77-421: Cream is a dairy product composed of the higher-fat layer skimmed from the top of milk before homogenization . In un-homogenized milk, the fat, which is less dense, eventually rises to the top. In the industrial production of cream, this process is accelerated by using centrifuges called " separators ". In many countries, it is sold in several grades depending on the total butterfat content. It can be dried to
154-493: A can opener by Robert Yeates in 1855. A less aggressive method was developed by French chemist Louis Pasteur during an 1864 summer holiday in Arbois . To remedy the frequent acidity of the local aged wines , he found out experimentally that it is sufficient to heat a young wine to only about 50–60 °C (122–140 °F) for a short time to kill the microbes, and that the wine could subsequently be aged without sacrificing
231-468: A milk allergy . People who experience lactose intolerance usually avoid milk and other lactose-containing dairy products, which may cause mild side effects , such as abdominal pain, bloating, diarrhea, gas, and nausea. Such individuals may use non-dairy milk substitutes . The American Institute for Cancer Research (AICR), World Cancer Research Fund International (WCRF), Cancer Council Australia (CCA) and Cancer Research UK have stated that there
308-489: A refrigerated shelf life of two to three weeks, whereas ultra-pasteurized milk can last much longer, sometimes two to three months. When ultra-heat treatment ( UHT ) is combined with sterile handling and container technology (such as aseptic packaging ), it can even be stored non-refrigerated for up to 9 months. According to the Centers for Disease Control , between 1998 and 2011, 79% of dairy-related disease outbreaks in
385-488: A tin can , so creating the modern-day process of canning foods. In 1812, the Englishmen Bryan Donkin and John Hall purchased both patents and began producing preserves . Just a decade later, Appert's method of canning had made its way to America. Tin can production was not common until the beginning of the 20th century, partly because a hammer and chisel were needed to open cans until the invention of
462-487: A heart-healthy eating pattern and choosing reduced-fat dairy over full-fat dairy reduces risk for some, but not all, cardiovascular risk factors". In 2019 the National Heart Foundation of Australia published a position statement on full fat dairy products, "Based on current evidence, there is not enough evidence to recommend full fat over reduced fat products or reduced fat over full fat products for
539-517: A heat exchanger, the product flows through a hold tube for a set period of time to achieve the required treatment. If pasteurization temperature or time is not achieved, a flow diversion valve is used to divert under-processed product back to the raw product tank. If the product is adequately processed, it is cooled in a heat exchanger, then filled. Direct microbiological techniques are the ultimate measurement of pathogen contamination, but these are costly and time-consuming, which means that products have
616-490: A less common variant. Gräddfil (usually 12%) and Creme Fraiche (usually around 35%) are two common sour cream products. In Switzerland, the types of cream are legally defined as follows: Sour cream and crème fraîche (German: Sauerrahm, Crème fraîche; French: crème acidulée, crème fraîche; Italian: panna acidula, crème fraîche) are defined as cream soured by bacterial cultures. Thick cream (German: verdickter Rahm ; French: crème épaissie ; Italian: panna addensata )
693-449: A lower-temperature process. Because of its mild heat treatment, pasteurization increases the shelf-life by a few days or weeks. However, this mild heat also means there are only minor changes to heat-labile vitamins in the foods. According to a systematic review and meta-analysis, it was found that pasteurization appeared to reduce concentrations of vitamins B12 and E , but it also increased concentrations of vitamin A . However, in
770-506: A milk product comparatively rich in fat, in the form of an emulsion of fat-in-skim milk, which can be obtained by separation from milk. Cream sold without further specification must contain no less than 350 g/kg (35%) milk fat. Manufacturers labels may distinguish between different fat contents, a general guideline is as follows: Canadian cream definitions are similar to those used in the United States, except for "light cream", which
847-469: A new method to preserve food. After some 14 or 15 years of experimenting, Appert submitted his invention and won the prize in January 1810. Later that year, Appert published L'Art de conserver les substances animales et végétales (" The Art of Preserving Animal and Vegetable Substances "). This was the first cookbook on modern food preservation methods. La Maison Appert ' The House of Appert ' , in
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#1732776415173924-693: A percentage followed by "milk fat", "B.F", or "M.F". In France, the use of the term "cream" for food products is defined by the decree 80-313 of April 23, 1980. It specifies the minimum rate of milk fat (12%) as well as the rules for pasteurisation or UHT sterilisation . The mention "crème fraîche" (fresh cream) can only be used for pasteurised creams conditioned on production site within 24h after pasteurisation. Even if food additives complying with French and European laws are allowed, usually, none will be found in plain "crèmes" and "crèmes fraîches" apart from lactic ferments (some low cost creams (or close to creams) can contain thickening agents, but rarely). Fat content
1001-618: A powder for shipment to distant markets, and contains high levels of saturated fat . Cream skimmed from milk may be called "sweet cream" to distinguish it from cream skimmed from whey , a by-product of cheese -making. Whey cream has a lower fat content and tastes more salty, tangy, and "cheesy". In many countries partially fermented cream is also sold: sour cream , crème fraîche , and so on. Both forms have many culinary uses in both sweet and savoury dishes. Cream produced by cattle (particularly Jersey cattle ) grazing on natural pasture often contains some carotenoid pigments derived from
1078-455: A precaution, modern HTST pasteurization processes must be designed with flow-rate restriction as well as divert valves which ensure that the milk is heated evenly and that no part of the milk is subject to a shorter time or a lower temperature. It is common for the temperatures to exceed 72 °C (162 °F) by 1.5–2 °C (2.7–3.6 °F). Pasteurization is not sterilization and does not kill spores. "Double" pasteurization, which involves
1155-406: A reduced shelf-life by the time pasteurization is verified. As a result of the unsuitability of microbiological techniques, milk pasteurization efficacy is typically monitored by checking for the presence of alkaline phosphatase , which is denatured by pasteurization. Destruction of alkaline phosphatase ensures the destruction of common milk pathogens. Therefore, the presence of alkaline phosphatase
1232-571: A result of enzymatic and non-enzymatic transformations in the structure of pectin if the processing temperatures are too high as a result. However, with mild heat treatment pasteurization, tissue softening in the vegetables that causes textural loss is not of concern as long as the temperature does not get above 80 °C (176 °F). "Pasteurizing" in the broad sense refers to any method that reduces microbes by an amount ( log reduction ) equivalent to Pasteur's process. Novel processes, thermal and non-thermal, have been developed to pasteurize foods as
1309-639: A result of hormones". In 2024, Cancer Research UK stated "there is no reliable evidence that casein or hormones in dairy causes cancer in people". The American Medical Association (AMA) recommends that people replace full-fat dairy products with nonfat and low-fat dairy products. In 2017, the AMA stated that there is no high-quality clinical evidence that cheese consumption lowers the risk of cardiovascular disease. In 2021, they stated that "taken together, replacing full-fat dairy products with nonfat and low-fat dairy products and other sources of unsaturated fat shifts
1386-416: A secondary heating process, can extend shelf life by killing spores that have germinated. The acceptance of double pasteurization varies by jurisdiction. In places where it is allowed, milk is initially pasteurized when it is collected from the farm so it does not spoil before processing. Many countries prohibit the labelling of such milk as "pasteurized" but allow it to be marked "thermized", which refers to
1463-814: A soft, sweet filling between them that is called "crème filling." In some cases, foods can be described as cream although they do not contain predominantly milk fats; for example, in Britain, " ice cream " can contain non-milk fat (declared on the label) in addition to or instead of cream, and salad cream is the customary name for a non-dairy condiment that has been produced since the 1920s. In other languages, cognates of "cream" are also sometimes used for non-food products, such as fogkrém (Hungarian for toothpaste), or Sonnencreme (German for sunscreen). Some products are described as "cream alternatives". For example, Elmlea Double , etc. are blends of buttermilk or lentils and vegetable oil with other additives sold by Upfield in
1540-424: A tendency to produce oily globules (called "feathering") when added to coffee . The stability of the cream may be increased by increasing the non-fat solids content, which can be done by partial demineralisation and addition of sodium caseinate , although this is expensive. Butter is made by churning cream to separate the butterfat and buttermilk . This can be done by hand or by machine. Whipped cream
1617-619: A way of reducing the effects on nutritional and sensory characteristics of foods and preventing degradation of heat-labile nutrients. Pascalization or high pressure processing (HPP), pulsed electric field (PEF), ionising radiation , high pressure homogenisation , UV decontamination , pulsed high intensity light , high intensity laser , pulsed white light , high power ultrasound , oscillating magnetic fields , high voltage arc discharge , and streamer plasma are examples of these non-thermal pasteurization methods that are currently commercially utilized. Microwave volumetric heating (MVH)
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#17327764151731694-584: Is "insufficient evidence to draw any firm conclusions as to whether exposure to dietary IGF-1 is associated with an increased incidence of cancer in consumers". The COC also stated it is unlikely that there would be absorption of intact IGF-1 from food by most consumers. A 2019 review concluded that higher-quality research was needed to characterise valid associations between dairy consumption and risk of and/or cancer-related mortality. A 2021 umbrella review found strong evidence that consumption of dairy products decreases risk of colorectal cancer. Fermented dairy
1771-648: Is a dairy . Dairy products are consumed worldwide to varying degrees. Some people avoid some or all dairy products because of lactose intolerance , veganism , environmental concerns , other health reasons or beliefs. Milk is produced after optional homogenization or pasteurization , in several grades after standardization of the fat level, and possible addition of the bacteria Streptococcus lactis and Leuconostoc citrovorum . Milk can be broken down into several different categories based on type of product produced, including cream, butter, cheese, infant formula, and yogurt. Milk varies in fat content. Skim milk
1848-547: Is a mild heat treatment of liquid foods (both packaged and unpackaged) where products are typically heated to below 100 °C (212 °F). The heat treatment and cooling process are designed to inhibit a phase change of the product. The acidity of the food determines the parameters (time and temperature) of the heat treatment as well as the duration of shelf life. Parameters also take into account nutritional and sensory qualities that are sensitive to heat. In acidic foods (with pH of 4.6 or less), such as fruit juice and beer ,
1925-493: Is also used for cakes . Whipped cream is served as a topping on ice cream sundaes , milkshakes , lassi , eggnog , sweet pies , strawberries, blueberries, or peaches. Cream is also used in Indian curries such as masala dishes. Cream (usually light/single cream or half and half ) may be added to coffee . Both single and double cream (see Types for definitions) can be used in cooking. Double cream or full-fat crème fraîche
2002-587: Is an ideal indicator of pasteurization efficacy. For liquid eggs , the effectiveness of the heat treatment is measured by the residual activity of α-amylase . During the early 20th century, there was no robust knowledge of what time and temperature combinations would inactivate pathogenic bacteria in milk, and so a number of different pasteurization standards were in use. By 1943, both HTST pasteurization conditions of 72 °C (162 °F) for 15 seconds, as well as batch pasteurization conditions of 63 °C (145 °F) for 30 minutes, were confirmed by studies of
2079-409: Is associated with significantly decreased bladder cancer and colorectal cancer risk. A 2023 review found no association between consumption of dairy products and breast cancer . The British Dietetic Association have described the idea that milk promotes hormone related cancerous tumour growth as a myth, stating "no link between dairy containing diets and risk of cancer or promoting cancer growth as
2156-413: Is commonly shown as "XX% M.G." ("matière grasse"). (usually 30%) (usually 15%) (usually 30%) (usually 15%) Russia, as well as other EAC countries , legally separates cream into two classes: normal (10–34% butterfat) and heavy (35–58%), but the industry has pretty much standardized around the following types: In Sweden , cream is usually sold as: Mellangrädde (27%) is, nowadays,
2233-411: Is composed of many thin vertical stainless steel plates that separate the liquid from the heating or cooling medium. Shell and tube heat exchangers are often used for the pasteurization of foods that are non-Newtonian fluids , such as dairy products, tomato ketchup and baby foods. A tube heat exchanger is made up of concentric stainless steel tubes. Food passes through the inner tube or tubes, while
2310-891: Is defined as cream thickened using thickening agents . In the United Kingdom, these types of cream are produced. Fat content must meet the Food Labelling Regulations 1996. In the United States, cream is usually sold as: Not all grades are defined by all jurisdictions, and the exact fat content ranges vary. The above figures, except for "manufacturer's cream", are based on the Code of Federal Regulations , Title 21, Part 131. Cream may have thickening agents and stabilizers added. Thickeners include sodium alginate , carrageenan , gelatine , sodium bicarbonate , tetrasodium pyrophosphate , and alginic acid . Other processing may be carried out. For example, cream has
2387-441: Is made by whisking or mixing air into cream with more than 30% fat, to turn the liquid cream into a soft solid. Nitrous oxide , from whipped-cream chargers may also be used to make whipped cream. Sour cream , produced in many countries, is cream (12 to 16% or more milk fat) that has been subjected to a bacterial culture that produces lactic acid (0.5%+), which sours and thickens it. Crème fraîche (28% milk fat)
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2464-471: Is made through a process that starts by slowly heating whole milk to produce a very high-fat (55%) product, similar to Indian malai . Reduced cream is a cream product in New Zealand, often used to make Kiwi dip . Some non-edible substances are called creams due to their consistency: shoe cream is runny, unlike regular waxy shoe polish; hand/body "creme" or "skin cream" is meant for moisturizing
2541-1166: Is milk with zero fat, while whole milk products contain fat. Milk is an ingredient in many confectioneries. Milk can be added to chocolate to produce milk chocolate . Butter , mostly milk fat, produced by churning cream Fermented milk products include: Yogurt , milk fermented by thermophilic bacteria , mainly Streptococcus salivarius ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus sometimes with additional bacteria, such as Lactobacillus acidophilus Cheese , produced by coagulating milk, separating curds from whey , and letting it ripen, generally with bacteria , and sometimes also with certain molds . Rates of dairy consumption vary widely worldwide. High-consumption countries consume more than 150 kilograms (330 lb) per capita per year. These countries are: Argentina, Armenia, Australia, Costa Rica, most European countries, Israel, Kyrgyzstan, North America and Pakistan. Medium-consumption countries consume 30 kilograms (66 lb) to 150 kg per capita per year. These countries are: India, Iran, Japan, Kenya, Mexico, Mongolia, New Zealand, North and Southern Africa, most of
2618-400: Is necessary. High-temperature short-time (HTST) pasteurization, such as that used for milk (71.5 °C (160.7 °F) for 15 seconds) ensures safety of milk and provides a refrigerated shelf life of approximately two weeks. In ultra-high-temperature (UHT) pasteurization, milk is pasteurized at 135 °C (275 °F) for 1–2 seconds, which provides the same level of safety, but along with
2695-450: Is no conclusive evidence. Fermented and low-fat dairy products are associated with a decreased risk of diabetes . Consumption of dairy products are also associated with a decreased risk of gout . A 2023 review found that higher intake of dairy products is significantly associated with a lower risk of inflammatory bowel disease . Some groups avoid dairy products for non-health-related reasons. Some religions restrict or do not allow
2772-613: Is often used when the cream is added to a hot sauce, to prevent it separating or "splitting". Double cream can be thinned with milk to make an approximation of single cream. The French word crème denotes not only dairy cream but also other thick liquids such as sweet and savory custards , which are normally made with milk, not cream. Different grades of cream are distinguished by their fat content, whether they have been heat-treated, whipped, and so on. In many jurisdictions, there are regulations for each type. The Australia New Zealand Food Standards Code – Standard 2.5.2 – Defines cream as
2849-429: Is related to the homogenization step that takes place prior to pasteurization. Before pasteurization milk is homogenized to emulsify its fat and water-soluble components, which results in the pasteurized milk having a whiter appearance compared to raw milk. For vegetable products, color degradation is dependent on the temperature conditions and the duration of heating. Pasteurization may result in some textural loss as
2926-408: Is slightly soured with bacterial culture, but not as sour or as thick as sour cream. Mexican crema (or cream espesa ) is similar to crème fraîche. Smetana is a heavy cream-derived (15–40% milk fat) Central and Eastern European sweet or sour cream. Rjome or rømme is Norwegian sour cream containing 35% milk fat, similar to Icelandic sýrður rjómi . Clotted cream in the United Kingdom
3003-460: Is stored at ambient temperature, bacteria and other pathogens soon proliferate. The US Centers for Disease Control (CDC) says improperly handled raw milk is responsible for nearly three times more hospitalizations than any other food-borne disease source, making it one of the world's most dangerous food products. Diseases prevented by pasteurization can include tuberculosis , brucellosis , diphtheria , scarlet fever , and Q-fever ; it also kills
3080-414: Is strong evidence that consumption of dairy products decreases risk of colorectal cancer . The AICR, WCRF, CCA and Prostate Cancer UK have stated that there is limited but suggestive evidence that dairy products increase risk of prostate cancer . The American Cancer Society (ACS) have stated that because dairy products "may lower the risk of some cancers and possibly increase the risk of others,
3157-406: Is used. Most liquid foods are pasteurized by using a continuous process that passes the food through a heating zone, a hold tube to keep it at the pasteurization temperature for the desired time, and a cooling zone, after which the product is filled into the package. Plate heat exchangers are often used for low- viscosity products such as animal milks, nut milks and juices. A plate heat exchanger
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3234-655: Is very low-fat cream, usually with 5 or 6 percent butterfat. Specific product characteristics are generally uniform throughout Canada, but names vary by both geographic and linguistic area and by manufacturer: "coffee cream" may be 10 or 18 percent cream and "half-and-half" ( crème légère ) may be 3, 5, 6 or 10 percent, all depending on location and brand. Regulations allow cream to contain acidity regulators and stabilizers . For whipping cream, allowed additives include skim milk powder (≤ 0.25%), glucose solids (≤ 0.1%), calcium sulphate (≤ 0.005%), and xanthan gum (≤ 0.02%). The content of milk fat in canned cream must be displayed as
3311-688: The dairy industry and other food processing industries for food preservation and food safety . By the year 1999, most liquid products were heat treated in a continuous system where heat is applied using a heat exchanger or the direct or indirect use of hot water and steam. Due to the mild heat, there are minor changes to the nutritional quality and sensory characteristics of the treated foods. Pascalization or high pressure processing (HPP) and pulsed electric field (PEF) are non-thermal processes that are also used to pasteurize foods. Heating wine for preservation has been known in China since AD 1117, and
3388-469: The plants they eat; traces of these intensely colored pigments give milk a slightly yellow tone, hence the name of the yellowish-white color: cream . Carotenoids are also the origin of butter 's yellow color. Cream from goat 's milk, water buffalo milk, or from cows fed indoors on grain or grain-based pellets, is white. Cream is used as an ingredient in many foods, including ice cream , many sauces , soups , stews, puddings, and some custard bases, and
3465-621: The ACS does not make specific recommendations on dairy food consumption for cancer prevention." It has been suggested that consumption of insulin-like growth factor 1 (IGF-1) in dairy products could increase cancer risk, particularly prostate cancer. However, a 2018 review by the Committee on Carcinogenicity of Chemicals in Food, Consumer Products and the Environment (COC) concluded that there
3542-616: The EU, dairy is responsible for 27% of all diet related emissions, on average, while plant-based milks cause 2.5–4.5 times fewer emissions. Pasteurization In food processing, pasteurization ( also pasteurisation ) is a process of food preservation in which packaged foods (e.g., milk and fruit juices ) are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life . Pasteurization either destroys or deactivates microorganisms and enzymes that contribute to food spoilage or
3619-630: The Middle East, and most of Latin America and the Caribbean. Low-consumption countries consume under 30 kg per capita per year. These countries are: Senegal, most of Central Africa, and most of East and Southeast Asia. For those with some degree of lactose intolerance , considering the amount of lactose in dairy products can be important to health. Dairy products may upset the digestive system in individuals with lactose intolerance or
3696-488: The United Kingdom packaged and shelved in the same way as cream, labelled as having "a creamy taste". Dairy product Dairy products or milk products , also known as lacticinia , are food products made from (or containing) milk . The most common dairy animals are cow , water buffalo , nanny goat , and ewe . Dairy products include common grocery store food around the world such as yogurt , cheese , milk and butter . A facility that produces dairy products
3773-467: The United States were due to raw milk or cheese products. They report 148 outbreaks and 2,384 illnesses (with 284 requiring hospitalization), as well as two deaths due to raw milk or cheese products during the same time period. Medical equipment, notably respiratory and anesthesia equipment, is often disinfected using hot water, as an alternative to chemical disinfection. The temperature is raised to 70 °C (158 °F) for 30 minutes. Pasteurization
3850-586: The complete thermal death (as best as could be measured at that time) for a range of pathogenic bacteria in milk. Complete inactivation of Coxiella burnetii (which was thought at the time to cause Q fever by oral ingestion of infected milk) as well as of Mycobacterium tuberculosis (which causes tuberculosis ) were later demonstrated. For all practical purposes, these conditions were adequate for destroying almost all yeasts , molds , and common spoilage bacteria and also for ensuring adequate destruction of common pathogenic, heat-resistant organisms. However,
3927-430: The composition of dietary patterns toward higher unsaturated to saturated fat ratios that are associated with better cardiovascular health". In 2017, the National Heart Foundation of New Zealand published an umbrella review which found an "overall neutral effect of dairy on cardiovascular risk for the general population". Their position paper stated that "the evidence overall suggests dairy products can be included in
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#17327764151734004-521: The consumption of dairy products. For example, some scholars of Jainism advocate not consuming any dairy products because dairy is perceived to involve violence against cows. Orthodox Judaism requires that meat and dairy products not be served at the same meal, served or cooked in the same utensils, or stored together, as prescribed in Deuteronomy 14:21. Veganism is the avoidance of all animal products, including dairy products, most often due to
4081-465: The disease. In 1910, Lederle, then in the role of Commissioner of Health, introduced mandatory pasteurization of milk in New York City . Developed countries adopted milk pasteurization to prevent such disease and loss of life, and as a result milk is now considered a safer food. A traditional form of pasteurization by scalding and straining of cream to increase the keeping qualities of butter
4158-572: The distance from country to city, raw milk (often days old) became recognized as a source of disease. For example, between 1912 and 1937, some 65,000 people died of tuberculosis contracted from consuming milk in England and Wales alone. Because tuberculosis has a long incubation period in humans, it was difficult to link unpasteurized milk consumption with the disease. In 1892, chemist Ernst Lederle experimentally inoculated milk from tuberculosis-diseased cows into guinea pigs, which caused them to develop
4235-501: The effect of milk heat treatment on this vitamin is a not a major public health concern. Results of meta-analyses reveal that pasteurization of milk leads to a significant decrease in vitamin C and folate , but milk is also not an important source of these vitamins. A significant decrease in vitamin B2 concentrations was found after pasteurization. Vitamin B2 is typically found in bovine milk at concentrations of 1.83 mg/liter. Because
4312-621: The ethics regarding how dairy products are produced. The ethical reasons for avoiding meat and dairy products include how dairy is produced, how the animals are handled, and the environmental effect of dairy production. According to a report of the United Nations' Food and Agriculture Organization in 2010 the dairy sector accounted for 4 percent of global human-made greenhouse gas emissions. Growing awareness of dairy products' environmental impact, specifically greenhouse gas emissions, has led to many people reducing or avoiding dairy. In
4389-431: The final quality. In honor of Pasteur, this process is known as pasteurization. Pasteurization was originally used as a way of preventing wine and beer from souring, and it would be many years before milk was pasteurized. In the United States in the 1870s, before milk was regulated, it was common for milk to contain substances intended to mask spoilage. Milk is an excellent medium for microbial growth, and when it
4466-695: The general population. For people with elevated cholesterol and those with existing coronary heart disease, reduced fat products are recommended." The position statement also noted that the "evidence for milk, yoghurt and cheese does not extend to butter, cream, ice-cream and dairy-based desserts; these products should be avoided in a heart healthy eating pattern". Recent reviews of randomized controlled trials have found that dairy intake from cheese, milk and yogurt does not have detrimental effects on markers of cardiometabolic health. Consumption of dairy products such as low-fat and whole milk have been associated with an increased acne risk, however, as of 2022 there
4543-412: The harmful bacteria Salmonella , Listeria , Yersinia , Campylobacter , Staphylococcus aureus , and Escherichia coli O157:H7 , among others. Prior to industrialization, dairy cows were kept in urban areas to limit the time between milk production and consumption, hence the risk of disease transmission via raw milk was reduced. As urban densities increased and supply chains lengthened to
4620-571: The heat treatments are designed to inactivate enzymes (pectin methylesterase and polygalacturonase in fruit juices) and destroy spoilage microbes (yeast and lactobacillus ). Due to the low pH of acidic foods, pathogens are unable to grow. The shelf-life is thereby extended several weeks. In less acidic foods (with pH greater than 4.6), such as milk and liquid eggs, the heat treatments are designed to destroy pathogens and spoilage organisms (yeast and molds). Not all spoilage organisms are destroyed under pasteurization parameters, so subsequent refrigeration
4697-440: The heating/cooling medium is circulated through the outer tube. Scraped-surface heat exchangers are a type of shell and tube which contain an inner rotating shaft having spring-loaded blades that serve to scrape away any highly viscous material that accumulates on the wall of the tube. The benefits of using a heat exchanger to pasteurize foods before packaging, versus pasteurizing foods in containers are: After being heated in
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#17327764151734774-528: The major milk-borne pathogens during a 15-second treatment are: (A log 10 reduction between 6 and 7 means that 1 bacterium out of 1 million (10 ) to 10 million (10 ) bacteria survive the treatment.) The Codex Alimentarius Code of Hygienic Practice for Milk notes that milk pasteurization is designed to achieve at least a 5 log 10 reduction of Coxiella burnetii . The Code also notes that: "The minimum pasteurization conditions are those having bactericidal effects equivalent to heating every particle of
4851-479: The microbiological techniques used until the 1960s did not allow for the actual reduction of bacteria to be enumerated. Demonstration of the extent of inactivation of pathogenic bacteria by milk pasteurization came from a study of surviving bacteria in milk that was heat-treated after being deliberately spiked with high levels of the most heat-resistant strains of the most significant milk-borne pathogens. The mean log 10 reductions and temperatures of inactivation of
4928-658: The milk to 72 °C (162 °F) for 15 seconds (continuous flow pasteurization) or 63 °C (145 °F) for 30 minutes (batch pasteurization)” and that "To ensure that each particle is sufficiently heated, the milk flow in heat exchangers should be turbulent, i.e . the Reynolds number should be sufficiently high". The point about turbulent flow is important because simplistic laboratory studies of heat inactivation that use test tubes, without flow, will have less bacterial inactivation than larger-scale experiments that seek to replicate conditions of commercial pasteurization. As
5005-428: The packaging, extends shelf life to three months under refrigeration. Food can be pasteurized either before or after being packaged into containers. Pasteurization of food in containers generally uses either steam or hot water. When food is packaged in glass, hot water is used to avoid cracking the glass from thermal shock . When plastic or metal packaging is used, the risk of thermal shock is low, so steam or hot water
5082-608: The pasteurization of milk while at the United States Marine Hospital Service, notably in his publication of The Milk Question (1912). States in the U.S. soon began enacting mandatory dairy pasteurization laws, with the first in 1947, and in 1973 the U.S. federal government required pasteurization of milk used in any interstate commerce. The shelf life of refrigerated pasteurized milk is greater than that of raw milk . For example, high-temperature, short-time ( HTST ) pasteurized milk typically has
5159-442: The pasteurization process does not have much effect on pigments such as chlorophylls , anthocyanins, and carotenoids in plants and animal tissues. In fruit juices, polyphenol oxidase (PPO) is the main enzyme responsible for causing browning and color changes. However, this enzyme is deactivated in the deaeration step prior to pasteurization with the removal of oxygen. In milk, the color difference between pasteurized and raw milk
5236-484: The recommended daily intake for adults is 1.1 mg/day, milk consumption greatly contributes to the recommended daily intake of this vitamin. With the exception of B2, pasteurization does not appear to be a concern in diminishing the nutritive value of milk because milk is often not a primary source of these studied vitamins in the North American diet. Pasteurization also has a small but measurable effect on
5313-438: The review, there was only limited research regarding how much pasteurization affects A, B12, and E levels. Milk is not considered an important source of vitamins B12 or E in the North American diet, so the effects of pasteurization on the adult daily intake of these vitamins is negligible. However, milk is considered an important source of vitamin A, and because pasteurization appears to increase vitamin A concentrations in milk,
5390-452: The risk of disease, including vegetative bacteria , but most bacterial spores survive the process. Pasteurization is named after the French microbiologist Louis Pasteur , whose research in the 1860s demonstrated that thermal processing would deactivate unwanted microorganisms in wine . Spoilage enzymes are also inactivated during pasteurization. Today, pasteurization is used widely in
5467-529: The sensory attributes of the foods that are processed. In fruit juices, pasteurization may result in loss of volatile aroma compounds. Fruit juice products undergo a deaeration process prior to pasteurization that may be responsible for this loss. Deaeration also minimizes the loss of nutrients like vitamin C and carotene . To prevent the decrease in quality resulting from the loss in volatile compounds, volatile recovery, though costly, can be utilized to produce higher-quality juice products. In regard to color,
5544-447: The skin. Regulations in many jurisdictions restrict the use of the word cream for foods. Words such as creme , kreme , creame , or whipped topping (e.g., Cool Whip ) are often used for products which cannot legally be called cream, though in some jurisdictions even these spellings may be disallowed, for example under the doctrine of idem sonans . Oreo and Hydrox cookies are a type of sandwich cookie in which two biscuits have
5621-411: The town of Massy , near Paris, became the first food-bottling factory in the world, preserving a variety of foods in sealed bottles. Appert's filled thick, large-mouthed glass bottles with produce of every description, ranging from beef and fowl to eggs, milk and prepared dishes. He left air space at the top of the bottle, and the cork would then be sealed firmly in the jar by using a vise . The bottle
5698-509: Was documented in Japan in the diary Tamonin-nikki written by a series of monks between 1478 and 1618. In 1768, research performed by the Italian priest and scientist Lazzaro Spallanzani proved that a product could be made "sterile" after thermal processing. Spallanzani boiled meat broth for one hour, sealed the container immediately after boiling, and noticed that the broth did not spoil and
5775-426: Was free from microorganisms. In 1795, a Parisian chef and confectioner named Nicolas Appert began experimenting with ways to preserve foodstuffs, succeeding with soups, vegetables, juices, dairy products, jellies, jams, and syrups. He placed the food in glass jars, sealed them with cork and sealing wax and placed them in boiling water. In that same year, the French military offered a cash prize of 12,000 francs for
5852-559: Was practiced in Great Britain in the 18th century and was introduced to Boston in the British Colonies by 1773, although it was not widely practiced in the United States for the next 20 years. Pasteurization of milk was suggested by Franz von Soxhlet in 1886. In the early 20th century, Milton Joseph Rosenau established the standards – i.e. low-temperature, slow heating at 60 °C (140 °F) for 20 minutes – for
5929-513: Was then wrapped in canvas to protect it while it was dunked into boiling water and then boiled for as much time as Appert deemed appropriate for cooking the contents thoroughly. Appert patented his method, sometimes called appertisation in his honor. Appert's method was so simple and workable that it quickly became widespread. In 1810, the British inventor and merchant Peter Durand , also of French origin, patented his own method, but this time in
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