Effect of α-keto acids on the development of flavour in Swiss Gruyere-type cheese

Casey, Michael G.; Bosset, J. O.; Bütikofer, Ueli; Fröhlich-Wyder, Marie-Thérèse

doi:10.1016/j.lwt.2003.09.002

Cited by 14 publications

(7 citation statements)

References 12 publications

(11 reference statements)

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“…This procedure was chosen, as this cheese has to be prepared from unpasteurized fresh milk and the daily milk amount of the 6 cows per group was necessary for the production of 1 cheese of the typical size of this brand. The Gruyère-type cheeses were produced as previously described by Casey et al (2004). Briefly, 100 mL of fresh (pH 4.9) and old (pH 4.25) starter culture were added to 120 L of fresh milk.…”

Section: Experimental Cheese Manufacturingmentioning

confidence: 99%

Ability of 3 tanniferous forage legumes to modify quality of milk and Gruyère-type cheese

Girard

Dohme‐Meier

Wechsler

et al. 2016

Journal of Dairy Science

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Condensed tannins (CT) may affect ruminal biohydrogenation of dietary polyunsaturated fatty acids. A feeding experiment was conducted with 24 Holstein cows to evaluate whether diets containing CT from different forage legumes can increase polyunsaturated fatty acids, especially n-3 fatty acid content in milk and cheese, without affecting negatively their physicochemical and sensorial properties. Cows were assigned to 4 treatment groups (n=6) for 52 d, divided into 2 periods: a control period (CoP) and an experimental period (ExP). During the CoP, cows received a basal diet composed of hay, corn silage, ExtruLin (Trinova Handel & Marketing AG, Wangen, Switzerland), concentrate, and alfalfa (AF) in a ratio of 45:25:5:7:18. In the ExP, in 3 of the 4 groups AF was replaced by either sainfoin (SF; 19% CT in dry matter) or 1 of 2 cultivars of birdsfoot trefoil [Polom (BP), 3% CT; Bull (BB), 5% CT]. At the end of each period, milk was collected on 3 consecutive days and analyzed for milk gross composition and fatty acid profile and was processed to Gruyère-type cheese. A trained panel assessed the sensory quality of raw milk and cheese using discriminative and descriptive tests. This experimental design consisting of AF in both the CoP and ExP allowed us to quantify effects due to lactation stage and experimental diets. In both the CoP and ExP, dry matter intake and milk yield did not differ among treatment groups. From the CoP to the ExP, milk urea content was reduced by 23% with SF, remained unchanged with BP, and tended to increase with AF and BB. The odor of the raw BB milk was judged to be different from AF milk. With SF, switching from the CoP to the ExP resulted in a 17% increase of the 18:3n-3 proportion in milk and cheese lipids. In BP cheese, the increase was 3%, whereas it tended to decrease in BB cheese. Additionally, the 20:5n-3 and 22:5n-3 proportions tended to increase in SF cheese from the CoP to the ExP. Compared with the AF cheeses, cheeses from cows fed CT-containing legumes were judged harder and tended to be less adhesive to the palate. In addition, SF and BP cheeses had less rind. In conclusion, feeding SF compared with BB and BP increased the content of 18:3n-3 in the milk and the cheese without a negative effect on flavor of the cheese. Despite a similar CT content, the 2 birdsfoot trefoil cultivars had opposite effects on milk urea and 18:3n-3 deposition, suggesting that, besides the content, the chemical structure may have had an important effect on the CT efficacy.

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Section: Experimental Cheese Manufacturingmentioning

confidence: 99%

Ability of 3 tanniferous forage legumes to modify quality of milk and Gruyère-type cheese

Girard

Dohme‐Meier

Wechsler

et al. 2016

Journal of Dairy Science

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“… 1 , 2 In this reaction, AAs are converted into their corresponding α-ketoacids due to the transfer of the α-amino group of an AA to a suitable acceptor, usually α-ketoglutarate, although pyruvate and oxaloacetate have also been reported as possible acceptors. 3 , 4 The α-ketoacids produced during transamination are intermediate compounds in the aroma development because they can be metabolized via a range of enzymatic and chemical reactions to provide several compounds that can have an impact on cheese flavor, such as alcohols, aldehydes, carboxylic acids, and esters. 1 In general, ATs are specific for an AA group, such as aromatic (Ar-AT) or branched-chain (Bc-AT) AAs, or for a single AA, such as aspartate (Asp-AT), although overlapping in their activities has been reported.…”

Section: Introductionmentioning

confidence: 99%

Aminotransferase and glutamate dehydrogenase activities in lactobacilli and streptococci

Peralta

Bergamini

Hynes

2016

Brazilian Journal of Microbiology

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Aminotransferases and glutamate dehydrogenase are two main types of enzymes involved in the initial steps of amino acid catabolism, which plays a key role in the cheese flavor development. In the present work, glutamate dehydrogenase and aminotransferase activities were screened in twenty one strains of lactic acid bacteria of dairy interest, either cheese-isolated or commercial starters, including fifteen mesophilic lactobacilli, four thermophilic lactobacilli, and two streptococci. The strains of Streptococcus thermophilus showed the highest glutamate dehydrogenase activity, which was significantly elevated compared with the lactobacilli. Aspartate aminotransferase prevailed in most strains tested, while the levels and specificity of other aminotransferases were highly strain- and species-dependent. The knowledge of enzymatic profiles of these starter and cheese-isolated cultures is helpful in proposing appropriate combinations of strains for improved or increased cheese flavor.

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“…Addition of α‐KG to cheese and meat fermentations enhanced the formation of flavour volatiles through the transaminase pathway (Yvon et al. 1998; Casey et al. 2004; Tjener et al.…”

Section: Introductionmentioning

confidence: 99%

Metabolic pathway of α-ketoglutarate in Lactobacillus sanfranciscensis and Lactobacillus reuteri during sourdough fermentation

Zhang

Gänzle

2010

Journal of Applied Microbiology

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Aim: To identify metabolites of α‐ketoglutarate (α‐KG) in Lactobacillus sanfranciscensis and Lactobacillus reuteri in modified MRS and sourdough. Methods and Results: Lactobacillus sanfranciscensis and L. reuteri were grown with additional α‐KG in mMRS and in wheat sourdough. In mMRS, α‐KG was used as an electron acceptor and converted to 2‐hydroxyglutarate (2‐OHG) by both organisms. Production of 2‐OHG was identified by high performance liquid chromatography (HPLC) and confirmed by gas chromatography (GC). Crude cell extracts of L. sanfranciscensis and L. reuteri grown with or without α‐KG exhibited OHG dehydrogenase activity of 6·3 ± 0·3, 2·3 ± 0·9, 1·2 ± 0·2, and 1·1 ± 0·1 mmol l−1 NADH (min x mg protein)−1, respectively. The presence of phenylalanine and citrate in addition to α‐KG partially redirected the use of α‐KG from electron acceptor to amino group acceptor. In wheat sourdoughs, α‐KG was predominantly used as electron acceptor and converted to 2‐OHG. Conclusions: Lactobacillus sanfranciscensis and L. reuteri utilize α‐KG as electron acceptor. Alternative use of α‐KG as amino group acceptor occurs in the presence of abundant amino donors and citrate. Significance and Impact of the Study: The use of α‐KG as electron acceptor in heterofermentative lactobacilli impacts the formation of flavour volatiles through the transamination pathway.

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Effect of α-keto acids on the development of flavour in Swiss Gruyere-type cheese

Cited by 14 publications

References 12 publications

Ability of 3 tanniferous forage legumes to modify quality of milk and Gruyère-type cheese

Ability of 3 tanniferous forage legumes to modify quality of milk and Gruyère-type cheese

Aminotransferase and glutamate dehydrogenase activities in lactobacilli and streptococci

Metabolic pathway of α-ketoglutarate in Lactobacillus sanfranciscensis and Lactobacillus reuteri during sourdough fermentation

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