Starter strain related effects on the biochemical and sensory properties of Cheddar cheese

A detailed investigation was undertaken to determine the effects of four single starter strains, Lactococcus lactis subsp. lactis 303, Lc. lactis subsp. cremoris HP, Lc. lactis subsp. cremoris AM2, and Lactobacillus helveticus DPC4571 on the proteolytic, lipolytic and sensory characteristics of Cheddar cheese. Cheeses produced using the highly autolytic starters 4571 and AM2 positively impacted on flavour development, whereas cheeses produced from the poorly autolytic starters 303 and HP developed off-flavours. Starter selection impacted significantly on the proteolytic and sensory characteristics of the resulting Cheddar cheeses. It appeared that the autolytic and/or lipolytic properties of starter strains also influenced lipolysis, however lipolysis appeared to be limited due to a possible lack of availability or access to suitable milk fat substrates over ripening. The impact of lipolysis on the sensory characteristics of Cheddar cheese was unclear, possibly due to minimal differences in the extent of lipolysis between the cheeses at the end of ripening. As anticipated seasonal milk supply influenced both proteolysis and lipolysis in Cheddar cheese. The contribution of non-starter lactic acid bacteria towards proteolysis and lipolysis over the first 8 months of Cheddar cheese ripening was negligible.     

Influence of a defined-strain starter and Lactobacillus plantarum as adjunct culture on volatile compounds and sensory characteristics of Manchego cheese

Three batches of Manchego cheese were manufactured using one of the following starter culture systems: (1) a defined strain starter culture comprising Lactococcus lactis subsp. lactis and Leuconostoc mesenteroides subsp. dextranicum; (2) the above-defined strain starter culture and an adjunct culture (Lactobacillus plantarum), all these strains being isolated from high-quality Manchego cheeses and (3) a commercial starter consisting of two strains of Lactococcus lactis. Differences in volatile profile and the sensory characteristics of these cheeses were studied. After 4 months of ripening, the two batches of cheese made with the defined strain starter cultures obtained the highest scores for sensory attributes and for the overall impression. Additionally, Purge & Trap and SDE analysis showed a more complex volatile profile in these cheeses than in those made with the commercial starter. Extending the maturation time to 8 months for cheeses made with the defined starter cultures led to significant higher levels of free fatty acids and ethyl esters in those cheeses made without adjunct culture. However, panelists did not find significant differences among the sensory characteristics of the two cheeses.     

Manufacture of Turkish Beyaz cheese added with probiotic strains

The survival of the probiotic strains Lactobacillus fermentum (AB5-18 and AK4-120) and Lactobacillus plantarum (AB16-65 and AC18-82), all derived from human faces, was investigated in Turkish Beyaz cheese production. Three batches of Turkish Beyaz cheese were produced: one with the test probiotic culture mix (P), another with a commercial starter culture mix including Lactoccocus lactis subsp. cremoris, Lactococcus lactis subsp. lactis (C) and the third with equal parts of the commercial starter culture mix and test probiotic culture mix (CP). The cheeses were ripened at 4 °C for 120 days and the viability of cultures was determined monthly. Cheese samples were analyzed for total solids, fat in solids, titratable acidity, pH, salt in total solids, proteolysis, sensory evaluation, aroma compounds and biogenic amines. While initial lactic acid bacteria load in P cheese was 2.7 × 10⁹ at the beginning, it was 7.42 × 10⁷ cfu/g at the end of 120 days of ripening. The results showed that test probiotic culture mix was successfully used in cheese production without adversely affecting the cheese quality during ripening. The chemical composition and sensory quality of P cheeses were also comparable with C cheeses. The present study indicates that probiotic cultures of human origin are feasible for Turkish Beyaz cheese production.     

Utilization of interesterified fat in the production of Turkish white cheese

The chemical, physicochemical, proteolysis, sensory, and texture characteristics of white cheeses made from interesterified fat were examined throughout ripening for 90 days. The water-soluble nitrogen based ripening indexes of cheeses increased throughout the ripening period. However, there were not large quantitative differences between the peptide profiles of the all cheese samples. Cheeses produced by using fully interesterified fat had higher values for hardness, chewiness, and gumminess than that of control cheese (p<0.05). The polyunsaturated to saturated fatty acid ratios of cheeses were increased due to the presence of interesterified fat. The cholesterol values of cheeses decreased at the rate of between 58.83–89.04% depending on interesterified fat addition. In the sensory analysis, similar scores were obtained for both the control cheese and the other cheeses. The results showed that interesterified fat in cheese production could be used to fully or partially replace the milk fat in cheese.     

Dried Tomato‐Flavored Probiotic Cream Cheese with Lactobacillus paracasei

Abstract: A dried tomato‐flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc‐37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10⁷ CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product. Practical Application: Lactobacillus paracasei Lpc‐37 is a probiotic bacterium and clinical studies have shown that this microorganism beneficially affects its host. In general, dried tomato‐flavored products and cream cheese are products with good acceptance by the consumers. Thus, regular consumption of the probiotic cream cheese developed in this study may have positive effects on health and well being of people if incorporated into their diet.     

Influence of fat replacers on chemical composition, proteolysis, texture profiles, meltability and sensory properties of low-fat Kashar cheese

Changes in chemical composition, proteolysis, lipolysis, texture, melting and sensory properties of low-fat Kashar cheese made with three different fat replacers (Simplesse D-100, Avicel Plus CM 2159 or beta-glucan) were investigated throughout ripening. The low-fat cheeses made with fat replacers were compared with full- and low-fat counterparts as controls. Reduction of fat caused increases in moisture and protein contents and decreases in moisture-in-non fat substance and yield values in low-fat cheeses. The use of fat replacers in the manufacture of low-fat Kashar cheese increased water binding capacity and improved overall quality of the cheeses. Use of fat replacer in low-fat cheese making has enhanced cheese proteolysis. All samples underwent lipolysis during ripening and low-fat cheeses with fat replacers had higher level of total free fatty acid than full- or low-fat control cheeses. Texture attributes and meltability significantly increased with addition of fat replacers. Sensory scores showed that the full-fat cheese was awarded best in all stages of ripening and low-fat variant of Kashar cheeses have inferior quality. However, fat replacers except beta-glucan improved the appearance, texture and flavour attributes of low-fat cheeses. When the fat replacers are compared, the low-fat cheese with Avicel Plus CM 2159 was highly acceptable and had sensory attributes closest to full-fat Kashar cheese.     

Proteolytic properties of Turkish white‐brined cheese (Beyaz peynir) made by using wild‐type Lactococcal strains

The development of proteolysis in white‐brined Turkish cheese made by using wild strains of Lactococcus lactis subsp. lactis (namely MBLL9, MBLL23 and MBL27) was monitored for 90 days. Proteolysis in cheeses was investigated using urea‐PAGE gel electrophoresis of pH 4.6‐insoluble and RP‐HPLC of both 70% ethanol‐insoluble and 70% ethanol‐soluble nitrogen fractions. Results indicated that developments of proteolysis in the experimental cheeses were strain dependent. The degradation of casein fractions was more evident in the cheeses made using strain MBLL23. The lowest levels of proteolysis and development of acidity were obtained in the cheese made using strain MBLL9.     

Effect of a nisin-producing lactococcal starter on the late blowing defect of cheese caused by Clostridium tyrobutyricum

Clostridium tyrobutyricum causes swelling, cracks and off-flavours of cheeses (late blowing defect, LBD) due to butyric acid fermentation. To control this spoilage bacterium, we investigated the use of nisinogenic Lactococcus lactis subsp. lactis INIA 415 as starter in cheeses contaminated with C. tyrobutyricum spores. Control cheese made with spores showed LBD after 14 days of ripening. However, in cheese made with the bacteriocin producer and spores, in which (unlike control cheese) bacteriocin activity was detected throughout ripening, LBD occurred after 21 days. At this stage, level of lactic acid was 1.22-fold higher (P < 0.01) and concentrations of propionic and butyric acids were 2.15- and 2.32-fold, respectively, lower (P < 0.01) in cheese made with the nisin producer than in control cheese, according to the less pronounced spoilage symptoms showed by the former cheese. The bacteriocin producer delayed the appearance of LBD, although it cannot arrest completely C. tyrobutyricum growth.     

Influence of proteolytic Lactococcus lactis subsp. cremoris on ripening of reduced-fat Cheddar cheese made with camel chymosin

This study investigated proteolysis in reduced-fat Cheddar cheese produced with camel chymosin and Lactococcus lactis subsp. cremoris with the ability to cleave the N-terminus of α_S1-casein. The aim was to match the activity of bovine chymosin, which leads to softer cheese structure than camel chymosin. Cheeses were analysed for gross composition, casein and peptide breakdown, release of free amino acids, structure parameters and sensory characteristics. Selected Lc. lactis subsp. cremoris increased the amount of peptides and, to a limited extent, the total amount of free amino acids in the cheeses. One group of experimental cheeses was found to have a significantly firmer structure, higher stress at fracture and modulus of deformability than the reference cheeses. The addition of the selected proteolytic dairy strains of Lc. lactis subsp. cremoris to the cheeses did not result in extended breakdown of α_S1-casein or a softer cheese structure.     

Effects of changes during ripening and frozen storage on the physicochemical and sensory characteristics of Cabrales cheeses

The physicochemical and organoleptic characteristics of two batches of Cabrales cheese, stored at −20°C for 4 and 8 months, respectively, were studied during subsequent ripening. Frozen storage did not result in significant alterations in overall compositional, rheological and sensory properties or the level of lipolysis. The extent of proteolysis was slightly lower in the cheeses frozen prior to ripening.     

EFFECT OF SOME HERB ESSENTIAL OILS ON LIPOLYSIS IN WHITE CHEESE

The influence of some herb essential oils on the lipolysis of white cheese was examined. The essential oils of Sirmo (wild Allium sp.), thyme (wild Thymus sp.) and mint (wild Mentha sp.) were added individually or in combinations to cheeses. The cheese samples were ripened for 90 days at 5C. Lipolysis rate increased from the beginning to the sixtieth day of ripening, then decreased up to 90 days in cheese samples. The highest lipolysis rate was observed in the control sample while the lowest was in thyme and sirmo-thyme added samples. Differences between cheese samples and ripening periods were found to be statistically significant (P<0.01) in terms of fatty acids production rates. Sirmo and mint essential oils did not affect the lipolysis of white cheese. The sensory acceptability ofsirmo and mint essential oils added cheeses was superior to that of other samples.     

Influence of starters on chemical, biochemical, and sensory changes in Turkish White-brined cheese during ripening

Turkish White-brined cheese was manufactured using Lactococcus strains (Lactococcus lactis ssp. lactis NCDO763 plus L. lactis ssp. cremoris SK11 and L. lactis ssp. lactis UC317 plus L. lactis ssp. cremoris HP) or without a starter culture, and ripened for 90 d. It was found that the use of starters significantly influenced the physical, chemical, biochemical, and sensory properties of the cheeses. Chemical composition, pH, and sensory properties of cheeses made with starter were not affected by the different starter bacteria. The levels of soluble nitrogen fractions and urea-PAGE of the pH 4.6-insoluble fractions were found to be significantly different at various stages of ripening. Urea-PAGE patterns of the pH 4.6-insoluble fractions of the cheeses showed that considerable degradation of α_s1-casein occurred and that β-casein was more resistant to hydrolysis. The use of a starter culture significantly influenced the levels of 12% trichloroacetic acid-soluble nitrogen, 5% phosphotungstic acid-soluble nitrogen, free amino acids, total free fatty acids, and the peptide profiles (reverse phase-HPLC) of 70% (vol/vol) ethanol-soluble and insoluble fractions of the pH 4.6-soluble fraction of the cheeses. The levels of peptides in the cheeses increased during the ripening period. Principal component and hierarchical cluster analyses of electrophoretic and chromatographic results indicated that the cheeses were significantly different in terms of their peptide profiles and they were grouped based on the use and type of starter and stage of ripening. Levels of free amino acid in the cheeses differed; Leu, Glu, Phe, Lys, and Val were the most abundant amino acids. Nitrogen fractions, total free amino acids, total free fatty acids, and the levels of peptides resolved by reverse phase-HPLC increased during ripening. No significant differences were found between the sensory properties of cheeses made using a starter, but the cheese made without starter received lower scores than the cheeses made using a starter. It was found that the cheese made with strains NCDO763 plus SK11 had the best quality during ripening. It was concluded that the use of different starter bacteria caused significant differences in the quality of the cheese, and that each starter culture contributed to proteolysis to a different degree.     

Use of Taiwanese ropy fermented milk (TRFM) and Lactococcus lactis subsp. cremoris isolated from TRFM in manufacturing of functional low-fat cheeses

Abstract: The purpose of this study was to manufacture new functional low‐fat cheeses using Taiwanese ropy fermented milk (TRFM) and Lactococcus lactis subsp. cremoris strains isolated from TRFM. After 28 d of ripening and storage, the viable populations of lactic acid bacteria (LAB) in the low‐fat cheeses made with L. lactis subsp. cremoris TL1 (TL1), L. lactis subsp. cremoris TL4 (TL4), and TRFM still maintained above 10⁸ CFU/g. The low‐fat cheeses made with TL1 and TRFM showed higher moisture contents than the cheeses made with TL4, full‐fat, and low‐fat cheese controls. The low‐fat cheeses made with TL1 and TL4 had higher customer preferential scores similar to full‐fat cheese control in the sensory evaluation. Additionally, the low‐fat cheeses fermented with TL1, TL4, and TRFM for 4 h had higher 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) free radical‐scavenging and ferrous ion‐chelating abilities than the cheeses fermented with the starters for 8 h, full‐fat, and low‐fat cheese controls. A better angiotensin‐converting enzyme (ACE) inhibition activity was also observed in the low‐fat cheeses made with TL1, TL4, and TRFM than that in the full‐fat and low‐fat cheese controls during ripening and storage period. Practical Application: As health‐conscious consumers continue to seek low‐fat alternatives in their diets, there remain strong interests for the dairy industry to develop low‐fat cheeses to meet the demands. This study clearly demonstrated that the low‐fat cheeses fermented with TL1 for 4 h showed a better overall acceptability and possessed antioxidative abilities and ACE inhibitory activities than other cheeses tested in this study. By improving its flavor and investigating the possible mechanisms of its functionalities in the future, this low‐fat cheese might possibly be commercialized and give a positive impact on cheese consumption in the future.     

Microbial diversity and dynamics of Pecorino di Filiano PDO,a traditional cheese of Basilicata region (Southern Italy)

The evolution of microbial populations of ‘Pecorino di Filiano’ (PF) cheese was investigated during ripening in natural cave and storeroom. 62.5% of isolates grow at 45 and 15 °C and 77.7% showed high salt concentrations tolerance. Brevibacterium linens was dominant in surface samples. Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus paracasei subsp. paracasei were more frequently isolated both surface and core samples, while Leuconostoc lactis and Leuconostoc mesenteroides subsp. mesenteroides prevailed among Leuconostoc isolates. Our results suggest the importance of the ripening environment of cheeses and how a biological ecosystem affects and produces the typical features of artisanal products.     

Effect of addition of native cultures on characteristics of Armada cheese manufactured with pasteurized milk: A preliminary study

Six batches of Armada cheese were produced, one from raw milk with no added starter, another from pasteurized milk with a commercial mesophilic starter and four from pasteurized milk with experimental starters. These starters included: Lactococcus lactis subsp. lactis and L. lactis subsp. lactis biovar. diacetylactis; or the same strains plus either Enterococcus raffinosus, Leuconostoc mesenteroides subsp. dextranicum or Lactobacillus plantarum, all isolated from Armada cheese made from raw milk. The highest counts of aerobic mesophilic bacteria and populations of lactic acid bacteria for all batches were reached in the first week of ripening. These counts declined later throughout the ripening, although not at identical rates in every batch. Counts of lactobacilli were significantly higher in cheeses made from raw milk and those inoculated with the lactobacilli strain than in the other batches, over the whole ripening period. Added native starters minimized growth of Enterobacteriaceae. Cheeses made with the starter containing the Enterococcus strain had the most favourable sensory attributes throughout ripening.     

Biogenic amine content and proteolysis in Manchego cheese manufactured with Lactobacillus paracasei subsp. paracasei as adjunct and other autochthonous strains as starters

Two different autochthonous strain starter cultures, in which the acidifying starter was composed of strains of Lactococcus lactis, were used for the manufacture of pasteurised milk Manchego cheese. Proteolysis parameters, biogenic amines and sensory characteristics were evaluated and compared with those of commercial starter Manchego cheese and raw milk Manchego cheese manufactured without starter. Autochthonous starter cheeses, and especially those including Lactobacillus paracasei subsp. paracasei as adjunct, presented higher levels of proteolysis than in commercial starter cheese. The concentrations of total biogenic amines in autochthonous starter cheeses were much lower than in raw milk cheese and even lower than in commercial starter cheese. Cheese manufactured with the adjunct strain gave the best results for both flavour intensity and flavour quality, and was the most preferred by panellists. The results suggest that the culture containing Lb. paracasei subsp. paracasei as adjunct could be used for the manufacture of industrial Manchego cheese.     

Use of high pressure treatment to attenuate starter bacteria for use as adjuncts for Cheddar cheese manufacture

Attenuated starter bacteria cannot produce acid during cheese manufacture, but contain enzymes that contribute to cheese ripening. The aim of this study was to investigate attenuation of starter bacteria using high pressure treatment, for use in combination with a primary starter for Cheddar cheese manufacture, and to determine the effect of such adjunct cultures on secondary proteolysis during ripening. Lactococcus lactis ssp. cremoris HP and L. lactis ssp. cremoris 303 were attenuated by pressure treatment at 200 MPa for 20 min at 20 °C. Cheddar cheese was manufactured using untreated cultures of both these starter strains, either alone or in combination with their high pressure-treated equivalents. High pressure-treated starters did not produce acid during cheese manufacture and starter counts in cheeses manufactured using high pressure-treated starter did not differ from those of the controls. Higher levels of cell lysis were apparent in cheese manufactured using high pressure-treated strains than in the controls after 26 d of ripening. Small differences were observed in the peptide profiles of cheeses, analysed by reversed-phase HPLC; cheeses manufactured using high pressure-treated starters also had slightly higher levels of amino acids than the relevant controls. Overall, addition of high pressure-treated starter bacteria as a secondary starter culture accelerated secondary proteolysis in Cheddar cheese.

Industrial relevance

Attenuated starters provide extra pool of enzymes, which can influence cheese ripening, without affecting the cheese making schedule. This paper presents an alternative method for attenuation of starter bacteria using high pressure treatment and their subsequent use to accelerate secondary proteolysis in Cheddar cheese during ripening.     

Influence of native lactic acid bacteria on the microbiological,biochemical and sensory profiles of Serra da Estrela cheese

Cheesemaking from batches of raw ewe's milk was carried out via inoculation with wild strains of Lactococcus lactis subsp. lactis ESB110019 and Lactobacillus plantarum ESB5004 independently, or combined with each other. Those two strains had been isolated from the native microflora of typical Serra da Estrela cheese. One control batch was processed in parallel without addition of any starter. The evolution in viable counts of the main micro-organisms (viz. lactic acid bacteria, Enterobacteriaceae, staphylococci and yeasts), as well as in secondary proteolysis (WSN, 2% TCASN, 12% TCASN and 5% PTASN), was monitored throughout ripening time (over a 63-day period) in cheeses from each batch. The sensory features of the fully ripened cheeses were also assessed. Cheeses manufactured with starter showed significantly lower levels of viable Enterobacteriaceae than those manufactured without starter; viable counts of enterococci and staphylococci did significantly increase after addition of L. lactis or Lb. plantarum, respectively. Proteolysis in terms of WSN and 5% PTASN was not significantly affected by the lactic acid bacteria tested when compared to the control, but L. lactis played a significant role toward increasing the 2% TCASN content of cheeses; both strains led to a statistically significant increase of the 12% TCASN. The scores for flavor and texture of the control cheeses were somewhat above those for the experimental cheeses manufactured with starter.     

Changes in Microbiological, Chemical, Rheological and Sensory Characteristics during Ripening of Vacuum Packaged Manchego Cheese

The effects of cheese age when packaged and of packaging material permeability on Manchego cheese characteristics were studied throughout a 6-month ripening period. Cheese age when packaged had no significant effect on microbial levels, proteolysis, lipolysis or flavor. However, moisture content and rheological characteristics were significantly different for cheeses packaged 1, 2 or 3 wk after salting. Packaging material had no influence on microbiological, chemical, rheological or sensory characteristics of Manchego cheese. Packaged cheese had a lower flavor intensity than nonpackaged cheese, but no significant differences in flavor quality between packaged and non-packaged cheese were recorded. Weight losses after 6 months were undetectable in packaged cheese, but they averaged 15.16% in non-packaged cheese.     

The effects of freezing and frozen storage of ewe's milk cheese on the viability and proteolytic activity of lactococci used as a starter

A study has been conducted on the effect of two freezing conditions (slow and fast) and frozen storage of ewe's milk cheese (?20 °C for 4 months) on the viability and the proteolytic (cascinolytic and aminopeptidase) activity ofLactococcus lactis subsp.lactis andL. lactis subsp.cremoris used as starters in the manufacture of cheese. The study was carried out on the lactococci subjected to freezing and frozen storage, either in the cheeses or in curds simulating a model system. As well as other parameters used to quantity microbial activity, the total viable counts during the subsequent cheese ripening have been analysed in the frozen cheeses. Frozen storage of the investigated lactococci, either in the cheese or in model systems, gave rise to significant decreases in the caseinolytic and aminopeptidase activities greater than did freezing alone. No clear differences were found in enzymatic activity values when using slow or fast freezing conditions. Storage of the cheeses under frozen conditions also affected microbial viability and consequently caused a greater decrease of the viable flora during subsequent ripening of the frozen stored cheeses.