Cheese Making Steps PDF

Cheese Cheese Making Steps: - There are so many different combs and ways to make cheese. - Because of this there are so many VARIETIES of cheese, not brands varietes. And with in each variety are varieties - Each step has so many different varieties. For example: Milk, t...

Cheese Cheese Making Steps: - There are so many different combs and ways to make cheese. - Because of this there are so many VARIETIES of cheese, not brands varietes. And with in each variety are varieties - Each step has so many different varieties. For example: Milk, there are so many different milk combinations, And so many different ways to ferment. - France has at least 246 cheese - Basic cheese making process: WRITE OUT IN STUDY GUIDE - Milk: Cow, sheep, goat, camel buffalo, even donkey? Pasteurized vs Raw? Fat content? Are we adding color? - LAB: We have so many different varieties, and within these varieties we have so many different strands to choose from. - Mesophilic culture: Moderate Temps - Thermophilic culture: growing at higher temperatures - Heterofermentative: more than one major product - Homofermentative: one major product - Citrate-Fermenting: Consuming the citrate - Enzyme: - Are we getting it from the calf or engineering it? - Engineering: enzymes produced by microorganisms, we like this because it is more economical and gives you more control over getting from the calf - Chymosin, and lipases - MIGHT also be using lipases - These are attacking the lipids to produce some compounds that MIGHT be beneficial - In many cases lipases are no good, and can produce some undesirable qualities. But when comes to cheese lipase can work. - Adjunct (additional Microorgansims) - Propionibacterium and penicillin - Added for specific characteristics and quality attributes of the cheese - Cut and cook - Big impact in terms of final product - Curd size variation: smaller curd more moisture removed. Larger curd less moisture removed - Temperature variation: higher cooking temps curd gets squeezed and we remove more moisture  - Are we adding water? We add water to dilute lactose. When you wash the curd with water we are removing more lactose. Remember: Lactose is soluble in water. How are we handling the curd? (impact on final product) - Are we salting the curd? If so how? (impact on final product) - Brine:immerse cheese block directly into salt water brine - Dry: Add dry salt directly to the curd - Rub: Only applying salt to the outer surface - How are we shaping the curd/cheese? Round triangle rectangular? - Are we aging it? What surface microorganisms are we using for aging? - Ex of commonly used ones are Brevibacterium, yeast, micrococci - Aging: storing cheese in a controlled temp, adding microorganisms that will grow on cheese which creates a unique flavor profile of the cheese - In U.S aging criteria= held of more than 60 days at more than 1.7 c and CAN be made from RAW milk - Aging is optional: MOST expensive cheeses are aged - Aging helps create a unique flavor profile/characteristics of the cheese Milk Source: - Most cheeses are made using cows milk, but we can use other milk as well - Goat milk - Feta and Chevre - Sheep milk - Roquefort and Romano - Water buffalo milk - OFTEN used for mozzarella - Milk from goat, sheep and water buffalo have higher fat compared to cows milk - Water buffalo and goat milk have NEARLY 2x as much fat when compared to cows milk - Fat contributes to the body, texture and smoothness of cheese. Richer and enhanced body. Also leads to you feeling fuller after eating the cheese - Milks with higher fat content can have more volatile compounds - Ex: Goats milk - if the fat is oxidized it leads to rancid flavor. With lots of fat we want to avoid oxidation - Milk may seem simple, but it is not → different variables like breed, feed and when milked (morning vs. evening) can cause the composition of the milk to vary - In summary: The milk source you use depends on the cheese you want to make  - Animal and % of fat is selected based on the type of cheese we want to make Milk: - IN THE U.S - Unaged = aged less than 60 days and MUST be made from pasteurized milk - Unaged does not mean not at all aged - Aged = held for more than 60 days at more than 1.7c CAN be from RAW milk - The aging process will inhibit scary microorganisms - We age the cheese for a more complex flavor profile - In many countries there is no requirement for pasteurization - Fermentation produces acid → acid production inhibits pathogenic/ spoilage microorganism - We are relying on the fermentation - IMPORTANT fermentation is done correct - Quality differences are SIGNIFICANT between cheese made from pasteurized and raw milk - Why? Pasturization can inactivate the microorganisms and enzymes present → so we will not have access to good ones that help with the quality attributes of the cheese - Typically more microorganisms and enzymes leads to a more complex flavor profile - Milk should be free from antibiotics - Why? Because the antibiotics can inactivate important microorganisms used for fermentation - Cheese will TYPICALLY be an off-white color. But colors are often added for Visual appeal of the consumers - Addition of color has no affect on flavor, texture etc - Midwest - consumers prefer orange colored cheddar cheese - Can use annato for this - Northeastern USA - Consumers prefer white cheddar - Can use a bleaching agent for this - Color depends on where you are selling Starter culture - Strain used depends on temp (process) and flavor profile we want - Depending on the need/ cheese and process - different starter cultures are used - Curd is exposed to HIGH cooking temperatures then thermophilic lactic acid bacteria culture is used - For cheeses like swiss, parm, and mozzarella  - Optimal temp is (40-45c) - A particular flavor is desired - Ex: Gouda - we want a specific flavor produced by diacetyl compounds, so we will use strains that produce those compounds - Mesophilic cultures like Lactococcus Lactis and Lactococcus Cremoris grow at 10-40c but their optimum tem is 28c to 32 c - Note: Thermophilic will grow in higher temperatures than mesophilic cultures - Mesophilic cultures are the MOST commonly used for yogurt and cheese. Used in MAJORITY of cheese - We want to make sure the product is held at optimal temperature for the strain we are using. - We want the microorganisms to grow and ferment nicely - Thermophilic cultures are the 2nd most widely used for cheese production - Lactobacillus helveticus and streptococcus thermophiles optimal temp is 42-45 c but can go as high as 52 c - Impt to make sure the temperature doesnt exceed the optimal temp for particular microorganism → we do not want to inactivate - Even a few degrees higher can inactivate - Homofermentative - Just one major product EX: LAB - Heterofermentative - more than one major produce acid + other metabolites - Ex of other metabolites include, co2, diacetyl, acetaldehyde, short fatty acids like acetic acid, propionic acid, ethanol - Leuconostoc cremoris and leuconostoc lactis will also ferment citrate and produce diacetyl - This is used in dutch cheeses such as gouda and edam - Diacetyl - buttery aroma and flavor - Small eye in dutch cheeses are from co2 production - TRADITIONAL amt of inoculum - 1% (weight/weight) for cheeses such as cheddar - EX: 99lbs milk and 1lbs culture - 2% (weight/weight) for mozzarella cheese and swiss cheese - Ex: 2lbs of culture - Currently in large scale manufacturing we can optimize/adjust the ph of the growth medium (milk) - When adjusting ph we will add less inoculum - Low ph can lead to inactivation of cells to compensate increase in inoculum - Currently cultures are HIGHLY concentrated and adjusted for the ph of the growth medium - Therefore small amt is sufficient  - Ex: 500ml can inoculate 5000L of milk (.01% inoculum) - Improper amt of inoculum can bet detrimental - Low amt of inoculum → delayed fermentation and acid development → production schedule issues and opportunities for spoilage or pathogenic organisms to grow (acid will usually inactive these) - Too High amount of inoculum → too much production of proteolytic enzymes that attack the proteins and change flavor, texture and yield - Ex: too much inoculum in cheddar cheese → rapid acid production → early loss of calcium and demineralization of the cheese - Due to modern tech we can reduce amt of inoculum when compared to traditional by 100x-200x - Defined culture - used in MANY cases known cultures - Undefined - unknowns or naturally present - Temperature of the milk needs to be prime depending on what microorganisms we are using - 30-40c for mesophilic cultures as a group - 35-45c for thermophilic cultures as a group - If we do not use prime temperatures the initial growth will be slower resulting in and increased lag phase - The microorganisms need time to adapt to new conditions - If using frozen culture it will take time for the microorganisms to grow→ they need to get themselves adapted and that takes time - Fermentation start time is critical → especially if manufacturing on and industrial scale - Larger factories require higher throughput - Throughput = amt of materials per unit time EX: 100lbs of cheese per hr - If start time is not proper it disrupts everything - Slow fermentation can result in poor quality cheese and in many cases will make the cheese unsafe Reasons for delayed fermentation (6) 1. Antibiotics could inhibit the culture (it is very easy to test for presence of antibiotics) 2. Natural immunoglobulin in milk → attack and bind bacteria → forms clumps and due to gravity will settle at bottom of vat (RARE) 3. Lactoperoxidase reaction: Lactoperoxidase enzyme oxidizes thiocyanate and in the presence of hydrogen peroxide will form a hypothiocyanite. This inhibits some LAB → less LAB for fermentation a. Lactoperoxidase needs to be present (not always present) b. Thiocyanate needs to to be present (not always present)  c. Hydrogen peroxide needs to be present (not always present) 4. Some microorganisms naturally present in milk will produce hydrogen peroxide that will directly inhibit some lab 5. Chemical agents used to sanitize vats can inhibit culture a. IMPORTANT TO RINSE AND CLEAN PROPERLY 6. Bacteriophage infection: viruses that infect starter culture (most common) Coagulation: - Most common ENZYME used for cheese production - Chymosin alone is no sufficient for cheese production - Why? Chymosin is great for coagulation but we need LAB for producing the unique flavor - In general chymosin is added immediately after the culture - In many cases we will use a pre-ripening period: LAB is introduced before adding chymosin→ produces a small amount of acid and slightly lowers the ph of the milk - Chymosin optimum activity on the kappa-casein is at a ph of 5.5 - As ph decreases chymosin is more active, not as active at higher ph - If ph is high more chymosin needs to be added, lower ph allows us to add less chymosin - With a lower ph the solubility of calcium increases - With a pre-ripening less chymosin can be added - Often when using chymosin we will also add calcium-chloride, this helps increase the yield - Yield = amount of cheese created - Amt of chymosin added depends on the cheese being made and the desired firmness - Typically 200ml of single-strength chymosin/ 1000kg of milk can coagulate in 30mins - The thickness of cheese is determined before cutting Cutting and cooking: - We have our coagulated mass→ we will cut using wired knives into die sized particles - When you cut the curd the surface area will increase → enhances syneresis - Hard, low moisture cheese like parm and swiss cheese - We will cut the curd into a smaller size, size of a rice kernel - Soft, high moisture cheese - We will cut the curd into larger pieces → we dont want to remove as much water  - The size of the curd indirectly affects fat loss - More fat is retained in large curds than in small ones - The curd is a calcium-casein complex that contains entrapped fat and bacteria (inculding starter culture organisms). BUT the main constituent of the curd is still water → the curd will contain these water soluble compounds including whey proteins, enzymes, vitamins, minerals, and lactose - More moisture removed from the curd more water soluble compounds removed - The curd is an intermediate product→ cheese is the final product - Syneresis begins as soon as the curds are cut and increases when curds are gently stirred and temp is increased - Initial rate of syneresis changes based on the starting ph of the curd - Lowe ph the greater the rate of syneresis - Cooking and stirring combo will also increase the rate of syneresis - All other factors equal, the higher the temp, and the longer the curds are cooked and stirred, the dryer the finished product will be - Increasing the temp, and cooking and stirring for longer will remove more moisture Curd handling: Variation in cheeses - Once we hit the desired acidity we will remove the whey - Curd cooking time temp combos depends on the cheese we are making → soft, firm. Dry - Ex: Cheddar: curds are pushed to sides of the vat, and whey is drained from the center. Screens are used to prevent curd loss - Ex: Swiss and parm: curds collected in a cheese cloth - In modern, large scale production the curds are pumped to draining tables or cheddaring machines and the whey is separated - If we want to reduce lactose content in the curd while also maintaining the moisture: - Remove part of the whey and wash the curd (add water) → the lactose will diffuse from the curd to the water (lactose is water soluble) → we will have less lactose for fermentation and produce a sweeter/ low-acid cheese - EX: Colby, gouda, havarti, edam with a ph of 5.2-5.4 - Washing the curd with warm water (abt 35c ) - Cooking continues because of the higher temp and syneresis continues as well - We get a drier cheese - Ex: gouda, edam, and havarti - Washing the curd with cold water (abt 15c) - Moisture content of cheese may increase  - Ex: colby - Ex: Mozzarella: Washing step removes lactose and galactose from the curd - We are often washing the curd to remove lactose - Less lactose leads to a sweeter cheese - Adding moisture at times as well - Fermentation will decrease the ph and increase the titratable acidity - Titratable acidity = amt of acid present we are typically looking at lactic acid when making cheese - The curd will stick together after removal of the whey - Cheddaring: Curd cut into slabs and piled on top of each other the fermentation continues - Top slab exerts pressure and the force helps remove moisture - Gravity and weight of curd block for moisture removal - If we stir the curds after draining additional whey is removed and moisture is lowered - By washing the curds we can make lots of changes in the cheese Salting - Salt is an important variable: - Enhances syneresis (reduces moisture) - Enhances flavor - Extends shelf life - Salt can be added in three ways - Brine: placing in a salt water bath - Ex: Swiss, mozzarella, and parm - Amt of salt added depends on diffusion rate (rate and which particles spread out), geometry (shape, large or small), duration, and brine strength - Small pieces in brine: Ex feta. High salt concentration. Salt does not need to go v. far (>3%) - Larger blocks: (ex: swiss) have low salt concentration in interior ( +200mV) of over 200 mV → removal of air + residual respiration and oxygen consumption by plant cells → Eh decreases → anaerobic. Salt solution will also help to remove the oxygen as well, when you add salt immersing it in brine Cabbage is still living even after harvest so will still respire a bit → removes oxygen and helps produce co2 ❖Pseudomonas, fungi, and other obligate aerobic microorganisms (remember cabbage is aerobic in nature)→high levels at the beginning → minimal or no growth later (some are salt‐sensitive) ❖Sauerkraut fermentation done at 16 to 20°C – mesophilic microbes can grow ❖Indigenous salt‐tolerant, mesophilic, facultative organisms grow (Enterobacter, Klebsiella, E. coli, and Erwinia) → active for short time (few hours) → LAB competes/overpowers, acids inhibits Facultative=Can grow in presence of oxygen or no oxygen Sauerkraut manufacturing: Fermentation ❖Initiation, heterofermentative, or gaseous phase: growth of Leuconostoc mesenteroides subsp. mesenteroides (salt‐tolerant, short lag phase, high growth rate at low temperatures) → metabolizes sugars via the heterofermentative pathway → lactic and acetic acids, CO2, ethanol ❖Weissella cibaria and other species of this genus may also appear at the beginning → acidic environment created (0.6% to 0.8%, as lactic acid) inhibits non‐LAB competitors. ❖CO2 production helps to create → anaerobic (as low as –200 mV) → This helps with LAB growth MV - means anaerobic MV + means aerobic ❖When acid concentration ~ 1.0%, L. mesenteroides is inhibited -Three reasons why Leuconstoc will grow first Salt tolerant Short lag phase High growth rate at low temperatures Leuconstoc will metabolize the sugars and produce LA, acetic acid, co2, and ethanol. BUT leuconostoc is not very acid tolerant so once it hits a certain point starts to inactivate Leuconstoc is a type of LAB Sauerkraut manufacturing: Fermentation ❖Primary or homofermentative phase: Lactobacillus plantarum and Lactobacillus brevis and other LAB – produces a lot of acid (1.4% to 1.6%) ❖L. plantarum - facultative heterofermentor (ferment different sugars via homo‐ or heterofermentative pathways) → stable in acidic environment and dominate the fermentation during this period (especially L. plantarum) L. Planetarium is versatile girly: Facultative, acid tolerant, and ferments dif sugars via homo or heterofermentative pathways Why is L. Planetarium the most dominant Stable in acidic environment so will dominate fermentation during this period ❖other LAB (Pediococcus pentosaceus, Pediococcus acidilactici, Lactobacillus curvatus, and Enterococcus spp.) may be present during primary fermentation → but as more acid is produced we will inactive these as well ❖When acidity ~1.6% and pH < 4.0 → acid‐tolerant L. plantarum dominates ❖Entire process → up to one to two months → fermentation is complete when acidity is ~1.7% & pH = 3.4 to 3.6 During the lab it takes shorter because we are fermenting at a higher temperature, but on a more industrial scale the process is a lot slower because we are fermenting at lower temperatures Sauerkraut manufacturing: End products ❖LA (main) + up to 0.3% acetic acid + up to 0.5% ethanol We have acetic acid due to heterofermentative pathways We have some ethanol due to anerobic fermentation ❖Small amounts of diacetyl, acetaldehyde, and other volatile flavor compounds are also produced during fermentation ❖CO2 → provides carbonation which helps enhances mouthfeel. ❖Mannitol is also produced during fermentation ❖Packaging: ❖US: commercial products → thermally processed after fem (about 75°C) → packaged in cans or jars → commercially sterile -Thermally process will completely stop the fermentation process and inactivate micros that are acid tolerant, this is also why it is considered commercially sterile ❖non‐pasteurized, refrigerated sauerkraut → packaged in glass jars or sealed plastic bags (removing CO2generated – venting system) We need Co2 venting system because with no pasteurization, we are not inactivating the microorganisms so we will continue to ferment in the fridge, we do not want any explosions ❖Spoilage In general most of micros will not be growing especially if past If we are not pasteurizing we need to take into consideration shelf life, yes with fermentation the spores are inactivated but other spoilage microorganisms can still grow, in turn we will have a shorter shelf life/ need to take that into consideration Bread Bread: History ❖Bread fermentation differs from other fermentation - goal: convert the grain to a more functional and consumable form rather than extending shelf‐life (grains have longer shelf-life than bread) - Grains have lower water activity so also have increased shelf life ❖Primary fermentation end products do not remain in bread ❖Bread making: $200 billion industry (globally) ❖USA: 100 kg of wheat flour (early in the 1900s) to 50 kg (1960s) to 70 kg (1980) to 65 kg (2000) - Wheat flour is a staple food in American diet - Why did Americans stop consuming wheat flour? ❖low‐carbohydrate and gluten‐free diets ❖>1/3rd of Americans think bread contributes to weight gain ❖Interest in other ethinic cuisine and other cultural changes (Asian, Latino, and other ethnic cuisines do not have that much bread) Wheat chemistry and milling ❖Breads: made from wheat, rye, barley, oats, corn, sorghum, and millet but wheat is most common - Multigrain bread - Wheat + other grains like oats, barley, corn, etc.. ❖Gluten (protein complex) gives bread its structure and elasticity which is necessary for leavening and shape of bread - In non-wheat flours the gluten complex is absent or poorly formed, making it harder to hold shape - Example: Gluten free bread, it is much harder and denser, and will not hold shape as well due to lack of gluten we need to add additional ingredients and treatments ❖Most commercial breads contain at least some wheat - Wheat helps with structure ❖Original wheat grain (seeds) have hard shell and difficult to use so scientist started cross breading of wheat varieties this lead to more manageable properties - Wheat is not genetically modified so wheat breeding is crucial! ❖Wheat kernel: germ, bran, and endosperm ❖Germ: contains the embryonic plant + oils + vitamins, + nutrients 2–3% of the total kernel weight. Smallest portion of the plant. Germ is essential for growth of plant, and is where the plant is coming from ❖Bran, the outer covering (coat made up of cellulose, fibrous carbohydrates, proteins, minerals, and vitamins) 12–13% of the kernel comprised of multiple distinct layers ❖Endosperm (protein (9–12%), starch (75–80%), water (12–14%), lipid (1%)) ~85% weight of kernel. This is the primary portion of wheat ❖“whole” wheat flour: entire kernel is crushed. - We are literally using the whole wheat kernel (germ, bran, and endosperm). 100kg of wheat will produce 100kg of whole wheat flour ❖Often constituents are separated (partially or nearly completely) - refined flours will usually contain majority endosperm with little or no germ or bran - White flour is primary endosperm ❖Depending on on flour we are making we will use different parts of the wheat ❖Wheat milling: convert wheat to flour ❖successive “gradual reduction” flour milling steps: grinding, sieving, and separation wheat fractions are removed or further processed ❖wheat kernels pass through series of paired‐rollers or stones (gap between each pair is successively narrower) - Gap will get successively narrower to further break down the grains ❖Rolls are spinning in different directions and at a different speeds, in text book example we might have up to 16 rolls ❖rolls will apply force that breaks down the wheat ❖Modern grinding devices ❖Break rolls (corrugated cast iron rollers) will have flutes or ridges that help enhance grinding or shearing action - Better at breaking down the kernel - Break rolls are the initial breakage ❖Reduction rolls (smooth rolls) - Much smaller gap and gap will get narrower to we can ground into much finer ❖Rolls run at different speeds this helps with shear force(instead of crushing) ❖Ground wheat will pass through sieves, the sieves retain the coarse material (bran with some endosperm) and permits fine flour to pass an air purifying device removes fine bran particles - Bran is much lighter ❖Fine particles will pass through the sieves and bigger products will go through another set of rolls and sieves again. This process happens again and again and again ❖milling produces dozens of different product streams ❖Common flour: flour removed from the early and late separations (less refined, higher in protein (>14%), and darker) will also have a bit more germ and bran when compared to patent flour. This is also primary endosperm but has more germ and bran when compared to patent flour ❖Patent flour: obtained from intermediate separation steps (least amount of germ and bran, white in color and high in protein (13%) this is best bread‐making quality - Has more endosperm compared to common flour - Primary endosperm with v. small amt of bran and germ ❖Used in USA and Canada for bread making ❖Other parts of the world: re‐combine the different flour fractions for strength (protein content) or functional properties (dough elasticity, bread flavor, oven spring) varies - Note: Protein plays an important role in bread strength ❖Patent flour extraction rates: 70–80% (ie. 70 to 80 kg of flour per 100 kg of wheat) - Compared to whole wheat flour, whole wheat is 100% because we are crushing the whole kernel ❖Patent flour will have some bitterness - Bitterness is due mainly to peptides and phenolics and, rancidity (due to lipolysis & oxidation) caused by milling and fractionation techniques Wheat composition ❖Composition: affects fermentation & physical structure of dough and bread. Because of this important to select a good one ❖US breads: made with refined white flour (only endosperm) - The refined white flour consists of protein and starch (+ small amount of hemicellulose and lipid) - Note: Patent flour is not refined we need further processing to get to refined flour ❖8 to 15% of wheat flour = protein ❖High protein flours (hard wheat): >11% protein these best for bread - Best for bread because structure is important and protein helps with that. Once we bake the air bubbles that are produced during fermentation get removed, so it is important we have good structure in place so bread does not collapse ❖Low‐protein flours (soft wheat): 85%) - We have higher humidity because we do not want bread to be dry ❖Proofing times vary depending on temperature ❖usually one hour causes increase in dough volume Meat History - Consumed for thousands of years - Origin as of now : Southern euro, Med Sea during Roman era, Asia - Likely made by accident - trial & error - Backslopping: taking a portion of successfully fermented product and adding it back to the next batch as the starter culture. Using micros part of final product as inoculum for the next batch of the product - Similar to yogurt - Backslopping: Increase the probability of success. Why? The final product has the organisms we want already - Numerous fermented meat products around the world - Variation based on geography - Preservation is likely major reason these products started being consumed more regularly - NOTE: History is speculation → High likelihood not 100% - Depending on the climate where the fermented food product is manufactured we will see differences - In warmer climates (middle east, mediterranean) the meats will have spices and are dried - Micros are growing like crazy potentially scary ones in warmer climates because of this you need to figure out a way to preserve. Many of the spices have antimicrobial properties. - Drying product decreases the water activity, so less growth of microorganisms - In colder climate spices were rarely added, and the meats are usually smoked or sometimes cooked after fermentation - Smoking: product absorbs smoke for smoked flavor - Liquid smoke: adds that flavor compound without actually smoking - Fermented meat - hurdle approach - Rather than using one particular method for inactivating microorganisms, we are using multiple methods - Drying, cooking, smoking, addition of salt and spices, nitrate salts. All of these add flavor and appeal. They all will also help with a longer shelf life even at room temperature. Each process inactivates different microorganisms. - Many of these products can be stored at room temperature. For example Jerkey. We will not have any issues with microbial growth because of the spices, cooking, etc… - Enhance flavor profile you will also enhance appeal - Products enclosed within casings have increased stability, preservation, no or minimal post-process microbial contamination - Ex: Hot dogs in plastic covering - Fermented meat industry is relatively new - Doesnt mean fermented meats are new - 20th century - modern production technologies developed that can be used for production of fermented meats - In the past before 20th century: craftsmen and very small scale producers were making fermented meats this would lead to poor product, quality, consistency, and safety  - Most of the time trial and error: product quality was not consistent and same with safety - In 20th century we now have equipment for grinding, mixing, stuffing, fermentation chambers (these have been developed in the last 60-70years) - This increased amount of fermented meat that was produced - In 1960s the industry identified the starter culture, developed various synthetic casings, and developed different curing agents - From the 1960s we have massive and rapid growth in fermented meat industry - Numerous fermented meat products are found around the world - Germany has more the 350 TYPES of sausages, spain has about 50 types - Depending on the country consumption varies - So many different varieties because we have so many different animals - Within each animal so many variations - Cut of meat, amount and coarseness of fat, casing material (what type you are using), level of dryness, are we smoking it? - Legal definitions: cured meat is defined differently in different parts of the world - Large manufacturers need to be aware of this Note: Not all sausages are fermented Composition of meat - Composition of meat is very important when it comes to fermentation of meat - Fresh meat is nutrient rich, because of this it provides a good nutrient source for the growth of microorganisms. - Meat itself provides lots of nutrients for growth of microorganisms - Fresh meat is also highly perishable - Lean skeletal bovine muscle composition: 75% water, 20% high quality protein, 2-3% lipid, 2-3% carbohydrates, non-protein nitrogen, and inorganic material - Primary component is water, next major component is is high quality protein - Water activity is 0.99 - this why it is highly peri - Ph is very close to neutral (6.8-7.0) before rigor - Rigor: as animals are slaughtered the tissues undergo various reactions, causes stiffening of muscles - Ph after rigor drops to 5.6-5.8 this is because of the post mortem glycolysis by endogenous enzymes. The ph will drop  - Composition varies on animal and its status before slaughter. Was the animal stressed or happy? - Microorganisms - Interior of intact meat: sterile - Exterior surface of intact meat: has aerobic and facultative bacteria - In many processes we will chop or ground the meat. The microorganisms from the outside will now be spread all over. We will have homogenously distributed them throughout the meat - Primary type that grows: aerobic microorganisms. - Within the meat we will have anaerobic pockets: in those conditions we can growth of anaerobic microorganisms like clostridium botulinum - Clostridium botulinum: v dangerous when spores turn into vegetative cells. Germinate Principles - Meat fermentation is less studies and less understood - Major field advancements were somewhat recent (1950s-1960s) - Backslopping is primary used - Backslopping - Benefits - Selects bacteria well suited for growth in the sausage environment (salts, low oxygen, acid due to fermentation) - Microorganisms are already adapted to final condition of the sausage - Much better probability of success - Bacterial population is heterogeneous (multiple species and strains) even if one fails (due to bacteriophage, salt sensitivity, etc), others can complete the fermentation - Also will increase probability of success - Disadvantages: - High inoculum size (5-20% of mass) - 1/5th of product is from previous batch – that is a lot of product - Fermentation times vary from batch to batch. This is difficult to control. This can cause issues for a large manufacturer - Products have inconsistent qualities (flavor, color, etc) - Slow or delayed fermentation can make the product unsafe. We dont growth of scary micros - If there is a recall we do not know where the trouble came from. You don’t know in which batch it happened, You are always using one from a previous batch. It’s hard to back track  - Most products are made from raw meat, because of this we will have pathogens. We need to make sure that these are inactivated - Can inactivate by cooking - If not cooking, you are primarily relying on the fermentation itself for inactivating the pathogens - If the fermentation is not done correctly we risk growth of pathogenic microorganisms - If pathogens reach high levels the subsequent acid or heating step is NOT sufficient to inactivate - Why? Because we are starting with large amount of microorganisms. - Three ways to make: - Natural Microflora: ones that are naturally occurring, less control and a lot of variation - Variation because we do not know what microorganisms we have and how many we have - Starter culture: Known microorganisms in a known amount. More controlled - Addition of acidulants. THIS IS NOT FERMENTATION WE DONT CARE - Fermentation has more complex flavor profile Starter culture - Microbial ecology of fermented sausage was not understood until 1940s. Found the primary microorganisms are LAB MOST NOT ALL. - Research in 1940s resulted in various patents from U.S and europe. Many of these were unsuccessful. This is because they worked very well in a smaller scale, but in large scale production it did not work - Because of advancement they figured out how to mass produce and make sure that the microorganisms are not dying quickly. Because of this meant fermentation was more successful - Lactobacillus cultures, have poor viability especially after freeze drying - In 1950s they figured out that we can use pediococcus cerevisae. This is still widely used today - Many european sausages are fermented at low temperatures (20c) - Lower temperatures advantages - Can slow down fermentation - Provides sufficient time for reduction of nitrate to nitrite - This process takes time - Nitrates: primarily used for inactivation of microorganisms and flavor changes and optimal color  - High temperature fermentation (40c) - 40c is primary temp for p.acidilactici. We will have Fast manufacturing - Metabolic differences: - All pediococci and lactobacilli ferment glucose, however only the lactobacill will ferement other sugars. - Lactose will only be fermented by lactobacilli - Depending on the composition of the sausage we have need to use different micros - USA: Most fermented sausages use starter culture-LAB (lactobacilli and pediococcoi species). These will primarily produce acid. As the acid is produced it will decrease the ph. This will inhibit growth of scary micros. - Important that the fermentation temp is optimal temp for strain so we can have short fermentation times. We can manufacturer fermented sausages faster - We will also had curing agent: nitrite - Europe: - They use nitrate as a curing agent. Nitrate needs to be converted to nitrite first. This process is done by enzymes naturally present in the product. - Nitrite cures the product and changes color and flavor - Additional flavors are due to the natural enzymes present like the proteolytic and lipolytic enzymes. - Low fermentation temp - Use LAB + coagulase negative staphylococcus and kocuria - LAB grows at slower rate, compared to other microorganisms - The other microorganisms grow nicely at much lower temperatures and are active over a prolonged period of time - Starter culture can cause problems and defects in the product - Example: when there is less sugar, the pediococci will go thorough the heterofermentative pathway. - This will produce LA + other stuff (carbon dioxide, acetic acid, ethanol) - Acetic acid will produce a sour, vinegar-like flavor - Some strains can produce hydrogen peroxide. These react with heme proteins in the muscle tissue and creates green pigments - Hydrogen peroxide and peroxide radicals can also promote lipid oxidation Protective properties of culture - LAB will predominantly grow and scavenge sugars and other nutrients faster than competitors.  - As LAB grows it will produce Co2 this will reduce the eh. So now aerobic microorganisms are inhibited. We now have an anaerobic environment - Some strains produce bacteriocins - Bacteriocins: proteinaceous substances with bactericidal activity, usually against bacteria that are close related to the producer organism - Proteins that inactivate bacteria that are closely related to the bacteria that produced the bacteriocins - Does not inactivate all microorganisms but will Inactivate scary microorganisms closely related to microorganisms that produce the bacteriocins. - Can also be added to non-fermented food products to inactivate scary micros - No guarantee bacteriocins will be produced consistently Non-LAB Culture - USA: Major LAB (Lactobacillus and pedicococcus) - Europe: LAB + Microbes in micrococcaceae family (gram-positive, coagulase-negative staphylococcus, micrococcus & kocuria). Other microorganisms are optional - Adding optional based on intended out come - Many additional microorganisms are not fermentative. They do not produce any acid end products - However can help in producing nitrate reductase enzyme. - This enzyme helps convert nitrate to nitrite - Nitrite- Color, flavor, and antimicrobial properties - Micrococcaceae helps metabolize lipid and proteins, this will help with flavor - Most of these are mesophilic (fermentation temp 18-25c) Five function the starter culture: 1. Produce lactic acid and lower the ph a. Scary micros inactivated 2. Produce desirable flavors 3. Out-compete spoilage and pathogenic microorganisms for substrates and nutrients a. Especially scary ones, NOT ALL JUST MOST 4. Lower Eh, since salmonella, s aureus, and other pathogens grow better aerobically 5. In case of the micrococcaceae cultures, enhance flavor, and color a. Microccocaecae helps us convert the nitrate into nitrite i. Nitrite helps with color and flavor profile Manufactoring: - Ingredients - Meat: Ground, whole, incorporated fat - so many different variations in terms of meat itself - Sugar: We need to add sugar for the microorganisms. Meat has glycogen but it is limited. - Typically.5%-2% w/w added. - Europe:.1%-.2% - less tangy and slower fermentation - If we do not add our fermentation will stop there is not enough natural sugar in meat. - Amount of LA produces is proportionate to amount of sugar we add. More sugar, more LA. - With more sugar the fermentation is much faster - Salt: 2-3% - Salt will help extract and solubilize muscle protein. These proteins are insoluble, but when we add salt, it helps us extract and improve solubility of the muscle protein - Helps create emulsion - Helps improve flavor - Culture: 70mL for 150kg of mixture - Curing agent  - Spices, flavoring, and other ingredients - Curing agents: - Four functions - Stabilize color after cooking - Enhance flavor - Inhibits bacteria and spores (clostridum botulinum) - Antioxidant - Need to be careful with adding nitrites in the meat -