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1.
In a preliminary study with commercial ewe's milk cheeses, there were statistically significant differences in the sensory evaluation scores and the amounts of short-chain (C4–C10) free fatty acids (FFAs) between cheeses made with lamb rennet paste or bovine rennet. Experimental ewe's milk cheeses were manufactured with 2 levels of artisanally produced lamb rennet paste and 2 levels of bovine rennet in 50 L vats, with a manufacturing replicate done within 1 week. Total coagulating activity was 2500 RU for cheeses manufactured with a high amount of rennet or 1000 RU for cheeses manufactured with a low amount of rennet. The two batches of lamb rennet pastes used had 4.0 (early Spring) and 6.5 U g−1 lipase (late Spring), whereas no lipase activity was detected in bovine rennets. The total concentration of FFAs in cheeses manufactured with lamb rennet paste was significantly higher than in cheeses manufactured with bovine rennet, regardless of ripening time and time of the year. Lipolysis in the former cheeses increased with the total units of lipolytic activity added. The increase in lipolysis in cheeses made with lamb rennet was primarily due to higher amounts of short-chain fatty acids (C4–C10). Butyric acid was the main FFA in cheeses made with lamb rennet paste, representing 34.5 μmol 100 μmol−1 (low level of rennet) and 44.2 μmol 100 μmol−1 (high level of rennet) of the total FFAs, whereas it represented only 17 μmol 100 μmol−1 of the total FFAs in all cheeses made with bovine rennet. The concentration of individual FFAs of chain length <C12 were significantly higher in cheeses made with lamb rennet paste than in cheeses made with bovine rennet. Cheeses made with lamb rennet paste received significantly higher intensity scores for odour and flavour intensity, sharp odour, ‘piquant’ and bitter flavours and ‘natural rennet’ odour and flavour.  相似文献   

2.
《International Dairy Journal》2000,10(5-6):369-373
Feta cheese (five trials) of different sodium content was made from split lots of curd by varying the salting procedure, i.e. dry salting with NaCl (control) or mixtures of NaCl/KCl (3 : 1 or 1 : 1, w/w basis) and filling the cans with brine made with NaCl or the above NaCl/KCl mixtures, respectively. Lipolysis in cheese was monitored during aging by using the acid degree value (ADV) method and gas chromatography (GC). It was found that the ADVs of control and experimental cheeses were similar (P>0.05) at all sampling ages (3, 20, 40, 60, 120 and 240 d). Moreover, the results of GC showed that there were neither qualitative nor significant (P>0.05) quantitative differences in the individual free fatty acids (FFA) of the control and experimental cheeses at the ages of 40 and 120 d. These findings indicated that the partial substitution of NaCl by KCl in the manufacture of Feta cheese had no effect on lipolysis during cheese aging.  相似文献   

3.
 The object of the present study was to determine the influence of the rennet type on the free fatty acid (FFA) content of Idiazábal cheese. Varying this parameter during cheese-making resulted in significant differences in FFA content in the cheeses during ripening. The main FFAs in both cheese batches were caproic acid (C6 : 0) and capric acid (C10 : 0). The differences between the extreme values for the lipolysis rate were around 45%, which emphasizes the importance of the cheese-making procedure employed on lipolysis in this type of cheese. The use of locally made rennet in the preparation of Idiazábal cheese increased the level of lipolysis in the cheese. Received: 4 December 1998 / Revised version: 18 March 1999  相似文献   

4.
Pasteurized (65°C, 30 min), pressurized (400 MPa, 22°C, 15 min) and pasteurized–pressurized milks were used for reduced-fat (approximately 32% of total solids) cheese production. Pressurization of milk increased the yield of reduced-fat cheese through an enhanced β-lactoglobulin and moisture retention. In addition, pressurisation of pasteurized skim milk improved its coagulation properties. The cheeses made from pasteurized–pressurized and pressurized milks showed a faster rate of protein breakdown than the cheese made from pasteurized milk, that might be mainly attributed to a higher level of residual rennet. Hardness of the experimental cheeses, as determined by both the sensory panel and instrumental analyses, decreased as the moisture content and proteolytic degradation of the cheese increased (pasteurized>pressurized>pasteurized–pressurized). In general terms, pressurization of reduced-fat milk prior to cheese-making improved cheese texture and thus accounted for a higher overall acceptability, except for the cheeses made from pasteurized–pressurized milk at 60 d of ripening, whose acceptability score was adversely affected by bitterness.  相似文献   

5.
《International Dairy Journal》2005,15(6-9):733-740
Fat-derived flavour compounds in four different batches of Gouda cheese were monitored over 2 years of ripening. The total free fatty acid (FFA) concentrations increased from 200–400 to 700–1200 mg kg–1 dry matter, in a fairly linear manner. Long-chain FFAs were predominant in the curds, but relatively more short and intermediate chain fatty acids were released during ripening. The production of δ-lactones was rapid initially, but reached a plateau at 55 mg kg–1 dry matter in about 20 weeks. The production of γ-lactones was slower and also decreased, but was noticeable over a longer time, giving 5.5 mg kg–1 dry matter in 90 weeks. Ethyl ester formation varied substantially. Ketone levels increased only very slightly during ripening; long chain alcohols and aldehydes were not found. Some individual FFAs and lactones exceeded reported flavour thresholds, and are expected to influence the flavour of Gouda cheese.  相似文献   

6.
Cheeses manufactured using traditional lamb rennet paste, lamb rennet paste containing Lactobacillus acidophilus, and lamb rennet paste containing a mix of Bifidobacterium lactis and Bifidobacterium longum were characterized for the lipolytic pattern during ripening. Lipase activity of lamb rennet paste, lamb rennet containing Lb. acidophilus, and lamb rennet containing a mix of bifidobacteria was measured in sheep milk cream substrate. Rennet paste containing probiotics showed a lipase activity 2-fold greater than that displayed by traditional rennet. Total free fatty acid (FFA) in sheep milk cream was lower in lamb rennet paste (981 μg/g of milk cream) than in lamb rennet containing Lb. acidophilus (1,382.4 μg/g of milk cream) and in lamb rennet containing a mix of bifidobacteria (1,227.5 μg/g of milk cream) according to lipase activity of lamb rennet paste. The major increase of FFA in all cheeses occurred during the first 30 d of ripening with the greatest values being observed for C16:0, C18:0 C18:1. At 60 d of ripening all cheeses showed a reduction in the amount of free fatty acids; in particular, total free fatty acids underwent a decrease of more than 30% from 30 to 60 d in cheeses manufactured using traditional lamb rennet paste, whereas the same parameter decreased 10% in cheeses manufactured using lamb rennet paste containing Lb. acidophilus and cheeses manufactured using lamb rennet paste containing a mix of B. lactis and B. longum. Cheese containing Lb. acidophilus was characterized by the greatest levels of total conjugated linoleic acids (CLA) 9-cis, 11-trans CLA and 9-trans, 11-trans CLA, whereas cheese containing bifidobacteria displayed the greatest levels of free linoleic acid. Rennet pastes containing viable cells of Lb. acidophilus and a mix of B. lactis and B. longum were able to influence the amount of FFA and CLA in Pecorino cheese during ripening.  相似文献   

7.
Aqueous extracts obtained from cell suspension cultures of Centaurea calcitrapa were used as proteolytic additive in the manufacture of a commercial bovine cheese, coagulated with animal rennet and typically ripened for 28 d. The cheese was assessed in comparison to standard cheese for two levels of addition of said extract, viz. 0.61 and 1.22 mg of total protein mL−1. The qualitative and quantitative evolutions of the nitrogen fractions were monitored in the experimental cheeses throughout the whole ripening period. In general, the chemical compositions of the cheeses were different depending on the amount of extract used, but no significant differences could be detected in the ripening index. With regard to electrophoretic profiles, the two types of cheese could be distinguished until up to ca. 7 d of ripening, but differences did essentially vanish by 28 d.  相似文献   

8.
Seventeen strains of mesophilic lactic acid bacteria, isolated from cheese (non-starter lactic acid bacteria, NSLAB) or sourdough, were used individually as adjunct cultures in a Caciotta cheese model system. Adjunct cultures were monitored by randomly amplified polymorphic DNA analysis and their cell counts mainly varied from ca. 9.0 to 8.0 log cfu g−1 throughout 36 days of ripening. Adjunct cultures influenced differently cheese proteolysis. Both NSLAB and sourdough strains caused an extensive secondary proteolysis; however, some NSLAB strains produced the highest concentration of free amino acids. Principal component analysis (PCA) differentiated cheeses manufactured with NSLAB strains Lactobacillus parabuckneri B9FST, Lb. paracasei B61F5, Lb. curvatus 2768 and Lb. rhamnosus ATCC 7469 based on the accumulation of Lys, Glu, Phe, Hist, Asp and Met. Assessment of cheese lipolysis showed that: (i) highest concentrations of free fatty acids (FFA) were found with NSLAB strains Lb. rhamnosus ATCC 7469 and Lb. casei subsp. pseudoplantarum 2742 (ca. 10 500 mg kg−1); (ii) PCA differentiated cheeses manufactured with NSLAB strains Lb. rhamnosus ATCC 7469 and Lb. casei subsp. pseudoplantarum 2742 based on the accumulation of palmitic (C16:0) and linoleic (C18:2) acids, and those with Lb. curvatus 2768 and Lb. parabuckneri B9FST based on the high concentration of short chain FFA; (iii) the cheese made with sourdough strain Lb. sanfranciscensis CB1 had the highest levels of unsaturated FFA.  相似文献   

9.
A microbiological, compositional, biochemical and textural characterisation of the pasta filata Caciocavallo Pugliese cheese during ripening is reported. Fully ripened cheese contained a total of ca. log 8.0 cfu g−1 mesophilic bacteria and ca. log 6.0 cfu g−1 presumptive staphylococci, while the number of thermophilic and mesophilic rod and coccus lactic acid bacteria varied during ripening. A two-step RAPD-PCR protocol was used to differentiate biotypes. The natural whey starter was composed mainly of Lactobacillus delbrueckii, Lb. fermentum, Lb. gasseri, Lb. helveticus and Streptococcus thermophilus strains. After day 1 of ripening, Lb. delbrueckii became dominant and some strains of Enterococcus durans and E. faecalis appeared. Non-starter lactic acid bacteria, such as Lb. parabuchneri and Lb. paracasei subsp. paracasei formed a large part of the lactic microflora at 42 and 60 d of ripening. The level of pH 4.6-soluble nitrogen increased from the outer to the inner of the cheese and also increased in each section as ripening progressed, attaining values of 18–15%. Urea-PAGE electrophoresis showed that degradation of αs1-casein was more rapid than that of β-casein throughout ripening and the rates at which both caseins were degraded greatly increased from the outside to the inside of the cheese. Based on the primary proteolysis products, both chymosin and plasmin appeared to be active. RP-HPLC profiles of the 70% ethanol-soluble, pH 4.6-soluble nitrogen, showed a large number of peaks, indicating a heterogeneous mixture of proteolytic products. There were both age- and section-related changes in the area of the different peptide peaks. Butyric (C4:0), caproic (C6:0), palmitic (C16:0) and oleic (C18:1) acids were the free fatty acids found at the highest concentrations. The level of short chain fatty acids (e.g., butyric and caproic) decreased from the middle and inner to outer sections of the cheese. Peptidase activity in the curd was pronounced, increased during ripening and varied with the cheese section. The greatest increase of the peptidase activity coincided with a change in the lactic microflora and with the prevalence of non-starter lactic acid bacteria. Microbial esterases were supposed to be active together with rennet paste. Little change in the firmness and fractures stress during maturation were found by textural analyses of the raw cheese. The flowability was similar to that of typical low-moisture Mozzarella cheese, while stretchability was lower. The heat-induced changes in phase angle of Caciocavallo Pugliese cheese indicated a phase transition from largely elastic rheological characteristics in unheated cheese to a more viscous and fluid character in melted cheese.  相似文献   

10.
Rennet pastes produced by lambs subjected to three different feeding systems (mother suckling [MS], artificial rearing [AR], and artificial rearing with Lactobacillus acidophilus supplementation [ARLB]) and slaughtered at two different ages (20 and 40 d) were used for the manufacture of Pecorino foggiano cheese. Composition and proteolysis during ripening of Pecorino foggiano cheese (four replicates batches) were analyzed. Proteolysis was greater in cheeses made with rennet pastes from lambs slaughtered at 20 d, as shown by analysis of nitrogen fractions (water-soluble N and proteose peptones). Supplementation of milk substitute with L. acidophilus may have influenced the growth dynamics of lactic acid bacteria in the rennet pastes, with positive effects on levels of lactobacilli in cheese at the beginning of the ripening time. Lower pH values in ARLB cheese during ripening, together with higher cell loads, suggest that supplementation of milk replacer with L. acidophilus resulted in higher proteolytic activity, as also confirmed by the composition of the pH 4.6—insoluble nitrogen fraction. No differences were found in total concentration of free amino acids among the experimental cheeses; phenylalanine, isoleucine, leucine, lysine were found at the highest levels. The addition of probiotic bacteria to milk substitute in lamb rearing appears to give good-quality lamb rennet paste.  相似文献   

11.
This study examined the use of hygienised kid rennet pastes in model cheese systems and also in goat milk semi-hard cheeses to promote lipolysis. The results obtained indicated that the use of rennet paste caused greater lipolysis and increased, mostly, the short-chain free fatty acid (FFA) content. The model systems made with whole goat’s milk using rennet paste and commercial rennet mixture exhibited a higher FFA content than did the rennet paste-free controls (31,600 vs. 25,600 μmol/kg cheese). For the pilot cheeses made with bovine rennet and rennet paste mixture, the increase in FFA level after 45 days of ripening compared with the cheeses prepared only with commercial rennet was as much as 6600 (μmol/kg cheese) and the increase in the butyric acid content was also 1650 (μmol/kg cheese). Moreover, after 15 days of ripening, industrially prepared cheeses made with rennet paste exhibited greater levels of FFA than did the cheeses made with commercial rennet (11,500 μmol/kg at 45 days of ripening). Their flavour was stronger and the organoleptic characteristics were better accepted, which implies less ripening time for commercial cheese manufacture.  相似文献   

12.
The Feta‐type cheese was prepared with different casein/fat (C/F) ratios of buffalo milk using microbial rennet. The manufactured Feta cheeses were subjected to physicochemical and sensory quality at 15‐day interval up to 60 days of ripening. Sensory analysis discriminated the different level of C/F ratio of buffalo milk cheeses predominantly by age. There was no significant difference (P < 0.01) observed in cheese made from C/F ratio of 0.6–0.7 in terms of flavour. The titratable acidity (TA), soluble protein and free fatty acid appear to be age‐dependent and increased throughout the ripening in all experimental cheeses.  相似文献   

13.
Milk subjected to instant infusion pasteurization (IIP) at 72 °C, 100 °C and 120 °C (holding time 0.2 s) exhibited increased rennet coagulation time and decreased curd firming rate for increasing heat treatment temperature, when compared with raw or high temperature short time pasteurized (HTST) milk. However, addition of 4.5 mm or 9.0 mm of calcium restored the impaired rennet coagulation ability. Open texture cheeses produced from IIP milk (100 °C and 120 °C) contained significantly more moisture, had lower pH and shorter texture than similar cheese from IIP at 72 °C and HTST pasteurized milk. Cheese ripening was also affected by heat treatment, and different patterns of casein breakdown and peptide formation resulted from cheeses made from milk treated to IIP at 100 °C and 120 °C compared with cheeses made using IIP at 72 °C or HTST.  相似文献   

14.
Cheddar cheeses were made from pasteurised milk (P), raw milk (R) or pasteurised milk to which 10 (PR10), 5 (PR5) or 1 (PR1) % of raw milk had been added. Non-starter lactic acid bacteria (NSLAB) were not detectable in P cheese in the first month of ripening, at which stage PR1, PR5, PR10 and R cheeses had 104, 105, 106 and 107 cfu NSLAB g−1, respectively. After ripening for 4 months, the number of NSLAB was 1–2 log cycles lower in P cheese than in all other cheeses. Urea–polyacrylamide gel electrophoretograms of water-soluble and insoluble fractions of cheeses and reverse-phase HPLC chromatograms of 70% (v/v) ethanol-soluble as well as -insoluble fractions of WSF were essentially similar in all cheeses. The concentration of amino acids were pro rata the number of NSLAB and were the highest in R cheese and the lowest in P cheese throughout ripening. Free fatty acids and most of the fatty acid esters in 4-month old cheeses were higher in PR1, PR5, PR10 and R cheeses than in P cheese. Commercial graders awarded the highest flavour scores to 4-month-old PR1 cheeses and the lowest to P or R cheese. An expert panel of sensory assessors awarded increasingly higher scores for fruity/sweet and pungent aroma as the level of raw milk increased. The trend for aroma intensity and perceived maturity was R>PR10>PP5>PR1>P. The NSLAB from raw milk appeared to influence the ripening and quality of Cheddar cheese.  相似文献   

15.
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.  相似文献   

16.
A preparation of exogenous alkaline phosphatase (ALP), containing 17,500 mU L−1, was added to pasteurized milk (PM) to study its role in cheese ripening. Three miniature Cheddar-type cheeses were made from PM containing no added ALP (control), PM plus 23 μL ALP (T1), to give ALP concentration similar to that in raw milk, and PM plus 46 μL ALP (T2). Milk, after addition of ALP, was held at 6 °C for 12 h before cheese manufacture and the experiment was replicated three times. The control, T1 and T2 milks contained ALP activity of 415, 2391 and 4705 mU L−1, respectively. The addition of ALP to PM caused significant (P<0.05) changes in moisture content of miniature cheeses but did not cause any changes in protein content. Levels of water-soluble N during ripening of the cheeses were similar for control, T1 and T2 cheeses. The concentration of amino acids was not affected by the level of ALP present in milk. However, reversed-phase HPLC showed differences in the peptide patterns of control, T1 and T2 cheeses, suggesting a role of ALP in cheese ripening. The results suggest that ALP may play a role in cheese ripening, but further studies are needed to confirm this.  相似文献   

17.
The contributions of the coagulant Cynara cardunculus and of the microflora of raw milk to the volatile-free fatty acid profile of Serra da Estrela cheese were evaluated. The experimental design included both a model system and, dual cheeses. The study in the model system showed that isovaleric acid was the predominant volatile compound after 7 d of ripening. The systems inoculated with Enterococcus faecium produced the highest amount of this volatile (ca. 135.8 mg kg−1 curd), while those inoculated with Lactobacillus plantarum produced the least (21.4 mg kg−1 curd); Lactococcus lactis produced moderate amounts (ca. 34.2 mg kg−1 curd) but a total amount of volatile-free fatty acids similar to those found in control samples. This is considered advantageous since this volatile fatty acid confers a harsh, piquant, mature flavour to cheese, coupled with the realisation that excess volatiles may result in off-flavours. The addition of cultures in experimental cheeses helped reduce ripening time to about one half. Inclusion of Lb. plantarum led to cheeses containing the highest amounts of volatiles, and exhibiting an aroma closest to that of typical Serra da Estrela cheese.  相似文献   

18.
Lactobacillus casei cells were immobilized on fruit (apple and pear) pieces and the immobilized biocatalysts were used separately as adjuncts in probiotic cheese making. In parallel, cheese with free L. casei cells and cheese only from renneted milk were prepared. The produced cheeses were ripened at 4 to 6°C and the effect of salting and ripening time on lactose, lactic acid, ethanol concentration, pH, and lactic acid bacteria viable counts were investigated. Fat, protein, and moisture contents were in the range of usual levels of commercial cheeses. Reactivation in whey of L. casei cells immobilized on fruit pieces after 7 mo of ripening showed a higher rate of pH decrease and lower final pH value compared with reactivation of samples withdrawn from the remaining mass of the cheese without fruit pieces, from cheese with free L. casei, and rennet cheese. Preliminary sensory evaluation revealed the fruity taste of the cheeses containing immobilized L. casei cells on fruit pieces. Commercial Feta cheese was characterized by a more sour taste, whereas no significant differences concerning cheese flavor were reported by the panel between cheese containing free L. casei and rennet cheese. Salted cheeses scored similar values to commercial Feta cheese, whereas unsalted cheese scores were significantly lower, but still acceptable to the sensory panelists.  相似文献   

19.
Cheese ripening acceleration is of continuous interest for the industry. High-pressure (HP) treatment of starter cultures used in cheese-manufacturing offers the potential to accelerate ripening by increasing the activity of their intracellular peptidases that contribute in the development of desired cheese organoleptic characteristics.The objective of the present research was the investigation of the effect of HP treatment (200 MPa-20 °C - 20 min) directly on white brined cheese or on the starter culture used for its manufacture (Str. thermophilus:L. lactis:L. bugaricus 2:1:1). For this purpose, the microbial, textural, physicochemical and organoleptic characteristics and proteolysis were assessed during the 2nd stage of ripening in cold stores. Control cheese without any treatment was also studied.Cheeses made with HP-treated starters had increased secondary proteolysis. Organoleptic scoring of these cheeses was higher during the whole storage period compared to control and HP-treated cheese. Their superiority was evident even at the early stages of ripening in cold stores, since no bitterness was detected. On the contrary, although HP treated cheeses showed the highest increase in aminopeptidases activities, this was not correlated with the studied ripening indices or the organoleptic characteristics.According to the results, HP-treated starter culture can accelerate proteolysis and potentially the ripening of cheese-in-brine.Industrial relevanceThe data obtained from this work suggest that application of HP treatment under optimized conditions on cheeses in brine starter cultures or on whole cheeses can be effectively used for the production of products with reduced ripening time. This is of great importance for the cheese industries, since the storage period for ripening is long (higher than two months), while applying HP treatment as suggested in this study, this time may be reduced to less than one month, producing cheeses of superior quality.  相似文献   

20.
Semi-hard cheeses were manufactured using Streptococcus thermophilus and Lactobacillus helveticus cultures and their ripening was characterised. During cheese manufacture, curds were cooked to a maximum temperature of 47, 50 or 53 °C, pre-pressed under whey at pH 6.15, moulded, pressed and brined. Increased cook temperature resulted in increased manufacture time, a significantly reduced growth rate of S. thermophilus during manufacture in the order 47≈50 °C>53 °C and in significantly lower mean viable cell counts of S. thermophilus up to 56 d of ripening. Increasing cook temperature had no significant effect on mean viable cell numbers of L. helveticus or non-starter lactic acid bacteria (NSLAB). Cheeses produced from curds cooked to 47 °C had significantly higher levels of moisture in non-fat substances (MNFSs), salt-in-moisture and a significantly lower pH and levels of butyrate compared with cheeses produced from curds cooked to 50 or 53 °C.  相似文献   

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