Search results for "Coffee"
showing 10 items of 97 documents
Influence of different coffee drinks preparations on ochratoxin A content and evaluation of the antioxidant activity and caffeine variations.
2011
Coffee is one of the most frequently consumed beverages in North America and Europe. It is well known that coffee contains caffeine and that coffee beans can be contaminated by Ochratoxin A (OTA). The operating conditions however affect OTA and caffeine extraction from the roasted coffee. OTA content found in the beverages can be greater than that found in the roasted coffee used to prepare it, representing a potential OTA related risk factor for the human health. Moreover the coffee beans and coffee based beverages have an anti oxidant activity. This study investigates the OTA content, the amount of caffeine, and the antioxidant activity in five different preparations: American coffee, Mok…
Improved sensitivity of ochratoxin A analysis in coffee using high-performance liquid chromatography with hybrid triple quadrupole-linear ion trap ma…
2016
A novel and sensitive method utilising high-performance liquid chromatography coupled to triple quadrupole-linear ion trap mass spectrometry (LC-QqQLIT-MS/MS) was developed in order to analyse the content of ochratoxin A (OTA) in coffee samples. The introduction of the triple-stage MS scanning mode (MS(3)) has been shown to increase greatly sensitivity and selectivity by eliminating the high chromatographic baseline caused by interference of complex coffee matrices. The analysis included the sample preparation procedure involving extraction of OTA using a methanol-water mixture and clean-up by immunoaffinity columns and detection using the MS(3) scanning mode of LC-QqQLIT-MS/MS. The propose…
Influence of roasting and different brewing processes on ochratoxin A content in coffee determined by high-performance liquid chromatography-fluoresc…
2008
A rapid and reliable procedure has been developed for the determination of ochratoxin A (OTA) in green and roasted coffee. The method consists of extraction of the sample with methanol-5% aqueous sodium hydrogen carbonate/1% PEG8000 (20:80), followed by immunoaffinity column (IAC) clean-up and, finally, high-performance liquid chromatography (HPLC) determination with fluorimetric detection. Mean recoveries for green and roasted coffee spiked at different levels ranging from 94 and 105% were obtained. The limit of determination (S/N = 3) was 0.032 ng g(-1) and the precision (within-laboratory relative standard deviation) was 6%. The method described has been used to assess the influence of r…
Ochratoxin A in instant coffee in Italy
2012
Abstract The occurrence of ochratoxin A (OTA) in instant coffee from different brands and types was assessed. The survey covered 44 soluble coffees, 10 of which were decaffeinated, and 6 coffee products; the samples were collected in supermarkets and retail stores of Italy in 2011. The OTA was extracted, cleaned-up by immunoaffinity columns, and detected by HPLC-fluorescence detection. The detection and quantification limits were 0.05 and 0.2 μg/kg, respectively. Recovery, from samples spiked at levels of 0.5, 3.0, and 6.0 μg/kg, was 86.0 ± 7.1%, 91.0 ± 4.2%, and 91.7 ± 5.9% respectively. Forty-eight samples (96%) contained OTA at levels ranging from 0.32 to 6.40 μg/kg, always below the Eur…
Sex differences in estimation of time intervals and in reaction time are removed by moderate but not high doses of caffeine in coffee
2002
Estimation of the passage of time in the seconds-to-minutes range and reaction time are strongly dependent on a hypothetical internal clock. Dopamine is the neurotransmitter most closely related to the rate of this clock. Caffeine, probably the most consumed drug in the world, leads to an augmentation of dopamine neurotransmission. In this study coffee, which reproduces the conditions under which caffeine is normally ingested, containing 3, 75, 150 or 300 mg of caffeine, was given to healthy male and female volunteers. A computerized time estimation and reaction time test was carried out 50 min after ingestion. Sex differences in placebo control subjects (who took decaffeinated coffee with …
Detection of a plant enzyme exhibiting chlorogenate-dependant caffeoyltransferase activity in methanolic extracts of arbuscular mycorrhizal tomato ro…
2012
When Glomus intraradices-colonised tomato roots were extracted in methanol at 6 degrees C, chlorogenic acid (5-caffeoylquinic acid), naturally present in the extract, was slowly converted by transesterification into methyl caffeate. The progress of the reaction could be monitored by HPLC. The reaction only occurred when the ground roots were left in contact with the hydro-alcoholic extract and required the presence of 15-35% water in the mixture. When the roots were extracted in ethanol, chlorogenic acid was transformed to ethyl caffeate in the same conditions. The reaction was also detected in Glomus mosseae-colonised tomato root extracts. It was also detectable in non-mycorrhizal root ext…
Coffee Silverskin and Spent Coffee Suitable as Neuroprotectors against Cell Death by Beauvericin and α-Zearalenol: Evaluating Strategies of Treatment
2021
Coffee silverskin and spent coffee have been evaluated in a neuroblastoma cell line (SH-SY5Y cells) against beauvericin (BEA) and α-zearalenol (α-ZEL)-induced cytotoxicity with different strategies of treatment. First, the direct treatment of mycotoxins and coffee by-products extracts in SH-SY5Y cells was assayed. IC50 values for α-ZEL were 20.8 and 14.0 µM for 48 h and 72 h, respectively and, for BEA only at 72 h, it was 2.5 µM. Afterwards, the pre-treatment with spent coffee obtained by boiling water increased cell viability for α-ZEL at 24 h and 48 h from 10% to 16% and from 25% to 30%, respectively
Chapter 18 - Sensory Evaluation—Profiling and Preferences
2017
International audience; Tasting has always been at the heart of coffee growing and production. Expert coffee tasting prevails while applying a correct and structured sensory evaluation still requires improvement. In reality, the key actors of the coffee sensory assessment all along the value chain are the expert coffee taster, the sensory analyst, and the consumer. A major challenge for sensory evaluation in coffee is bridging the gap between the expert tasters and consumers. It is especially important in coffee because, as a natural crop product, supplies and the quality of those supplies constantly change, and consumer preferences evolve over time. Thanks to the continuous innovation in t…
Phthalate esters in coffee brew samples: Analytical method by GC-MS, profile, levels and sources
2012
The present study was aimed to develop a procedure for the analysis of trace concentration of phthalate esters (PEA) in coffee brew stored in plastic cups. Phthalates are esters of phthalic acid, generally have high boiling points, lowvolatility are insoluble in water andpredominantly fat-soluble. Phthalates with higher molecular weights, such as bis(2-ethylhexyl) phthalate (DEHP) are largely used as additives and plasticizers in plastic material (PVC), while those with lower molecular weights are components of solvents, adhesive, wax, ink, pharmaceutical products, insecticide materials and cosmetic. Dimethyl phthalate and diethyl phthalate are present in plastics based on cellulose esters …
Life cycle analysis of innovative building materials based on circular coffee ground supply chain
2022
The construction sector is widely recognized as one of the most polluting mainly due to its intensive exploitation of natural resources and large energy consumption to produce traditional building materials. In the last years, alternative building materials have been developed with the aim to reduce the environmental burden of this sector. In particular, the use of geopolymer mortars as alternative cementitious materials is gaining increasing acceptance among scientists. Numerous laboratory studies demonstrate their suitability for construction applications, highlighting the potential environmental benefits that can be obtained from their large-scale production. This study aims to perform a…