38 research outputs found

    Evaluation of extraction methods for determination of phenolic compounds, organic acids and sugars in lingonberries (Vaccinium vitis-idaea)

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    Health benefits of lingonberries (Vaccinium vitis-idaea) have been linked to phenolic compounds, whereas organic acids and sugars are important for the taste of the berries. Contents of these compounds combined can be used to determine lingonberry quality. Extraction is a critical step in analyses, and many different methods have been used. The aim of the study was to evaluate different extraction methods and to determine if one single extraction method could be used to measure the content of phenolic compounds, organic acids, and sugars in lingonberries. Depending on extraction method and season, the concentrations of anthocyanins, flavonols, selected flavan-3-ols, and cinnamic acid containing compounds (CAC) in the lingonberries were 48-105, 14-32, 73-189, and 12-23 mg 100 g-1 fw, respectively. The organic acids (2.3-2.9 mg 100 g-1 fw) were mainly citric and quinic acid and the sugars (5.3-6.9 g 100 g) were glucose and fructose. 70% methanol was the best extraction solvent for anthocyanins, whereas 70% acetone was more efficient for flavan-3-ols. For extraction of CAC, flavonols, organic acids and sugars, 70% methanol and 70% acetone were equally efficient. Similar results were obtained from fresh and freeze-dried berries, but deviation between parallels was lower when extracting from freeze-dried berries. Considering both accuracy and time of preparation, extracting freeze-dried berries with 70% methanol was considered the best extraction method for analyzing compounds important for quality of lingonberries

    Effect of ripening temperature on the chemical composition of lingonberries (Vaccinium vitis-idaea L.) of northern and southern origin

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    Lingonberries (Vaccinium vitis-idaea L.) from two locations, northern (69â—¦N, 18â—¦E) and southern (59â—¦N, 10â—¦E) Norway, were grown under controlled conditions in a phytotron at two temperatures (9 and 15 â—¦C) to study the effects of the ripening temperature and origin on the chemical composition of the berries. The concentrations of phenolic compounds, sugars, and organic acids as well as the profile of volatile organic compounds (VOCs) were determined using chromatographic and mass spectrometric methods. Five anthocyanins, eleven flavonols, eight cinnamic acid derivatives, three flavan-3-ols, three sugars, three organic acids, and 77 VOCs were identified, of which 40 VOCs had not previously been reported in lingonberries. Berries from both locations, were found to have higher contents of anthocyanins and cinnamic acid derivatives when ripened at lower temperature (9 â—¦C), compared to the higher temperature (15 â—¦C). Lingonberries of northern origin had a different VOC profile and higher contents of anthocyanins and organic acids than berries originating from the south. Lingonberries from the northern location also had higher proportions of cyanidin-3-O-glucoside and cyanidin-3-O-arabinoside than lingonberries from the southern location. The results show that the composition of lingonberries is influenced by both the environment and the origin of the plants, with phenolic compounds mainly influenced by the growth temperature and VOCs mainly influenced by plant origin

    Composition of Sugars, Organic Acids, Phenolic Compounds, and Volatile Organic Compounds in Lingonberries (Vaccinium vitis-idaea L.) at Five Ripening Stages

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    Wild lingonberries are a traditional source of food in the Nordic countries and an important contributor to economic activity of non-wood forest products in the region. Lingonberries are a rich source of bioactive compounds and can be a valuable contributor to a healthy diet. However, there are few studies available on how the bioactive compounds in lingonberries develop as they ripen. In this investigation, we examined the content of 27 phenolic compounds, three sugars, four organic acids, and 71 volatile organic compounds at five ripening stages. The study showed that, while the highest content of phenolic compounds was found early in the development, the organoleptic quality of the fruits improved as they ripened. From the first to the last stage of development, anthocyanins went from being nearly absent to 100 mg/100 g fw, and there was an increased content of sugars from 2.7 to 7.2 g/100 g fw, whereas the content of organic acids decreased from 4.9 to 2.7 g/100 g fw, and there were several changes in the profile of volatiles. The contents of flavonols, cinnamic acid derivatives, flavan-3-ols, and the total concentration of phenolic compounds were significantly lower in the fully ripe berries compared to berries in the early green stage. In addition to the changes occurring due to ripening, there was observed variation in the profile of both phenolic compounds and volatiles, depending on the growth location of the berries. The present data are useful for the assessment of harvest time to obtain the desired quality of lingonberries

    Antioxidative protection of dietary bilberry, chokeberry and Lactobacillus plantarum HEAL19 in mice subjected to intestinal oxidative stress by ischemia-reperfusion

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    <p>Abstract</p> <p>Background</p> <p>Ischemia-reperfusion (I/R) in the intestines is an inflammatory condition which activates leukocytes and reactive oxygen species (ROS) and leads to lipid peroxidation and DNA damage. Bilberry and chokeberry fruits are rich sources of polyphenols which may act as antioxidants and prevent lipid peroxidation. Lactic acid bacteria (LAB) may improve microbial status in the intestines and increase the metabolic activity towards polyphenolic degradation. The aim of the study was to clarify antioxidative effects of bilberry and chokeberry fruits alone and with addition of a LAB-strain, <it>Lactobacillus plantarum </it>HEAL19, in an I/R-model in mice.</p> <p>Methods</p> <p>Male BALB/cJ mice were fed the experimental diets for 10 days. Diets consisted of standard chow supplemented with either bilberry (<it>Vaccinium myrtillus</it>) or chokeberry (<it>Aronia × prunifolia</it>) powder alone or in combination with the LAB-strain <it>Lactobacillus plantarum </it>HEAL19. I/R-injury was induced by holding superior mesenteric artery clamped for 30 minutes followed by reperfusion for 240 minutes. Thereafter, colonic and caecal tissues and contents were collected. Malondialdehyde (MDA) was used as indicator of lipid peroxidation and was measured by a calorimetric assay, lactobacilli were cultured on Rogosa agar plates and <it>Enterobacteriaceae </it>on VRBG agar plates, anthocyanins and phenolic acids were analysed by HPLC-DAD-ESI-MSn.</p> <p>Results</p> <p>MDA was significantly decreased in the colon of groups fed bilberry alone (p = 0.030) and in combination with <it>L. plantarum </it>HEAL19 (p = 0.021) compared to the IR-control but not in chokeberry-fed groups. Supplementation with bilberry or chokeberry alone reduced the total number of lactobacilli on the mucosa. Higher concentrations of anthocyanins were found in the colon than in the caecum content of mice. A more varied composition of different anthocyanins was also observed in the colon content compared to the caecum of bilberry-fed mice. Phenolic acids formed by microbial degradation of the dietary polyphenols in the gut could be detected. More phenolic metabolites were found in the intestines of bilberry-fed mice than in the chokeberry-fed ones.</p> <p>Conclusions</p> <p>Bilberry alone and in combination with <it>L. plantarum </it>HEAL19 exerts a better protection against lipid peroxidation than chokeberry. These dietary supplements may be used to prevent or suppress oxidative stress.</p

    Effect of temperature on stability of anthocyanins, ascorbic acid and color in strawberry and raspberry jams

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    Strawberry (cv. Senga Sengana) and raspberry (cv. Veten) were processed into jams at 60, 85 or 93 °C and stored at 4 or 23 °C for 8 and 16 weeks. High processing temperature reduced ascorbic acid, total monomeric anthocyanins (TMA) and total phenolics (TP) in strawberries (p 90%), TMA (> 42%) and TP (> 69%). Storage temperature affected stability of anthocyanins, but had minor effect on ascorbic acid, which declined rapidly independent of storage temperature. Storage temperature also explained most of the variance (> 40%) in Chroma of the jams and L* of raspberry jams (53%). Bioactive compounds and color were more stable in raspberry jams than in strawberry jams.acceptedVersio

    Optimization of Extraction of Apple Pomace Phenolics with Water by Response Surface Methodology

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    Response surface methodology was employed to optimize the extraction of apple pomace phenolics with water. The constructed models were adequate to explain the behavior of the extraction system and predict the responses, total phenolics, and 5-hydroxymethylfurfural. Among the studied factors, temperature, extraction time, and solvent to solid ratio had the greatest influence on the responses. Water extraction using a combination of 100 degrees C for temperature, 37 min for extraction time, and 100 mL/g for solvent to solid ratio provided an opportunity to extract the antioxidants of apple pomace by limiting the formation of 5-hydroxymethylfurfural. Twenty-nine phenolic compounds were characterized in apple pomace by HPLC-MS. Phenolic content of apple pomace was 8341 mg/kg of dry matter at optimized conditions, which offer an alternative, safer way to extract antioxidants than by use of organic solvents

    The stability of phenolic compounds and the colour of lingonberry juice with the addition of different sweeteners during thermal treatment and storage

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    Lingonberries (Vaccinium vitis-idaea L.) are rich in phenolic compounds associated with several health benefits. The berries are also astringent, sour, and bitter and the addition of a sweetener is necessary to increase the palatability of lingonberry products. The addition of a sweetener may, however, affect the stability of phenolic compounds in the product. The aim of this study was thus to determine the effects of the addition of sweeteners (sucrose, acesulfame K or sucralose) and temperature on the stability of anthocyanins, flavonols, flavan-3-ols, hydroxycinnamic acids and the colour of lingonberry juice during thermal treatment and storage. The addition of sweeteners did not affect the stability of phenolic compounds or the colour of lingonberry juice during thermal treatment or storage. The stability of the phenolic compounds was significantly affected by temperature. Anthocyanins were the least stable of the phenolic compounds. The half-lives of total anthocyanins were 3.8, 2.0 and 0.8 h at 75, 85 and 95 °C, respectively. The half-lives during storage were 12.8 and 2.7 weeks at 6 and 22 °C, respectively. Cyanidin-3-galactoside, the major anthocyanin in lingonberries, was extensively degraded during storage, probably due to galactoside side-activities of the enzyme preparation used in juice production. After thermal treatment, the juices were darker and bluer, with lower chromaticity, while after storage, the juices were lighter, more yellow, and had higher chromaticity
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