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1. Type of process These days thetypes of pressure driven separation pro cesses are defined by the pore ize of the semi permeable membrane and the amount of pressure although the classifications are still somewhat subjective and youl find some overlap Table 1 describes the most common classes of the separation process In general RO or reverse osmo sis uses the highest pressures and membranes that only allow the smallest particles through while MF or microfiltration is associated with lower pressure and larger pore izes The actual pores aren t visiblein RO membranes instead its the structure of the water within the membrane that is important Think of themembraneas a water swollen ge and itis water itself that moves through themembrane based on the ability of several water molecules to form a tetrahedral orice lke structure via hydrogen bonding Only molecules that fit into this tetrahedral structure can cross the RO membrane One molecule that does cross is lactic acid because itis a small moleculethat binds to hydrogen Both UF and MF separate compounds based on size fundamentally acting as a sieve that rejects molecules too largeto fit through the pores whileallowing smaller molecules to enter the permeate stream The pressure is the driving force Of course system parameters like membrane composition and operating conditions will havea major influence on operation For example temperature pressure and con2. Jim Path at 608 262 2253 or Bill Wendorff at 608 263 2015 for more details Mar 14 Wisconsin CIP Workshop Madison WI Call Bill Wendorff at 608 263 2015 Mar 15 Dairy HACCP Workshop Madison WI Call Marianne Smukowski at 608 265 6346 Mar 27 31 Wisconsin Cheese Technology Short Course Madison WI Call Bill Wendorff at 608 263 2015 Apr 5 WDPA Butter amp Cheese Evaluation Clinic Wis Dells WI For information call Brad Legreid at 606 836 3334 Apr 11 12 Master Starter Culture Seminar Madison WI Call Jim Path at 608 262 2253 Apr 11 14 Basic Cheesemaker s License Short Course River Falls WI Call Ranee May for further info at 715 425 3150 Apr 26 27 International Cheese Technology Expo Madison WI For information call Judy Keller at 608 255 2027 May 2 3 Whey and Whey Utilization Short Course Madison WI Cal Bi Wendorff at 608 263 2015 May 17 18 Applied Dairy Chemistry Short Course Madison WI Call il Wendorf at 608 263 2015 June6 7 Wisconsin Cheese Grading Short Course Madison WI Call Bill Wendorff at 608 263 2015 c Dairy PIPELINE The Dairy Pipeline Center for Dairy Research 1805 Linden Dr Madison W 53706 phone 608 262 5970 fax 608 262 1578 Karen Paulus Editor Technical Reviewers Mark Johnson CDR Norm Olson Dept of Food Science Jim Path CDR Marianne Smukowski CDR Tom Szalkucki CDR Karen Smith CDR Bill Wendorff Dept of Food Sci
3. camefrom different geographical regions A group of cheese experts n 15 from industry government and academia tasted the cheeses and generated a basic language of 23 words to describe cheese flavor Then a descriptive panel began to fine tune the language and identify standard references for the terms These references will allow anyoneto easily train a descriptivepanel a panel that evaluates cheeses using the same language as other panels Using descriptive analysis Tuo 3 month old Cheddar blocks were graded by a USDA cheese grader and evaluated by descriptive cheese 1 A cbitter si flat analysis with the Cheddar language Cheese A bitter sifat Cheese grade results Notice that the cheeses received the same grade However the graph of the descriptive analysis illustrates that these two cheeses have vastly different flavor profils The differencesin flavor profile between these two cheeses xn could bevery important for product develop mentor end forothy product applica tion Using descrip tiveanalysis with the Chetda enouage Descriptive analysis with Cheddar language not all terms are listed cooked lactone allows us to profile the favor of the cheeses illustrating the differences in flavor profiles Weall know that Americans are consuming more cheese and amore types of cheese than ever before To develop new cheese types or sell the right cheeseto the ri
4. limit is in effect Again water is added so the standardization agent does not have excessive solids The profile of the modified standardization agent is displayed automatically by the program Current status of EACY We are developing an on line help system for EACY as well as a user s manual We are also beta testing the software with the help of volunteer Wisconsin cheese manufacturers We need more volunteer firms to improvethe quality of EACY If your firm would liketo obtain a beta version of EACY in exchange for provid ing feedback please contact Brian Gould usingthe email address below After participating in this beta testing your firm will receive free copy of thefinal version of EACY as wall as free uparades for a year If you are interested contact Dr Brian W Gould Wisconsin Center for Dairy Research 608 263 3212 GouldGaae wisc edu Curd Cie Curd clinic doctor for this issue is John Lucey assistant professor of Food Science UW Madison TZ Questions for the Curd Clinic Writeto CDR UW Dairy Pipeline 1605 Linden Dr Madison WI 53706 FAX 608 262 1578 e mail Paulus ecdr wisc edu pd Factors that affect watering off Structure iow pH excessive proteolysis high MINES high fat Temperature high storage temperatures Time salt gradients after brining proteolysis 0 wenotce that some packaged cheeses seem to leak uid into the package What causes thi
5. reference sample and two coded samples Ask them to choose the coded sample that matches the reference sample The following tests are examples of attribute difference tests you can use them to determineif two or more samples differ with respect to a defined attribute For example Which oneis sweeter Paired preference A common atributedifferencetest used to show which sample has more of the tribute you ae testing Ranking Thisis one method which you can useto rank samples according to intensity of oneattribute References Sensory Evaluation Techniques M Meilgaard D Sc G CivilleB S B Carr M S CDR Press Inc 1991 industry and academia have used their own descriptors Terms used by sensory panels at different sites generally do not have published definitions or references making communication difficult and replication of test results very difficult if not impossible Recently Dairy Management Inc funded a project to develop a standard descrip tivelanguage or Cheddar cheese with definitions and references for individual terms In the past researchers have proposed a universal language for describing Cheddar cheese or cheese in general However these studies used very small sample sets 20 to 30 cheeses and the language was not developed by cheese experts In the present study a collection of 250 Cheddar cheeses was screened to generate 70 representative Cheddar cheeses The cheeses varied by age and they
6. Wisconsin Center for Dairy Research DAIRY PIPELINE A Technical Resource for Dairy Manufacturers Fall 1999 Volume 11 Number 4 Mechanics of Membrane Processes Part 1 By Karen Smith Ph D CDRS Whey Applications Program Membrane technology is used throughout thefood industry particularly in the dairy segment According to the Ultrafil tration and Microfiltration Handbook dairy applications account for the majority o installed membrane capacity in the ood industry Although membrane technology continues to eolveand improve the basic concepts emerged in thel700 s Abbe Nollet was to first to observe osmosis when water diffuses from a dilute solution to a more concentrated one through a semi permeable membrane Back in those days natural substances like pig bladders and onion skins were used as semi permeable membranes or membranes that let solvents through while holding solids back Inthe 18005 the earliest artificial membranes were developed from nitrocellulose Then leading into the early 19005 the field of physics expanded with thermodynamic theories that influenced membrane development By the 19408 and 505 membranes were commonly used to remove microorgan isms for example by filtering drinking water Atthe same time scientists began to try reverse osmosis to remove salt from seawater By the Os ceramic membranes were used commercially in everything from nuclear power reactors to dairy plantsin France What s In
7. c for funding parts of theresearch presented Thanks to Mark Smith SteveWrightand Rhodia Inc f r ther support ofthe Cheddar flavor language Sensory language FAQ s D is sensory language proprietary No Thisis a common question among people new to Sensory analysis and a question that has been previously posed and debated in arbitration in other commodity areas You can usea different word for a particular term or createa foreign language to evaluate your product but anyone who knows descriptive analysis would beableto taste your product and identify the flavors The flavor of your cheese is not a secret to your competitors how you created or developed that flavor is 0 Can a standard language be developed for cheese texture or for other types of cheese A Yes Oncewefinish Cheddar flavor language we wil begin to apply it to other cheese types Weare also develop ing standard descriptive language for texture 0 Does descriptivesensory analysis wth thestandard Cheddar language take the place of cheese grading or ADSA judging No Descriptiveanalysis ith the standard Cheddar language will give the industry another analytical tool for research product development and marketing As dis cussed earlier grading and judging ae useful and have unique applications Descriptive analysis withthe Cheddar language provides an additional sensory tool to identify and quantify specific flavors in cheese without refer
8. cen tration all affect permeability Membrane structures What can we make membranes out of It really varies you can makernembranes out of inorganic materials ike ceramics or stainless steel and arange of organic materials likenylon polypropylene cellulose etc Of course different materials are useful for different applications In the dairy industry itis important to use membrane materials that arent toxic that are heat and pH resistant and that are stabletthrough chemical cleaning You might also prefer a lou cost high flux model Speaking of flux it another term you need to know when discussing filtration Flux is a measurement that describes theamount of permeate produced in a given time unt for a given membrane area in a specific time period Its impor tant because lux affects the economics of the system and is an indication of membrane fouling and cleaning possibili ties The lower the flux the greater the membrane area required to process the same amount of product in a given time Pressure feed velocity temperature viscosity or thickness and turbulence all influence flux Now that you have mastered the basics in thenext Dairy Pipeline l II be covering membrane configurations and the roleof membraneprocessingin thedairy industry ve seecesecoecocnccecocccoococoececoccoonccecocccoscecoocecsececoccecocccoscecoocec 3 Annual Wisconsin Dairy Field Reps Conference February 1 2 2000 Crown Plaza Hotel Madison Eas
9. d strength This is caused by strengthening of internal hydrophobic interactions within the casein particles You can easily see this effect in some yogurts which can water off when left out at room tempera ture return it to the refrigerator to chill and the water can be ab sorbed Timeis another factor Long storage times affect susceptible cheeses because they allow the opportunity for breakdown of thestructure once again impairing the ability to retain moisture Additionally the larger the cheese block the more time that is required for salt and moisture equilibrium The cheese may continue to lose moisture to the surface after manufacture If the cheese is already wrapped then this moisture accumulates inside the package Late acid development in theblock might also be involved in this defect Many traditional brine salted cheeses lose moisture by evaporation during storage If wax or plasticoat is used it is applied after the cheese surface has partially dried out However rindless cheeses are increas ingin popularity Replacing the rind with packaging material means that surface moisture might accumulate inside the packaging material You may need to make these cheeses with a lower moisture content than Tindless cheese or you may need to allow enough timeto lose any free moisturebeforeyou package the cheese Parmesan provides a good example If itis dry salted and shelf dried prop
10. eese from flavor and aroma to functionality and texture Whether your cheese tops a pizza fills an enchilada or graces a tablein afive star restaurant sensory quality is evaluated at some level Yes we do have mechanical tests that mimic or predict various sensory measurements but sensory testing remains a fundamental and irreplaceable too for three reasons No equipment required Sensory testing does not require the up front purchase of an expensive piece of machinery Sound sensory testing can be conducted by outside suppliers or contractors or by a few individuals who also perform other jobs atthe plant Versatility There are numerous sensory tests depending on the specific objectives you need Sensory tests can be simple or complex you can design them to measure aroma texture or flavor Perception by human subjects Ultimate the consumer judges sensory quality Thus human evalua tion of sensory properties is perhaps the best predictor of fallow human perceptions When used appropriately sensory analysis isan extremely powerful tol Traditional tools Thedairy industry has developed two traditional tools for evaluating flavor and texture quality cheese grading and ADSA scorecard judging Both techniques involve one or more expert evaluators who generate an overall quality scoreor grade forfa cheese whilealso noting specific defects These tools have been used for more than 50 years and both industry and academia continuet
11. ence The Dairy Pipeline is published by the Center for Dairy Research and funded by the Wisconsin Milk Marketing Board To subscribe to the Pipeline simply phone fax or e mail your request to CDR Form on page 11 We welcome your questions and comments Send them to Karen Paulus Editor e mail Paulusicdrwisc edu phone 608 262 8015 You can also find the Dairy Pipeline on our website www cdrwiscedu EEE Wisconsin Center for Dairy Research Nonprofi Org University of Wisconsin Madison US Postage CDR 1605 Linden Drive PAID Madison Wisconsin 53706 1565 Madison WI Permit No 658 ADDRESS SERVICE REQUESTED
12. enceto good or bat Ll what can the Cheddar language do tat radingor ADSA judging does not do The Cheddar languageis a descriptive analysis tool for flavor profiling You can useit to identify and quantify all theflavorsin your cheese You can also apply statistical analyssto results which allow you to analyze the data and identify how sensory descriptors relate to chemical com pounds jnstrumental analyses and consumer preference With grading and judging only defects are identified and statista analysis cannot be conducted M News from CDR All the folks who work at CDR have been getting a head start on seasonal indulgences weve been tasting shortbread brownies cakes and cookies made in the Applications Lab Its all dueto Kathy Nelson recently hired Research Specialist who has been testing milkfat fraction formulations When sheis done with her analysis the products areours to sample and they have been worth sampling Kathy earned a Masters degree in Food Science at UW Madison in 1989 and moved to Minneapolis to work at Pillsbury as a product scientist in the Baked Goods section She left the corporate world take classes at the Culinary Institute in New York before opening her own catering business Kathy notes that she really enjoyed the cooking but her business skills didn t match up to her cooking prowess She enjoys working at CDR a setting that provides an ideal combinati
13. erly then you wont see any watering off However vacuum packed Parmesan can cause some rouble Try lating it dry longer before you packageit check the humidity in your ripening room and consider better whey drainage during manufacture Blue cheese a high salt high moisture cheese begins with a high acid curd that may haveimore moisturethan the cheese can absorb The cheese surface usually dries out in the storage room However when you package the cheese you may see some watering off expecially ifthe moistureis too high and you havent allowed enough timefor drying Pandas a high acid salty Hispanic cheese that easily waters off at room temperature However panela is most often used as a cooking cheese The slighty sweet flavor of lactose on the cheese surface isan expected flavor that also browns when the cheeseisfried all part of the panda experience Watering off can be problem anytime packaged cheeseis stored inap propriately at a temperature that is too high f you can rulethat out as the cause then you need to look at moisture retention in your cheese For an indepth discussion of theroleof casein review the Spring 99 issueof the Dairy Pipeline qv 1 Calendar Feb 1 2 Wisconsin Dairy Field Reps Conference Madison WI Call Bill Wendorff at 608 263 2015 Feb 22 23 Wisconsin Process Cheese Short Course Madison WI Call
14. ght market is essential to determine consumer preference In 1997 Dairy Management Inc conducted a market segmentation study of cheese consumption From this study we know the market segments of cheese consumption and how the different segments consume cheese Using this information wecould go to any region in the U S and characterize the cheese consumers in that area We know that regional flavor preferences exist but we dont averdiablevalid substantial information on theflavors that particular market segments prefer in cheese By combining market segmentation data with descriptive sensory analysis with a universal cheese language we could determine those preferred flavors Applying this information would then allow more specific niche marketing On the same note flavor profiling by descriptive analysis can also hep to match the right cheese with the right consumer or the right buyer for the right application Sensory analysis is an extremely powerful tool with multiple dimensions and many applications in the cheese industry Using analytical descriptivesensory tools to identify and quantitateal flavors in cheese can provide critical informa tion for product development research quality control and marketing ge Acknowledgements This is a condensed version of a talk presented at the 1999 Marschall Cheese Seminar in Santa Clara California reprinted with permission Thanks is extended to Dairy Management In
15. iry Research developed a computer program CHYIELD that cheese makers could use to analyze alternative milk standardization procedures CHYIELD worked well but after a feu years it was dear that weneeded to improveil For example there was no internal check of the protein or solids contents of standardized cheese milk This is particularly important when you add high protein dry products such as NFDM as your standardizing agent Also CHYIELD paid little attention to obtaining a detailed mass balance of supply versus utilization of the components of the cheese milk In addition the ability to produce alternative types of by products was limited A major limitation of CHYIELD was that it was a DOS based program and unableto use many features of Windows programs In 1998 we decided to revamp CHYIELD to overcomethe shortcomings listed above We call our new program EACY Economic Analysis of Cheese Vid Al the features in the original program are incorporated within EACY which isa native Windows program that runs under Windows 95 Windows 98 and Windows NT We have also added many new features For example EACY allows the user to limit the maximum solids content of the standardized cheese milk If this limit is reached the program automatically adds water to the standardization agent to reduce the solids content The user can also specify the total solids percentage ofthe standard agent when the total solids
16. le and quantifiable information No judgement of good or bad is made Attributes present are identified and the intensity quantified You can analyzetthe data by statistical methods directly correlating them to instrumental measurements tis this qualifi able what s there and quantifiable how much is there information that makes descriptive analysis an invaluabletool in product develop ment research quality control and consumer studies Evaluating Flavor Both aroma and taste makeup flavor a critical component in cheese application and marketing Extensive research has been con ducted with instrumental analysis of flavor components but for now sensory evaluation remains the best way to assess cheese flavor Developing a standard Cheddar flavor language Although descriptive sensory analysis isan extremely useful tool in product development and research it can be even more useful Right now standard descriptive language for evaluat ing cheese doesnt exist Instead researchers in continued on page Difference Tests Thesearebrief descriptions of some simplesensory difference tests often used to determine product differ ences or to select and train panelists to discern differences Triangle test Each participant has three coded samples One is different and two are identical Ask them to pick out the different sample Duo trio tests Each participant receives a
17. methanol urea Nanofiltration NF Pesmeate monovalent ions Retentate divalents ions sugars proteins and fat Operating pressure 150 to 300 psig Theory diffusion and flow through pores controlled by mass transfer Ultrafiltration UF Permeate minerals NPN and sugars Retentate protein and fats Operating pressure 30to 150 psig Theory shape charge flexibility molecular weight determine ability to cross membrane Microfiltration MF Pesmeate minerals sugars small proteins e Retentate fat and large proteins Operating pressure 20 to 100 psig Theory sizedetermines ability to cross membrane Filtration flow In traditional filtration the entire stream passes through the filtering medium theincoming stream is perpendicular and the filter retains trapped solids Figure 3 RO UF and MF usea cross flow filtration Figure 4 where the feed stream passes parallel to thefiter or membrane At any time only some ofthe water and particles will cross the membrane which does limit the applications For example it difficult to senarateall the protein from lactose with 100 efficiency since al thesolution doesnt cross the membrane Compared tothe traditional method cross flow streams are self cleaning because the fouling material is continually swept along and away from the membrane surface allowing longer operating times Figure 4 Cross flow filtration
18. o use them widely to providea rapid relatively simple way to assess overall sensory quality While sound and useful tools these techniques provide an expert opinion of quality However consumer opinion and expert opinion of cheese quality may not match Further these techniques only list the defects present Individual defect intensities are not quantified and positiveattributesareneither identified nor quantified It isnt possible to usestatistical analysis with grading Also it isnt appropriate to use statistical analysis for quality scores from scorecard judging because thescalesarenot linear However ou can use additional analytical sensory tests to augment these traditional tools and add a new dimen sion to sensory testing Analytical sensory tools Mainstream sensory analysis involves a versa tileset of tools that fall into two categories discriminative tests and analytical tests Discriminative tests are difference tests They measure general differences in products and indudethe following triangle tests duo trio tests paired preferenceand ranking tests These tests are simpleto set up require little or no training of personnel and are easy to interpret Qualiiable information is provided essentially you are asking Does a difference exist Quanti fiable information regarding the degree of differenceis not provided you havent answered howmuch Analytical sensory tests also called descriptive analysis provide qualifiab
19. on of science and culinary skill MM Aren t you glad you listened to your Mom when she said Drink your milk Mom was right Dairy ingredients provide essential nutrients and offer unique functional attributes to foods Thearticle Dairy Ingredients for Health written by Kimberlee Burrington appears as the cover story in Food Product Design October 1999 issue The article explores the components and derivatives of milk and tells why it does a body good To read the article in its entirety check out the editorial library at www foodproductdesign com Wisconsin Process Cheese Seminar February 22 23 2000 Babcock Hall Madison Wisconsin TheWisconsin Process Cheese Short Course is a two day hands on short course designed to cover the basics of formulation and manufacture of pasteurized process and cold pack cheese products This course wll begin ith the basic theories and chemistry of process cheese manufacture and will include the practical aspects of process cheese making The hands on laboratory sessions will over the manufacture of various process cheese products For more information contact Jim Path at 608 262 2253 or Bill Wendorff 608 263 2015 Sponsored by University of Wisconsin Madison Center for Dairy Research Department of Food Science and Cooperative Extension Service College of Agricultural amp Life Sciences Economic Analysis of Cheese Yield In 1992 researchers at the Wisconsin Center for Da
20. s problem and how can 1 prevent it A Although lteinformation has been published about this probem some cheeses do indeed exude whey watering off after manufac ture In general watering off is more commonly observed in low pH or high acid cheeses such as Cheshire Feta and young Blue This a physico chemical problem generally related to theinabilityof the cheese structure to retain all moisture Structure temperature and time all contribute to the problem of tree water technically its free serum Cheese is a casein based matrix made from aggregated casein particles which fuse to form afirm network structure This matrix is responsible forthe texture and water holding ability of cheese Mineral and sat content pH moisture and levels of proteolysis all influencethestructural matrix Cheese needs an appropriate structure to retain all the moisture during storage ince much of that moisture is physically retained within the cheese matrix If the pH is too low or thereis excessive proteolysis then the cheese can become crumbly Now it is physically less able to retain moisture n cheese with a high fat content or a high moisture content high moisturein the nonfat solids or MINFS thereis more stress on the cheese which influences its ability to retain moisture and possibly proteolysis Storagetemperature also influences watering of At high temperatures cheese becomes softer and curd strands junctions may decrease in size an
21. side Mechanics of Membrane Processes Evaluating Sensory Quality of Cheese Beyond Good Versus Bad 5 News from CDR 8 Curd Gini 10 Calendar Back page University of Wisconsin Extension Type of filter In the past filtration processes have relied on depth filters a typeof filter made with fibers or beads in a mesh like structure Figure 1 Particles in the feed solu tion becometrapped or adsorbed within the filter net work eventually clogging the filter and requiring replace ment In contrast membranes are screen filters with pores the pores are more rigid and uniform Figure 2 Poresizeand shape determines the passage of particles allowing a more narrowly defined sizethan the mesh openings in a depth filter Components that dont fit through the pores in a screen filter remain on the mem brane surface Since they dont become trapped within the membrane tructureintesnal fouling is less and you can reusethemembrane Figure 1 Depth Filter continued on page College of Agricultural and Life Sciences Figure 2 Table 1 Screen Filter Figure 3 Feed stream Filtered stream z Perpendicular filter flow Reverse osmosis RO Retains molecules in ionic sizerange Poresizeat resolution of scanning electron microscope Operating pressure 200t01 200psig Theory ability of compound to mimic tetrahedral structure of water determines ability to permeate for example
22. t Tuesday Feb 1 Moming Quality Milk Production in Wisconsi Moderator Larry Tuschen UW Milk Quality Systems Pamela Ruegg DVM Research Update on Milk Quality Bill Wendorff Bulk Tank Culture Interpretations Nigel Cook DVSC UF RO of Raw Milk Robert Fassbender lt lt Afternoon Panel Discussion Working Together for Milk Quality Moderator Jim Glaeser Jim Wickert Rating officer Phil Carley Inspector David Rhoda DVM Veterinarian Jeff Montsma Fidd Rep Ken Bolton County Dairy Agent Milk Pricing Issues Moderator Denny Zimmer True Protein Impact on Milk Pricing Bob Cropp Dairy Industry Investment with Check off Programs Will Dahl Business Meeting Social Conference Wednesday Feb 2 oming Critical Regulatory Issues for Quality Milk Moderator Bob Bradley Environmental Issues on Dairy Farms JimArts Johnes Disease Current Issues Libby Balzer DVM Update on Milk Surveys Randy Daggs Current Concerns from WDATCP Tom Leitzke MM Interested Contact Bill Wendorff at 608 263 2015 A coesecccacoscocsecocacoscocsecocacoscocsecooscoscocsecoescoscocsecooscoscocsecoo Evaluating Sensory Quality of Cheese Beyond Good Versus Bad by MaryAnne Drake asst professor Mississippi State University and the Southeast Dairy Foods Research Center Sensory quality is a critical issue in cheese production and marketing because it encompasses all aspects of ch
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