roasting
Dotaz
Zobrazit nápovědu
The aim of the present study was to determine concentrations of 15 macro- and micro-elements in 10 commercially available plantation Arabica coffee brands. The elemental concentration was studied in 50 samples of green and roasted coffee beans of various roasting degrees and their infusions. There were four different roasting degrees: City + (C+), Full city (FC), Full city ++ (FC++), and Dark (D). The attention was given to the impact of the roasting process on the elemental composition. Statistically significant differences were found between the green coffee beans and the different roasting degrees in both macro- and micro-elements. The results showed that roasting degrees affected the concentration of elements in resulting infusions. Dietary intakes for macro- and micro-elements based on RDA and PTWI (in the case of Al) were calculated. Based on the RDA values for macro- and micro-elements, it can be concluded that coffee infusions are not an important source of elements in nutrition. In the case of Al, consumption of coffee was considered non-hazardous based on the PTWI value.
RATIONALE: The major objective of this exploratory study was to implement selected ion flow tube mass spectrometry, SIFT-MS, as a method for the on-line quantification of the volatile organic compounds, VOCs, in the headspace of the ground roasted coffee. METHODS: The optimal precursor ions and characteristic analyte ions were selected for real-time SIFT-MS quantification of those VOCs that are the most abundant in the headspace or known to contribute to aroma. NO+ reagent ion reactions were exploited for most of the VOC analyses. VOC identifications were confirmed using gas chromatography/mass spectrometry, GC/MS, coupled with solid-phase microextraction, SPME. RESULTS: Thirty-one VOCs were quantified, including several alcohols, aldehydes, ketones, carboxylic acids, esters and some heterocyclic compounds. Variations in the concentrations of each VOC in the seven regional coffees were typically less than a factor of 2, yet concentrations patterns characteristic of the different regional coffees were revealed by heat map and principal component analyses. The coefficient of variation in the concentrations across the seven coffees was typically below 24% except for furfural, furan, methylfuran and guaiacol. CONCLUSIONS: The SIFT-MS analytical method can be used to quantify in real time the most important odoriferous VOCs in ground coffee headspace to sufficient precision to reveal some differences in concentration patterns for coffee produced in different countries.
- MeSH
- aldehydy analýza MeSH
- alkoholy analýza MeSH
- analýza hlavních komponent MeSH
- analýza potravin metody MeSH
- Coffea chemie MeSH
- hmotnostní spektrometrie metody MeSH
- káva chemie MeSH
- ketony analýza MeSH
- manipulace s potravinami MeSH
- mikroextrakce na pevné fázi metody MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí metody MeSH
- těkavé organické sloučeniny analýza chemie MeSH
- Publikační typ
- časopisecké články MeSH
The concentration of putrescine (PUT), spermidine (SPD) and spermine (SPM) was determined in chilled meat and kidneys of 18 rabbits and in liver of 12 animals 24h after slaughter. Very low PUT concentrations were detected only in kidneys. Mean SPD levels were 2.2, 2.2, 61.7 and 32.7mgkg(-1) in saddle, leg, liver and kidneys, respectively. The respective SPM concentrations were 14.7, 8.0, 115 and 88.4mgkg(-1). SPD and SPM losses of about one third of the initial levels were apparent in saddles stored at -18°C for 8months. Losses of both polyamines of about 15-20% of the initial concentrations were found in saddles stored aerobically at +2°C for up to 9days. Stewing of saddles caused significant SPD and SPM losses of about 20-25%, while upon roasting and pan-roasting without oil a decrease of about 50% of the initial concentration was observed.
U konzumace kávy byla vysledována spojitost se snížením rizika vzniku různých onemocnění vč. ochrany před DNA poškozením a některými druhy maligních nádorů. Chemopreventivní účinek kávy byl popsán v řadě studií in vitro i in vivo ve zvířecích experimentech a v posledních letech i ve studiích u lidí. V rámci bioaktivních složek tohoto nápoje bylo nalezeno několik mechanizmů chemopreventivního působení, a to zejména ochrana před oxidačním stresem, indukce detoxikačních jaterních enzymů zbavujících organizmus kancerogenů a protizánětlivý efekt. Vlastní antioxidační účinek kávy je dán v součtu jak obsahem kyseliny chlorogenové, tak do jisté míry i vlastním procesem pražení, a nejvyšší antioxidační potenciál byl proto popsán u středně pražené varianty. Pražení vede ke tvorbě specifických složek v kávových zrnech, tzv. melanoidinů, které mají antioxidační a protizánětlivý účinek. Vedle toho je káva zdrojem dvou specifických diterpenů cafestolu a kahweolu, které mají protinádorový potenciál. Pražená káva tedy působí v chemoprevenci díky obsahu různých protinádorových složek komplexním mechanizmem. Ve studiích byla prokázána aktivace apoptózy, potlačení růstu i metastazování nádorových buněk a inhibice angiogeneze. Na základě metaanalýz proběhlých epidemiologických studií byla nalezena spojitost mezi konzumací kávy a nižším výskytem různých druhů zhoubných nádorů. Tento přehledový článek shrnuje molekulární mechanizmy, experimentální data i epidemiologické důkazy chemopreventivního účinku kávy.
Coffee consumption is associated with a reduced risk of several diseases including cancer. Its chemopreventive effect has been studied in vitro, in animal models, and more recently in humans. Several modes of action have been proposed, namely, inhibition of oxidative stress and damage, activation of metabolizing liver enzymes involved in carcinogen detoxification processes, and anti-inflammatory effects. The antioxidant activity of coffee relies partly on its chlorogenic acid content and is increased during the roasting process. Maximum antioxidant activity is observed for medium-roasted coffee. The roasting process leads to the formation of several components, e.g., melanoidins, which have antioxidant and anti-inflammatory properties. Coffee also contains two specific diterpenes, cafestol and kahweol, which have anticarcinogenic properties. Roasted coffee is a complex mixture of various chemicals. Previous studies have reported that the chemopreventive components present in coffee induce apoptosis, inhibit growth and metastasis of tumor cells, and elicit antiangiogenic effects. A meta-analysis of epidemiological studies showed that coffee consumption is associated with a lower risk of developing various malignant tumors. This review summarizes the molecular mechanisms and the experimental and epidemiological evidence supporting the chemopreventive effect of coffee.
- MeSH
- antiflogistika MeSH
- antioxidancia MeSH
- apoptóza fyziologie MeSH
- chemoprofylaxe * MeSH
- epidemiologické studie MeSH
- inhibitory angiogeneze MeSH
- káva * MeSH
- klinické zkoušky jako téma MeSH
- lidé MeSH
- metaanalýza jako téma MeSH
- metastázy nádorů prevence a kontrola MeSH
- nádory mortalita prevence a kontrola MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Acrylamide is a potential carcinogen. Several toxicological studies have demonstrated its genotoxic carcinogenicity in animals thus indicating potential human health risks. It is present in several carbohydrate-rich foods on frying, baking and roasting at temperatures higher than 120 °C. Most of the acrylamide dietary exposure has its origin in potato products, coffee, bakery products and chocolate. Acrylamide forms in potato products during their processing, retail, catering and home preparation.
- MeSH
- akrylamidy * analýza chemie otrava škodlivé účinky toxicita MeSH
- dávka bez pozorovaného nepříznivého účinku MeSH
- hodnocení rizik MeSH
- lidé MeSH
- Maillardova reakce * MeSH
- manipulace s potravinami * MeSH
- potraviny klasifikace škodlivé účinky toxicita MeSH
- primární prevence MeSH
- průmysl zpracování potravin MeSH
- Check Tag
- lidé MeSH
The Sarepta, oder Bergpostill (1562) by Johann Mathesius is a book of sermons on mining and mineral subjects in which the composition and generation of metals in ore veins are discussed in terms of the sulfur-mercurius theory. Gur was an embodiment of mercurius or of sulfur and mercurius. Sulfur was evident in the sulfurous odor of the mines, in the supposed effects of subterranean heat, and in the deposition of mineral sulfur during the roasting of the ores. The toxic smoke given off during smelting was considered to be an additional manifestation of mercurius. Mathesius's sermons offer a glimpse of the ways miners' understanding of ores overlapped with alchemists' theories.
- MeSH
- alchymie * MeSH
- dějiny 16. století MeSH
- hornictví dějiny MeSH
- rtuť chemie dějiny MeSH
- síra chemie dějiny MeSH
- stříbro MeSH
- Check Tag
- dějiny 16. století MeSH
- Publikační typ
- biografie MeSH
- časopisecké články MeSH
- historické články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Putrescine (PUT), spermidine (SPD) and spermine (SPM) concentrations using a UPLC method, in chilled mutton, lamb and livers 24 h after slaughter were determined. PUT concentrations were quantifiable only in some samples. Mean SPD concentrations were 4-6, 13.5 and 16.8 mg kg-1 in the meats, sheep and lamb livers, respectively. The respective SPM concentrations were 17-25, 128 and 79 mg kg-1. SPD and SPM losses of about one fifth and half of the initial level, respectively, were apparent in mutton loins stored at -18°C for 6 months. Significant losses of SPD and SPM were found in mutton loins stored aerobically, vacuum-packaged or in a modified atmosphere at +2°C. Boiling and stewing of mutton legs caused SPD and SPM losses of about 40% and roasting of about 60% of the initial content.
The escalating global population is anticipated to intensify the demand for high-quality proteins, necessitating the exploration of alternative protein sources. Edible insects are a promising solution, owing to their nutritional richness and sustainability. However, their digestibility and protein quality, particularly after culinary treatment, remains underexplored. In the present study, we investigated the effects of various culinary treatments on the protein digestibility of two insect species, Tenebrio molitor and Gryllus assimilis. Our findings revealed that culinary treatments such as boiling, roasting, drying, and microwave heating significantly influenced the digestibility of both insect species. Notably, drying emerged as the most effective method, leading to a substantial increase in digestibility. Furthermore, we assessed protein quality using the digestible indispensable amino acid score (DIAAS) and found that the choice of the calculation method significantly influenced the evaluation of protein quality. By including the sum of the anhydrous amino acids, we eliminated the potential overestimation of protein content and obtained a more reliable assessment of protein quality. Our results underscore the importance of culinary treatments and calculation methods in determining the suitability of insects as protein sources for human nutrition.
- Publikační typ
- časopisecké články MeSH
