Lipid Oxidation Changes of Arabica Green Coffee Beans during Accelerated Storage with Different Packaging Types

Green solvents in dispersive liquid-liquid microextraction for the determination of carbonyl compounds in coffee extracts

This work presents a greener approach for ultrasound-assisted (UA) dispersive liquid-liquid microextraction (DLLME) of carbonyl compounds from coffee samples, before GC-MS determination. This work aims to substitute the solvents used in the traditional DLLME procedures with greener alternatives and to decrease the volume of solvents used. Low-density solvents, 1-octanol and isooctane, were evaluated as the extraction solvent. Optimization of critical experimental parameters was conducted in two stages: an asymmetrical screening design 2331 // 8, followed by a Doehlert experimental design. In the first experimental design 4 parameters were optimized: the volume of aqueous phase volume (1.5 mL), the concentration of the derivatization reagent solution pentafluorophenylhydrazine (1.12 g/L) and the volume and type of extraction solvent (60 µL of isooctane). In the second experimental design, 15 min of derivatization at 50 °C were selected as optimized conditions. The enrichment factor associated with the DLLME procedure enabled the efficient extraction of nine carbonyl compounds (acetaldehyde, acrolein, benzaldehyde, diacetyl, formaldehyde, furfural, glyoxal, malondialdehyde, and methylglyoxal) from coffee samples. The method demonstrated strong analytical performance, with figures of merit including r2 ≥ 0.9990, limits of detection between 289 and 436 µg/L, intraday, and interday precisions < 9.5 %. Recovery values for all nine carbonyl compounds ranged from 90.0 to 110.0 %. The greenness of the developed methodology was assessed using the AGREEprep tool, yielding a score of 0.59. Acetaldehyde, benzaldehyde and furfural were quantified in most coffee samples analyzed, with no significant differences observed in carbonyl compounds composition.

Coffee as a Source of Antioxidants and an Elixir of Youth

Coffee is more than a universally loved beverage; it is a complex matrix of bioactive compounds that contribute to its multifaceted health benefits. From its role as a potent source of antioxidants to its potential anti-aging effects, coffee has proven to be a valuable component of a balanced diet. This paper highlights the extensive scientific evidence supporting coffee's ability to combat oxidative stress, enhance cognitive function, and improve metabolic and cardiovascular health. Additionally, its role in modulating key cellular pathways underscores its potential to positively influence aging and longevity. This manuscript emphasizes coffee's broader cultural, economic, and historical significance, illustrating its enduring relevance in contemporary society. Despite minor discrepancies in research findings, the preponderance of evidence underscores coffee's potential as a functional food with profound implications for healthspan and aging. While promising, translating findings to humans requires further clinical research.

Effect of Temperature and Storage on Coffee's Volatile Compound Profile and Sensory Characteristics

The study investigated the effects of storage temperature, type of coffee, and brewing method on coffee's volatile compound profile and sensory quality. Three types of coffee were included in the study: Arabica, Robusta, and their 80/20 blend. Samples were stored at 5 °C and 20 °C for one month, after which the changes in the composition of volatile compounds were analysed and the sensory quality of espresso and cold brew coffee was assessed. The results showed that storing coffee at a lower temperature slows the changes in the profile of volatile compounds such as aldehydes, alcohols, pyrazines, and furans, helping preserve the desired aroma and flavour characteristics. Storage at higher temperatures resulted in greater changes in the volatile profile and sensory quality, with higher perceptions of earthy, sharp, and smoky notes and lower chocolatey and sweet notes. The brewing method also had a significant effect on the sensory quality. The espresso coffee had a higher intensity of coffee aroma, chocolate flavour, smoky aroma, and roasted notes. In contrast, cold brew coffee was perceived as sweeter, fruitier, and had more pronounced rum notes. The coffee type also significantly influenced the aroma and flavour profile. Arabica had a more harmonious and mild aromatic profile, while Robusta had a sharper aroma. The blend of Arabica and Robusta combined the characteristics of both coffees and offered a balanced aromatic profile.

Application of ATR-FTIR for Green Arabica Bean Shelf-Life Determination in Accelerated Storage

Coffee bean oxidation is associated with enzymatic and non-enzymatic browning, the degradation of desirable aromatic compounds, the development of undesirable flavors, increased susceptibility to microbial spoilage, and volatile compound losses. This study investigated natural dry process (DP) and honey process (HP) green coffee beans stored in GrainPro® bags for 0, 5, 10, and 20 days under accelerated storage conditions at 30 °C, 40 °C, and 50 °C with relative humidity of 50%. A kinetic model was used to estimate the shelf life of the green coffee beans. DP recorded durability of 45.67, 29.9, and 24.92 days at 30 °C, 40 °C, and 50 °C, respectively, with HP 60.34, 38.07, and 19.22 days. Partial least squares (PLS) analysis was performed to build the models in order to predict the shelf life of coffee based on peroxide (PV) and thiobarbituric acid reactive substances (TBARS) values. In terms of prediction with leave-one-out cross-validation (LOOCV), PLS provided a higher accuracy for TBARS (R2 = 0.801), while PV was lower (R2 = 0.469). However, the auto-prediction showed good agreement among the observed and predicted values in both PV (R2 = 0.802) and TBARS (R2 = 0.932). Based on the variable importance of projection (VIP) scores, the ATR-FTIR peaks as 3000-2825, 2154-2150, 1780-1712, 1487-2483, 1186-1126, 1107-1097, and 1012-949 cm-1 were identified to be the most related to PV and TBARS on green coffee beans shelf life. ATR-FITR showed potential as a fast and accurate technique to evaluate the oxidation reaction that related to the loss of coffee quality during storage.

A review: Effects of microbial fermentation on the structure and bioactivity of polysaccharides in plant-based foods

Fermented plant-based foods that catering to consumers' diverse dietary preferences play an important role in promoting human health. Recent exploration of their nutritional value has sparked increasing interest in the structural and bioactive changes of polysaccharides during fermentation, the essential components of plant-based foods which have been extensively studied for their structures and functional properties. Based on the latest key findings, this review summarized the dominant fermented plant-based foods in the market, the involved microbes and plant polysaccharides, and the corresponding modification in polysaccharides structure. Further microbial utilization of these polysaccharides, influencing factors, and the potential contributions of altered structure to the functions of polysaccharides were collectively illustrated. Moreover, future research trend was proposed, focusing on the directional modification of polysaccharides and exploration of the mechanisms underlying structural changes and enhanced biological activity during fermentation.

Gas chromatography-mass spectrometry analysis of fatty acids in healthy and Aspergillus niger MH078571.1-infected Arabica coffee beans

The organic composition of Arabica coffee beans, particularly fatty acids, significantly influences their overall quality. After measuring its composition of fatty acids, it contained a high percentage of saturated fatty acids (SFA), including caprylic, lauric, myristic, palmitic, margaric, fat, and orchid. Moreover, the sample contained unsaturated fatty acids (USFA), namely palmitoleic acid (C16:1), oleic acid (C18:1), linoleic acid (C18:2), and alpha-linoleic acid (C18:3). Coffee beans are susceptible to infection by fungi during storage, the development of which has adverse effects on the beans. The present study aimed to examine the impact of Aspergillus niger MH078571.1 infection on the diversity and abundance of fatty acids in green Arabica coffee beans. The impact of Aspergillus niger on the consumption of fatty acids in Arabica coffee beans was assessed. The findings of the study indicate that the duration of storage had a significant impact on the levels of fatty acids, specifically miristic (C14:0), margaric (C17:0), and stearic (C18:0), which increased as the storage period and temperature increased. Conversely, the percentage of oleic acid decreased under these conditions. This trend was observed across different storage temperatures (0, 8, and 25°C) in untreated coffee beans affected by fungal activity.

Effect of green and roasted coffee storage conditions on selected characteristic quality parameters

The paper attempts to determine the best storage conditions for green and roasted coffee beans. Coffee beans were processed in various ways-some of them were washed or left in their natural state after harvesting, then they were stored in two types of packaging with different permeability, i.e. jute bag and GrainPro polymer bag, ensuring stable conditions in three temperature chambers, i.e. - 10, 10 and 20 °C. The grains treated in this way were evaluated after 3, 6, 9, and 12 months. The selection of the analyzed parameters (in roasted coffee-cupping and 3 selected volatile organic compounds; in green coffee-average water activity, content of volatile fatty acids, 6 selected volatile organic compounds) was to monitor the ongoing processes, and thus the qualitative changes taking place in grains. The research shows that grain stored at 20 °C ages the fastest. Grains stored in - 10 °C and 10 °C chambers perform similarly well. The evaluation of the parameters shows that among the grains stored in these two chambers, the method of grain processing (Natural/Washed) had a greater impact on the results, while the type of packaging did not differentiate the grains to such a significant extent.