduct a randomized, double-blinded, placebo-controlled study, we randomly divided 99 healthy female subjects into three groups; the first group received a drink containing 25 mg of lingonberry extract and 30 mg of amla fruit extract; the second group received a drink containing double the volume of extracts received by the first group; and the third group received a placebo drink. Each participant drank 50 mL of their assigned drink once daily for 12 weeks. The primary endpoint was skin elasticity, and the secondary endpoints included skin thickness, stratum corneum water content, and degree of wrinkles around the eyes. After 12 weeks of LAE drink intake, skin elasticity showed significant, dose-dependent improvements (P < 0.01). Skin thickness, stratum corneum water content, and the degree of wrinkles also significantly improved (P < 0.001) in a dose-dependent manner. The improvements in skin elasticity and thickness, as well as in the stratum corneum water content and the degree of wrinkles, observed upon oral intake of LAE indicate that LAE may be considered a candidate anti-aging agent for preventing skin weakening.

Composition of Sugars in Wild and Cultivated Lingonberries (Vaccinium vitis-idaea L.).

Products of lingonberries are widely used in the human diet; they are also promising beauty and health therapeutic candidates in the cosmetic and pharmaceutical industries. It is important to examine the sugar profile of these berries, due to potential deleterious health effects resulting from high sugar consumption. The aim of this study was to determine the composition of sugars in wild clones and cultivars or lower taxa of lingonberries by HPLC-ELSD method of analysis. Acceptable system suitability, linearity, limits of detection and quantification, precision, and accuracy of this analytical method were achieved. The same sugars with moderate amounts of fructose, glucose, and low amounts of sucrose were found in wild and cultivated lingonberries. Cultivar 'Erntekrone' and wild lingonberries collected from full sun, dry pine tree forests with lower altitude and latitude of the location, distinguished themselves with exclusive high contents of sugars. The changes in the sugar levels during the growing season were apparent in lingonberries and the highest amounts accumulated at the end of the vegetation. According to our findings, lingonberries seem to be an appropriate source of dietary sugars.

Antioxidant Activities of Vaccinium vitis-idaea L. Leaves within Cultivars and Their Phenolic Compounds.

Lingonberry leaves are the subject of numerous studies because of antioxidant properties, positive influence on the health and potential use in the prevention and treatment of chronic diseases. In this work, the radical scavenging, reducing, chelating activities, and phenolic composition of ten lingonberry leaves cultivars, one subspecies, and one variety were investigated. Furthermore, the antioxidant activity of individual phenolic compounds, that can be found in lingonberry leaves, were analyzed, and structure-activity relationship was determined. Wide diversity for phenolic profile and antioxidant properties of lingonberry leaves has been observed in the present material. Cultivars 'Kostromskaja rozovaja', 'Rubin', and Vaccinium vitis-idaea var. leucocarpum surpassed all others tested cultivars and lower taxa by contents of phenolic compounds and antioxidant activity. Leaves of lingonberry cultivars and lower taxa are rich in arbutin, flavonol glycosides, proanthocyanidins, and the latter were considered to be the major contributor to antioxidant properties of lingonberry leaves.

Genetic variation associated with healthy traits and environmental conditions in Vaccinium vitis-idaea.

BACKGROUND: Lingonberry (Vaccinium vitis-idaea L.), one of the least studied fruit crops in the Ericaceae family, has a dramatically increased worldwide demand due to its numerous health benefits. Genetic markers can facilitate the selection of berries with desirable climatic adaptations, agronomic and nutritious characteristics to improve cultivation programs. However, no genomic resources are available for this species. RESULTS: We used Genotyping-by-Sequencing (GBS) to analyze the genetic variation of 56 lingonberry samples from across Newfoundland and Labrador, Canada. To elucidate a potential adaptation to environmental conditions we searched for genotype-environment associations by applying three distinct approaches to screen the identified single nucleotide polymorphisms (SNPs) for correlation with six environmental variables. We also searched for an association between the identified SNPs and two phenotypic traits: the total phenolic content (TPC) and antioxidant capacity (AC) of fruit. We identified 1586 high-quality putative SNPs using the UNEAK pipeline available in TASSEL. We found 132 SNPs likely associated with at least one of the environmental or phenotypic variables. To obtain insights on the function of the genomic sequences containing the SNPs likely to be associated with the environmental or phenotypic variables, we performed a sequence-based functional annotation and identified homologous protein-coding sequences with functional roles related to abiotic stress response, pathogen defense, RNA metabolism, and, most interestingly, phenolic compound biosynthesis. CONCLUSIONS: The putative SNPs discovered are the first genomic resource for lingonberry. This resource might prove useful in high-density quantitative trait locus analysis, and association mapping. The identified candidate genes containing the SNPs need further studies on their potential role in local adaptation of lingonberry. Altogether, the present study provides new resources that can be used to breed for desirable traits in lingonberry.

Glioprotective Effects of Lingonberry Extract Against Altered Cellular Viability, Acetylcholinesterase Activity, and Oxidative Stress in Lipopolysaccharide-Treated Astrocytes.

Altered astrocytic function is a contributing factor to the development of neurological diseases and neurodegeneration. Berry fruits exert neuroprotective effects by modulating pathways involved in inflammation, neurotransmission, and oxidative stress. The aim of this study was to examine the effects of the lingonberry extract on cellular viability and oxidative stress in astrocytes exposed to lipopolysaccharide (LPS). In the reversal protocol, primary astrocytic cultures were first exposed to 1 µg/mL LPS for 3 h and subsequently treated with lingonberry extract (10, 30, 50, and 100 µg/mL) for 24 and 48 h. In the prevention protocol, exposure to the lingonberry extract was performed before treatment with LPS. In both reversal and prevention protocols, the lingonberry extracts, from 10 to 100 µg/mL, attenuated LPS-induced increase in reactive oxygen species (around 55 and 45%, respectively, P < 0.01), nitrite levels (around 50 and 45%, respectively, P < 0.05), and acetylcholinesterase activity (around 45 and 60%, respectively, P < 0.05) in astrocytic cultures at 24 and 48 h. Also, in both reversal and prevention protocols, the lingonberry extract also prevented and reversed the LPS-induced decreased cellular viability (around 45 and 90%, respectively, P < 0.05), thiol content (around 55 and 70%, respectively, P < 0.05), and superoxide dismutase activity (around 50 and 145%, respectively, P < 0.05), in astrocytes at both 24 and 48 h. Our findings suggested that the lingonberry extract exerted a glioprotective effect through an anti-oxidative mechanism against LPS-induced astrocytic damage.

Lingonberry anthocyanins protect cardiac cells from oxidative-stress-induced apoptosis.

Lingonberry grown in northern Manitoba, Canada, contains exceptionally high levels of anthocyanins and other polyphenols. Previous studies from our lab have shown that lingonberry anthocyanins can protect H9c2 cells from ischemia-reperfusion injury and anthocyanin-rich diets have been shown to be associated with decreased cardiovascular disease and mortality. Oxidative stress can impair function and trigger apoptosis in cardiomyocytes. This study investigated the protective effects of physiologically relevant doses of lingonberry extracts and pure anthocyanins against hydrogen-peroxide-induced cell death. Apoptosis and necrosis were detected in H9c2 cells after hydrogen peroxide treatment via flow cytometry using FLICA 660 caspase 3/7 combined with YO-PRO-1 and then confirmed with Hoechst staining and fluorescence microscopy. Each of the 3 major anthocyanins found in lingonberry (cyanidin-3-galactoside, cyanidin-3-glucoside, and cyanidin-3-arabinoside) was protective against hydrogen-peroxide-induced apoptosis in H9c2 cells at 10 ng·mL-1 (20 nmol·L-1) and restored the number of viable cells to match the control group. A combination of the 3 anthocyanins was also protective and a lingonberry extract tested at 3 concentrations produced a dose-dependent protective effect. Lingonberry anthocyanins protected cardiac cells from oxidative-stress-induced apoptosis and may have cardioprotective effects as a dietary modification.

Supplementing diet with Manitoba lingonberry juice reduces kidney ischemia-reperfusion injury.

BACKGROUND: Lingonberry (Vaccinium vitis-idaea L.) contains high levels of anthocyanins which are bioavailable in the kidney and may be protective against ischemia-reperfusion (IR)-induced acute kidney injury. This study investigated the effect of lingonberry juice on the IR-induced stress-activated signalling pathway and inflammatory response in the kidney. RESULTS: Sprague-Dawley rats subjected to kidney IR had significantly impaired kidney function, with increased activation of the JNK signalling pathway and increased inflammatory response, measured using a multiplex panel containing an extensive array of inflammatory biomarkers. In rats fed 1 mL lingonberry juice daily for 3 weeks prior to IR, kidney function was protected and attenuation of inflammatory response and JNK signalling was reflected in the reduction of the measured biomarkers. In vitro results in cultured HK-2 cells confirmed that lingonberry anthocyanins reduced JNK signalling and inflammatory gene expression after IR. CONCLUSION: This study shows, for the first time, that daily supplementation with lingonberry juice may protect against loss of kidney function induced by IR injury by modulating JNK signalling and inhibiting the subsequent inflammatory response. © 2017 Her Majesty the Queen in Right of Canada. Journal of the Science of Food and Agriculture © 2017 Society of Chemical Industry.

Phytochemical Properties and Antioxidant Activities of Extracts from Wild Blueberries and Lingonberries.

Among Vaccinium species, blueberries (Vaccinium myrtillus L.) and lingonberries (Vaccinium vitis-idaea) are popular in the human diet. In this study, total phenolic, total flavonoid and total monomeric anthocyanin contents in the ethanol-water extracts of blueberry and lingonberry fruits grown wild in the forests in the central region of Poland were assayed. Antioxidant activities of the extracts from each plant were also evaluated for scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reducing power by cupric reducing antioxidant capacity (CUPRAC) method. Total phenolics in the blueberry extracts ranged from 4.58 to 5.28 mg GAE CE/g fw. The extracts from lingonberry fruits contained higher total contents of phenolic compounds (5.82-7.60 mg GAE/g fw) as well as total flavonoids (5.22-6.47 µmol CE/g fw) than those from blueberries (3.74-4.18 µmol CE/g fw). For the total monomeric anthocyanin contents, the blueberry extracts presented significantly higher values (3.01-3.93 mg cyanidin-3-glucoside (C3G) equivalent/g fw) in comparison to the lingonberry extracts (0.32-0.47). Blueberry extracts exhibited higher antioxidant activity measured by both assays in comparison to lingonberry extracts. Water extracts from fresh and dried fruits also exhibited significant antioxidant activities for both types of berries. Considering the health benefits that have been associated with polyphenolic consumption, these fruits could appear as a good source of this group of phytochemical compounds for their direct consumption or their use as ingredients for the design of new food products or food supplements.

Partridgeberry polyphenols protect rat primary cortical neurons from oxygen-glucose deprivation-reperfusion-induced injury via suppression of inflammatory adipokines and regulation of HIF-1α and PPARγ.

OBJECTIVES: The aim of this study was to investigate the neuroprotective ability of partridgeberry polyphenols in rat primary cortical neurons against oxygen-glucose deprivation/reperfusion (OGD/R) injury in vitro and explore the underlying therapeutic mechanism(s). METHODS: The OGD/R injury was induced in rat primary cortical neurons by incubation with deoxygenated glucose-free medium in a hypoxia chamber. RESULTS: The strongest activity in this regard was exhibited by partridgeberry-derived PPF2 and PPF3, i.e. the flavan-3-ol- and flavonol-rich polyphenol fractions of partridgeberry (P ≤ 0.05). Moreover, partridgeberry polyphenol pre-treatment reduced the membrane damage in primary neurons, as measured by the lactose dehydrogenase (LDH) release assay (P ≤ 0.05). Furthermore, PPF2 and PPF3 pre-treatment (100 µg ml(-1)) for 24 hours, before OGD/R, resulted in the strongest suppression of interleukin (IL)-6 and tumor necrosis factor-α induction by OGD/R injury, compared with the control group (P ≤ 0.05). Additionally, the protein levels of hypoxia-inducible factor (HIF-1α) and PPARγ, quantified by ELISA presented a significant modulation following PPFs treatment (100 µg ml(-1)), favorably toward neuroprotection, compared with the respective controls after OGD/R injury in vitro (P ≤ 0.05). CONCLUSION: In summary, partridgeberry polyphenols at concentrations of 1-100 µg ml(-1), significantly induced a decline in OGD/R injury-triggered apoptosis in vitro, suppressed the inflammatory biomarkers in primary neurons, and modulated the activity of HIF-1α and proliferator-activated receptor gamma (PPARγ) following hypoxic injury.

Influence of polyphenols from lingonberry, cranberry, and red grape on in vitro digestibility of rice.

Dietary polyphenols are abundant antioxidants in the human diet and are associated with lower rates of diabetes and cardiovascular disease. This study aims to determine the effects of cooking white rice (WR) added with lingonberry (WRLB), cranberry (WRCB), and red grape (WRRG) on in vitro digestibility. There was significantly lower level of glucose release for WRRG compared with WR (p < 0.05). WRLB and WRCB showed no effect on glucose release compared with WR (p > 0.05). Increasing concentrations of red grape polyphenol decreased digestibility of white rice (p < 0.05). A positive correlation between the red grape phenolic content and the resistant starch was observed (R = 0.9854). Red grape polyphenol had the greatest impact on reducing in vitro digestibility of white rice. The addition of polyphenols in carbohydrate-rich foods may be a practical means to reduce the high glycemic response of rice eaten around the world.

Prevention of urinary tract infections with vaccinium products.

Cranberries exert a dose-dependent inhibition of the adherence of E. coli fimbriae to uroepithelial cells. This was demonstrated in vitro but also ex vivo in vitro with urine from cranberry consumers. The active principle has not been identified in detail but type-A proanthocyanidins (PAC) play an important role in the mechanism of action. Since the three species, American cranberry (Vaccinium macrocarpon), European cranberry (Vaccinium oxycoccus) and/or lingonberry (Vaccinium vitis-idaea), have different patterns of type-A PACs, results from one species cannot be transferred to the others. It seems likely that most of the studies with monopreparations from V. macrocarpon were underdosed. Whereas photometric PAC quantification may overestimate the true content on co-active compounds, reversed phase high-performance liquid chromatograpy may underestimate them. Recent studies with PAC doses in the upper range (DMAC method) or declared type-A PAC content in the daily dose reveal a dose-dependent trend of clinical effectiveness, however, with a possible ceiling effect. In order to clarify this, future three-arm studies should investigate Vaccinium preparations with higher type-A PAC doses than previously used. We analysed two popular European vitis-idaea products, a mother juice and a proprietary extract. Both preparations may be appropriate to confirm the Vaccinium urinary tract infection-preventive effect beyond doubt.

Interactions between corn starch and lingonberry polyphenols and their effects on starch digestion and glucose transport.

This study investigated the interaction mechanism between corn starch (CS) and lingonberry polyphenols (LBP) during starch gelatinization, focusing on their effects on starch structure and physicochemical properties. Moreover, it explored the effect of this interaction on starch digestion and glucose transport. The results indicated that LBP interacted non-covalently with CS during starch gelatinization, disrupted the short-range ordered structure of starch, decreased gelatinization enthalpy of starch, and formed a dense network structure. Furthermore, the incorporation of LBP remarkably reduced the digestibility of CS. In particular, the addition of 10 % LBP decreased the terminal digestibility (C∞) from 77.87 % to 60.43 % and increased the amount of resistant starch (RS) by 21.63 %. LBP was found to inhibit α-amylase and α-glucosidase in a mixed manner. Additionally, LBP inhibited glucose transport in Caco-2 cells following starch digestion. When 10 % LBP was added, there was a 34.17 % decrease in glucose transport compared with starch digestion without LBP. This study helps establish the foundation for the development of LBP-containing starch or starch-based healthy foods and provides new insights into the mechanism by which LBP lowers blood glucose.

Long-term remission of candidiasis with fermented lingonberry mouth rinse in an adult patient with APECED.

We report a long-term remission in candidiasis in a 57-year-old Finnish female with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) suffering from recurrent oral, esophageal, gastric, vaginal, and anal candidiasis since childhood. Candidiasis treatment with antifungal medicines fluconazole, itraconazole, posaconazole, voriconazole, caspofungin, nystatin, or amphotericin-B during 2008-2021 had variable effects and intermittent development of antifungal resistance and hospital periods. The patient started using fermented lingonberry juice (FLJ) as a mouth rinse daily in April 2021. No symptoms or mucosal signs of candidiasis in any part of the digestive system or vaginal area have been noticed during this exceptionally long-term 2 ½ year remission in candidiasis without antifungal medications.

Lingonberry (Vaccinium vitis-idaea L.) Skin Extract Prevents Weight Gain and Hyperglycemia in High-Fat Diet-Induced Model of Obesity in Mice.

The percentage of obese people is increasing worldwide, causing versatile health problems. Obesity is connected to diseases such as diabetes and cardiovascular diseases, which are preceded by a state called metabolic syndrome. Diets rich in fruits and vegetables have been reported to decrease the risk of metabolic syndrome and type 2 diabetes. Berries with a high polyphenol content, including lingonberry (Vaccinium vitis-idaea L.), have also been of interest to possibly prevent obesity-induced metabolic disturbances. In the present study, we prepared an extract from the by-product of a lingonberry juice production process (press cake/pomace) and investigated its metabolic effects in the high-fat diet-induced model of obesity in mice. The lingonberry skin extract partly prevented weight and epididymal fat gain as well as a rise in fasting glucose level in high-fat diet-fed mice. The extract also attenuated high-fat diet-induced glucose intolerance as measured by an intraperitoneal glucose tolerance test (IPGTT). The extract had no effect on the levels of cholesterol, triglyceride or the adipokines adiponectin, leptin, or resistin. The results extend previous data on the beneficial metabolic effects of lingonberry. Further research is needed to explore the mechanisms behind these effects and to develop further health-promoting lingonberry applications.

Unveiling the evolutionary history of lingonberry (Vaccinium vitis-idaea L.) through genome sequencing and assembly of European and North American subspecies.

Lingonberry (Vaccinium vitis-idaea L.) produces tiny red berries that are tart and nutty in flavor. It grows widely in the circumpolar region, including Scandinavia, northern parts of Eurasia, Alaska, and Canada. Although cultivation is currently limited, the plant has a long history of cultural use among indigenous communities. Given its potential as a food source, genomic resources for lingonberry are significantly lacking. To advance genomic knowledge, the genomes for 2 subspecies of lingonberry (V. vitis-idaea ssp. minus and ssp. vitis-idaea var. 'Red Candy') were sequenced and de novo assembled into contig-level assemblies. The assemblies were scaffolded using the bilberry genome (Vaccinium myrtillus) to generate a chromosome-anchored reference genome consisting of 12 chromosomes each with a total length of 548.07 Mb [contig N50 = 1.17 Mb, BUSCO (C%) = 96.5%] for ssp. vitis-idaea and 518.70 Mb [contig N50 = 1.40 Mb, BUSCO (C%) = 96.9%] for ssp. minus. RNA-seq-based gene annotation identified 27,243 and 25,718 genes on the respective assembly, and transposable element detection methods found that 45.82 and 44.58% of the genome were repeats. Phylogenetic analysis confirmed that lingonberry was most closely related to bilberry and was more closely related to blueberries than cranberries. Estimates of past effective population size suggested a continuous decline over the past 1-3 MYA, possibly due to the impacts of repeated glacial cycles during the Pleistocene leading to frequent population fragmentation. The genomic resource created in this study can be used to identify industry-relevant genes (e.g. anthocyanin production), infer phylogeny, and call sequence-level variants (e.g. SNPs) in future research.

Determination of benzoate in cranberry and lingonberry by using a solid-contact benzoate-selective electrode.

Benzoic acid is used as a preservative in processed food, and occasionally in cosmetics and pharmaceuticals, while benzoic acid occurs naturally in, e.g., cranberry and lingonberry. Therefore, the determination of benzoate is of interest for product quality assurance, food safety, and personal health. In this work, a solid-contact benzoate-selective electrode (benzoate-ISE) was developed by utilising poly(3,4-ethylenedioxythiophene) (PEDOT) as solid contact and a solvent polymeric membrane containing a 1,3-bis(carbazolyl)urea derivative as ionophore. The benzoate-ISE was characterised in parallel with an ionophore-free control-ISE by electrochemical impedance spectroscopy and potentiometry. The presence of the ionophore in the membrane improved the selectivity to benzoate. Benzoate-ISEs and control-ISEs were used further to determine the benzoate concentration in cranberry and lingonberry by standard addition. The results obtained with both types of ISEs were compared with those obtained by ion chromatography. The results obtained with benzoate-ISEs were consistent with those obtained with ion chromatography. On the contrary, the control-ISE (without ionophore) gave significantly higher benzoate concentrations, especially in the case of cranberry where the benzoate concentration was low (ca 0.2 g kg-1) compared to lingonberry (ca 1 g kg-1). Hence, the benzoate-selectivity of the ionophore was crucial to obtain a benzoate-ISE that was practically applicable for determination of benzoate concentrations in cranberry and lingonberry.

Phenolic distribution in liquid preparations of Vaccinium myrtillus L. and Vaccinium vitis idaea L.

INTRODUCTION: Liquid preparations such as tinctures and 'bud extracts' of bilberry and lingonberry are typical products used in some European countries but they have not been widely studied to date. OBJECTIVE: Our aim was to define a phytochemical profile in terms of phenolic compounds for liquid preparations of Vaccinium myrtillus L. (bilberry) and Vaccinium vitis idaea L. (lingonberry) foliar tissues, and evaluate their stability. METHODS: Up to 17 extracts of lingonberry, and bilberry have been analysed by HPLC equipped with a diode-array detector (DAD) in combination with MS. Some of these samples were freshly prepared (laboratory extracts). RESULTS: Phenolic profiles of the bud extracts and tinctures of bilberry and lingonberry were obtained at 330 nm, typical of the cinnamoyl compounds and suitable to distinguish these two species. Analogously, the profiles at 280 nm were used to detect the arbutin derivatives recognised as the typical markers of lingonberry leaves only. Among the cinnamoyl derivatives, chlorogenic acid was the main compound found in bilberry samples, while caffeoyl arbutin was the principal marker in lingonberry samples. In quantitative terms, the hydroxycinnamic acids were the main class in bilberry bud extracts ranging between 4.67 and 6.81 mg/L (from 52 to 84% of the total phenols). The young sprouts of this species, independently from the extraction mixture, show a higher phenolic content than adult leaves of the same plant. CONCLUSIONS: The analytical method allowed to define fingerprints of bilberry and lingonberry liquid preparations. Moreover, without applying accelerated ageing protocols, the stability over time of 11 samples was evaluated up to 6 months, demonstrating negligible variations.