Capítulo 4 Resultados
4.1 Amplificador de 1 canal
4.1.1 Análisis Transitorio
With the advances in biotechnology, microorgan-isms with special characteristics for the manufactur-ing of fermented foods have become available. The most significant example is the approval by the FDA of Chy-Max (chymosin produced by genetic manip-ulation) used in the production of cheese. Its avail-ability greatly reduces the reliance on chymosin from young calves and produces economic savings.
Other products with similar or other properties are also available in the market. Genetically modified lactic acid bacteria and yeasts used in fermented food production are also available nowadays to re-duce production costs. Gradual acceptance by con-sumers is the key to the further development and success of biotechnology (Barrett et al. 1999, Early 1998, Geisen and Holzapfel 1996, Henriksen et al.
1999, Jay 1996, Kosikowski and Mistry 1997, Scott et al. 1998, Spreer 1998, Walstra et al. 1999).
Readers should refer to the references in this chap-ter and other references available for further infor-mation.
PROCESS MECHANIZATION IN THE MANUFACTURE OF
FERMENTED FOODS
Fermented foods produced by traditional methods are labor intensive and rely a great deal on the expe-rience of the manufacturers. The main drawback is product inconsistency. In most developed countries, products such as many cheeses, yogurts, breads, sausages, and soy sauce are now made by highly mechanized processes to standardize the products (Prasad 1989, Hamada et al. 1991, Iwasaki et al.
1992, Caudill 1993, Dairy and Food Industries Supply Association 1993, Gilmore and Shell 1993, Muramatsu et al. 1993, Luh 1995, Kamel and Stauffer 1993, Belderok 2000). This not only pro-vides product consistency, but also reduces produc-tion costs. Consumers benefit from these develop-ments. However, some consumers, even in developed countries, still prefer the traditional products, even at an increased cost, because of their unique product characteristics. There are also fermented products that are still made by traditional or semimechanized processes because mechanization processes have not been developed for them.
55 Table 3.1. Approximate Composition of Cow’s Milk
Average Content in Milk Range Average Content in Dry Matter
Components (% w/w) (% w/w) (% w/w)
Water 87.1 85.3–88.7
Solid-not-fat 8.9 7.9–10.0 69
Fat in dry matter 31 22–38 31
Lactose 4.6 3.8–5.3 36
Fat 4 2.5–5.5 31
Protein 3.25 2.3–4.4 25
Caesin 2.6 1.7–3.5 20
Mineral substances 0.7 0.57–0.83 5.4
Organic acids 0.17 0.12–0.21 1.3
Miscellaneous 0.15 1.2
Sources: Early 1998, Jenness 1988, Koshikowski and Mistry 1997, Robinson 1986, Spreer 1998, Walstra et al. 1999.
Table 3.2. Kinds of Fermented Dairy Products with Examples
Kinds Examples
Fermented liquid milks
Lactic fermentation Buttermilk, Acidophillus,
With alcohol and lactic acid Kefir, Koumiss
With mold and lactic acid Villi
Concentrated Ymer, Skyr, Chakka
Yogurts
Viscous/liquid Yogurt
Semisolid Strained yogurt
Solid Soft/hard frozen yogurt
Powder Dried yogurt
Cheeses
Extra hard Parmesan, Romano, Sbrinz
Hard with eyes Emmeental, Gruyere, Swiss
Hard without eyes Cheddar, Chester, Provolone
Semi-hard Gouda, Edam, Caerphilly
Semi-hard, internally mold ripened Rouquefort, Blue, Gorgonzola Semisoft, surface ripened with bacteria Limburger, Brick, Munster Soft, surface mold ripened Brie, Camembert, Neufchatel
Soft, unripened Cream, Mozzarella, USA–Cottage
Sources: Early 1998, Jenness 1988, Kosikowsi and Mistry 1997, Robinson 1986, Spreer 1998, Walstra et al. 1999.
56
Fermented Liquid Processed Cheese
Ingredients Milk Products Yogurt Natural Cheese Products
Milk
Raw Optional Optional Optional Optional
Standardized (fat and milk solids) Preferred Preferred Preferred Preferred
Milk powders Optional Optional Optional Optional
Microorganisms
Starter bacteria Required Required Required Required
Mold Optional Optional Optional Optional
Yeast Optional Optional Optional Optional
Genetically modified microorganisms Optional Optional Optional Optional Coagulant
Rennet Preferred Preferred Preferred Preferred
Acid Optional Optional Optional Optional
Microbial protease(s) Optional Optional Optional Optional
Common salt (sodium chloride) No No Required Required
Sugar Optional Optional No No
Vitamins Preferred Preferred Preferred Preferred
Buffering salts (calcium chloride hydroxide phosphates, sodium or
potassium phosphates) Optional Optional Optional Optional
Bleaching (decolorizing) agents No No Optional Optional
Antimicrobial agents Optional Optional No Preferred
Dyes (coloring agents) No No Optional Optional
Flavoring compounds (fruits, spices spice oils, fruits, fruit flavors,
artificial smoke) Optional Optional Optional Optional
Stabilizers No Preferred No Preferred
Emulsifiers Optional Optional No Preferred
Sources: Early 1998, Jenness 1988, Kosikowski and Mistry 1997, Robinson 1986, Spreer 1998, Walstra et al. 1999.
57
Table 3.4. Some Common Organisms Used in Fermented Milk Products Fermented
Microorganisms Buttermilk Cream Milk Yogurt Kefir Cheese
Bifidobacterium bifidum X X X
Enterococcus durans X
Enterococcus faecalis X
Geotrichum candidum X
Lactobacillus acidophilus X
Lactobacillus casei X
Lactobacillus delbrueckii subsp. bulgaricus X X X
Lactobacillus heleveticus X
Lactobacillus kefir X
Lactobacillus lactis X
Lactobacillus lactis biovar.diacetylactis X X
Lactobacillus lactis subsp. cremoris X X X
Lactobacillus lactis subsp. lactis X
Lactobacillus lactis var. hollandicus X
Leuconostoc mesenteroidis subsp. cremoris X
Leuconostoc mesenteroides subsp. dextranicum X
Propionibacterium freudenreichii subsp. shermanii X
Penicillium camberberti X
Penicillium glaucum X
Penicillium roqueforti X
Streptococcus thermophilus X X
Sources: Davies and Law 1984, Jay 1996, Robinson 1990.
Table 3.5. Dairy Starter Cultures
Physical Form Usage
Liquid cultures in skim milk or whole milk For inoculation of intermediate cultures (antibiotic free)
Liquid culture—frozen For inoculation of intermediate cultures For inoculation into bulk cultures Dried culture—from normal liquid culture For inoculation of intermediate culture
Spray dried cultures For inoculation into bulk cultures
For direct-to-vat inoculation.
Frozen cultures in special media (frozen at 40°C) For inoculation into bulk cultures For direct-to-vat inoculation Frozen concentrated culture (in sealed containers For inoculation into bulk cultures
at196°C)
For direct-to-vat inoculation Single strain lypholized cultures (in foil sachets For inoculation into bulk cultures
with known activity)
For direct-to-vat inoculation
Sources: Early 1998, Jenness 1988, Kosikowski and Mistry 1997, Robinson 1986, Spreer 1998, Walstra et al. 1999.
58
Kinds Preparation Steps Timing
Regular starter culture Preparation of starter culture blanks 8:00 a.m
Storing milk blanks 11:00 a.m.
Activating lypholized culture powder 3:00 p.m.
Daily mother culture preparation 3:00 p.m.
Semibulk and bulk starter preparation 3:00 p.m.
Frozen culture and bulk starter application Store frozen culture at 40°C or less Warm to 31°C and use directly
Reconsitituted milk or whey-based starter Reconstitution 8:00 a.m.
Heating and tempering 8:30 a.m
Inoculating and incubating 10:00 a.m.
Bulk starter from ultrafiltrated milk Ultrafiltration 1:00 p.m.
Heating and tempering 3:30 p.m.
Inoculating and incubating 5:00 p.m.
Sources: Early 1998, Jenness 1988, Kosikowski and Mistry 1997, Robinson 1986, Spreer 1998, Walstra et al. 1999.
Table 3.7. Temperature Requirements and Acid Production for Some Dairy Microbes
General Maximun Product Standard Temperature Titratable Acidity
Microorganisms Groupa for Incubation, °C Produced in Milk, %
Bacteria
Bifidobacterium bifidum 1, 2 36–38 0.9–1.0
Lactobacillus acidophilus 1, 2 38–44 1.2–2.0
Lactobacillus delbrueckii subsp. bulgarius 1 43–47 2.0–4.0
Lactobacillus lactics subsp. cremoris 2 22 0.9–1.0
Lactobacillus subsp. lactis 2 22 0.9–1.0
Leuconostoc mesenteroides subsp. cremoris 2 20 0.1–0.3
Streptococcus durans 2 31 0.9–1.1
Streptococcus thermophilus 2 38–44 0.9–1.1
Molds
Penicillium roqueforti 3 11–16 NA
Penicillium camerberti 3 10–22 NA
Sources: Davies and Law 1984, Emmons 2000, Jay 1996, Law 1997, Nath 1993, Robinson 1990, Scott et al. 1998, Specialist Cheesemakers Association 1997.
aProduct group: 1 = yogurt, 2 = fermented liquid milk, 3 = cheese.
59
Table 3.8. Classification of Cheese According to Moisture Content, Scald Temperature, and Method of Ripening
Hard cheese (moisture 20–42%; fat in dry matter, 32–50%, minimum) Plastic Curd, Low Scald, Medium Scald, High Scald, Lactic Starter or Lactic Starter Lactic Starter Propionic Eyes Propionic Eyes
Gouda Cheddar Parmesan Provolone
Cheshire Svecia Beaufort Mozzarella
Semi-hard cheese (moisture 45–55%; fat in dry matter, 40–50%, minimium)
Lactic Starter Smear Coat Blue-veined Mold
St. Paul Limburg Roquefort
Lanchester Munster Danablue
Soft cheese (moisture >55%; fat in dry matter, 4–51%, minimum)
Acid- Smear Coat or Normal Lactic Unripened
Coagulated Surface Mold Surface Mold Starter Fresh
Cottage cheese (USA) Brie Camembert Quarg Cottage (UK)
Quesco-Blanco Bel Paese Neufchatel Petit Suisse York
Sources: Early 1998, Jenness 1988, Robinson 1986.
Table 3.9. Approximate Weight of Cheese Block for Various Cheese Varieties
Cheese Variety Approximate Weight (kg)
Hard to semi-hard or semisoft
Wensleydale 3–5
Caerphilly 3–6
White Stilton 4–8
Single Gloucester 10–12
Leichester 13–18
Derby 14–16
Sage Derby 14–16
Cheddar 18–28
Cheshire 20–22
Dunlap 20–27
Double Gloucester 22–28
Lancashire 22
Internally mold-ripened (blue-veined) cheese
Blue Wensleydale 3–5
Blue Vinney 5–7
Blue Stilton 6–8
Blue Cheshire 10–20
Soft cheese
Colwich 0.25–0.50
Cambridge 0.25–1.00
Melbury 2.5
Sources: Early 1998, Jenness 1988, Kosikowski and Mistry 1997, Law 1997, Nath 1993, Robinson 1986, Scott et al.
1998, Specialist Cheesemakers Association 1997, .
60 Packaging Materials
Low permeability to oxygen, carbon dioxide, and water vapor
Strength and thickness of film
Stability under cold or warm conditions Stability to fats and lactic acid
Resistance to light, especially ultraviolet Ease of application, stiffness, elasticity Ability to seal and accept adhesives Laminated films to retain laminated
Low shrinkage or aging unless shrinkage is a requisite
Ability to take printed matter Should not impart odors to the cheese Suitability for mechanization of packaging Hygienic considerations in storage and use Cost effectiveness as a protective wrapping
Sources: Early 1998, Emmons 2000, Nath 1993, Kosikowski and Mistry 1997, Robinson 1986, Scott et al.
1998, Specialist Cheesemakers Association 1997, Spreer 1998, Walstra et al. 1999.
Standardize cheese milks.
Homogenize cheese milks.
Heat-treat or pasteurize cheese milks.
Add starter.
Add color and additives.
Coagulation/curdling:
Cut coagulum/curd.
Stir and scald.
Wash curd cheese.
Salt cheese.
Press cheese.
Coat, bandage, and wrap cheese.
Let cheese ripen.
Package for retail.
Store.
Sources: Davies and Law 1984; Early 1998; Jay 1996;
Jenness 1988; Kosikowski and Mistry 1997; Nath 1993;
Robinson 1986, 1990; Scott et al. 1998; Specialist Cheesemakers Association 1997; Spreer 1998; Walstra et al. 1999.
Table 3.12. Cheese Ripening Conditions
Types of Cheese Storage Period (days) Temperature (°C) Relative Humidity (%)
Soft 12–30 10–14 90–95
Mold ripened 15–60 4–12 85–95
Cooked, e.g., Emmental
Cold room 7–25 10–15 80–85
Warm room 25–60 18–25 80–85
Hard, e.g., Cheddar 45–360 5–12 87–95
Sources: Davies and Law 1984, Robinson 1986, Jenness 1988, Robinson 1990, Robinson and Tamimie 1991, Nath 1993, Jay 1996, Kosikowski and Mistry 1997, Specialist Cheesemakers Assocciation 1997, Early 1998, Scott et al.
1998, Spreer 1998, Walstra et al. 1999.
61 Table 3.13. Basic Steps in Making Cottage Cheese Standardize skim milk.
Pasteurize milk with standard procedure and cool to 32°C.
Inoculate with active lactic starter, add rennet, and set curd:
Rennet addition—at 2 ml single strength (prediluted, 1:40) per 1000 kg milk within 30 minutes of starter addition
Specifications Short Set Medium Set Long Set
Starter concentration 5% 3% 0.5%
Temperature of milk set 32°C 27°C 22°C
Time from setting to cutting 5 hr 8 hr 14–16 hr
Final pH and whey titratable acidity—4.6 and 0.52%, respectively.
Cut curd with 1.3, 1.6, or 1.9 cm wire cheese knife.
Cook curd:
Let curd cubes stand for 15–30 minutes and cook to 51–54°C at 1.7°C per 10 minutes.
Roll the curds gently every 10 minutes after initial 15–30 minute wait.
Test curd firmness and hold 10–30 minutes longer to obtain proper firmness.
Wash curd:
First wash with 29°C water temperature Second wash with 16°C water temperature Third wash with 4°C water temperature Drain washed curd (by gravity) for about 2.5 hours.
Salt and cream at 152 kg creaming mixture per 454 kg with final 0.5–0.75% salt content and 4% fat content (varies with products and optional).
Package in containers.
Store at refrigerated temperature.
Sources: Early 1998, Kosikowski and Mistry 1997, Nath 1993, Robinson 1986, Scott et al. 1998, Spreer 1998, Walstra et al. 1999.
62 Cheese
Standardize cheese milk.
Homogenize milk.
Pasteurization and additional heating of milk.
Cool milk to 31°C.
Inoculate milk with lactic starter (0.5–2% active mesophilic lactic starter).
Add rennet or other protease(s)—198 ml single strength (1:15,000) rennet per 1000 kg milk.
Dilute the measured rennet 1:40 before use.
Agitate at medium speed.
Set the milk to proper acidity—25 minutes.
Cut the curd using 0.64 cm or wider wire knife.
Stir for 5 minutes at slow speed.
Cook the curd at 38°C for 30 minutes with 1°C for every 5 minute increment. Maintain temperature for another 4–5 minutes and agitate periodically at medium speed.
Drain the curd at 38°C.
Cheddar the curd at pH 5.2–5.3.
Mill the curd slabs.
Salt the curd at 2.3–3.5 kg salt per 100 kg curd in three portions in 30 minutes.
Waxed cheddar cheese:
Hoop and press at 172 kPa for 30–60 seconds then 172–344 kPa overnight.
Dry the cheese at 13°C at 70% RH for 2–3 days.
Paraffin the whole cheese at 118°C for 6 seconds.
Rindless cheddar cheese:
Press at 276 kPa for 6–18 hours.
Prepress for 1 minute, followed by 45 minutes under 686 mm vacuum.
Remove and press at 345 kPa for 60 minutes.
Remove and vacuum seal in bags with hot water shrinkage at 93°C for 2 seconds.
Ripen at 85% RH at 4°C for 60 days or longer, up to 9–12 months, or at 3°C for 2 months then 10°C for 4–7 months, up to 6–9 months.
Sources: Early 1998, Kosikowski and Mistry 1997, Nath 1993, Robinson 1986, Scott et al. 1998, Spreer 1998, Walstra et al. 1999.
Cheese
Standardize cheese milk to 3% milk fat—treatment with H2O2-catalase optional.
Pasteurize the milk.
Inoculate with starters:
Streptococcus thermophilus, 330 ml per 1000 kg milk
Lactobacillus delbruechii subsp. bulgaricus, 330 ml per 1000 kg milk
Propionibacterium freudenreichii subsp.
shermanii, 55 ml per 1000 kg milk
Add rennet, 10–20 minutes after inoculation—154 ml single-strength (1:15,000) rennet extract per 1000 kg milk, prediluted 1:40 with tap water before addition. Stir for 3 minutes.
Let milk set (coagulate) for 25–30 minutes.
Cut the curd with 0.64 wire knife; let stand undis-turbed for 5 minutes; stir at medium speed for 40 minutes.
Cook the curd slowly to 50–53°C for about 30 minutes and stir at medium speed, then turn off steam and continue stirring for 30–60 minutes with pH reaching 6.3–6.4.
Allow the curd to drip for 30 minutes.
Press the curd—with preliminary pressing, then at 69 kPa overnight.
Salt the curd:
First salting—in 23% salt brine for 2–3 days at 10°C
Second salting—at 10–16°C, 90% RH. Wipe the cheese surface from the brine soaking, then sprinkle salt over cheese surface daily for 10–14 days
Third salting—at 20–24°C, 80–85% RH. Wash cheese surface with salt water and sprinkle with dry salt 2–3 times weekly for 2–3 weeks Rinded block Swiss cheese:
Cure—at 7°C or lower (USA) or 10–25°C (Europe) for 4–12 months.
Package in container and store at cool temperature.
Rindless block Swiss cheese:
Wrap or vacuum pack the blocks.
Cure stacked cheese at 3–4°C for 3–6 weeks.
Store at cool temperature.
Sources: Early 1998, Kosikowski and Mistry 1997, Nath 1993, Robinson 1986, Scott et al. 1998, Spreer 1998, Walstra et al. 1999.
63 Table 3.16. Basic Steps in Making Blue
Cheese
Milk preparation:
Separate cream and skim milk.
Pasteurize skim milk by HTST, cool to 30°C.
Bleach cream with benzoyl peroxide (optional) and heat to 63°C for 30 seconds.
Homogenize hot cream at 6–9 mPa and then 3.5 mPa, cool, and mix with pasteurized skim milk.
Inoculate milk at 30°C with 0.5% active lactic starter. Let stand for 1 hour.
Add rennet—158 ml single strength (prediluted 1:40) per 1000 kg milk. Mix well.
Let coagulate or set, 30 minutes.
Cut curd with 1.6 cm standard wire knife.
Cook curd at 30°C, let stand 5 minutes, and then agitate every 5 minutes for 1 hour. Whey should have 0.11 to 0.14 titratable acidity.
Drain whey by gravity for 15 minutes.
Inoculate with Penicillium roqueforti spores—2 kg coarse salt and 28 g P. requeforti spore powder per 100 kg curd followed by thorough mixing.
Add food grade lipase (optional).
Salting:
First salting—dip the curd in 23% brine for 15 minutes, then press or mold at 22°C, turning every 15 minutes for 2 hours and every 90 minutes for rest of day.
Second salting—salt cheese surface every day for 5 days at 16°C, 85% RH.
Final dry salting or brine salting in 23% brine for 24–48 hours. Final salt concentration about 4%.
Incubate for 6 days at 16°C, 95% RH. Wax and needle air holes or vacuum pack and needle air holes.
Mold filament development in air holes at 16°C for 6–8 days.
Cure at 11°C and 95% RH for 60–120 days.
Cleaning and storing:
Strip off the wax or vacuum packaging bag.
Clean cheese, dry, and repack in aluminum foil or vacuum packaging bags.
Store at 2°C.
Product shelf life—2 months.
Sources: Early 1998, Kosikowski and Mistry 1997, Nath 1993, Robinson 1986, Scott et al. 1998, Spreer 1998, Walstra et al. 1999.
Table 3.17. Basic Steps in Making American Style Camembert Cheese
Standardize milk.
Homogenize milk.
Pasteurize milk at 72°C for 6 seconds.
Cool milk to 32°C.
Inoculate with 2% active lactic starter followed by 15–30 minutes acid ripening to 0.22% titratable acidity.
Add annatto color at 15.4 ml per 1000 kg milk (optional).
Add rennet —220 ml single-strength (prediluted 1:40) rennet per 1000 ml, then mix for 3 minutes and let stand for 45 minutes.
Cut curd with 1.6 cm standard wire knife.
Cook curd at 32°C for 15 minutes with medium speed stirring.
Drain curd at 22°C for 6 hours with occasional turning.
Inoculate with Penicillium camerberti spores by spray gun on both sides of cheese once.
Press and mold curd by pressing for 5–6 hours at 22°C without any weight on surface.
Surface salt cheese; let cheese stand for about 9 hours.
Cure—at 10°C, 95% RH for 5 days undisturbed, then turn once and continue curing for 14 days.
Packaging, storage, and distribution:
Wrap cheese and store at 10°C, 95–98% RH for another 7 days.
Move to cold room at 4°C and cut into wedges, if required, and rewrap.
Distribute immediately.
Sources: Early 1998, Kosikowski and Mistry 1997, Nath 1993, Robinson 1986, Scott et al. 1998, Spreer 1998, Walstra et al. 1999.
64 Cheese
Standardize milk with 5% fat, enzyme treated and decolorized.
Homogenize milk.
Pasteurize by standard procedure and cool to 32°C.
Inoculate with 2% active lactic starter as cheddar cheese and allow to ripen for 1 hour.
Add rennet at 198 ml single-strength rennet (predi-luted, 1:40) per 1000 kg milk and let set for 30–40 minutes.
Cut the curd with 1.6 cm standard wire knife and let stand 15–20 minutes.
Allow curd to drip for 18–20 hour at 12–18 kg on 2000 cm2, with pH and titratable acidity developed to 4.6 and 0.55%, respectively.
Prepare cheese blocks of 13 13 10 cm each.
Salt in 23% salt brine for 1 day at 10°C.
Can and box cheese blocks in 14% salt brine (sealed container).
Cure for 2–3 months at 10°C.
Soak cured cheese in skim milk for 1–2 days before consumption to reduce salt.
Yield—15 kg/100 kg of 5% fat milk.
Source: Robinson and Tamime 1991.
Table 3.19. Basic Steps in the Production of Yogurt
Standardize liquid milk.
Homogenize liquid milk.
Heat-treat or pasteurize liquid milk at 90°C for 5 minutes or equivalent.
Cool pasteurized milk to 1–2°C above inoculation temperature.
Add starter (inoculation), 1–3% operational culture.
Add flavor, sweetener, gums, and/or color (optional).
Incubate at 40–45°C for 2.5–3.0 hours for standard cultures.
Break curd (optional).
Cool to 15–20°C in 1–1.5 hours.
Add live culture (optional).
Package.
Store at ≤ 10°C.
Sources: Chandan and Shahani 1993, Tamime and Robinson 1999.
Be Used in Yogurt Manufacturing
Kind Name of Gum
Natural Agar
Alginates Carageeenan Carob gum Corn starch Casein Furcelleran Gelatin Gum arabic Guar gum Karaya gum Pectins Soy protein Tragacanth gum Wheat starch Modified gums Cellulose derivatives
Dextran
Low-methoxy pectin Modified starches Pregelatinized starches Propylene glycole alginate Xanthin
Synthetic gums Polyethylene derivatives Polyvinyl derivatives Sources: Chandan and Shahani 1993, Tamime and Robinson 1999.
65 Table 3.21. Some Common Flavors for Yogurt
Natural Characteristic—
Retail Flavor Impact Compound Synthetic Flavoring Compound Available
Apricot NA g-Undecalactone
Banana 3-Methylbutyl acetate NA
Bilberry NA NA
Blackcurrant NA trans- and cis- p-Methane-8-thiol-3-one
Grape, Concord Methyl antranilate NA
Lemon Citral 15 compounds
Peach g-Decalactone g-Undecalactone
Pineapple NA Allyl hexanoate
Raspberry 1-p-Hydroxyphenyl-3-butanone NA
Strawberry NA Ethyl-3-methyl-3-phenylglycidate
Sources: Chandan and Shahani 1993, Tamime and Robinson 1999.
Table 3.22. Permitted Yogurt Colorings Name of Color Maximum Level (mg /kg)
Intigotine 6
Brilliant black PN 12
Sunset yellow FCF 12
Tartrazine 18
Cochineal 20
Carminic acid 20
Erythrosine 27
Red 2G 30
Ponceau 48
Caramel 150
Sources: Chandan and Shahani 1993, Tamime and Robinson 1999.
Table 3.23. Existing or Proposed Standards for Commercial Yogurt Composition [% Fat and
% Solid-not-fat (SNF)] in Selected Countries
% Fat
Country Low Medium Normal % SNF
Australia NA 0.5–1.5 3 NA
France 0.5 NA 3 NA
Italy 1 NA 3 NA
Netherlands 1 NA 3 NA
New Zealand 0.3 NA 3.2 NA
UK 0.3 1.0–2.0 3.5 8.5
USA 0.5–1.0 2 3.25 8.5
West Germany 0.5 1.5–1.8 3.5 8.25–8.5
FAO/WHO 0.5 0.5–3.0 3 8.2
Range 0.3–1.0 0.5–3.0 3–3.5 8.2–8.5
Sources: Chandan and Shahani 1993, Tamime and Robinson 1999.
66 Processing
Standardize milk.
Heat milk to 85–95°C, then homogenize.
Cool milk to 19–25°C and transfer to fermentation tank.
Add 1–2% start culture (inoculation).
Allow shock-free fermentation to pH 4.65–4.55.
Homogenize gel.
Cool to 4–6°C.
Fill bottles, jars, or one-way packs or wholesale packs.
Sources: Davies and Law 1984, Early 1998, Jay 1996, Jenness 1988, Kosikowski and Mistry 1997, Robinson 1990, Spreer 1998, Walstra et al. 1999.
Table 3.25. Basic Steps in Kefir Processing Preparation of mother “kefir”
Standardize milk for preparation of mother
“kefir.”
Pasteurize milk at 90–95°C for 15 minutes and cool to 18–22°C.
Spread kefir grains at the bottom of a container (5–10 cm thick) and add pasteurized milk (20–30 times the amount of kefir grains).
Ferment for 18–24 hours, mixing 2–3 times.
Kefir grains float to the surface.
Filter out the kefir grains with a fine sieve, wash the grains with water, and save for the next fermentation.
Save the fermented milk for the next-step inoculation.
Preparation of drinkable kefir
Blend fermented milk from above with 8–10 times fresh, pasteurized, untreated milk.
Pour into bottles, then close the bottles and ferment mixture for 1–3 days at 18–22°C.
[Another option is to mix the fermented milk with fresh milk at 1–5% and ferment at 20–25°C for 12–15 hours (until pH 4.4–4.5 is reached), then ripen in storage tanks 1–3 days at 10°C. Product is not as traditional but is acceptable.]
Cool to refrigerated temperature.
Cool to refrigerated temperature.