Giorgia Perpetuini, Alessio Pio Rossetti, Arianna Rapagnetta, Rosanna Tofalo
{"title":"Unlocking the potential of Kluyveromyces marxianus in the definition of aroma composition of cheeses","authors":"Giorgia Perpetuini, Alessio Pio Rossetti, Arianna Rapagnetta, Rosanna Tofalo","doi":"10.3389/fmicb.2024.1464953","DOIUrl":null,"url":null,"abstract":"IntroductionThe cheese microbiota is very complex and is made up of technologically-relevant, spoilage, opportunistic and pathogenic microorganisms. Among them lactic acid bacteria and yeasts are the main ones. One of the most interesting dairy yeasts is <jats:italic>Kluyveromyces marxianus</jats:italic> because of its technological properties including the ability to produce aroma compounds.MethodsThis study investigated the contribution of <jats:italic>Kluyveromyces marxianus</jats:italic> to the gross composition and aroma profile of cow cheeses. Experimental cheeses were prepared by inoculating a co-culture of <jats:italic>K. marxianus</jats:italic> FM09 and a commercial strain of <jats:italic>Lacticaseibacillus casei</jats:italic> and compared with cheeses obtained with only <jats:italic>L. casei</jats:italic>. The gross composition was determined by a FoodScan™ 2 Dairy Analyser, and free amino acids were evaluated at 507 nm after reaction with Cd-ninhydrin. The volatile organic compounds were extracted by head-space solid phase micro-extraction and analyzed by gas chromatography–mass spectrometry coupled with odor activity values. qRT-PCR was applied to determine the expression of genes involved in esters synthesis and degradation.ResultsThe inoculation of <jats:italic>K. marxianus</jats:italic> induced an increase of pH and a reduction of protein content of cheeses, in agreement with the stronger proteolysis detected in these cheeses. <jats:italic>K. marxianus</jats:italic> influenced the content of aroma compounds both quantitatively and qualitatively. In particular, an increase of higher alcohols, esters and organic acids was observed. Moreover, 12 compounds were detected only in cheeses obtained with the co-culture. These differences were in agreement with the odor activity values (OAV). In fact, only 11 compounds showed OAV &gt; 1 in cheeses obtained with the commercial strain, and 24 in those obtained with the co-culture. The qPCR analysis revealed an over expression of <jats:italic>ATF</jats:italic>1, <jats:italic>EAT</jats:italic>1, and <jats:italic>IAH</jats:italic>1 genes.Conclusion<jats:italic>Kluyveromyces marxianus</jats:italic> could act as an important auxiliary starter for cheese production through the development and diversification of compounds related to flavor in short-aged cow cheeses.","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0000,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers in Microbiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.3389/fmicb.2024.1464953","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
IntroductionThe cheese microbiota is very complex and is made up of technologically-relevant, spoilage, opportunistic and pathogenic microorganisms. Among them lactic acid bacteria and yeasts are the main ones. One of the most interesting dairy yeasts is Kluyveromyces marxianus because of its technological properties including the ability to produce aroma compounds.MethodsThis study investigated the contribution of Kluyveromyces marxianus to the gross composition and aroma profile of cow cheeses. Experimental cheeses were prepared by inoculating a co-culture of K. marxianus FM09 and a commercial strain of Lacticaseibacillus casei and compared with cheeses obtained with only L. casei. The gross composition was determined by a FoodScan™ 2 Dairy Analyser, and free amino acids were evaluated at 507 nm after reaction with Cd-ninhydrin. The volatile organic compounds were extracted by head-space solid phase micro-extraction and analyzed by gas chromatography–mass spectrometry coupled with odor activity values. qRT-PCR was applied to determine the expression of genes involved in esters synthesis and degradation.ResultsThe inoculation of K. marxianus induced an increase of pH and a reduction of protein content of cheeses, in agreement with the stronger proteolysis detected in these cheeses. K. marxianus influenced the content of aroma compounds both quantitatively and qualitatively. In particular, an increase of higher alcohols, esters and organic acids was observed. Moreover, 12 compounds were detected only in cheeses obtained with the co-culture. These differences were in agreement with the odor activity values (OAV). In fact, only 11 compounds showed OAV > 1 in cheeses obtained with the commercial strain, and 24 in those obtained with the co-culture. The qPCR analysis revealed an over expression of ATF1, EAT1, and IAH1 genes.ConclusionKluyveromyces marxianus could act as an important auxiliary starter for cheese production through the development and diversification of compounds related to flavor in short-aged cow cheeses.
期刊介绍:
Frontiers in Microbiology is a leading journal in its field, publishing rigorously peer-reviewed research across the entire spectrum of microbiology. Field Chief Editor Martin G. Klotz at Washington State University is supported by an outstanding Editorial Board of international researchers. This multidisciplinary open-access journal is at the forefront of disseminating and communicating scientific knowledge and impactful discoveries to researchers, academics, clinicians and the public worldwide.