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Fermented Milk and cheese Poduction.pptx
- 1. Kamau S M Lecturer:Dairy Training institute Fermented Milk and Cheese Production
- 2. Fermented milk products Milk Products be made by mesophilic or thermophilic fermentation. Mesophilic fermentation uses starter cultures (fermentation microorganisms) that have optimum growth temperature of 30oC and they have a growth temperature range of 20 - 40oC. The incubation is usually for 14–16 h or until a pH of 5.0 is achieved. Thermophilic starter cultures grow from 30 to 46 °C for 8–10 hours; With a final pH of 4.7
- 3. What is fermentation? Fermentation is a bio chemical breakdown of a substance usually sugars by bacteria, yeasts, or other microorganisms Fermentation usually results in various products such as organic acids (lactic acid, butyric acid, etc.), alcohols (ethyl alcohol, butyl alcohol, etc.) and gases (hydrogen, carbon hydroxide, etc.).
- 4. Dairy starter cultures Dairy starter cultures are harmless, specially selected microorganisms of known and stable metabolic activities that are inoculated into milk to produce fermented products of desirable characteristics (appearance, body, texture and flavor). When inoculated in milk they convert the milk sugar, lactose, into lactic acid for curd formation and other by products responsible for flavour, aroma and consistency development.
- 5. Producer Country Website Christianand Hansen Denmark http://www.chr-hansen.com Danisco Denmark http://danisco.com DSM The Netherlands http://www.dsm.com Alce Italy http://www.mofi nalce.it Centro Sperimenti del Latte Italy http://www.csl.it Valio Finland http://www.valio.fi BioSource Flavors, Inc. United States http://www.biosourcefl avors.com CSK Food Enrichment The Netherlands http://www.cskfood.com BIOPROX France http://www.bioprox.com
- 6. Yoghurt This isthe most ppopular fermented milk product made using thermophilic starter culture, it has mild acidic taste, rich in aromatic diacetyl flavor and has a smooth viscous texture.
- 7. Classification of yoghurt Chemical composition - they are classified as full-fat, reduced-fat or low-fat, fruit yoghurt Method of production- they can be grouped as set, stirred, drinking Flavor type- can be classified into subgroups such as Plain/natural yogurt, flavoured yoghurt (strawberry, vanilla etc) Post-incubation process - can be grouped as concentrated, dried, and frozen, long life Textural characteristics – can be grouped as thick yoghurt, thin ,smooth
- 8. Cultured butter milk(mala) Milk product made using mesophilic starter cultures, it has mild acidic taste with an aromatic diacetyl flavor and a smooth viscous texture. In Kenya its popularly known as maziwa lala (mala for KCC)
- 9. Processing of fermented products Processing of fermented milk involves heat treatment of milk, inoculation with starter cultures and incubation to achieve the desired characteristic of body, texture and flavour of the fermented milk product. The fermented milk must be cooled immediately after attaining the required acidity to stop the fermentation process (further acid development).
- 10. Raw milk qualityfor fermented milk production Physical dirt - Should be clean, if not sieve or clarify Antibiotics – antibiotics prevent growth of bacteria in the starter culture Colostrum - the high amount of whey proteins causes wheying off resulting in thin watery product. They also act as natural inhibitors in milk. Mastitis - low sugar (lactose) in mastitis milk does not allow production of enough lactic acid resulting in a flat tasting product Water - added water prevents formation of a firm coagulum. Chemicals- e.g. detergents, sanitizers, preservatives, which are injurious to the consumer or will prevent growth of bacterial culture. Microbial: - should be low in initial microbial load. Some microorganism’s produce bacteriocins which might prevent fermentation or be in competition with the starter culture
- 11. Additives and ingredients Other dairy products: SMP, Whey powder, Lactose Sugar /Sweeteners Flavours (fruits, natural flavors and/or synthetic flavors) Colours Stabilizers (gelatin, pectin) Thickeners (Corn starch, SMP)
- 12. Average amounts ofingredients added in yoghurt making Sugar 4.0 -6.0% Skim milk powder 1.0 – 3.0% Starch ( Corn flour) 0.5 – 1.0% Pectin/gelatin 0.1 to 0.5% Food colour According to consumer preference
- 13. YOGHURT MAKING PROCEDURES SETYOGHURT STIRRED/DRINKING YOGHURT High quality milk. Filter. Standardize (optional). Optional enrichment with Skim Milk Powder, max. 3%, Sugar, max 6%, Stabilizer e.g. gelatin, colour. Pasteurize 850 C/30 min. or 900 C/15 min. Cool to inoculation temperature 38 – 450 C (optimum 420 C) Optional additional of flavour Additional of starter culture Incubation till coagulation (3 – 6hrs ) Additional of starter culture Cooling to 4 0 C overnight Packaging into individual cups Stir, optional addition of flavour, fruits, nuts Incubation till coagulation 3 – 6 hrs Cooling to 4 0 C overnight Whipped / Stirred /Drinking Yoghurt Set/ Firm/ Eating Yoghurt
- 14. CHARACRTERISTIC OF GOODYOGHURT Appearance Smooth, porcelain-like, no whey separation Colour Natural milk colour or Colour of the corresponding flavouring Odour Characteristic sourish, clean and aromatic or typical for the used flavouring Taste Typical, characteristic, full, pleasant, mild to slightly acidic and sweet if sweetened Consistency Gelatinous, viscous, slightly ropy, no bubbles, no lumps, no separated whey
- 15. Processing Procedure Cultured ButterMilk (Mala) High quality milk required Standardization Milk is usually heated to 85 °C for 30 minutes or 90 °C for 15 minutes Cool to 20-25 °C (room temperature) Addition of mesophilic starter culture. Incubation 14-16 hours, to an acidity of 0.7% lactic acid. Packaging
- 16. Defect. Probable cause(s) 1)Wheying off Over incubation Too high incubation temps. Contamination with unwanted microorganisms 2) Grainy / curdy/ small lumps Over incubation Too high incubation temps. Contamination 3) High acid development Over incubation Too high incubation temps. Contamination 4) Thin or low viscosity Low total solids Over stirring Disturbing during setting 5) Flat taste/no acid development Weak starter culture Milk with preservatives/antibiotics Little sugar in milk (as for mastitis milk) 6) No fermentation Dead starter culture Milk with preservatives/antibiotics 7) Mouldy or Yeasty flavour Air in the coagulum/gassy Sugar not pasteurized introducing yeast contamination Over exposure to the environment leading to contamination and high storage temps 8) Bitter Breakdown of proteins due to molds or to molds or bacterial contamination
- 17. Cheese Cheese isthe fresh or matured solid or semi-solid product obtained by coagulating whole milk, skim milk, cream, whey cream, or buttermilk or any combinations of these materials through action of rennet, or other coagulating agents and by partially draining the whey resulting from such coagulation (FAO/WHO; 1978.)
- 18. Ripened cheese Curedor Ripened cheese is cheese which is not ready for consumption shortly after manufacture but which must be held for such time at such temperature and such other conditions as will result in the necessary biochemical and physical changes characterizing the cheese. E.g. Gouda, cheddar
- 19. Un-ripened cheese Uncured,Unripened or Fresh cheese is cheese which is ready for consumption shortly after manufacture E.g. Mozarrella, cottage
- 20. Reasons for cheesemaking Value addition of milk Utilization of excess milk Increasing nutritional value per unit volume Increasing shelf life of milk Improving digestibility of milk
- 21. GENERAL CHEESE MAKING OPERATIONS The cheese making process involves a set of organized and well coordinated steps known as a Recipe. It details the order, timing and limits of each operation. The recipe is specific to the cheese type
- 22. CHEESE MILK PREPARATIONS ANDPRE-TREATMENTS Filtration and clarification Butterfat standardization Pasteurization Thermization