Coffee Samples Research Articles (Page 1)

NIR spectroscopy and chemometrics-based traceability of specialty Brazilian green canephora coffee.

Assessment of naturally occurring radionuclides and radiation safety in coffee samples from Saudi markets

Occurrence and co-occurrence of aflatoxins, T-2, and HT-2 in instant coffee collected from China.

Exploring HDES as a sustainable green extractant phase in HF-MMLLE technique for assessment of PAHs in hot beverages and evaluation of potential dietary exposure risks for the Brazilian population.

Sensitive determination of caffeoylquinic acid in food and blood samples using nanostructured conducting polymer composite modified electrode.

A multivariate optimization of a green ultrasound-assisted extraction method using a natural deep eutectic solvent for the determination of Fe, Mn, and Zn in instant coffee samples by F AAS.

Coffee is among the most consumed beverages worldwide and is recognized for its bioactive compounds, which exert diverse physiological effects. This study evaluated the impact of roasting degree on the in vitro antioxidant activity and digestive enzyme inhibition of brews from four Mexican regions, as well as their in vivo effects on carbohydrate and lipid absorption. Antioxidant capacity was assessed through radical scavenging and lipid peroxidation inhibition, while inhibition of lipase, α-amylase, and α-glucosidase was also determined. Oral starch (OSTT) and lipid (OLTT) tolerance tests were conducted in healthy Wistar rats. Antioxidant activity was strongly influenced by region and roasting degree. All coffee samples exhibited radical scavenging activity and lipid peroxidation inhibition. With respect to enzyme inhibition, all coffees showed ~67–70% inhibition of lipase activity. For amylase, unroasted coffee from Oaxaca displayed the highest inhibition (34%, p < 0.001). For glucosidase, unroasted samples showed low inhibition (~6–19%), which increased substantially at the medium roast degree (~55% across all samples) but decreased again at the high roast degree (~27%). In OSTT, serum glucose levels were reduced after 120 min by ~20%, 21%, and 18% in rats treated with unroasted, medium-roast, and high-roast coffee, respectively, compared with the negative control. In OLTT, serum triglycerides decreased by ~26% (Chiapas), ~58% (Colima), ~32% (Oaxaca), and ~54% (Hidalgo). Crop region and roasting degree influence the phytochemical profile and bioactivity of Mexican coffee. Although unroasted coffees had the highest concentration of bioactive compounds, roasting enhanced specific bioactivities, particularly enzyme inhibition and lipid-lowering effects in vivo.

Indole-3-acetic acid (IAA) is a natural hormone found in all plants and can also be used as a plant growth regulator, which is banned in the EU. To differentiate between its natural presence and pesticide usage, the origin and fate of IAA during coffee roasting were studied. Green beans from the Coffea arabica and Coffea canephora varieties were spiked with a stable isotope precursor, 13C11-tryptophan, and roasted to different degrees. Liquid and gas chromatography coupled with mass spectrometry were used to analyze the degradation products. Alkaline hydrolysis determined free and bound IAA proportion in the coffee samples. The study found that IAA levels increased during roasting, forming indole-3-acetaldehyde and further degrading into 3-methylindole. Hydrolysis experiments showed that IAA was released from the coffee matrix, with higher amounts released during longer roasting times. These results indicate that IAA naturally occurs in green coffee and is not likely due to pesticide use.

Adhesive tapes as sampling probes and thermal desorption substrates, in search of direct analysis of particulate solid samples using Soft Ionization by Chemical Reaction In Transfer mass spectrometry.

Detection of ground coffee adulteration using FTIR coupled with pattern recognition techniques.

Ultra-sensitive and real-time detection of quercetin in food samples using nanozyme 2D CuO nanosheet printed flexible electrode.

ABSTRACTThe consumption of specialty coffee has been growing and attracting an increasing number of enthusiasts both in Brazil and worldwide. Annually, new research is conducted to understand consumer perceptions regarding the nuances of this beverage. This study aimed to explore the sensory perceptions of specialty coffees using the Temporal Dominance of Sensations (TDS) methodology across different roast levels, comparing responses from trained panels and regular consumers. Using samples of Coffea arabica from Minas Gerais in Brazil, the study applied the TDS technique to assess the sensory impact of three distinct roast levels (light, medium, and dark) on both primary (category‐level attributes per the SCA Flavor Wheel) and secondary (sub‐category descriptors) attributes. Coffee samples were analyzed by a panel of trained evaluators based on the Q Grader training protocol and a group of regular specialty coffee consumers. The results revealed distinct sensory profiles across roast levels, with notable differences between trained panelists and consumers. Light roasts were associated with sour and fruity notes, especially by trained panelists, while consumers more often perceived bitter and fermented attributes. Medium roasts showed greater sensory balance, and dark roasts were predominantly bitter for both groups, though trained panelists also identified fermented and alcoholic notes more clearly. Trained evaluators demonstrated greater sensitivity and were able to discern a wider range of sensory attributes. In addition, they spent less time selecting the first sensation and showed higher dominance rates for most attributes compared to the panel of regular specialty coffee consumers for both primary and secondary attributes. This divergence not only emphasizes the role of sensory training in enhancing perceptual acuity but also underlines the importance of aligning coffee sensory claims with consumer expectations and perception.

Coffee is one of the most consumed beverages worldwide, being an integral part of culture, economy, and daily life. Soluble coffee stands out for its practicality and wide acceptance in the market. Its chemical composition can vary according to the origin of the beans, processing, and storage conditions, directly affecting its quality and authenticity. In this context, the determination and discrimination of ions in soluble coffee samples are relevant strategies for quality control and detection of possible adulterations. In this study, five brands of soluble coffee marketed in Vitória da Conquista, Brazil, were analyzed by ion chromatography (IC) for the quantification of K⁺, Na⁺, Mg²⁺, NH₄⁺ and Ca²⁺. Multivariate data analysis, using principal component analysis (PCA), was applied to explore the ionic profiles. Two principal components explained 75.86% of the total variance. PC1 (48.23%) was dominated by K⁺, Na⁺ and Mg²⁺, while PC2 (27.63%) was mainly influenced by NH₄⁺ and Ca²⁺. Score plots revealed two distinct groups of soluble coffee samples, reflecting heterogeneity in ionic composition and highlighting differences among manufacturers. The results demonstrate that IC combined with exploratory data analysis is effective for the discrimination of soluble coffee samples, contributing to quality monitoring, authenticity verification, and food safety.

Determination of cadmium and lead in tea and coffee beverages by direct magnetic sorbent sampling flame atomic absorption spectrometry.

Caffeine detection in green tea and coffee samples using nanoelectronic device based on bimetallic FeNi-metal organic framework.

Voltammetry sensor based on poly(L-methionine)/reduced graphene oxide/β-cyclodextrin for the simultaneous determination of caffeine, dopamine and serotonin.

Pesticide residues in Green, roasted, and capsule coffee from the Egyptian market: Occurrence, processing effects, and health risk assessment.

Coffee adulteration is a growing concern in the food industry due to economic and quality implications. This study evaluates a rapid, non-targeted fingerprinting method based on flow injection analysis–mass spectrometry (FIA-MS) for detecting common coffee adulterants. A total of 119 samples were analyzed, including 43 coffee samples and 76 samples of common coffee adulterants (16 chicory, 10 barley, and 50 flour samples). FIA-MS combined with chemometric analysis allowed for the classification of pure and adulterated coffee samples with over 95% accuracy. Compared to LC-MS, the FIA-MS method showed a similar performance while offering significantly faster analysis and lower solvent consumption, making it a practical and sustainable option for high-throughput screening. For PLS regression studies, calibration and prediction errors were consistently below 0.91% and 11.7%, respectively. Furthermore, the methodology was compared with a non-targeted LC-MS approach, showing an excellent performance.

The heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were quantified in 26 roasted coffee samples (19 Arabica and 7 Robusta) consumed in Turkey using ICP-OES. Cd and Pb were not detected in any sample. Cr was found only in Robusta samples, with a mean concentration of 0.58mg/kg. The average concentrations of Cu, Fe, Mn, Ni, and Zn were 12.34 and 13.10mg/kg, 13.67 and 14.69mg/kg, 23.37 and 11.66mg/kg, 0.04 and 1.17mg/kg, and 8.31 and 7.19mg/kg in Arabica and Robusta coffee samples, respectively. The heavy metal concentrations were compared with international limits and literature values. To assess the human health risk posed by heavy metals in the coffee samples, the estimated daily intake (EDI), hazard quotient (HQ), and hazard index (HI) were calculated based on average coffee consumption. All the EDI values were below the oral reference doses (RfDs), and both the HQ and HI values were less than 1, indicating no significant non-carcinogenic health risk associated with coffee consumption. Descriptive statistics summarized heavy metal levels, while inferential statistical tests evaluated differences among the coffee-growing regions and between the coffee bean species.

Exploring the feasibility of shortened extraction times for HS-SPME: A study with coffee samples