Dairy technology A TRAINING ABOUT THE PRODUCTION AT FRIESLANDCAMPINA VIETNAM IN HA NAM COMMISSIONED BY FRIESLANDCAMPINA Course Dairy technology A TRAINING ABOUT THE PRODUCTION AT FRIESLAND CAMPINA VIETNAM IN HA NAM COMMISSIONED BY FRIESLAND CAMPINA Carried out by Fons Michielsen, mbo Life Sciences, P.O Box 878, 8901 BR LEEUWARDEN, Netherlands fons@aocfriesland.nl test Ha Nam, Vietnam PREFACE For over 20 years now this training is performed to employees of Friesland Foods It started in the early ‘90's of the last century with a training to workers in Leeuwarden, producing evaporated milk and sweetened condensed milk Gradually, more and more staff became interested, and not only of the supply point Leeuwarden, but of different factories too Of course, its contents are modified since and adapted to new demands, new scientific insights and new target groups, taking the training In 2004 I was asked to write a dairy course for the factories outside the Netherlands with the same structure as the courses mentioned before The first and second part of the course, i.e Milk science (1), Microbiology (2), Checks on raw milk (3), Statistics of filling (4) and Cleaning and Disinfecting (5), Overview (6), Heat (7), Separating the cream (8), Standardisation (9), Homogenisation (10), information about the production of milk powders (11) and Recombination (12) are applicable for most production sites The third and final part depends on the local production and will be adapted for each factory It may contain Consumer Milk Products (non fermented), Cultured Consumer Milk Products, Lactic Acid Drinks, yoghurt, drinking yoghurt, Butter and Butter oil, Cheese, Sterilised Evaporated Milk and Sweetened Condensed Milk, Milk Powders and compositions, Whey Products, Fruit Juices and Fruit Drinks, Filling and Packing, Quality Control and Quality Requirements These courses intend to give background information The how question can easily be answered at the production site These courses intend to answer the why question: why we act like we act during processing I realize that it may be quite a challenge for you to absorb this course But I really hope that, afterwards, you will say: it was quite a lot of work but it was worth doing it Because: now I really understand Leeuwarden, September ‘08 Fons Michielsen mbo Life Sciences Leeuwarden 08-‘12 -I- Ha Nam, Vietnam mbo Life Sciences Leeuwarden 08-‘12 -II- Ha Nam, Vietnam TABLE OF CONTENTS PREFACE TABLE OF CONTENTS PREFACE TABLE OF CONTENTS Milk science 1.1 introduction 1.2 milk fat 1.3 protein 1.4 lactose 1.5 glucose syrup 1.6 salts and trace elements 1.7 enzymes 1.8 physical properties of milk and other emulsions 3 7 17 37 69 85 101 107 117 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Microbiology introduction growth conditions dying off rate of growth and dying off origin of microorganisms in milk measures to control microorganisms in dairy products some figures questions 139 139 145 155 163 167 171 175 177 Checks on raw milk 179 4.1 4.2 4.3 Statistics of filling introduction average and standard deviation questions 193 193 199 209 5.1 5.2 5.4 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11 5.12 Cleaning and disinfecting introduction ways of cleaning important factors mechanical strength temperature time chemistry checking disinfecting the procedure ourselves questions 211 211 213 225 227 227 227 229 233 233 235 235 235 Overview 239 7.1 7.2 Heating what is heat what is steam 243 243 245 mbo Life Sciences Leeuwarden 08-‘12 -III- Ha Nam, Vietnam 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 7.15 the steam boiler types of heat treatment pasteurisation: the theory heat transfer structure of a plate heat exchanger heat management271 measurement and control tubular heat exchanger scraped surface heat exchanger batch pasteurisation direct heating heating packed products questions 251 255 257 261 265 8.1 8.2 Separating the cream introduction questions 299 299 305 9.1 9.2 9.3 9.4 9.5 9.6 9.7 Standardising standardising for fat content standardising for total solids standardising market milk for fat and total solids standardising on the ratio fat : milk solids non fat standardising on the ratio fat : milk solids non fat : sugar standardising in practice questions 307 307 317 319 321 323 325 333 10 10.1 10.2 10.3 10.4 10.5 Homogenising principles consequences three methods to check homogenisation degree practical implementation questions 341 341 341 351 355 357 11 11.1 11.2 11.3 11.4 11.5 Milk powder properties introduction evaporation lactose crystallisation drying questions 361 361 365 373 375 399 12 12.1 12.2 Recombination introduction questions 403 403 413 13 13.1 13.2 13.3 13.4 13.5 Long life milk the product the process results of heating quality defects of long life milk, fresh and recombined quality checks 415 415 415 425 427 429 mbo Life Sciences Leeuwarden 279 283 289 289 289 293 295 08-‘12 -IV- Ha Nam, Vietnam 13.6 questions 433 14 14.1 14.2 14.3 Pumps and valves Pumps Valves Questions 445 445 453 463 15 15.1 15.2 15.3 15.4 15.5 15.6 15.7 15.8 15.9 15.10 15.10 The production of yoghurt introduction types of yoghurt lactic acid bacteria production of stirred yoghurt the yoghurt starter culture phage infection texture new developments production short life yoghurt at DLV product properties questions 467 467 469 473 477 501 505 507 511 515 517 519 16 16.1 16.2 16.3 16.4 16.5 16.5 Drinking yoghurt and lactic acid drink pectin pectin and casein drinking yoghurt manufacture lactic acid drink production possible defects questions 521 523 525 529 537 541 547 17 17.1 17.2 17.3 17.4 SCM the production microbiological aspects storage properties and probable defects questions 549 549 559 567 581 18 18.1 18.2 18.3 18.4 18.5 Powders, blending and packaging raw materials blending packaging checks and hazards questions 583 583 585 587 593 595 19 19.1 19.2 19.3 19.4 19.5 19.6 19.7 19.8 Packaging introduction the Tetra Brik package combibloc filler preformed plastic bottles preformed plastic cups filling cans weight check questions 597 597 599 603 605 607 607 613 613 mbo Life Sciences Leeuwarden 08-‘12 -V- Ha Nam, Vietnam 20 20.1 20.2 20.3 20.4 20.5 20.6 20.7 Membrane filtration introduction composition of retentate and permeate construction of cross flow membrane equipment the dynamics of the filtration ceramic microfiltration three examples of cross flow filtration questions 617 617 623 627 637 641 645 651 21 21.1 21.2 21.3 waste water treatment origin of waste water waste water treatment questions 653 653 659 665 22 22.1 22.2 22.3 22.4 22.5 22.6 Additives rheology classification emulsifiers thickening and gelling structural stabilisers questions 667 667 669 671 671 693 695 APPENDIX CHEMICAL APPENDIX END NOTES GLOSSARY mbo Life Sciences Leeuwarden 08-‘12 -VI- Ha Nam, Vietnam mbo Life Sciences Leeuwarden 22 Additives 08-‘12 692 Ha Nam, Vietnam 22 Additives One of the more interesting favourable co-operations is the one that develops between an alginate and a high-ester pectin By using a blend, you can get it to gel under conditions that neither one would ordinarily gel under Normally with a high-ester pectin you would need low pH and high solids With an alginate, you'll need a calcium source and a higher pH, one above By mixing these together, a gel will form in a pH range lower than needed for an alginate and higher than required for a high-ester pectin (in the to pH range) without the high solids or the calcium ions Other examples are the cooperation between locust bean gum and κ-carrageenan or locust bean gum and xanthan: although locust bean gum is a thickening agent it will gell in the presence of κ-carrageenan or xanthan A very common example of synergy is between xanthan and guar: combining them results in higher viscosity than expected 22.5 Structural stabilisers A group of relatively small molecules is frequently used in dairy industry to prevent coagulation of protein These are orthophosphates like sodium dihydrogen phosphate and sodium monohydrogen phosphate and polyphosphate molecules like sodium Illustration 22.16 Phosphates hexametaphosphate (see illustration 22.16) Sodium hexametaphosphate is correctly speaking a hexamer of composition (NaPO3)6 "Sodium hexametaphosphate" of commerce is a mixture of polymeric metaphosphates, of which the hexamer is one, and is usually the compound referred to by this name It is more correctly termed sodium polymetaphosphate It hydrolyses in aqueous solution, particularly under acidic conditions, to sodium trimetaphosphate and sodium orthophosphate Ortho- and polyphosphates in general are applied in food industry because of the following properties: (pH) buffering, sequestering (means Ca2+-binding), bacteriostatic, protein stabilising (the negative charge of phosphates increases the repulsion and hydration of protein molecules), anti caking and nutritional mbo Life Sciences Leeuwarden 08-‘12 693 Ha Nam, Vietnam mbo Life Sciences Leeuwarden 22 Additives 08-‘12 694 Ha Nam, Vietnam 22 Additives 22.6 Questions What is a Newtonian fluid? Mention three other types of behaviour on shear stress and give a short explanation of each What is yield stress? What exactly is a stabiliser in food technology? What types of structural stabilisers (classes) you know? What are hydrocolloids in general and what function they have in general? Explain the difference between a thickener and a gelling agent Mention hydrocolloids and their main properties What type of material is: glycerol mono stearate, κ-carrageenan, sodium hexametaphosphate? 10 What we mean with synergy between structural stabilisers? 11 Will synergy occur between thickeners, gelling agents or a combination? 12 Is gelatin, technically spoken, a hydrocolloid? Explain 13 Why is hydration an important step in the functioning of gums? mbo Life Sciences Leeuwarden 08-‘12 695 Ha Nam, Vietnam mbo Life Sciences Leeuwarden 23 Pre- and probiotics 08-‘12 696 Ha Nam, Vietnam 23 Pre- and probiotics 23 PRE- AND PROBIOTICS 23.1 Introduction So far, we have encountered antibiotics (chapter and 15) and symbiosis (chapter 15) We proceed now with prebiotics and probiotics, since these are very popular marketing issues and so relevant for the food processing industry Antibiotics are compounds or substances that inhibits the growth of bacteria or kills them According to the original definition (1942) these substances were produced by microorganisms only, but now we have many (semi)synthetic antibiotics as well Symbiosis is a co-operation of two different species that have biological interaction: they have a fitness benefit from each other but they are not dependent from each other for survival In fact, symbiosis is a rather broad term and the definition given reflects on a specific form of symbiosis, the so called mutualism But in yoghurt we commonly speak about symbiosis Prebiotics are non digestible substances that provide a beneficial physiological effect on the host by selectively stimulating the favourable growth or activity of a limited number of indigenous bacteria (FAO 2001) Probiotics are live microorganisms, which when administered in adequate amounts confer a health benefit on the host (FAO 2001) When comparing the intestinal microflora or microbiota of (breast fed) infants with the intestinal microflora of adults it appears that the composition is different: infants have a much higher count of lactobacilli and bifidobacteria It was also known that the occurrence of several diseases in breast fed infants is reduced, compared to adults and infants that are fed with infant formula The gut of the infants is colonized in the first days of their lives with mainly lactobacilli and bifidobacteria, probably from skin, faeces, human milk etc It is not understood how these bacteria get access to the mammary gland, but it is a fact The human milk contains, next to the well known components as fat, protein, lactose and salt, also some carbohydrates, up to %, that cannot be digested by the enzymes in the gut, but that nevertheless seem to play an important role in the digestive system These carbohydrates can be metabolized by the lactobacilli and bifidobacteria, which convert these carbohydrates to small organic acids (mainly short chain fatty acids or SCFA) like acetic, propionic and butyric acid The ability to metabolize prebiotics is both strain and substrate specific The SCFA benefit the lactobacilli and bifidobacteria, fight detrimental bacteria, suppress the chance of colony cancer and provide energy to the body Next to this, the carbohydrates seem to act as soluble receptors for pathogenic bacteria: instead of attaching the mucosa and subsequent colonizing the gut, they “attach” to the these carbohydrates and are flushed out of the intestine The microorganisms, that are beneficial for our body we call probiotic bacteria The carbohydrates that beneficially effects the microflora of our gut we call prebiotics Of course, probiotics in the gut not need the prebiotics for growth And when prebiotics are orally administered they are also beneficial without probiotic administration They will modulate the gut microflora composition, promoting lactobacilli and bifidobacteria and repressing harmful bacteria like clostridia From some prebiotics is also known that they also induce changes in colonic epithelium stimulating proliferation in the crypts, increasing the concentration of polyamines, changing the profile of mucins, and modulating endocrine as well as immune functions mbo Life Sciences Leeuwarden 08-‘12 697 Ha Nam, Vietnam mbo Life Sciences Leeuwarden 23 Pre- and probiotics 08-‘12 698 Ha Nam, Vietnam 23 Pre- and probiotics The prebiotics that are available in breast milk are shown in illustration 23.1 They consist mainly of galactose and glucose with some other sugars (fucose) and some amino groups attached to it Another characteristic is that they are oligosaccharides, so up to 15 units long Illustration 23.1 Prebiotics available in human milk 23.2 Prebiotics A good functioning gut is very important for a healthy life Prebiotics play an important role in this It is not true that every person benefits from the intake of prebiotics, because people with a healthy and good functioning microflora in the gut and a good immunoregulatory system will not become “healthier” Prebiotics selectively stimulate the growth and/or activity of a limited number of beneficial microorganisms (probiotics) in (mainly) the colon This selective stimulation seems to be limited to non-digestible saccharides with not too many monomers, so polysaccharides with a chain length above a certain value don’t seem to behave as prebiotics That is why the focus in industrial production of prebiotics (second generation prebiotics) is on oligosaccharides The human gastrointestinal tract can only digest a few glycosidic linkages For example, β-glycosidic linkages cannot be digested (except the one in lactose), so oligosaccharides with β-glycosidic linkages can act as prebiotics Of course, the effect different oligosaccharides with (mainly) β-glycosidic linkages have on beneficial microorganisms is different: human oligosaccharides may stimulate probiotics in a different way than second generation prebiotics But from research there is overwhelming evidence that added oligosaccharides with mainly β-glycosidic linkages have beneficial effect on the gastrointestinal microflora A natural source of prebiotics is bovine milk and although mbo Life Sciences Leeuwarden 08-‘12 Illustration 23.2 Inulin The blue part is the glucose unit 699 Ha Nam, Vietnam mbo Life Sciences Leeuwarden 23 Pre- and probiotics 08-‘12 700 Ha Nam, Vietnam 23 Pre- and probiotics the composition of these prebiotics shows much resemblance with breast milk, the amount in bovine milk is approximately 20x less than in breast milk and difficult to obtain However, there is a very good other source of prebiotics: in the roots of some plants like chicory, artichokes and in the (bulb of the) onion a substance called inulin (illustration 23.2) occurs as storage carbohydrate The inulin is a linear β (2÷1) fructan, consisting of glucose molecule at the one end and - 60 fructose units (av - 12) The inulin is processed to a fructooligosaccharide (FOS) by hydrolysis of inulin to a length of - fructose units (av = 4) A second example of a second generation prebiotic is GOS or galactoO H 2O C H H 2O C H oligosaccharide This is a linear (4÷1) H O O O H O β-galactan, consisting of glucose O O H O H O H O molecule at the one end and max - H O galactose units It is produced from O H O H lactose by enzymatic action under very well defined process conditions Illustration 23.3 GOS Research shows that - in general - GOS obtains higher metabolic scores than FOS (and that bifidobacteria show less selectivity towards prebiotics than lactobacilli) GOS production is very attractive for the dairy industry, since it is a way to bring whey to value GOS is produced by Friesland Campina under the brand name Vivinal GOS H 2O C H A third example is raffinose It is a trisaccharide composed of galactose, fructose, and glucose It can be found in beans, cabbage, brussels sprouts, broccoli, asparagus, other vegetables, and whole grains It has no β-glycosidic linkages but an α-glycosidic linkage between galactose and glucose Raffinose can be hydrolyzed by the enzyme α-galactosidase (α-GAL), an Illustration 23.4 Raffinose enzyme not found in the human digestive tract Other members of the raffinose family of oligosaccharides (RFOs) are the tetrasaccharide stachyose, and the pentasaccharide verbascose RFOs are almost ubiquitous in the plant kingdom, being found in a large variety of seeds from many different families, and they rank second only to sucrose in abundance as soluble carbohydrates Since humans (and other monogastric animals (pigs and poultry)) not possess the α-GAL enzyme to break down RFOs, also these oligosaccharides pass undigested through the stomach and upper intestine In the lower intestine, they are fermented by gas-producing bacteria which possess the α-GAL enzyme and make carbon dioxide, methane, and/or hydrogen - leading to the flatulence commonly associated with eating beans and other vegetables Other oligosaccharides that are mentioned as prebiotics are (iso)malto-oligosaccharides, pecto-oligosaccharides and soybean oligosaccharides mbo Life Sciences Leeuwarden 08-‘12 701 Ha Nam, Vietnam mbo Life Sciences Leeuwarden 23 Pre- and probiotics 08-‘12 702 Ha Nam, Vietnam 23 Pre- and probiotics 23.3 Probiotics Describing prebiotics is relatively simple compared to probiotics There is quite a range of microorganisms that seem to have probiotic properties But mentioning probiotic properties is quite different from claiming probiotic properties on a label A label claim must be proven And claims on health benefits must not only be proven at the start, but must be maintained as well Clinical studies to support and maintain this type of claims are necessary and very expensive indeed, so dairy factories or dairy companies can seldom permit this In general, probiotics can mainly be found in the genus Bifidobacterium and Lactobacillus, although some probiotic properties can also be found in other genus Probiotic properties are not species specific, but strain specific Mentioning on a label that the product contains Bifidobacterium doesn’t mean anything, nor does the name adidophilus milk Research papers mention probiotic properties of strains, for example L acidophilus LAVRI-A1, L rhamnosus GG, B animalis Bb-12, L acidiphilus La5, L reuteri SD2112 etc But research on the probiotic properties is one thing, therapeutic effect another: research starts commonly with in vitro experiments, since these are not too costly and relatively easy to carry out What counts is the results of in vivo experiments (on humans) The bacteria must first survive the time of minimal durability (shelf life) of the product This is easier in the case of yoghurt than in the case of cheese! Then they must survive the gastrointestinal tract to reach the colon in sufficient numbers The FAO/WHO states that the bacterial count at expiry date must be > 106 cfu/ml Research papers claim a daily dose of 108 - 109 to have therapeutic effect This means a product intake of approx 250 ml/day As a result, the beneficial effects of the strains must be reached within these figures So when a strain has probiotic properties, but must be present in the food in 1010 cfu/ml, this strain is not an option Acting like a consumer I called one of the dairy factories in the Netherlands, that produces acidophilus milk The label claims that this product contains microorganisms that promote a healthy gut and that they fight harmful bacteria I asked the marketing manager of the factory if he could found the claim He answered me straight away mentioning the specific strain of one of the species mentioned on the label (L casei 431) and the producer of this culture (who is responsible for maintenance of the claim)! Verification on internet proved the validity of his answer The therapeutic effect of probiotic bacteria can be very diverse It is about allergic diseases, atopic dermatitis, necrotizing enterocolitis, immunomodulation in general, diarrhea, hypocholesterolemic effects, anticarcinogenic effects, gastric mucosal inflammation and more So both short term effects as well as long term effects can be achieved, but again: depending on the strain One strain will not combine all the therapeutic effects mentioned The main location for bacterial growth in the gastrointestinal tract is the colon But bacteria can also grow in other parts See illustration 23.5 mbo Life Sciences Leeuwarden 08-‘12 703 Ha Nam, Vietnam mbo Life Sciences Leeuwarden 23 Pre- and probiotics 08-‘12 704 Ha Nam, Vietnam Sometimes the probiotic strain is the main starter culture for the product So the sensorial properties of the product are a result of the fermentation of the probiotic culture In other situations, the probiotic culture is an adjunct culture: it does not create the product properties but it is added to a dairy product (commonly yoghurt or fermented buttermilk) This means that the probiotic culture is propagated in a different fermentation than the product fermentation tank: the propagated probiotic culture is dosed to the fermented product 23 Pre- and probiotics ) cf/m (g in u lp ta o T 01 12 th u o m ch a m sto ciS o trep ilsp b cto a L a n eilo V s g erfin l.p C m en o u d ciS o trep ilsp b cto a L s g erfin l.p C m n jeu V a n eilo li co E s g erfin l.p C sp cterim a b u E m ileu ciS o trep ilsp b cto a L sp cterim a b u E a n eilo V li co E sp id ctero a B ln co m rectu B sp id ctero a sp cterim a b u E icS b ero n a sp m cteru a b d ifo B ci o trep S li co E ilsp b cto a L a n eilo V ,C s g erfin lp ,C s g erfin lp Illustration 23.5 Bacterial count in gastrointestinal tract 23.4 Questions What is the difference between probiotics and prebiotics? Can probiotics act without prebiotics and vice versa? Explain Mention main characteristics of the construction of prebiotics Mention main characteristics of the action of prebiotics What we mean with the expression second generation prebiotics? Mention common groups of prebiotics What are two most important genus of probiotics? What species are best in probiotic activities? What benefits may humans have from probiotics? 10 Will everyone benefit from the intake of pre- and/or probiotics? 11 What would your advice be to someone who wants to improve intestinal health? mbo Life Sciences Leeuwarden 08-‘12 705 Ha Nam, Vietnam mbo Life Sciences Leeuwarden 08-‘12 706 ... AT FRIESLAND CAMPINA VIETNAM IN HA NAM COMMISSIONED BY FRIESLAND CAMPINA Carried out by Fons Michielsen, mbo Life Sciences, P.O Box 878, 8901 BR LEEUWARDEN, Netherlands fons@aocfriesland.nl ... test Ha Nam, Vietnam PREFACE For over 20 years now this training is performed to employees of Friesland Foods It started in the early ‘90's of the last century with a training to workers in Leeuwarden,... taking the training In 2004 I was asked to write a dairy course for the factories outside the Netherlands with the same structure as the courses mentioned before The first and second part of the course,