Activity In Cheese Research Articles

Application of Ammoides Pusilla as a Natural Food Preservative for Shelf-Life Extension of Cream Cheese

ABSTRACT The study aimed to evaluate Ammoides pusilla‘s potential as a preservative for cream cheese, specifically exploring the antimicrobial activity of its essential oil (EO) and its impact on cheese quality during storage. EO demonstrated potent antibacterial effects, particularly against L. monocytogenes, while Bacillus cereus exhibited resistance. Cheese samples enriched with A. pusilla EO and plant powder displayed improved physicochemical parameters, featuring reduced acidity rates across all enriched samples and superior water retention capacity in plant powder-enriched samples compared to the control. The incorporation of A. pusilla impacted cheese color, revealing a diminished rate of the yellowish component increase and the lightness component decrease during storage. A. pusilla, particularly through plant powder, enhances antioxidant activity in cheese. The yeast and mold growth models predicted an extended shelf life for A. pusilla-fortified cheeses ranging from 4 to 7 days. Sensory evaluations indicated consumer preference for low-rate EO and plant powder-enriched samples.

Application of Agri-Food By-Products in Cheesemaking

Agri-food companies produce large quantities of plant by-products that in many instances contain functional bioactive compounds. This review summarizes the main applications of agro-industrial by-products in cheesemaking, considering their bioactivities and functional properties. Polyphenol-rich by-products increase antioxidant and antimicrobial activity in cheeses, positively impacting their shelf life. Contrasting results have been obtained regarding the color and sensory properties of enriched cheeses depending on the selected by-products and on the technology adopted for the extract preparation. Furthermore, functional compounds in cheeses perform a prebiotic function and their bioavailability improves human health. Overall, the use of agri-food by-products in cheese formulation can offer benefits for agri-food chain sustainability and consumer health.

Effects of milk types used in Antep cheese production on some cheese organoleptic quality parameters and brine composition during 5‐month ripening

Antep cheese is a local Turkish cheese characterized by scalding during production and ripened in brine. In this study, Antep cheeses were produced using mixtures of different milk types (cow, sheep, and goat milk) and ripened for 5 months. The composition, proteolytic ripening extension index (REI), free fatty acid (FFA) content, and volatile compounds of the cheeses and the variation of the brines were analyzed for the 5-month ripening period. Low proteolytic activity in cheese during ripening caused the cheeses to have low REI values (3.92%-7.57%), although it was observed that some parts of the water-soluble nitrogen fractions diffused into the brine, causing a lower REI. As a result of lipolysis during ripening, total FFA (TFFA) concentrations in all cheeses were increased, whereas the highest increases were detected in the concentrations of short-chain FFAs. The highest FFA concentrations were determined in cheese produced using goat milk, and the volatile FFA ratio in TFFA exceeded 10% in the third month of ripening. Although it was observed that the milk types used in the production had significant effects on the change of volatile compounds of the produced cheeses and their brines, the impact of the ripening time was more important. PRACTICAL APPLICATION: This study investigated Antep cheese made with different milk types. Volatile compounds and soluble nitrogen fractions were transferred to the brine by diffusion during ripening. The volatile profile of the cheese varied with milk type, but ripening time was the primary factor influencing volatile compounds. This suggests that the targeted organoleptic properties of the cheese are determined by ripening time and conditions. Additionally, changes in the brine's composition during the ripening process provide insight into how to manage the brine as waste.

A COMPARATIVE STUDY ON THE EFFECT OF HIGH HYDROSTATIC PRESSURE ON RIPENING OF TURKISH WHITE CHEESE FROM DIFFERENT MILK SPECIES

High pressure treatment has diverse effect on cheeses depending on their characteristics. In this study, pressure application on Turkish White cheese (300 and 450 MPa/5 min) and the changes during ripening were investigated. The 450 MPa pressure process showed an enhanced effect on proteolytic and lipolytic activity of cheeses. Besides, 450 MPa pressure treatment was very effective on the microbiological profile, but the other treatment condition exhibited a more moderate antimicrobial effect. Although, the total mold-yeast were detected after high-pressure treatment, their existence to a considerable degree was seen at the end of storage.

Analysis of the cheese components’ influence on the dehydration process under reduced pressure

This work is aimed at studying the influence of various components’ content on the process of vacuum dehydration. It was found that with an increase in the proportion of fat in dry matter from 10 to 20 %, the duration of disinfection increases by 4 %. The further grows of the fat proportion from 20 to 50 increases the process duration by 54 %. It was revealed, when cheeses, with the fat proportion equal from 10 to 50 %, a change their fat proportion by 1 %, the duration of dehydration decreases by 4.25 minutes, and the drying rate grows by 0.0065 %/min. It has been discovered that with an increase in the table salt concentration with the same mass fraction of cheese moisture 53–55 %, a decrease in the rate of dehydration is observed as well. In the period with a constant drying rate at a concentration of sodium chloride of 1 %, the drying speed is 0.98 %/min; 2 % – 0.8 %/min; 3 % – 0.72 %/min; 4 % – 0.54 %/min. The amount of water activity in cheeses was investigated. It was established that with an increase in the concentration of table salt from 1 to 4 %, the water activity of cheese before drying changes by 0.131; after drying – by 0.174.

Redefining the effect of salt on thermophilic starter cell viability, culturability and metabolic activity in cheese

This study investigated the differential effect of salt concentration in the outside and inside layers of brine salted cheeses on viability, culturability and enzyme activity of starter bacteria. The high-salt environment of the outside layer caused a sharp decrease in L. helveticus viability as measured by traditional plate counts. Remarkably, this was associated with lower release of intracellular enzymes (LDH), reduced levels of proteolysis and larger membrane integrity as measured by flow cytometry (FC) following classical Live/Dead staining. FC analysis of light scattering properties highlighted a significant reduction in size and granularity of the microbiota located in the cheese surface, suggestive of cell shrinkage and condensation of internal macromolecules probably due to hyperosmotic stress. The microbiota of the cheese surface were found to experience greater oxidative stress, as measured by FC analysis of the total levels of reactive oxygen species, compared to that of the interior layer. These results lead us to postulate that the physiology and health status of the microbiota were significantly different in the outer and inner layers of the cheese. The hyperosmotic environment of the outer layer resulted in reduced cell lysis, as measurable by assays based upon membrane integrity, but rather triggered cell death via mechanisms involving cell shrinkage and ROS-mediated damage of vital intracellular components. This study challenges the current thinking on how salt controls microbial activity in ripening cheese, especially in cheeses which are brine salted as local variations in biochemical ripening indices can differ significantly from the outside to the inside of a ripening cheese.

Determination of mTG Activity in Low-Fat Semi-Hard Cheese Using Fluorescent Labelling.

A method to directly determine enzyme activity in cheese has not been published yet despite the fact that mTG mediated gel strength or hardness modification may be unpredictable and unfavorable during ripening and/or storage. The present study was performed to determine enzyme activity of semi-fat semi-hard Hungarian Trappist cheese. The widely known hydroxamate method was not suitable to even detect enzyme treatment, because of the disturbing effect of milk proteins. However incorporation of a dansylated glutamine dipeptide into milk protein contributed to monitoring the enzyme activity. The fluorescent measurement reflected mTG activity by increasing fluorescence intensity at 532nm in a 5-min continuously running assay. The presented dipeptide assay allows the determination of enzyme activity after 2min measurement by the manufacturing stage: cutting and up-heating. This assay can be used to monitor mTG activity during manufacture of low-fat semi-hard cheese type, in case if it was produced according to general recommendation of enzyme preparation providers (enzyme dosage: 0.1%, v/w). According to the preliminary calibration this assay can define mTG activity in the range of 0.05-0.3U/g.

EFEITO DA APLICAÇÃO DE Brevibacterium linens NA MATURAÇÃO DE QUEIJOS TIPO SAINT PAULIN DE CASCA TRATADA

Brevibacterium linens (B. linens) são predominantes na casca de queijos como Gruyère, Limburgo, Reblochon, Port du Salut e Saint Paulin. No entanto, o queijo tipo Saint Paulin fabricado no Brasil, não possui a casca tratada com bactérias e sim, apenas com uma solução salina e corante urucum, o que o deixa com sabor mais suave do que as variedades européias. O objetivo deste trabalho foi avaliar a influência da utilização da Brevibacterium linens na maturação de queijos tipo Saint Paulin. Os queijos foram produzidos utilizando-se três diferentes tratamentos: controle, sem adição de B. linens, com aplicação de B. linens na casca do queijo por esfregaço e com B. linens adicionada ao leite destinado à fabricação dos queijos. Índices de proteólise e pH (próximo a casca e no centro do queijo) foram avaliados durante a maturação, nos tempos 1, 15, 30 e 54 dias, e a composição centesimal foi avaliada no dia 1 de maturação, em três repetições. A análise de pH e de composição centesimal, não indicou diferença significativa (p > 0,05) entre os tratamentos. Os tratamentos com a utilização de B. linens apresentaram maiores índices de proteólise em relação ao tratamento controle. Assim, a utilização desse tipo de cultura adjunta B. linens incentiva a atividade proteolítica no queijo. Além disso, pode ser adicionada tanto no leite como na morge (solução salina) aplicada na casca do queijo.

Alkaline phosphatase activity in cheese as a tracer for cheese milk pasteurization

Alkaline phosphatase (ALP) activity is used throughout the world as a marker for the proper pasteurization of milk, to guarantee its hygienic safety. The Standard ISO 11816-2/IDF 155-2 describes the analysis of ALP in cheese. However, the method has been questioned in the past because there have sometimes been ambiguous results. The critical operations of the analytical procedure are more precisely defined and a zonal cheese sampling adopted. ALP inactivation is firstly evaluated in the relevant steps of controlled cheese makings of hard (Emmental), semi-hard (Raschera) and soft (Chaource) cheeses. Application of the improved procedure in over 700 samples of typical cheeses from France, Italy and Switzerland proved the applicability of the method. Based on this large study, a limit for ALP activity in cheese from pasteurized milk is proposed at 10 mU/g.

Investigation of Geotrichum candidum gene expression during the ripening of Reblochon-type cheese by reverse transcription-quantitative PCR

Cheese ripening involves the activity of various bacteria, yeasts or molds, which contribute to the development of the typical color, flavor and texture of the final product. In situ measurements of gene expression are increasingly being used to improve our understanding of the microbial flora activity in cheeses. The objective of the present study was to investigate the physiology and metabolic activity of Geotrichum candidum during the ripening of Reblochon-type cheeses by quantifying mRNA transcripts at various ripening times. The expression of 80 genes involved in various functions could be quantified with a correct level of biological repeatability using a set of three stable reference genes. As ripening progresses, a decrease in expression was observed for genes involved in cell wall organization, translation, vesicular mediated transport, and in cytoskeleton constituents and ribosomal protein genes. There was also a decrease in the expression of mitochondrial F1F0 ATP synthase and plasma membrane H+ ATPase genes. Some genes involved in the catabolism of lactate, acetate and ethanol were expressed to a greater extent at the beginning of ripening. During the second part of ripening, there was an increased expression of genes involved in the transport and catabolism of amino acids, which could be attributed to a change in the energy source. There was also an increase in the expression of genes involved in autophagy and of genes possibly involved in lifespan determination. Quantification of mRNA transcripts may also be used to produce bioindicators relevant for cheesemaking, for example when considering genes encoding enzymes involved in the catabolism of amino acids.

Effect of Allium sativum and Fish Collagen on the Proteolytic and Angiotensin-I Converting Enzyme-inhibitory Activities in Cheese and Yogurt

There is an increasing demand of functional foods in developed countries. Yogurt plays an important role in the management of blood pressure. Several bioactive peptides isolated from Allium sativum or fish collagen have shown antihypertensive activity. Thus, in the present study the effects of A. sativum and/or Fish Collagen (FC) on proteolysis and ACE inhibitory activity in yogurt (0, 7 and 14 day) and cheese (0, 14 and 28 day) were investigated. Proteolytic activities were the highest on day 7 of refrigerated storage in A. sativum-FC-yogurt (337.0 +/- 5.3 microg g(-1)) followed by FC-yogurt (275.3 +/- 2.0 microg g(-1)), A. sativum-yogurt (245.8 +/- 4.2 microg g(-1)) and plain-yogurt (40.4 +/- 1.2 microg g(-1)). On the other hand, proteolytic activities in cheese ripening were the highest (p < 0.05) on day 14 of storage for plain and A. sativum-cheeses (411.4 +/- 4.3 and 528.7 +/- 1.6 microg g(-1), respectively). However, the presence of FC increased the proteolysis to the highest level on day 28 of storage for FC- and A. sativum-FC cheeses (641.2 +/- 0.1 and 1128.4 +/- 4.5 microg g(-1), respectively). In addition, plain- and A. sativum-yogurts with or without FC showed maximal inhibition of ACE on day 7 of storage. Fresh plain- and A. sativum-cheeses showed ACE inhibition (72.3 +/- 7.8 and 50.4 +/- 1.6 % respectively), the presence of FC in both type of cheeses reduced the ACE inhibition to 62.9 +/- 0.8 and 44.5 +/- 5.0%, respectively. However, refrigerated storage increased ACE inhibition in cheeses (p < 0.05 on day 28) in the presence of FC more than in the absence. In conclusion, the presence of FC in A. sativum-yogurt or cheese enhanced the proteolytic activity. Thus, it has potential in the development of an effective dietary strategy for hypertension associated cardiovascular diseases.

The Effect of Yeast Species from Raw Milk in China on Proteolysis and Aroma Compound Formation in Camembert-Type Cheese

The influence of selected yeast strains (Pichia fermentans, Issatchenkia orientalis, Yarrowia lipolytica) on Camembert-type cheeses has been investigated by monitoring their microbial and compositional changes. During the ripening period from day 1 to day 15, the yeast strains grew exponentially and then slowed to a moderate growth rate. Our results indicated that the selected strains did not significantly affect the general characteristics of cheese but rather the content and ratio of individual free amino acids (P < 0.05). In the cheese with added I. orientalis, a greater amount of small peptides and a higher concentration of non-protein nitrogen and NH3 were found. Meanwhile, the presence of adjunct yeasts did not enhance the lipolysis activity in cheese. A principal component analysis of 30 free fatty acids and volatile compounds differentiated five cheeses out of eight according to the content of specific free fatty acids and volatile compounds. In terms of the ripening period, two groups of cheeses at 15 and 45 days were distinguished.

Inhibition of rennet activity in cheese using equine blood serum

The objective of this study was to inactivate chymosin in Cheddar-type cheese curd using equine blood serum. This blood serum was added (0.1–2%, v/v) to cheesemilk at 15 °C after completion of the first phase of renneting and before aggregation of the rennet-altered casein micelles, to inhibit the residual coagulant in Cheddar-type cheeses. Throughout ripening the level of pH 4.6-soluble nitrogen expressed as a percentage of total nitrogen was significantly higher in the control cheeses than in experimental cheeses and was about twice that of the experimental cheeses after ripening for 180 days. During ripening, there was almost no hydrolysis of αs1-casein in the cheeses made from milk containing 0.25–2% blood serum. Throughout ripening there were large quantitative differences between the peptide profiles of control and experimental cheeses. The results of this study suggest that the addition of equine blood serum to cheesemilk (0.25–2%) was very effective at inhibiting the residual chymosin activity in Cheddar-type cheeses during ripening; the activity of plasmin remained unaffected by the added blood serum. This study describes an easy and effective method for producing cheese curd free from residual coagulant activity, which will help to study the separate roles of the coagulant and other proteolytic enzymes in cheese ripening.

Effects of moisture and salt migration on cheese firmness in cheese-in-sausage products

Moisture and salt migration are responsible for the softening of cheese, called cold melt, found in cheese-in-sausage products. By characterizing the rate of moisture and salt migration in model cheese-in-sausage systems, diffusion coefficients for water and salt in cheese were obtained. As expected, the rate of moisture migration was greater when the initial driving force (difference in water activities of cheese and sausage) were greatest. These conditions also led to most rapid softening of the cheese. An edible barrier was found to reduce but not completely inhibit moisture migration and softening, whereas formulation to match water and salt activity of sausage and cheese virtually eliminated moisture migration and softening.

Application of Single Strand Conformation Polymorphism — PCR method for distinguishing cheese bacterial communities that inhibit Listeria monocytogenes

The aim of this study was to compare the microbial communities of different cheeses where Listeria monocytogenes either grew or did not grow. For this purpose, (i) isolates from the most inhibitory cheese ecosystem were identified and their ability to produce anti- Listeria substances was determined, (ii) bacterial communities of cheeses with and without L. monocytogenes growth were compared using the Single Strand Conformation Polymorphism method. The study showed SSCP to be an effective tool for differentiating between the bacterial communities of different cheeses manufactured with the same technology. All the cheeses with the lowest L. monocytogenes counts on day 8 were distinguished by the dominance in their SSCP profiles, after amplification of the V2 region of the 16S rRNA gene, of 3 peaks whose nucleotide sequences comigrated with Enterococcus faecium and Enterococcus saccharominimus, Chryseobacterium sp and Corynebacterium flavescens, Lactococcus garvieae and Lactococcus lactis respectively. However, no anti- Listeria compounds were produced under our experimental conditions. These six bacterial species were inoculated, separately or together, into pasteurised milk and their anti-listerial activity in cheese was evaluated. The area of inhibition between the control and trial curves confirmed that L. monocytogenes is inhibited by E. saccharominimus, C. flavescens, L. lactis, L. garvieae and the mixture of all six bacterial strains. Further studies should be performed to determine the metabolites involved in L. monocytogenes inhibition.

Proteolysis of Hispánico Cheese Manufactured Using Lacticin 481-Producing Lactococcus lactis ssp. lactis INIA 639

Hispánico cheese was manufactured using lacticin 481-producing Lactococcus lactis ssp. lactis INIA 639, bacteriocin-nonproducing L. lactis ssp. lactis INIA 437, or a combination of both strains, as starter cultures. Lactobacillus helveticus LH 92, a culture of high amino-peptidase activity sensitive to lacticin 481, was added to all vats. Milk inoculation with the bacteriocin producer promoted early lysis of Lb. helveticus cells in cheese. Cell-free aminopeptidase activity in cheese made with the 3 lactic cultures was 1.8 times the level reached in cheese made only with L. lactis strain INIA 437 and Lb. helveticus, after 15 d of ripening. Proteolysis (as estimated by the o-phthaldialdehyde method) in cheese made with the 3 lactic cultures was twice as high, and the level of total free amino acids 2.4 times the level found in cheese made only with L. lactis strain INIA 437 and Lb. helveticus, after 25 d of ripening. Hydrophobic and hydrophilic peptides and their ratio were at the lowest levels in cheese made with the 3 lactic cultures, which received the lowest scores for bitterness and the highest scores for taste quality.

Primary proteolysis studied in a cast cheese made from microfiltered milk

Primary proteolysis was studied in a starter-free cheese model made from microfiltered (MF) milk (19.0% casein,<0.2% whey proteins). Specificity of plasmin and chymosin activity was investigated in the pH range 5.0–6.0, by analysis of peptide composition using high-performance liquid chromatography and liquid chromatography–mass spectrometry. Hydrolysis experiments with purified caseins were performed to aid identification of peptides released by specific activities. Plasmin had no activity in cheese below pH 5.4, while its activity increased from pH 5.4 to 6.0. Chymosin activity on the Phe23–Phe24 bond of αS1-casein had an optimum pH around 5.3, while release of the bitter peptide β-casein (f193–209), effected by chymosin, was highest at pH 6.0. At pH <5.3, the specificity of chymosin on αS1-casein changed, and the peptide bond Leu20–Leu21 was cleaved at an increasing rate with decreasing pH. Demineralisation of the MF retentate generally increased proteolytic activity.

Determination of lipase activity in cheese using trivalerin as substrate

Abstract Lipolysis during cheese ripening is usually assessed by the accumulation of free fatty acids (FFA). An assay to determine total lipolytic activity present in a cheese during ripening was established. Finely grated cheese (1 g) was directly incubated with trivalerin (204 mg) as a substrate at 35 °C for 4 h. Free valeric acid was extracted and quantified by gas chromatography. The assay was linear with time up to 24 h and up to 0.11 Lipase Units g −1 cheese. The total amount of lipolytic activity determined with this assay was consistent with the total amount of FFA present in 5 types of cheese. In Idiazabal cheese samples manufactured with or without lipase added, the total lipolytic activity determined during ripening remained constant up to 6 months of ripening. In addition to trivalerin, other possible substrates investigated were triolein, triundecanoin and the endogenous butyric acid-containing triacylglycerols present in the cheese sample. Activities measured with these substrates were considerably lower than values obtained with trivalerin due to the high levels of oleic acid present in cheese, or to difficulties in mixing triundecanoin (solid at 35 °C) with the grated cheese sample. Endogenous triacylglycerols gave increasingly lower activity values as ripening time progressed due to substrate depletion.

Mechanisms of incorporation and release of enzymes into cheese during ripening

The enzymes involved in cheese ripening and the factors affecting their activity in cheese is reviewed. The review begins by outlining the various enzymes that contribute to cheese ripening including those originating from milk, coagulant, starter and non-starter Lactic Acid Bacteria, and those added as exogenous preparations to accelerate flavour development. Factors influencing the retention, release and residual activity of these enzymes in cheese are discussed along with an outline of innovative methods to enhance the retention and release of exogenous enzymes.

Quality of milk and of Canestrato Pugliese cheese from ewes exposed to different ventilation regimens

Effects of ventilation regimen on the quality of ewes' milk and on proteolysis in Canestrato Pugliese cheese during ripening were studied. Cheeses were manufactured from the bulk milk of Comisana ewes subjected to three different ventilation regimens, which were designated low (LOV, 23 m3/h per ewe), moderate (MOV, 47 m3/h per ewe) and programmed ventilation regimen (PROV, 73 m3/h per ewe; fan set to maintain 70% relative humidity). Bulk milk was analysed for chemical and microbial composition, renneting parameters and plasmin-plasminogen activities. At 1, 15, 30 and 45 d of ripening, the cheeses were analysed for gross chemical composition, nitrogen fractions, and plasmin and plasminogen activities. The pH 4.6-insoluble nitrogen fractions were analysed by urea-PAGE. Free amino acid content was determined at the end of ripening. Lower concentrations of bulk milk somatic cell count (BMSCC) and of mesophilic bacteria were found in the MOV group than in the LOV and the PROV groups. A lower plasminogen (PG) to plasmin (PL) ratio (PG/PL) was observed in the MOV and PROV than in the LOV cheeses. Irrespective of treatment, PL activity in cheeses was higher at 15d of ripening, while a sudden decrease of PL and PG activities was observed at 30 d, which was associated with a marked increase in non-protein nitrogen. The peptide profile characterized in the urea-PAGE showed a greater intensity of alpha- and beta-CN hydrolysis in the MOV than in the PROV and LOV cheeses. The results provide evidence that a proper ventilation regimen is critical for optimizing the hygienic quality of milk and the proteolysis of Canestrato Pugliese cheese during ripening.