Search Results (60)

Norovirus (NoV) is a symptomatic virus that is the leading cause of gastrointestinal disease. It spreads easily through the fecal–oral route and contact with contaminated food or surfaces. Maintaining a high level of hygiene in food industry settings and refocusing food production on isolating and testing natural compounds that exhibit antimicrobial and antioxidant properties are important elements in preventing NoVs infection. This study evaluated plant extracts prepared by cold brew and cold concentrate techniques for their antioxidant and antiviral activity. The extracts obtained demonstrated high antioxidant activity, with notable variation depending on the plant material, ranging from moderate to very strong levels. Correspondingly, high antiviral potential was observed, reaching the nearly complete inactivation of the virus. Remarkably, the highest virucidal effects were already achieved at relatively elevated, but not maximal, antioxidant activity levels. The results of the study indicate that cold water extraction techniques allow for the obtention of plant extracts showing strong virus-inactivating activity and favorable antioxidant activity. Full article

This review explores the accumulated research and technological potential of Saccharomyces eubayanus, a cold-tolerant wild yeast first isolated in 1997 from the Andean-Patagonian forests of Argentina but formally described in 2011. S. eubayanus has garnered attention since it was identified as the missing parent of the lager-beer yeast S. pastorianus and because it demonstrated valuable fermentative skills and an unexpected large intraspecific genetic diversity. The article recapitulates the characterization of the fermentative capacity of the type strain, as well as its ability to produce distinctive aromatic profiles compared to conventional lager yeasts. We discuss how these features have driven the development of improved strains through experimental evolution and the generation of interspecific hybrids with S. cerevisiae exhibiting appropriate fermentation performance and a broad aromatic diversity. We also aim to address the applications of S. eubayanus in commercial brewing, especially in the craft beer industry, and highlight its potential to add value and/or regional identity to beer through novel flavor profiles. Finally, the review outlines the main challenges limiting large-scale implementation, emphasizing the importance of continued research into strain development and brewing strategies to fully harness the potential of this wild yeast species. Full article

A comprehensive overview is provided on factors and processes influencing the final quality of a cup of coffee, with an emphasis on the brewing method’s central role. Coffee quality assessment, both at the bean and cup level, combines objective parameters (color, moisture, bean defects, density) with a notable degree of subjectivity, as consumer sensory perception is ultimately decisive. The brewing technique is described as a critical determinant of the final chemical, physical, and sensory attributes. Key parameters such as aroma profile, pH, titratable acidity, total and filtered solids, lipid and fatty acid content, viscosity, foam (crema), and colorimetric indices are detailed as essential metrics in coffee quality evaluation. Roasting creates most of coffee’s key aroma compounds. The brewing method further shapes the extraction of both volatile and other bioactive compounds like caffeine, chlorogenic acids, and lipids. Brewing methods significantly affect acidity, “body,” and crema stability, while water quality, temperature, and pressure are shown to impact extraction results and sensory properties. Attention is paid to how methods such as Espresso, filter, French press, and cold brew yield distinct physicochemical and sensory profiles in the cup. Overall, the review highlights the multifaceted nature of coffee cup quality and the interplay between raw material, processing, and preparation, ultimately shaping the coffee sensory experience and market value. Full article

High-pressure carbon dioxide (HPCD) has been widely used in the extraction of high-quality bioactive compounds. The flavor profiles of cold brew coffee (CBC) prepared by HPCD, traditional cold brew (TCB), and ice drip (ID) were comprehensively evaluated by chromatographic approaches, and their variations were investigated by multivariate statistical methods. ID produced the lightest coffee color while HPCD produced the darkest. No significant difference was found in pH among the three coffee processes. The concentrations of chlorogenic acids and caffeine were the highest in ID but the lowest in HPCD. Seventeen of the forty-eight volatiles were identified as key aroma compounds, contributing nutty, cocoa, caramel, baked, and other coffee flavors to all CBCs. Among them, linalool (OAV = 100.50) was found only in ID and provided ID with unique floral and fruity notes; 2-methyl-5-propylpyrazine (OAV = 17.70) was found only in TCB and gave a roasted aroma. With significantly lower levels of medicine-like and plastic off-flavors, HPCD had a refined aroma experience featuring nutty, cocoa, and caramel notes, though their contents were not the highest. Orthogonal partial least squares discriminant analysis (OPLS-DA) identified 36 aromas that could differentiate three cold brew methods, with TCB and HPCD being the most similar. Aroma sensory tests showed that no significant difference was perceived between TCB and HPCD. These findings provide a profound understanding of CBC flavor produced by cold brew methods from the aspect of composition, indicating that HPCD has great potential to realize TCB-like flavor characteristics in a shorter time. Full article

Malt bagasse is the primary solid waste product from the brewing process, with notable environmental implications. Due to its nutritional value, it has potential as animal feed, primarily through ensilage. Alfalfa pellets can enhance this silage by adding digestible nitrogen and fibre. However, the high moisture content favours microbial contamination, particularly by fungi like Fusarium, which produces harmful mycotoxins. This study evaluated the impact of winter silage on fungal diversity, Fusarium presence, and mycotoxin contamination in malt bagasse, comparing the pre- and post-silage stages with the addition of alfalfa pellets. Results showed a diverse range of fungi, including Mucor, Cladosporium, Fusarium, and Penicillium, as well as yeasts. Fungal contamination was higher before silage, although the addition of alfalfa increased it after silage was produced. Fusarium verticillioides was the most common Fusarium species. Mycotoxin analysis detected DON (1.4 ppb) in only one sample. A two-month winter silage process under cold-temperate conditions appears to reduce fungal contamination and preserve feed quality. These findings support silage as a circular strategy to manage brewery waste safely, but further research and policy measures are needed to minimise biological risks in the brewing and livestock sectors amid climate change. Full article

Coffee is the second most traded commodity in the world. With such a high popularity throughout the world, there have been many variations in the beverage. Cold-drip coffee is prepared by slowly filtering cold water through a bed of ground coffee. This study aims to identify differences in antioxidant profiles between coffee prepared through cold-drip and standard hot-brew methods. While specific studies have been undertaken on the antioxidant capacity of coffee, many were benchtop analyses with the inability to study individual compounds. In this study, taking advantage of post-column derivatisation in specially designed chromatography columns coupled with the cupric reducing antioxidant capacity (CUPRAC) assay, it was observed that there is indeed a difference in antioxidant profiles as a result of the method of preparation. Further, while many core components were similar between different preparation methods, cold-drip coffee yields a lower concentration of antioxidants than the same coffee prepared as a hot brew. The reproducibility and variation between different coffee brands were also explored. Full article

The cold brew method consists of soaking roasted and ground coffee beans either in cold or ambient water (4–23 °C) for up to 24 h. Using this technique, a drink with a unique sensory profile is obtained. This study was conducted to determine the shelf life of a cold brew organic coffee drink (pH~5.0) made from organic beans subjected to three roast levels: light, medium and dark. The drink was pasteurized at 90 °C/30 s, ultra-clean filled into high-density polyethylene bottles, and stored at 4 °C in the dark. Physicochemical, enzymic tests, instrumental color analysis, and microbiological and sensory assays were carried out. The product remained microbiologically stable under refrigeration for all roast levels; however, the beverage made from light roasted beans failed at the beginning of the study, in contrast to the those prepared from medium and dark roasts, which achieved 150 days of shelf life. Full article

Coffee contains several bioactive compounds, such as alkaloids and phenolic compounds, which contribute to its flavor and are influenced by the brewing method. The differences in coffee compounds based on brewing conditions have been studied in previous research, but no studies have yet utilized orbitrap mass spectrometry for this purpose. This study compared non-volatile and aromatic compounds in hot and cold brew coffee using high-resolution orbitrap mass spectrometry, followed by multivariate statistical analysis including principal component analysis and volcano plotting. A total of 163 non-volatile compounds and 93 volatile compounds were identified and annotated, with 18 non-volatile and 13 aroma-active compounds indicating differences between the brewing methods. Notably, certain quinic acids, such as 4,5-dicaffeoylquinic acid, and coumarin derivatives were more abundant in hot brew coffee, indicating that non-volatile compounds are significantly affected by extraction temperature. However, the major non-volatile compounds, including chlorogenic acid and trigonelline, are not affected by brewing conditions. For volatile compounds, phenolic compounds and indole were sensitive to temperature, while pyrazine and furan compounds were more influenced by extraction time. Additionally, in our results, several previously unreported bioactive compounds were detected in coffee, suggesting a need for further research to understand their potential functions and benefits. Full article

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. Full article

Coffee is one of the most widely consumed beverages in the world due to its sensory and health benefits. The caffeine content, a bioactive compound of coffee, depends on many factors, including the brewing method, which is the subject of ongoing scientific research. In addition, various methods are used in studies to determine the caffeine content. However, it is worth noting that there is considerable variation in the individual analytical parameters within these methods. The aim of this study was to update the data on the effects of different brewing methods on the caffeine content of the brew and to present the current state of knowledge on techniques for the determination of this compound. A literature review was conducted, taking into account the latest studies in this field. The results showed that the caffeine content (mg/100 mL) of the brew prepared with the Cold Brew method was 48.50–179.95, Espresso—50.40–965.60, French Press—52.00–123.90, AeroPress—56.35–120.92, and Moka—128.00–539.90. These methods were characterized by different brewing parameters (time, water temperature and pressure, ratio of coffee to water), which differentiated the caffeine content. In addition, some methods were characterized by a wide range of caffeine content, suggesting that even minor variations in brewing method parameters may affect the content of this ingredient. High-performance liquid chromatography (HPLC) was the predominant method used. The detector wavelengths, along with other parameters of the HPLC method, such as gradient profiles and column temperatures, can affect the precision and accuracy of the analysis, and these differences can modify analyte retention and detection, leading to discrepancies in results. These results point to the need for studies that consider various brewing methods and a wide range of coffee types, including roast and origin, to accurately determine the effects of these factors on caffeine content determined by one precise method. Full article

The impact of the roasting degree on ultra-high-pressure cold brew (UHP) coffee remains unclear, although it has been found that UHP technology accelerates the extraction of cold brew (CB) coffee. Therefore, this study investigated the effects of three different degrees of roasting (light, medium, and dark) on the physicochemical characteristics, volatile and non-volatile components, and sensory evaluation of UHP coffee. Orthogonal partial least-squares-discriminant analysis (OPLS-DA) and principal component analysis (PCA) were used to assess the effects of different roasting degrees. The results showed that most physicochemical characteristics, including total dissolved solids (TDSs), extraction yield (EY), total titratable acidity (TTA), total sugars (TSs), and total phenolic content (TPC), of UHP coffee were similar to those of conventional CB coffee regardless of the degree of roasting. However, the majority of physicochemical characteristics, non-volatile components, including the antioxidant capacity (measured based on DPPH and ABTS) and melanoidin, caffeine, trigonelline, and CGA contents increased significantly with an increase in roasting degree. The sensory evaluation revealed that as the roasting degree rose, the nutty flavor, astringency, bitterness, body, and aftertaste intensities increased, while floral, fruity, and sourness attributes decreased. The HS-SPME-GC/MS analysis showed that most volatile components increased from light to dark roasting. Moreover, 15 representative differential compounds, including hazelnut pyrazine, linalool, butane-2,3-dione, and 3-methylbutanal, were identified by calculating the odor-active values (OAVs), indicating that these contributed significantly to the odor. The PCA showed that the distance between the three roasting degree samples in UHP coffee was smaller than that in CB coffee. Overall, the effect of roasting degrees on UHP coffee was less than that on CB coffee, which was consistent with the results of physicochemical characteristics, volatile components, and sensory evaluation. Full article

Coffee, one of the most widely consumed commodities globally, embodies a sensory experience deeply rooted in social, cultural, and hedonic contexts. The cold brew (CB) method, characterized by cold extraction, is a refreshing and unique alternative to traditional coffee. Despite its growing popularity, CB lacks defined preparation parameters and comprehensive analysis of its aromatic composition. In this study, we aimed to obtain a representative extract of the volatile matrix of CB and characterize the aroma of sensory-active compounds using advanced techniques such as headspace–solid-phase Microextraction (HS-SPME) and headspace-solid-phase extraction (HS-SPE) for volatile compound extraction, followed by gas chromatography–olfactometry–mass Spectrometry (GC-O-MS) for compound identification. Optimization of the HS-SPME parameters resulted in the identification of 36 compounds, whereas HS-SPE identified 28 compounds, which included both complementary and similar compounds. In HS-SPME, 15 compounds exhibited sensory activity with descriptors such as floral, caramel, sweet, and almond, whereas seven exhibited sensory activity with descriptors such as chocolate, floral, coffee, and caramel. This comprehensive approach to HS-SPME and HS-SPE aroma extraction with GC-O-MS offers an efficient methodology for characterizing the aroma profile of CB, paving the way for future research and quality standards for this innovative coffee beverage. Full article

This study investigates agro-industrial by-products as sources of bioactive compounds, particularly focusing on phenolic compounds known for their antioxidant properties. With growing interest in natural alternatives to synthetic antioxidants due to safety concerns, this study highlights the health benefits of plant-derived phenolic compounds in food preservation and healthcare products. Traditional and advanced analytical techniques were used to obtain phytochemical profiles of various residue extracts, including espresso (SCG) and cold-brew spent coffee grounds (CBCG), pineapple peel (PP), beetroot pomace (BP), apple pomace (AP), black carrot pomace (BCP), and garlic peel (GP). Assessments of total phenolic content (TPC), total flavonoid content (TFC), and antioxidant capacity (AC) supported their revalorization. CBCG showed the highest TPC, TFC, and AC. TPC content in by-products decreased in the order CBCG > SCG > GP > BCP > PP > AP > BP, with a similar trend for TFC and AC. Phytochemical profiling via FI-ESI-FTICR-MS enabled the preliminary putative identification of a range of compounds, with polyphenols and terpenes being the most abundant. Univariate and multivariate analyses revealed key patterns among samples. Strong positive correlations (Pearson’s R > 0.8) indicated significant contribution of polyphenols to antioxidant capacities. These findings highlight the potential of agro-industrial residues as natural antioxidants, advocating for their sustainable utilization. Full article

Barley (Hordeum vulgare L.) is the fourth-largest cereal crop widely grown for livestock feed, brewing malts and human food. The TIFY family is a plant-specific protein family with diverse functions in plant growth, development and stress responses. However, a genome-wide comprehensive analysis of the TIFY gene family has not yet been characterized in Hordeum vulgare. In the present study, 21 and 22 TIFY family members were identified in the genomes of Hv_Morex and Hv_Barke, respectively. The HvTIFY proteins could be divided into the TIFY, ZIM/ZML and JAZ groups, and the JAZ group could be further clustered into six subgroups. HvTIFY genes were conserved in the two genotypes, and all of the duplicated gene pairs in the barley TIFY family were dominated by intense purifying selection. Tandem duplication was the main driving force for the expansion of the HvTIFY gene family. In silico gene expression profiling revealed most members of the Hv_Morex JAZ group were predominantly expressed in reproductive organs and root tissues and were also more involved in the responses to cold treatment and spot blotch infection than other groups. Quite a few JAZ genes (Hv_MoJAZ1, Hv_MoJAZ4, Hv_MoJAZ6, Hv_MoJAZ9, Hv_MoJAZ11, Hv_MoJAZ12 and Hv_MoJAZ14) were found to be tightly associated with the growth of barley and the responses to cold and spot blotch infection stresses. The genome-wide comprehensive analysis of the structure and function of the HvTIFY genes will contribute further to our understanding of the functions of these genes in response to abiotic and biotic stresses in Hordeum vulgare. Full article

This study applied pulsed electric fields (PEFs) to accelerate the withering and drying processes during cold-brewed black tea production. PEF pretreatment was administered at 1.0, 1.5, and 2.0 kV/cm electric field strengths, combined with varying withering times from 8 to 12 hr. During the 12-hour withering process, the redness value (a*) and total color change (∆E) of PEF-treated leaves significantly increased (p < 0.05). Furthermore, the homogenous redness of tea leaves during fermentation depended on the PEF strength applied. In addition, PEF pretreatment remarkably reduced the drying time, up to a 50% reduction at a 2.0 kV/cm field strength. Additionally, the 2.0 kV/cm PEF-pretreated black tea exhibited a notable 42% increase in theaflavin (TF) content and a 54% increase in thearubigin (TR) content. Sensory evaluation scores were highest for black tea that received PEF pretreatment at 2.0 kV/cm. These findings highlight the significant potential of PEFs in enhancing the efficiency of withering and drying processes while positively impacting the physicochemical and sensory properties of cold-brewed black tea. Full article