Cheese industry

Clostridium sporogenes and Clostridium botulinum ( Van Wazer , 1971, Tanaka et al , 1979 .1986; WAGNER, 1986; STEEG Ter et al , 1995. ; LOESSNER et al . 1997) prolongingshelf life of the finished product . This effect is explained by the fact that the walls and thecell membranes of many microorganisms are stabilized by Ca2 + ions . theassociation with anions which can not pass through the membrane , as is the case withorthophosphates and citrates , destabilizes the envelope microorganisms ( BOUTONNIER ,2002) .literature review153 . TECHNOLOGY IRONThe main steps that includes the manufacture of specialty cheese areshown in Figure I-3 .3.1 . Selection of raw materials and quality controlPrior to use , the materials selected will be subject to controlrigorous about their physicochemical and bacteriological composition and characteristicsorganoleptic ( ROOM al. , 1997).3.2 . Peeling , cutting and grinding of the cheesesIn some cases , the hardness of the cheese can lead to difficulties and meltingpresence in the final product of unmelted particles .The peeling is traditionally done by scraping or abrasion , or bynew techniques such as jets of hot water under pressure. To facilitate mixingwith the other ingredients and reduce the cast time , it is imperative to fragmentcheeses (Figure I-3) .This coarse grinding is usually followed by finer grinding in a double-worm pieces leading to a grid whose perforations are 2 to 10 mmdiameter according to the acceptable level of intensity by the finished product.3.3 . Preparation of Formula and process technologyWater and melting salts are added to the cheese and dairy raw materials,then a set of pre-grinding is carried out for a few minutes to obtain amixture ready to be melted ( McSWEENEY et al. , 2004).The order of addition of raw materials depends on the equipment available , the type ofcooker and cooking time . According McSWEENEY et al. , (2004) , the typical order of additionis as follows : the wheels of cheese, emulsifying salts dry mixture , ingredientsdairy such as milk powder , water and coloring agents such other technology , thehydrocolloids and preservatives.literature review16Figure I-3 . Main routes of processed cheese ( GUINEA et al. , 2004)Cutter - Mixer cooker cooker mixermixturemixtureCooking / Castpasteurizationor sterilizationcoolingdoubleor envelopebyinjection wateror relaxation /vaporizationmixtureCooking / CasttankpreheatingCooking / Castinterchangethermalscraped surfaceUpérisateurpasteurization orsterilization injectiondirect steampasteurizationor sterilizationindirectcoolingVacuum chambercoolingexpansion / vaporizationWater cheesepowdersmilkwheycaseinscaseinatesbuttercreamAMFSaltsmeltingpremeltcleaningrankingfragmentationcoarsefragmentationdelicatedosageweightpremixmixtureCooking / Caststabilizationthermal:pasteurizationor sterilizationcooling(T < 100 ° C )creamingpackagingcoolingcheesemeltedliterature review173.3.1 . Cast itselfThis is the key of the processed cheese manufacturing operation , it may be carried out underfacilities continuously connected to water pumps , steam and vacuum ( Figure I-4 ) . Time andmelting temperature varies between 70 and 95 ° C for 4 to 15 minutes , depending onthe intensity of the stirring , the desired texture of the final product and its characteristicsconservation ( FOX et al . 2000). Heat treatments are usually sufficient toeliminate all vegetative forms ( Warburton et al. , 1986), but remains inadequate torid of spore forms. Above 130 ° C are required foreliminate few spores ( Zehren and Nusbaum , 1992; Mafart et al , 2001. ) .In continuous cookers , the mixture may be heated to 140 ° C for 2 to 20seconds ( UHT sterilizing value of a 4 min treatment , that is to say a practice scheduleequivalent to 4 minutes at 121 ° C ) , then cooled and maintained at a sterilization temperaturebetween 70 and 95 ° C for 4 to 15 minutes ( Zuber et al , 1987; . BLOND et al , 1988. ;TATSUMI et al , 1989. ; TATSUMI et al , 1991. ; BEGUERIA , 1999) .pumpA Cutter: mixing / cooking / melting ingredients at a temperature of 90 ° C.Upérisateur B : direct injection of steam into the food product .C Lodger : maintaining the sterilization temperature of 140 ° C for a few seconds .Expansion chamber D / flash under reduced pressure with flash vaporization of a portion of waterproduct and simultaneous cooling thereof to a temperature of 90 ° C.Condenser E : condensation of the vapor evaporated from the product water .Creaming F : Setting the consistency of melted cheese by stirring hot .Packaging G melted cheese at a temperature of 70-75 ° C.Figure I-4. Treatment principle of direct UHT sterilization : upérisation ( BOUTOUNIER ,2002)ingredientsABCsteampressurecheesemeltedD EGFwaterlukewarmwatercoldwaterproductliterature review183.3.2 . homogenizationThe melt must be homogenized at pressures between 5 and 15 mPa .Homogenization has a number of effects ( Meyer, 1973) :• Improved stability of the fat emulsion by reducing the size offat globules ;• Improved consistency , structure , appearance and smoothness ofspecialty cheeses ;• Promotes a finer dispersion of fat globules ( Walstra and JENNESS , 1984) ;• Promotes general thickening.However, because of its additional cost , the extension of the time of manufacture,homogenization is recommended only for products high in fat( CARIC KALAB and 1993).3.3.3 . packagingThe transfer of the cheese is more by stainless steel pipingsupplying couleuses to avoid recontamination packaging .The hot liquid cheese is packed in lacquered aluminum foil orheat sealable plastic material containers . The cheese may also be packed intube in tin , or plastic casings ( MEYER, 1973; Zehren andNusbaum , 1992; NORONHA et al. , 2008b).3.3.4 . coolingA slow cooling can promote the development of the Maillard reaction ,but its speed varies depending on the type of product; it must be fast for processed cheesespreads and cheese specialties to interrupt the process of creaming andStore in a product essential for obtaining short structure of spreadabilitysatisfactory . It must be slow for blocks.This cooling may be achieved by movement within the mat to the ambient airbut the best results are obtained in cooling tunnels ( ECK and GILLIS ,1997) .literature review193.3.5 . Finished product storageProducts boxed are stored in warehouses where the temperature isaround 10 to 15 ° C and the shelf life can be estimated at between 6 to 12 months if theoptimal during different stages of production requirements are met ( ECKGILLIS , 1997; GUINEA et al, 2004 . ; BUNKA et al. , 2008). At storage temperaturesbetween 30 and 35 ° C , contamination by molds , yeasts and Clostridiumbotulinum may occur which can lead to a secretion of toxins ( KAUTTER et al . 1979; Tanaka et al , 1979. ; Eckner et al . 1994).literature review203.4 . Manufacturing defectsDuring the technological process and during storage , some defectstechnology may occur (Table I- 7).Table I -7. Possible causes of manufacturing defects and possible remedies to consider( Berger et al. , 1989)Appearance ofdoughPossible Cause RemedyThe paste is nothomogeneous- The pH is low, and its value depends onthe raw material used (egEmmental requires a higher pHcheddar )- The salt content of iron is low- The short cooking time is- Increasing the pH- Increase the dose- Increase timecheesemolten liquid- The raw material used is notrefined , can not squirt orConversely, is too old and does not swell- The melting salts used werenot crémants- The mixture contains an amountHigh water- Mix the raw materialyoung with another refined- Put a sparkling salt melt- Check the water qualityDough formsthe son- The use of salts is not adequate- Melting time short- Dose melting salts is not accurate- A low speed stirrer- Increase time- Increase the dose of salts- Increase the speed ofstirrersat the opening ofkneading the doughis too softhigh pH Decrease pHAt the opening ofkneading the dough isrelativelythicklow pH increase the pHMelted apronounced tastecheeseThis is in most cases , ahigh employment cheese too old wherehigh pH- If it is possible to mixthe raw material to ayounger cheese.- Reduce the amount of saltreplacing the castdifference citratesodium that masks the tasteundesirableliterature review213.5. Factors favoring the melting3.5.1 . Effect of cheese ripeningMore cheese is ripened , most proteins are hydrolyzed , they lose most of theiremulsifying properties . Hence the need to keep a required minimum amount of caseinintact ( Patart , 1987).3.5.2 . Effect of pHPhases peptization ( breakdown ) and restructuring are only possible ina pH range between 5.2 and 6.2 . To pH = 5, the emulsifying capacitycasein is altered and no longer provides the emulsion ( MARCHESSEAU et al. , 1997).3.5.3 . Effect of emulsifying saltsThe peptizing action does not result in a continuous increase of the nitrogen notsedimentable ( NNS ) when the concentration of polyphosphate is growing. There is apolyphosphate concentration beyond which value remains almost constant NNS( CAVALIER - Salou and Cheftel , 1991) (Figure I-5) .The ability peptizing pyrophosphate is low. This results in a lownon sedimentable calcium , reflecting the lack of chelating power of this salt vis-à -vis thecalcium . Orthophosphate is almost zero. This salt is capable of formingcalcium bridges between casein molecules . TATSUMI et al. (1975) note thatorthophosphate causes association of molecules of calcium caseinate . NAKAJIMAet al. ( 1975) think orthophosphate preferentially reacts with the colloidal calciumto form insoluble salts .To produce a suitable peptization , must contain polyphosphate used toleast three phosphorus atoms per molecule ; beyond the influence of the condensation is notsensitive ( DIMITRELI et al. , 2005). Furthermore , no sufficient peptization with the apparraîtpolyphosphates presence of the polymerization rate which is at least equal to tripolyphosphatein the mixture of emulsifying salts ( Lee et al , 1979 . 1986 ENNIS et al, 1999 . ) .literature review22Figure I-5 . Effect of salt concentration on the melting percentage of NNS ( 300 000rev / h at 20 ° C) ( CAVALIER - Salou and Cheftel , 1991).3.5.4 . Effect of premeltIt helps to accelerate the reaction kinetics and stabilizes the emulsion in promotingprotein interactions / lipids; it is used to improve the stability and texture of cheesemelted ( Berger et al. , 1993).3.6 . Biochemical phenomena of meltingBiochemical phenomena of melting can be summarized in three phasesmain (Figure I-6) .3.6.1 . peptizationAfter the cheese finely ground raw materials and brought into contact withwater and melting salts are present at the start of the stage of disintegration . The melting saltschelate calcium protein bound and thus transform paracaseinate insoluble calciumparacaseinate soluble in sodium ( Lee et al , 1979 . SCHÄFFER et al, 1999 . ) .After the exchange of calcium against sodium, peptide chains are partlyplace and dissociated ; this is the stage peptization ( Schäffer et al. , 2001).3.6.2 . Creaming - restructuring phaseAccording ÉTIENNE (1992 ) , the step of creaming is a thickening of the producthas two origins:- Peptization proteins , allowing hydration chains , resulting in aswelling medium and an increase in viscosity.Para- soluble caseinate (in%of total casein )Melting salt (%)Sodium citrate ●Sodium phosphate ▲literature review23- The calcium pyrophosphate formed during the heat treatment have a sizewhich allows them to be inserted between the protein chains to form ionic bondsIntra- and inter -protein resulting in gelling of the network .The formation of the protein network is even faster than it incorporates thepremelt ; the latter ( already structured molten cheese ) will give the mixture in which itis introduced a model promoting interactions , which will accelerate the kineticsrestructuring ( Lee et al. , 1986).3.6.3 . coolingIt is during this phase that gelation occurs . The protein network formedthrough hydrogen , hydrophobic and ionic bonds established , will form a structure forgel will strongly trap the emulsified fat and water of hydration( BOWLAND et al , 2001 . Hennelly et al, 2005 . ) .Figure I-6 . Schematic representation of the biochemical phenomena of iron ( PACKAGE1988)caseinatehydratedstabilizationtemperatureEnablingareashydrophobic emulsionfalltemperatureEmulsificationhydrationswellingcreamingWater retention andfatjellificationcoolingcheesemeltedCaCa caseinateresidualNa caseinatewatertemperature increasemixingshorteningFat globules andlipid dropletsChelation of CadispersionpeptizationshorteningdispersedCa caseinateproteolysisCa caseinate"Native"waterMelting saltNa NaEnablingareashydrophilicdenaturationproteinsliterature review244. QUALITY CONTROL4.1 . Quality of the starting materialThese checks must be made ​​upon the arrival of raw materials at the place ofmanufacturing ( BOUTONNIER , 2002).• physicochemical Plan : pH, solids and fat. It is also desirableto perform a content analysis on casein , in particular for cheeserefined and verify the absence of contaminants.• Sensory Plan: external and internal appearance , texture, color and flavor .• bacteriological Plan : estimation of the initial microbial load in total bacteria andsporulated .4.2 . Quality in manufacturingFor the main steps of the method of casting, several parameters must be monitored( BOUTONNIER , 2002) .• Preparation, dosage: respect the proportions of ingredients by controlling the massesof the respective ingredients .• premix , mixing : pulp consistency , pH and the water content and ifpossible to the fat .• Cooking , cast : time and melting temperature , stirring speed .• Thermal Stabilization: time and temperature of pasteurization or sterilization ,time and cooling temperature .• Creaming : time, temperature and mixing intensity , quality and quantity of premeltadded .• Packaging: packaging temperature , no son of cheese, foldingand seal welds for flexible packaging , followed by masses , labelingand banding .• Cooling: time and temperature.4.3 . Quality of the finished product• Presentation of cheese packed (general control).• Packing : appearance, sealing .literature review25• freed from its packaging Product:o External appearance : brightness , color, no holes , crystals , particlesunmelted , greasy exudation ... ;o texture: by penetrometer consistency , spreadability analysis ;o flavor : olfaction , retro-olfaction and gustation .• Functionality Tests : heat stability , ability to recast in differentconditions ( hot air oven , microwave oven ...) . This list is not exhaustive, onlythe main qualitative controls were mentioned .Further checks are performed , including those specific to each type of cheesemelted and all quantitative controls .Chapter II: Materials and Methods26Chapter II: Materials and Methods1. Places of workAll work is performed in the workshop of cheese and laboratoryphysical chemistry and microbiology of dairy Beni Tamou Blida . Sessions analyzessensory were performed in the laboratory of the Institute of Nutrition,Food and Food Processing Technologies ( INATAA UMC ) .2 . Types of cheese studiedOur study focused on two types of cheese portions; said triangular portions" Metija " rectangular portions and said " Ladhidh Camembert ."3 . Manufacture cheese specialties3.1 . MetijaThe formula for the cheese specialty Metija consists of :• Powder- Crosslinked starch ( hydroxypropyl distarch phosphate E 1422 ) at 3 % belowas a white powder , pH = 6-8 and maximum moisture content of 20 % ;- Melting salts ( sodium citrate E 331 , E 339 Sodium phosphate , diphosphate E 450Calcium phosphate and polyphosphate E 452 ) ;- Casein and rennet casein acid ;- Table salt NaCl;- Milk Powder with 0% fat.• MaterialsPartially hydrogenated vegetable fat , premelt , proteinaceous materialdairy ( Cheddar, fresh dough , cream cheese , fresh cheese, white pasta water stools,pasta, and pasta melted ) .Materials and methods27• WaterThe amount of water added into the cheese was determined by taking into account theamount of humectant agents and water supplied to the vapor state (condensate ) in thecooking .The manufacturing process is illustrated in Figure II -1 . A quantity of 25 % of waterTotal injected is cold and the powders in the mixer where they are mixedfor 10 minutes. The materials are then added , and finally hot water at 70 ° C isinjected. The whole is mixed for 45 minutes. The prebaking is carried out at 90 ° C ( 68 ° C to110 ° C ) , and the mixture undergoes a UHT treatment at 138 ° C for 3 seconds ( 132 ° C to 145 ° C ) ,then the product is cooled and packaged.Figure II-1 . Main stages of manufacture of specialty cheese Metija3.2 . Ladhidh CamembertFor Ladhidh Camembert , after preparation of the formula in the same way thatMetija for , but not crosslinked starch , the mixture undergoes the following operations :- Crushing ( at 30 ° C for 200 seconds , speed knife 2500 rev / min) ;- Injection of steam at 110 ° C ( first amount of water ) ;Preparation of FormulaBlend ingredients