Search Results (6)

The present study comprises the second part of our previous work that dealt mainly with the phytochemical and physicochemical characterization of commercial unroasted green coffee beans, clove, cinnamon–clove and nutmeg ethanolic extracts of grape origin. In the present study, we focused on producing a discriminating model concerning commercial unroasted green coffee beans, clove, cinnamon, cinnamon and clove mixture (1:1, w/w), and nutmeg fine powders based on multivariate analysis of variance and supervised learning from tentative data of volatile compounds analysis, carried out with solid phase dynamic extraction in combination with gas chromatography–mass spectrometry. Results showed that 7 volatile compounds, i.e., ethylene, methanol, 3-methylpentane, ethyl acetate, 9-hexadecen-1-ol, toluene, and methyl acetate, could differentiate the investigated samples resulting in a 100% classification rate using the cross-validation method of linear discriminant analysis. Results were further confirmed using partial least squares regression analysis. The study contributes to the typification of commercial unroasted green coffee beans, cinnamon, clove, cinnamon and clove mixture, and nutmeg, based on selected volatile compounds. In addition, the study provides further support to the literature by means of a possible substitution of these products in rapid analysis tests, given the statistical models developed. Full article

Yearly, thousands of tons of wasted coffee grounds are produced according to high coffee consumption. Still, after the coffee brewing, wasted coffee grounds contain some amounts of caffeine (CAF). CAF, in turn, contains multiple O and N chelating atoms in its structure. These have a potential to be reductors for complexes of metals. In this context, within the present study, a set of CAF extracts derived from coffee beans and coffee grounds were obtained and then used for the one-step reduction of ReO₄⁻ ions with no additional toxic chemicals. Within this approach, CAF was applied as a secondary, green resource for the synthesis of unique rhenium nanoparticles (ReNPs) containing Re species at 0 and +6 oxidation states. The obtained ReNPs were identified and characterized with the use of X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Further, the capping and stabilization of ReNPs by CAF were verified with the aid of Fourier transformation infrared spectroscopy (FT-IR). The so-obtained “green” ReNPs were then used as a homogenous catalyst in the catalytic hydrogenation of 4-nitrophenol (4-NP). This new nanomaterial revealed a superior catalytic activity, leading to the complete reduction of 4-NP to 4-aminophenol within 40–60 min with a first-order rate constant of 0.255 min⁻¹. Full article

The current investigation focuses on the effect of different concentrations of green coffee bean powder (GCBp) on the physicochemical, microbiological, and sensory characteristics of whole wheat bread (WWB). C1 bread formulation (containing 1% GCBp) exhibited the highest loaf volume, suggesting optimal fermentation. Moisture analysis revealed minor alterations in the moisture retention attributes of the bread formulations. Impedance analysis suggested that C1 exhibited the highest impedance with a high degree of material homogeneity. Swelling studies suggested similar swelling properties, except C5 (containing 5% GCBp), which showed the lowest swelling percentage. Furthermore, color and microcolor analysis revealed the highest L* and WI in C1. Conversely, higher concentrations of GCBp reduced the color attributes in other GCBp-containing formulations. FTIR study demonstrated an improved intermolecular interaction in C1 and C2 (containing 2% GCBp) among all. No significant variation in the overall textural parameters was observed in GCBp-introduced formulations, except C2, which showed an improved gumminess. Moreover, the TPC (total phenolic content) and microbial analysis revealed enhanced antioxidant and antimicrobial properties in GCBp-incorporated formulations compared to Control (C0, without GCBp). The sensory evaluation showed an enhanced appearance and aroma in C1 compared to others. In short, C1 showed better physicochemical, biological, and sensory properties than the other formulations. Full article

Coffea liberica presents the smallest proportion of cultivated coffee worldwide. Its taste varies highly from C. arabica spp. or C. canephora spp. As the unfermented taste of C. liberica is often described as lactic, and animalic with aromatics of blue cheese, fermentation experiments of C. liberica coffee cherries were conducted. Coffee cherry fermentation is carried out to modify and enhance the sensory profile of green and roasted coffee beans. Various microorganisms change the composition of organic precursor compounds, reducing off-flavours during green bean coffee processing and roasting. For the comparison of the sensory properties of fermented coffee beans, SCA-trained experts grade the coffees by specific sensory attributes. Roasted and ground coffee powder, as well as ground raw coffee samples, were analysed by headspace-gas chromatography–mass spectrometry/ion mobility spectrometry (GC-MS/IMS) to determine the volatile fingerprint of unfermented and fermented C. liberica coffee. Eight different unfermented C. liberica samples were analysed and the volatile profiles compared to those of arabica spp. and canephora spp. The unfermented coffee beans differ in origin and processing. Furthermore, single-origin C. liberica fermented with two different wine yeasts was compared to unfermented C. liberica. The fermented coffee beans share the same variety, processing, and profile of roasting and differ only in their origin and fermentation inoculum. This study presents the direct comparison of the aromatic fingerprint measured in the instrument. Compound regions in the spectra associated with different coffee species and ferments are shown. The potential of GC-IMS for fast comparison of the aromatic fingerprint is demonstrated. Full article

In the search for oils of commercial interest that serve as new sources for the generation of cosmetic, pharmaceutical, or nutraceutical products, the green coffee beans oil (Coffea arabica L.) was studied. This research aimed to evaluate the oxidative stability of microencapsulated green coffee oil (Coffea arabica) by spray drying. The green coffee oil emulsions were produced by microfluidization using mesquite gum and octenyl succinic anhydride modified starches (OSA-starch) as wall-material. The particle size, polydispersity, and zeta potential on the microfluidized emulsions were optimized. The results showed that microfluidization had positive effects on the reduction of the emulsion droplets and the zeta potential, developing stable emulsions for both polymers. Then, the optimal microfluidization conditions were used to evaluate the impact of the spray drying conditions on the microencapsulation efficiency, morphology, and oxidation stability of the green coffee oil microcapsules under accelerated storage conditions (32% relative humidity (RH) at 25 °C). The microencapsulation efficiency was approximately 98% for both wall-materials. The morphology of the microcapsules showed spherical shapes and polydisperse sizes, a typical characteristic of spray-dried powders. The oxidative stability of the microcapsules was lower than the bulk green coffee oil (87.39 meq of O₂/kg of oil), reaching values of 60.83 meq of O₂/kg of oil for mesquite gum and 70.67 meq of O₂/kg of oil for OSA-starch. The microcapsules produced have good potential for the development of nutraceutical foods or cosmetic formulations with adequate stability. Full article

Extracts of olive leaf, green coffee bean and beetroot may deliver cardiovascular benefits. This study sought to evaluate the effects of regularly consuming a combination of these extracts on blood pressure (BP), arterial compliance, blood lipids, blood glucose and insulin sensitivity. A double-blind randomised placebo-controlled crossover trial was conducted in adults with untreated high normal or borderline elevated BP. They were randomised to take an active supplement, comprising 500 mg olive leaf extract, 100 mg green coffee bean extract and 150 mg beet powder, or a matching placebo twice daily for six weeks, followed by the alternate supplement for a further six weeks. Assessments of 24-h ambulatory BP (ABP), clinic BP arterial compliance (pulse-wave analysis), blood lipids, blood glucose and insulin were obtained at baseline and at the end of each treatment phase. Baseline clinic BP in 37 overweight middle-aged men and women who completed the trial averaged 145/84 mmHg. There was no significant effect of treatment on ABP or any other outcome measure. The failure to confirm prior evidence of the antihypertensive benefits of these extracts emphasises the importance of placebo control and the value of ABP monitoring. Further dose-response evaluation of olive leaf, green coffee bean or beetroot extracts is required to confirm or refute the purported benefits. Full article