Espresso Coffee preparation: analytical study to improve the quality of the product

The PhD project was divided into three main parts. The first part aimed to develop and optimize efficient and simply methods for the quantification of nine phytoestrogens in green coffee, and three lignans in ground and espresso coffee (EC), using HPLC-MS/MS. For this purpose, different extraction processes, i.e., acid and base hydrolysis, enzymatic hydrolysis, organic solvent extraction, and a combination of these, have been studied. The best performing procedures, in term of recovery and quantitative data, were chosen, validated and finally applied to different samples coming from diverse geographical origins. The final objective was to characterize the content of these compounds in the whole coffee chain, from green beans to cup. The second part concerned the optimization of espresso coffee extraction, by modifying some machine variables aiming to produce a good quality espresso coffee, lowering the amount of coffee powder used for espresso preparation. The variables under study were the particle size distribution (PSD) of roast and ground (R&G) coffee, the design of the filter basket and the height of perforated disc. The EC quality was investigated from chemical point of view and it concerned the total solids (TS) analysis and the quantification of caffeine, chlorogenic acids and trigonelline. In addition, some analysis on volatile fraction were also performed. The third part of the project focused on promoting and adding value to coffee silverskin (CS) in the perspective of its application in the food industry. The work aimed to characterize the odor-active compounds in CS and compare them with those present in coffee beans. The characterization of aroma fraction was carried out by gas chromatography-olfactometry/flame ionization detector (GC-O/FID) and by comparing the odors and odorants with those found in coffee beans. The identification was carried out by comparing with reference compounds the retention index and the odor quality. Finally, for unequivocal identification, after fractionation, the samples were analysed into comprehensive two-dimensional gas chromatography-mass spectrometry (GCxGC- MS). Moreover, the Aroma Extract Dilution Analysis (AEDA) was performed to assess the potency of each odors/odorants. 7 Regarding the phytoestrogen characterization, we found two enzymatic digestions, i.e., clara-diastase (Method 3.10-EC) and taka-diastase (Method 5-R&G), as the most performing processes for lignan extraction from espresso and R&G coffee, respectively. Secoisolariciresinol was the lignans present at the highest concentration in espresso (27.9-52.0 μg L-1) and in R&G coffee (84.4-257.8 μg kg-1). Moreover, the extraction yield of lignans revealed that they are almost completely extracted during coffee percolation. For green coffee matrix, the best performing process was Method 7-GC, a double extraction composed of base hydrolysis in MeOH and enzymatic digestion with clara-diastase and we found that lignans (total content: 286.5-8131.8 μg kg-1) were more abundant than isoflavones (total content: 3.4-300.0 μg kg-1). Our studies on espresso coffee optimization showed higher levels of TS, caffeine, trigonelline and chlorogenic acids for reference samples (ECs extracted with mixed particles) and for 200-300 μm mesh size, when standard filter (A) was set in the machine. By decreasing the amount of R&G coffee, similar TS levels and contents of bioactive compounds to standard condition, were obtained for reference compounds. The best filter baskets, in term of quantitative data, were A and B and the study on perforated discs suggested that using lower amount of ground coffee permits to obtain the same extraction yield increasing the height of perforated disc. From our investigations on CS, four volatile compounds were identified for the first time in coffee. In detail, 4-methyloctanoic acid and trans-4,5-epoxy-(E)-2-decenal were characterized in coffee beans and silverskin, while 6-acetyl-2,3,4,5-tetrahydropyridine and 5-methyl-2-methoxyphenol only in coffee beans. The highest flavour dilution (FD) factors in CS were obtained for furaneol, 2- methoxy-4-vinylphenol and 2-methoxyphenol and, moreover, other typical coffee aroma volatiles were found, e.g., 2-furfurylthiol, 2,3-butanedione, vanillin, 2-isobutyl-3-methoxypyrazine, etc. Some aromas, such as furaneol, 2-methoxy-4-vinylphenol, vanillin, trans-4,5-epoxy-(E)-2-decenal, 2- acetyl-1-pyrroline and 2-acetylpyrazine, occurred with similar FD factors in CS and coffee beans. Our studies demonstrated that CS contains an interesting odor-active compound fraction with high similarity to coffee beans

Effect of brewing methods on acrylamide content and antioxidant activity studying eight different filter coffee preparation

The aim of this study was to investigate the parameters affecting the extraction of positive molecules such as chlorogenic acids and antioxidants, as well as potentially carcinogenic substances such as acrylamide, in different coffee brewing methods. Three coffee varieties, each assigned a different roasting degree, were used to prepare coffee brews following eight different preparation methods. Acrylamide was quantified using the HPLC-MS/MS instrument, while chlorogenic acids and caffeine were quantified using the HPLC-DAD system. Three spectrophotometric analyses were also performed (DPPH, TFC and TPC) to evaluate antioxidant activity. The results showed that the main brewing parameters, which have the greatest influence on the final content of these compounds, were the volume of water used, more specifically the brewing ratio (coffee to water ratio), the extraction time and the particle size of the coffee powder. In addition, the variables that have the greatest impact on the discrimination of the preparation methods studied are total chlorogenic acid content, TFC, TPC, caffeine and the DPPH assay. For this reason, the recipe and infusion parameters used for each of the extraction systems are the key factors that determine the extraction of coffee components and, consequently, the quality of the cup

Assessment and Comparison of Phytochemical Constituents and Biological Activities between Full Flowering and Late Flowering of Hypericum perforatum L.

This study assessed the impact of full and late flowering stages on the polyphenols and enzyme inhibitory properties of Hypericum perforatum from Poland. Recognizing the significance of phenolic compounds in disease prevention and melatonin’s emerging protective role, we employed an UHPLC-MS/MS system to quantify 38 phenolic compounds, not typical of St. John’s wort, and to develop a new method for melatonin quantification. Afterward, the extracts were tested for their antioxidant capabilities (using phosphomolybdenum, DPPH, ABTS, FRAP, CUPRAC and ferrous chelating assays). Moreover, we investigated enzymes (acetylcholinesterase, butyrylcholinesterase and tyrosinase) involved in neurodegenerative disorders and (α-amylase and α-glucosidase) in diabetes. This study recognized the importance of phenolic compounds in disease prevention and explored the emerging protective role of melatonin, taking into account the floral ontogeny of the plant. Indeed, the full-flowering plant contained the greatest concentration of phenolic compounds (a total of 65,276.5 μg/g): hyperoside (18,726.59 μg/g), isoquercitrin (11,895.02 μg/g) and delphindin-3.5-diglucoside (10,619.51 μg/g), and showed the highest inhibitory enzyme activity. Moreover, only full-flowering St. John’s wort contained melatonin (40 ng/g). Our results offer additional perspectives on the chemical-biological characteristics of H. perforatum and scientific knowledge that testifies to the importance of considering plant growth conditions for the development of nutraceuticals

Coffee by-products as sustainable novel foods: Report of the 2nd international electronic conference on foods—“future foods and food technologies for a sustainable world”

The coffee plant Coffea spp. offers much more than the well-known drink made from the roasted coffee bean. During its cultivation and production, a wide variety of by-products are accrued, most of which are currently unused, thermally recycled, or used as fertilizer or animal feed. Modern, ecologically oriented society attaches great importance to sustainability and waste reduction, so it makes sense to not dispose of the by-products of coffee production but to bring them into the value chain, most prominently as foods for human nutrition. There is certainly huge potential for all of these products, especially on markets not currently accessible due to restrictions, such as the novel food regulation in the European Union. The by-products could help mitigate the socioeconomic burden of coffee farmers caused by globally low coffee prices and increasing challenges due to climate change. The purpose of the conference session summarized in this article was to bring together international experts on coffee by-products and share the current scientific knowledge on all plant parts, including leaf, cherry, parchment and silverskin, covering aspects from food chemistry and technology, nutrition, but also food safety and toxicology. The topic raised a huge interest from the audience and this article also contains a Q&A section with more than 20 answered questions

Coffee By-products as Sustainable Novel Foods: Report of The 2nd International Electronic Conference on Foods - "Future Foods and Food Technologies for a Sustainable World"

The coffee plant Coffea spp. offers much more than the well-known drink made from the roasted coffee bean. During its cultivation and production, a wide variety of by-products are accrued, most of which are currently unused, thermally recycled, or used as fertilizer or animal feed. Modern, ecologically oriented society attaches great importance to sustainability and waste reduction, so it makes sense to not dispose of the by-products of coffee production but to bring them into the value chain, most prominently as foods for human nutrition. There is certainly huge potential for all of these products, especially on markets not currently accessible due to restrictions, such as the novel food regulation in the European Union. The by-products could help mitigate the socioeconomic burden of coffee farmers caused by globally low coffee prices and increasing challenges due to climate change. The purpose of the conference session summarized in this article was to bring together international experts on coffee by-products and share the current scientific knowledge on all plant parts, including leaf, cherry, parchment and silverskin, covering aspects from food chemistry and technology, nutrition, but also food safety and toxicology. The topic raised a huge interest from the audience and this article also contains a Q&A section with more than 20 answered questions

Polyphenols, Saponins and Phytosterols in Lentils and Their Health Benefits: An Overview

The lentil (Lens culinaris L.) is one of the most important legumes (family, Fabaceae). It is a natural functional food rich in many bioactive compounds, such as polyphenols, saponins and phytosterols. Several studies have demonstrated that the consumption of lentils is potentially important in reducing the incidence of a number of chronic diseases, due to their bioactive compounds. The most common polyphenols in lentils include phenolic acids, flavan-3-ol, flavonols, anthocyanidins, proanthocyanidins or condensed tannins, and anthocyanins, which play an important role in the prevention of several degenerative diseases in humans, due to their antioxidant activity. Furthermore, lentil polyphenols are reported to have antidiabetic, cardioprotective and anticancer activities. Lentil saponins are triterpene glycosides, mainly soyasaponins I and βg. These saponins have a plasma cholesterol-lowering effect in humans and are important in reducing the risk of many chronic diseases. Moreover, high levels of phytosterols have been reported in lentils, especially in the seed coat, and β-sitosterol, campesterol, and stigmasterol are the most abundant. Beyond their hypocholesterolemic effect, phytosterols in lentils are known for their anti-inflammatory activity. In this review, the current information on the nutritional composition, bioactive compounds including polyphenols, saponins and phytosterols, and their associated health-promoting effects are discussed

Optimization of Solvent-Free Microwave-Assisted Hydrodiffusion and Gravity Extraction of Morus nigra L. Fruits Maximizing Polyphenols, Sugar Content, and Biological Activities Using Central Composite Design

Black mulberry, Morus nigra L. (family: Moraceae), is a healthy food and medicinal plant. Microwave hydrodiffusion and gravity (MHG) is one of the most innovative applications of solvent-free microwave extraction. The aim of this study was to optimize for the first time the MHG solvent-free extraction of polyphenols and sugars from M. nigra fruits. Optimization was carried out using a central composite design (CCD) with selected responses such as extraction yield, total polyphenol (TPC), flavonoid (TFC), anthocyanin (TAC), and sugar (TSC) contents, in addition to DPPH radical scavenging, and a-glucosidase (AGHi), lipase (Li), and xanthine oxidase (XOi) inhibition as tools to evaluate the best parameters for efficient and rapid extraction of black mulberry. The optimized extract was characterized in terms of the aforementioned parameters to validate the models, and was further analyzed for 36 individual polyphenols using HPLC-MS/MS. The optimized MHG extract was finally compared with traditional extracts, and demonstrated much better performance in terms of TPC, TAC, and Li, while the traditional extracts showed better XOi and AGHi. In conclusion, MHG is a valuable green technique for the production of non-degraded black mulberry polyphenol-rich extract and we suggest its larger use in the pharmaceutical and food industries

Role of Panax ginseng and ginsenosides in regulating cholesterol homeostasis

Hypercholesterolemia is harmful for human health since it may favor atherosclerosis and increase the risk of cardiovascular disease. To investigate the effect of a Panax ginseng extract and of some major components thereof (namely, ginsenosides Rb1 and Rb2) on cholesterol homeostasis in vitro, we quantitated total and free cholesterol levels and monitored the changes in the levels of key mediators of cholesterol synthesis, efflux and clearance. Treatments with ginsenosides and the extract reduced intracellular cholesterol levels by modulating the SREBP-2-HMGCR and LXR-IDOL signaling pathways. In addition, we observed an upregulation of the expression of the membrane transporters ABCA1 and ABCG1 and of cholesterol 7-hydroxylase suggesting the stimulation of processes for cholesterol excretion and cholesterol conversion into bile acids. Furthermore, both ginsenosides targeted HMGCR and inhibited its activity via a statin-like mechanism. Globally, our findings aid in deciphering the mechanisms of action of a major class of ginseng components in regulating lipid metabolism

Sociology and History of Science: News Questions, Contexts and Epistemological Perspectives

For historians of sociology , one of the most important problems of the twenty-first century is to replace the discipline in the age of scientific knowledge

Fecal Protein Profile in Eight Dogs Suffering from Acute Uncomplicated Diarrhea before and after Treatment

Acute diarrhea is a very frequent condition affecting dogs; nevertheless, little is known about what happens in the GI tract during such conditions. Proteomics allows the study of proteins present in a specific biologic substrate, and fecal proteomic investigations have been recently implemented to study GI diseases in dogs. In the present study, the fecal protein profiles of eight dogs suffering from acute uncomplicated diarrhea at the time of inclusion was investigated for the first time, and then the same patients were followed, replicating two further evaluations at two subsequent time points (after 2 and 14 days from the first presentation), with the aim of gaining possible new insights regarding the pathologic changes in the gastrointestinal environment during such conditions. Two-dimensional gel electrophoresis (2-DE) was performed, followed by mass spectrometry. Nine spots, corresponding to four (groups of) proteins (i.e., albumin, alkaline phosphatase, chymotrypsin-C-like, and some immunoglobulins), showed significant differences at two or more of the three time points investigated, almost all behaving similarly and decreasing at T1 (2 days after the onset of the condition) and significantly increasing at T2 (14 days after the onset), mainly evidencing a reaction of the organism. Further studies including a greater number of patients and possibly different techniques are needed to confirm the present finding