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Kolenc Z, Langerholc T, Hostnik G, Ocvirk M, Štumpf S, Pintarič M, Košir IJ, Čerenak A, Garmut A, Bren U. Antimicrobial Properties of Different Hop ( Humulus lupulus) Genotypes. PLANTS (BASEL, SWITZERLAND) 2022; 12:plants12010120. [PMID: 36616249 PMCID: PMC9824274 DOI: 10.3390/plants12010120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 06/12/2023]
Abstract
The antimicrobial activity of hop extracts obtained from different hop genotypes were investigated against Staphylococcus aureus and Lactobacillus acidophilus. In this study the pure xanthohumol, purified β-acids rich fraction, as well as α-acids with β-acids rich fraction were used to test antimicrobial activity against Staphylococcus aureus and Lactobacillus acidophilus; whereby, the antimicrobial activity of different hop extracts against Lactobacillus acidophilus was studied for the first time. Microbial susceptibility to purified hydroacetonic extracts from different hop varieties was investigated by the broth microdilution assay to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The hop hydroacetonic extracts were more effective against Staphylococcus aureus than against Lactobacillus acidophilus. Strong inverse correlations of MIC and MBC values were obtained with xanthohumol, cohumulone, n+adhumulone, colupulone and n+adlupulone contents, suggesting that the identified chemical hop compounds are directly responsible for antimicrobial effects. Moreover, the effect of the growth medium strength on the MIC values of hop extracts against Staphylococcus aureus was systematically investigated for the first time. The current study also reveals the effect of different hop extracts on Staphylococcus aureus, which responds to their presence by lag phase extension and generation time prolongation.
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Affiliation(s)
- Zala Kolenc
- Laboratory of Physical Chemistry and Chemical Thermodynamics, Faculty of Chemistry and Chemical Technology, University of Maribor, Smetanova Ulica 17, SI-2000 Maribor, Slovenia
| | - Tomaž Langerholc
- Department of Microbiology, Biochemistry, Molecular Biology and Biotechnology, Faculty of Agriculture and Life Sciences, University of Maribor, Pivola 10, 2311 Hoče, Slovenia
| | - Gregor Hostnik
- Laboratory of Physical Chemistry and Chemical Thermodynamics, Faculty of Chemistry and Chemical Technology, University of Maribor, Smetanova Ulica 17, SI-2000 Maribor, Slovenia
| | - Miha Ocvirk
- Department for Agrochemistry and Brewing, Slovenian Institute of Hop Research and Brewing, Cesta Žalskega Tabora 2, SI-3310 Žalec, Slovenia
| | - Sara Štumpf
- Laboratory of Physical Chemistry and Chemical Thermodynamics, Faculty of Chemistry and Chemical Technology, University of Maribor, Smetanova Ulica 17, SI-2000 Maribor, Slovenia
| | - Maša Pintarič
- Department of Microbiology, Biochemistry, Molecular Biology and Biotechnology, Faculty of Agriculture and Life Sciences, University of Maribor, Pivola 10, 2311 Hoče, Slovenia
| | - Iztok Jože Košir
- Department for Agrochemistry and Brewing, Slovenian Institute of Hop Research and Brewing, Cesta Žalskega Tabora 2, SI-3310 Žalec, Slovenia
| | - Andreja Čerenak
- Department for Plants, Soil and the Environment, Slovenian Institute of Hop Research and Brewing, Cesta Žalskega Tabora 2, SI-3310 Žalec, Slovenia
| | - Alenka Garmut
- Department of Microbiology, Biochemistry, Molecular Biology and Biotechnology, Faculty of Agriculture and Life Sciences, University of Maribor, Pivola 10, 2311 Hoče, Slovenia
| | - Urban Bren
- Laboratory of Physical Chemistry and Chemical Thermodynamics, Faculty of Chemistry and Chemical Technology, University of Maribor, Smetanova Ulica 17, SI-2000 Maribor, Slovenia
- Department of Applied Natural Sciences, Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška Ulica 8, SI-6000 Koper, Slovenia
- Institute of Environmental Protection and Sensors, Beloruska Ulica 7, SI-2000 Maribor, Slovenia
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Díaz AB, Durán-Guerrero E, Lasanta C, Castro R. From the Raw Materials to the Bottled Product: Influence of the Entire Production Process on the Organoleptic Profile of Industrial Beers. Foods 2022; 11:3215. [PMCID: PMC9601789 DOI: 10.3390/foods11203215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
In the past few years, there has been a growing demand by consumers for more complex beers with distinctive organoleptic profiles. The yeast, raw material (barley or other cereals), hops, and water used add to the major processing stages involved in the brewing process, including malting, mashing, boiling, fermentation, and aging, to significantly determine the sensory profile of the final product. Recent literature on this subject has paid special attention to the impact attributable to the processing conditions and to the fermentation yeast strains used on the aromatic compounds that are found in consumer-ready beers. However, no review papers are available on the specific influence of each of the factors that may affect beer organoleptic characteristics. This review, therefore, focuses on the effect that raw material, as well as the rest of the processes other than alcoholic fermentation, have on the organoleptic profile of beers. Such effect may alter beer aromatic compounds, foaming head, taste, or mouthfeel, among other things. Moreover, the presence of spoilage microorganisms that might lead to consumers’ rejection because of their impact on the beers’ sensory properties has also been investigated.
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Affiliation(s)
- Ana Belén Díaz
- Chemical Engineering and Food Technology Department, Faculty of Sciences-IVAGRO, University of Cadiz, Agrifood Campus of International Excellence (CeiA3), Polígono Río San Pedro, s/n, 11510 Puerto Real, Cadiz, Spain
| | - Enrique Durán-Guerrero
- Analytical Chemistry Department, Faculty of Sciences-IVAGRO, University of Cadiz, Agrifood Campus of International Excellence (CeiA3), Polígono Río San Pedro, s/n, 11510 Puerto Real, Cadiz, Spain
- Correspondence: ; Tel.: +34-956-016456
| | - Cristina Lasanta
- Chemical Engineering and Food Technology Department, Faculty of Sciences-IVAGRO, University of Cadiz, Agrifood Campus of International Excellence (CeiA3), Polígono Río San Pedro, s/n, 11510 Puerto Real, Cadiz, Spain
| | - Remedios Castro
- Analytical Chemistry Department, Faculty of Sciences-IVAGRO, University of Cadiz, Agrifood Campus of International Excellence (CeiA3), Polígono Río San Pedro, s/n, 11510 Puerto Real, Cadiz, Spain
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Abstract
Mixed microbial cultures create sour beers but many brewers do not know which microbes comprise their cultures. The objective of this work was to use deep sequencing to identify microorganisms in sour beers brewed by spontaneous and non-spontaneous methods. Twenty samples were received from brewers, which were processed for microbiome analysis by next generation sequencing. For bacteria, primers were used to amplify the V3-V4 region of the 16S rRNA gene; fungal DNA detection was performed using primers to amplify the entire internal transcribed spacer region. The sequencing results were then used for taxonomy assignment, sample composition, and diversity analyses, as well as nucleotide BLAST searching. We identified 60 genera and 140 species of bacteria, of which the most prevalent were Lactobacillus acetotolerans, Pediococcus damnosus, and Ralstonia picketti/mannitolilytica. In fungal identification, 19 genera and 26 species were found, among which the most common yeasts were Brettanomyces bruxellensis and Saccharomyces cerevisiae. In some cases, genetic material from more than 60 microorganisms was found in a single sample. In conclusion, we were able to determine the microbiomes of various mixed cultures used to produce beer, providing useful information to better understand the sour beer fermentation process and brewing techniques.
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Rodríguez-Saavedra M, González de Llano D, Moreno-Arribas MV. Beer spoilage lactic acid bacteria from craft brewery microbiota: Microbiological quality and food safety. Food Res Int 2020; 138:109762. [PMID: 33292943 DOI: 10.1016/j.foodres.2020.109762] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 09/27/2020] [Accepted: 09/28/2020] [Indexed: 01/28/2023]
Abstract
Craft beer is more susceptible to microbial spoilage because it does not have a pasteurization or filtration process, with lactic acid bacteria (LAB) being the most common beer spoilage microorganism. The aim of this study was to isolate LAB in a craft brewery and their characterization from a food safety and microbiological quality perspective, with a special focus on their abilities to produce biogenic amines (BA) and spoil the beer. The results of 60 monitored points inside the craft brewery showed that LAB associated with the craft brewing processes belonged to Lactobacillus, Pediococcus, and Leuconostoc genera, and most of them were detected in the filling area, which can lead to secondary contamination. Two isolates of L. brevis showed the most significant beer spoilage ability because they could grow in more acidic conditions, at a higher hop and alcohol content, and they displayed horA, horC, and hitA genes, which spoiled the vast majority of the tested beers. In addition, the aforementioned L. brevis isolates showed the highest BA production.
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Affiliation(s)
- Magaly Rodríguez-Saavedra
- Instituto de Investigación en Ciencias de la Alimentación (CIAL), CSIC-UAM, c/Nicolás Cabrera, 9. Campus de Cantoblanco, 28049 Madrid, Spain
| | - Dolores González de Llano
- Instituto de Investigación en Ciencias de la Alimentación (CIAL), CSIC-UAM, c/Nicolás Cabrera, 9. Campus de Cantoblanco, 28049 Madrid, Spain
| | - M Victoria Moreno-Arribas
- Instituto de Investigación en Ciencias de la Alimentación (CIAL), CSIC-UAM, c/Nicolás Cabrera, 9. Campus de Cantoblanco, 28049 Madrid, Spain.
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