Search Results (1,183)

Coffee silverskin, a by-product of the coffee roasting industry, offers significant potential for valorization due to its bioactive compound content. This study optimized the Pressurized Liquid Extraction (PLE) process for recovering phenolic compounds and caffeine from coffee silverskin. A factorial design identified the temperature and ethanol concentration as the key parameters influencing extraction yield, antioxidant capacity (TEAC), total phenolic content (TPC) and caffeine and phenolic acid contents. These factors were further optimized using a central composite design (CCD) and Response Surface Methodology (RSM). The optimal extraction conditions—140 °C and 55% ethanol—achieved a balanced enhancement across all responses: 12.1% extraction yield, 65.3 mg TE/g dry extract for antioxidant capacity, 88.4 mg GAE/g dry extract for total phenolic content, 56.7 mg caffeine/g dry extract, and 10.6 mg chlorogenic acid equivalents/g dry extract for phenolic acid content. Compared to conventional methods, the optimized PLE demonstrated superior bioactive compound recovery while employing environmentally friendly solvents. This approach underscores PLE’s potential as a sustainable technology for valorizing agro-industrial by-products, contributing to both waste reduction and the development of antioxidant-rich products. Full article

In this review, we present a compilation of results from studies of coffee carried out with accelerator-based analytical techniques employing swift ions. The fundamentals of these techniques are presented in detail. Moreover, different aspects of coffee are discussed, including the analysis of ground and roasted coffee beans, the effects of the drip brewing process on the final beverage, the importance of the water temperature for the extraction of elements during coffee preparation and how chemical markers can help discriminate coffee for forensic purposes. According to the experimental results, a matrix of different coffee types is represented by large amounts of carbon followed by mild amounts of oxygen. Moreover, elemental maps of roasted coffee beans show how the elements are distributed over the scanned area, thus providing valuable information on the co-localization of different elements within the beans. Concerning the drip brewing process, the results suggest that chlorine, potassium and phosphorus are quite soluble in hot water and therefore make their way into the drinking coffee. Moreover, the extraction of elements during the drip brewing process is dependent on the water temperature. The results obtained with ion-based techniques are discussed in perspective with those obtained by other analytical methods, including inductively coupled plasma technique in its various configurations. Advantages and drawbacks of these techniques are discussed. In this way, the present review opens up new possibilities for the analysis of coffee that go beyond traditional analytical techniques. Full article

Jarosite residue (JR), a hazardous solid waste generated in non-ferrous metallurgy, poses significant environmental challenges due to its large volume and poor storage stability. However, its high content of valuable metals (such as iron, zinc, gallium, indium, silver, …) makes its efficient recovery and comprehensive utilization highly significant. This study investigates the “oxidative roasting–reductive smelting” process for JR treatment. The reduction thermodynamics of JR-R (roasted JR) were analyzed, and the effects of smelting temperature, time, and slag basicity on the reduction and smelting process were examined. The results indicate that increasing slag basicity and temperature generally decreases slag viscosity. Thermodynamic calculations demonstrate that reductive smelting effectively enriches valuable metals (>1039 °C). The optimal conditions for reductive smelting of JR were determined to be as follows: smelting temperature of 1550 °C, smelting time of 60 min, and slag basicity of 0.9. Under these conditions, the process achieved an Fe grade of 92.87% in pig iron with a recovery rate of 90.66%, a Ga grade of 377 g/t with a recovery rate of 94.91%, and Zn and In volatilization rates of 99.91% and 83.36%, respectively. This study provides a feasible approach for the comprehensive recovery of valuable metals such as Ga, Fe, Zn, and In from JR, offering promising economic and social benefits. Full article

Frequent consumption of processed meat has been classified as carcinogenic to humans by the International Agency for Research on Cancer (Group 1), while red meat has been classified as probably carcinogenic (Group 2A). Mutagenic and carcinogenic compounds formed by heating in protein-rich food include, among others, heterocyclic aromatic amines (HAAs). Modifying the heat treatment of meat and using natural additives with antioxidant properties can lead to a reduction in their formation. The aim of this study was to determine polar HAAs (imidazoquinolines, IQ and MeIQ; imidazoquinoxalines, 8-MeIQx and 4,8-DiMeIQx; and phenylimidazopyridine, PhIP) in pork loin prepared without additives and with three types of dried fruit (apricots, cranberries, and prunes), baked in a roasting bag. HAAs were isolated from meat samples by solid-phase extraction. Quantitative analysis was performed by high-performance liquid chromatography with fluorescence detection (FLD) and a diode array detector (DAD). Only two HAAs, 8-MeIQx and PhIP, were detected in extracts isolated from meat samples. The total content of these compounds in meat roasted without additives was 5.9 ng/g. Using a dried fruit stuffing content of 200 g/kg of meat reduced these concentrations in dishes prepared with prunes, apricots, and cranberries by 42%, 47%, and 77%, respectively. Full article

It is essential to recycle zinc leaching residue (ZLR) generated by the conventional zinc hydrometallurgy process, as it is a hazardous and potentially valuable industrial waste. A combined calcification roasting–acid leaching process was developed to selectively separate and recover zinc from ZLR. This work investigates the effectiveness of using calcium oxide as an additive to transform zinc ferrite during the roasting process. The feasibility of the reaction was investigated based on thermodynamic calculations and compositional analysis. The transformation ratio of zinc ferrite reached 95.27% after roasting at 900 °C for 2 h with a Ca/Fe molar ratio of 3. During the calcification roasting process, the zinc ferrite was effectively converted into zinc oxide and calcium ferrite. The selective leaching of zinc was achieved at an L/S of 15, 25 g/L H₂SO₄, 60 °C, and 90 min. The extraction ratios of Zn and Fe were 86.26% and 0.06%, respectively. After the leachate was evaporated and purified, metallic zinc with a purity of 99.53% was obtained by constant current electrolysis for 60 min with a current efficiency of 86.7%. The proposed process provides a viable alternative method for recycling zinc resources from ZLR by an environmentally friendly method. Full article

The coffee processing industry is amongst the most energy-intensive industrial sectors, with the roasting process requiring substantial quantities of energy. To enhance sustainability, various energy optimization and recovery methods have been proposed. This study evaluates the environmental benefits of integrating energy recovery techniques in a typical coffee processing industry using a Life Cycle Assessment (LCA) approach. Specifically, two alternative scenarios were compared to a baseline processing line; (i) Scenario A, which involves recycling hot air streams to reduce natural gas consumption, and (ii) Scenario B, which utilizes an Organic Rankine Cycle (ORC) to convert waste heat to electricity. The LCA analysis indicated that Scenario A achieved a 25% reduction in greenhouse gas emissions and an 18% decrease in fossil fuel use. Scenario B demonstrated even greater environmental benefits, with a 40% reduction in greenhouse gas emissions and a 36% decrease in fossil fuel depletion. These findings underline the potential of integrating energy recovery technologies to enhance the sustainability of coffee production, offering valuable insights for industry stakeholders and researchers focused on sustainable manufacturing practices. Full article

Coffee is one of the most widely consumed beverages globally, with Americans averaging 3.1 cups per day. However, before coffee beans can be brewed into a drinkable form, they undergo several critical stages, including harvesting, processing, roasting, grinding, and extraction. During the processing and roasting phases, a significant challenge arises: stones that are similar in size and shape to coffee beans can inadvertently mix into the batch. These stones are difficult to detect using conventional methods, and their presence can have severe consequences. When stones are ground alongside coffee beans, they can cause significant damage to the grinder’s burrs. Commercial coffee grinders typically employ conical or flat burrs, which consist of two circular discs or an inner blade and a disc. These burrs undergo specialized heat treatment and surface processing to ensure durability and precision, making them highly expensive components. Replacing damaged burrs is not only costly but also requires meticulous calibration of the parallelism between the inner blade and the disc to maintain grinding quality. The introduction of stones into the grinding process can lead to equipment damage, resulting in operational downtime and financial losses. To address this issue, this paper proposes a novel method based on Empirical Mode Decomposition (EMD) for detecting stones in coffee beans. The approach analyzes the acoustic wave patterns generated when stones impact or rotate within the grinder. Full article

This study examined the responses of four legumes—chickpeas (Cicer arietinum L.), red kidney beans (Phaseolus vulgaris L., Taishokintoki), adzuki beans (Vigna angularis), and peanuts (Arachis hypogaea)—to storage and roasting under high-temperature and high-humidity conditions (HTC beans). Roasting enhanced antioxidant activity in HTC chickpeas and peanuts, with chickpeas also showing increased resistant starch. In contrast, kidney beans showed reduced resistant starch after storage, with minimal recovery upon roasting, while refrigeration better preserved resistant starch. For adzuki beans, roasting reduced resistant starch in control samples but not in HTC samples. Reducing sugars decreased in all beans after roasting. These findings highlight roasting as a promising method for repurposing HTC chickpeas and peanuts for functional food applications. Limitations include variability among legumes and the need for further mechanistic and sensory studies. Full article

Xinjiang is one of China’s most significant energy bases, and the generated fly ash (FA) contains a high concentration of metallic elements that can be used as a valuable resource. In this study, we looked into a roasting-acid leaching process technique for efficiently extracting gallium metal (Ga) from FA, employing sodium fluoride (NaF) as the roasting auxiliary and citric acid inzter (C₆H₈O₇) acid leaching. After high-temperature activation by NaF, the glassy phase of FA was converted into silica aluminate with excellent acid solubility, and Ga was extracted from FA via acid leaching. The effects of optimal roasting and acid leaching process conditions on the Ga leaching rate were investigated. The results showed that it exhibited 83.71% Ga extraction under the conditions of a roasting temperature of 850 °C, FA-NaF coordination ratio of 1:0.5, roasting time of 10 min, C₆H₈O₇ solution concentration of 1.75 mol/L, ratio (S/L) of 1:15, acid leaching temperature of 100 °C, and acid leaching time of 1 h. The results also indicated that it was possible to obtain a higher extraction efficiency for the Ga extracts under the conditions of roasting temperature of 850 °C and FA-NaF coordination ratio of 1:0.5. Full article

The aim of this study was to determine the influence of the nut roasting process (conventional and microwave methods) and long-term storage (12 months) on phytosterol content and stability. This study was conducted using hazelnuts (Corylus avellana), common walnuts (Juglans regia L.), and shelled peanuts (Arachis hypogaea L.). Two roasting methods were examined: conventional (temp. 170 °C, roasting time 10–20 min.) and microwave (temp. 60 °C, pressure 40 hPa, roasting time 140–180 s). In the studied nuts (raw, roasted and stored), five main types of phytosterols were identified: campesterol, stigmasterol, ß-sitosterol, delta 5-avenasterol and cycloartenol. It was shown that the microwave roasting method caused a two-fold decrease in sterol loss compared with conventional roasting. Moreover, the long-term storage of roasted walnuts using the microwave method showed double the amount of sterols preserved compared with those roasted using the conventional method. The amount of ß-sitosterol, which was the most stable during roasting, depended more on storage duration than on roasting process. The cycloartenol content in the roasted nuts did not depend on storage duration. The sterols present in nuts, raw or roasted using either method, transform more during the first 6 months of storage. Full article

Fly ash consists of significant amounts of lithium, which is an essential resource for developing batteries. This study proposed an efficient method for extracting lithium from fly ash. First, we explored the parameters affecting the activation effect of sodium carbonate roasting and the leaching efficiency of lithium using acid leaching. Additionally, ultrasonic pre-treatment was applied to enhance activation. A further mechanism for the roasting extraction of lithium was symmetrically analyzed. The results showed that ultrasonic treatment at 200 W for 1 h under alkaline leaching conditions (sodium hydroxide solution 4 mol/L, reaction temperature 80 °C, leaching time 2 h, solid–liquid ratio 1 g:30 mL) achieved a lithium leaching rate of 90.74%, surpassing the 84.72% with traditional roasting–alkaline leaching. Under optimal acid leaching conditions (850 °C for reaction of 2.5 h, fly ash-to-sodium carbonate ratio (R_fs) 1:2, sulfuric acid 2 mol/L, reaction temperature 80 °C, solid–liquid ratio 1 g:30 mL, and leaching time 1.5 h), the leaching rate reached 96.62%. With ultrasonic pre-treatment and acid leaching, the highest leaching rate of 98.68% achieved under optimal conditions: reaction temperature 850 °C for 2.5 h, mass R_fs at 1:1.5, sulfuric acid 2 mol/L, reaction temperature 80 °C, solid–liquid ratio 1 g:35 mL, and leaching time 120 min. The study demonstrated that ultrasonic pre-treatment outperforms the traditional method, achieving a higher leaching rate with fewer roasting additives and lower energy consumption. Full article

Nuts are widely recognized for their exceptional nutritional value, being rich in bioactive compounds such as polyphenols, mono- and polyunsaturated fatty acids, dietary fiber, and essential minerals. This review focuses on the effects of roasting technologies, specifically of pistachios, hazelnuts, and almonds, evaluating the changes in polyphenol contents, lipid profiles, and the release of volatile organic compounds through the Maillard reaction. Roasting, a common processing technique, enhances the sensory attributes of nuts, including flavor, aroma, and texture, while simultaneously influencing their nutritional and chemical profiles. The Maillard reaction, triggered during roasting, plays a crucial role in developing the characteristic flavors of roasted nuts, but can also lead to the formation of acrylamide under certain conditions. Understanding the balance between enhancing sensory quality and retaining nutritional properties is essential for optimizing roasting conditions. Innovative technologies offer sustainable and efficient alternatives to traditional methods. By focusing on these three major nut varieties, this review provides valuable insights into the changes that occur before and after roasting, highlighting strategies to balance sensory qualities and nutritional preservation. Further research is essential to refine these techniques, enabling the production of high-quality nuts that deliver superior health benefits while meeting consumer expectations. Full article

The Maillard reaction (MR) between sugars and amino acids, peptides, or proteins is understood to occur gradually during the production and aging of sparkling wines, where it contributes to caramel, roasted, and toasted aromas. Divalent metal ions can accelerate the MR, although this has not been previously reported in wine or wine-like conditions. In this work, the effect of calcium (Ca) and magnesium (Mg) ions on the concentration of 10 Maillard reaction-associated products (MRPs) was measured in modified sparkling base wine during accelerated aging at 50 °C for four weeks. Chardonnay base wine was modified by the addition of fructose (0.02 M) and a single amino acid (lysine, glycine, cysteine; 0.01 M) in combination with Ca²⁺ or Mg²⁺ at zero, low (10 mg/L), or high (50 mg/L) dose levels. MRPs were quantified by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC/MS), sugar concentration was measured by enzymatic assay, and amino acids and free metal ions were monitored by capillary electrophoresis. Fructose levels did not substantially decrease during aging despite increases in all MRPs, suggesting that trace sugars or α-dicarbonyl species present in the wine matrix likely play a greater role in MRP formation than fructose. Aging duration and amino acid content had a greater effect than metal addition on the composition of the MRPs. Treatments containing cysteine and 50 mg/L Ca²⁺ had elevated concentrations of benzaldehyde and furfural ethyl ether following 4 weeks of accelerated aging. This work identified key MRPs that increase during base wine accelerated aging and informs future research on the relationship between wine composition and aging markers. Full article

This essay is a personal response to the questions that arose to confront my Christian faith as I attempted to navigate a way forward amidst the impact and consequences of a cancer diagnosis for, firstly, my sister and then my husband. It is a navigation that is still, and in some respects will always be, ongoing, but in reflecting on how the ‘wrong’ questions might be replaced by the ‘right’ ones, this essay seeks to retain hope as a guiding principle to light the way ahead. Full article

Coffee quality, which ultimately is reflected in the beverage aroma, relies on several aspects requiring multiple approaches to check it, which can be expensive and/or time-consuming. Therefore, this study aimed to develop and calibrate an electronic nose (e-nose) coupled with chemometrics to approach coffee-related quality tasks. Twelve different metal oxide sensors were employed in the e-nose construction. The tasks were (i) the separation of Coffea arabica and Coffea canephora species, (ii) the distinction between roasting profiles (light, medium, and dark), and (iii) the separation of expired and non-expired coffees. Exploratory analysis with principal component analysis (PCA) pointed to a fair grouping of the tested samples according to their specification, indicating the potential of the volatiles in grouping the samples. Moreover, a supervised classification employing soft independent modeling of class analogies (SIMCA), partial least squares discriminant analysis (PLS-DA), and least squares support vector machine (LS-SVM) led to great results with accuracy above 90% for every task. The performance of each model varies with the specific task, except for the LS-SVM models, which presented a perfect classification for all tasks. Therefore, combining the e-nose with distinct classification models could be used for multiple-purpose classification tasks for producers as a low-cost, rapid, and effective alternative for quality assurance. Full article