9 research outputs found

    Comparison of nine common coffee extraction methods: instrumental and sensory analysis

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    The preparation of a cup of coffee may vary between countries, cultures and individuals. Here, an analysis of nine different extraction methods is presented regarding analytical and sensory aspects for four espressi and five lunghi. This comprised espresso and lungo from a semi-automatic coffee machine, espresso and lungo from a fully automatic coffee machine, espresso from a single-serve capsule system, mocha made with a percolator, lungo prepared with French Press extraction, filter coffee and lungo extracted with a Bayreuth coffee machine. Analytical measurements included headspace analysis with HS SPME GC/MS, acidity (pH), titratable acidity, content of fatty acids, total solids, refractive indices (expressed in °Brix), caffeine and chlorogenic acids content with HPLC. Sensory analysis included visual, aroma, flavor and textural attributes as well as aftersensation. The technical differences in the extraction methods led to a higher concentration of the respective quantities in the espressi than in the lunghi. Regarding the contents per cup of coffee, the lunghi generally had a higher content than the espressi. The extraction efficiency of the respective compounds was mainly driven by their solubility in water. A higher amount of water, as in the extraction of a lungo, generally led to higher extraction efficiency. Comparing analytical data with sensory profiles, the following positive correlations were found total solids ↔ texture/body, headspace intensity ↔ aroma intensity, concentrations of caffeine/chlorogenic acids ↔ bitterness and astringenc

    Exploring indicators of food choice for chimpanzees at Taï National Park, Cîte d’Ivoire : aroma and antioxidants

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    This study explored the food choice for chimpanzees at Taï National Park, Cîte d’Ivoire and attempted to link these to the aroma and antioxidants content. The focus was on the aroma composition and antioxidant content of the fruits of the tree Sacoglottis gabonensis (Baill.) Urb., S. gabonensis, at different ripeness stages, in order to elucidate potential drivers for the selection of presumably ripe fruits by the apes. Flavour analyses have revealed clear differences between the unripe, ripe and to a lesser extent also between ripe and overripe fruits. Eating fruits at a ripe stage implies that chimpanzees are rewarded with high level of macro-nutrients, e.g. carbohydrates together with low content of unwanted bitter compounds. Yet, ripe fruits do not represent a ripeness stage with highest antioxidant content and highest antioxidant content was found in unripe fruit, which is gradually decreasing while ripening

    Can we measure the freshness of roasted coffee?

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    We analysed different freshness indices with HS GC-MS (ratios of distinct aroma molecules) for coffee packed in different materials. Whole beans packed in non-airtight packagings had a shelf life of smaller than two months, whereas for airtight packed coffees, the ratios did not change significantly with time up to almost one year, except the dimethyl disulfide/ methanethiol ratio, showing an intrinsic decomposition of the aroma of coffee with time. This temporal evolution results from the transformation of methanethiol to dimethyl disulphide, reflecting the freshness of coffee the best. Capsule systems are airtight up to approximately 40 weeks of storage time

    Curcuma DMSO extracts and curcumin exhibit an anti-inflammatory and anti-catabolic effect on human intervertebral disc cells, possibly by influencing TLR2 expression and JNK activity

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    Background As proinflammatory cytokines seem to play a role in discogenic back pain, substances exhibiting anti-inflammatory effects on intervertebral disc cells may be used as minimal-invasive therapeutics for intradiscal/epidural injection. The purpose of this study was to investigate the anti-inflammatory and anti-catabolic potential of curcuma, which has been used in the Indian Ayurvedic medicine to treat multiple ailments for a long time. Methods Human disc cells were treated with IL-1ÎČ to induce an inflammatory/catabolic cascade. Different extracts of curcuma as well as curcumin (= a component selected based on results with curcuma extracts and HPLC/MS analysis) were tested for their ability to reduce mRNA expression of proinflammatory cytokines and matrix degrading enzymes after 6 hours (real-time RT-PCR), followed by analysis of typical inflammatory signaling mechanisms such as NF-ÎșB (Western Blot, Transcription Factor Assay), MAP kinases (Western Blot) and Toll-like receptors (real-time RT-PCR). Quantitative data was statistically analyzed using a Mann Whitney U test with a significance level of p < 0.05 (two-tailed). Results Results indicate that the curcuma DMSO extract significantly reduced levels of IL-6, MMP1, MMP3 and MMP13. The DMSO-soluble component curcumin, whose occurrence within the DMSO extract was verified by HPLC/MS, reduced levels of IL-1ÎČ, IL-6, IL-8, MMP1, MMP3 and MMP13 and both caused an up-regulation of TNF-α. Pathway analysis indicated that curcumin did not show involvement of NF-ÎșB, but down-regulated TLR2 expression and inhibited the MAP kinase JNK while activating p38 and ERK. Conclusions Based on its anti-inflammatory and anti-catabolic effects, intradiscal injection of curcumin may be an attractive treatment alternative. However, whether the anti-inflammatory properties in vitro lead to analgesia in vivo will need to be confirmed in an appropriate animal model.ISSN:1476-925

    Comparison of nine common coffee extraction methods : instrumental and sensory analysis

    Get PDF
    The preparation of a cup of coffee may vary between countries, cultures and individuals. Here, an analysis of nine different extraction methods is presented regarding analytical and sensory aspects for four espressi and five lunghi. This comprised espresso and lungo from a semi-automatic coffee machine, espresso and lungo from a fully automatic coffee machine, espresso from a singleserve capsule system, mocha made with a percolator, lungo prepared with French Press extraction, filter coffee and lungo extracted with a Bayreuth coffee machine. Analytical measurements included headspace analysis with HS SPME GC/MS, acidity (pH), titratable acidity, content of fatty acids, total solids, refractive indices (expressed in Brix), caffeine and chlorogenic acids content with HPLC. Sensory analysis included visual, aroma, flavor and textural attributes as well as aftersensation. The technical differences in the extraction methods led to a higher concentration of the respective quantities in the espressi than in the lunghi. Regarding the contents per cup of coffee, the lunghi generally had a higher content than the espressi. The extraction efficiency of the respective compounds was mainly driven by their solubility in water. A higher amount of water, as in the extraction of a lungo, generally led to higher extraction efficiency. Comparing analytical data with sensory profiles, the following positive correlations were found total solids - texture/body, headspace intensity – aroma intensity, concentrations of caffeine/chlorogenic acids – bitterness and astringency
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