Fat in ice cream

The main ingredients provide the required sensory properties: ice gives cooling, fat provides creaminess, air gives lightness and softness, sugar provides sweetness and flavors enhance its taste.

Milk fat or butterfat, as it is sometimes called, is the most important component of ice cream. It is also the most expensive major ingredient of ice cream, and so the higher the fat content, generally the more expensive the product.

Milk fat gives ice cream a rich and creamy flavor. Fat also contributes to producing a smooth texture and greater resistance to melting.

The fat also is a concentrated source of calories and contributes heavily to the energy value of ice cream.

A milk fat content between 14% and 22% is ideal for producing a rich tasting, full bodied ice cream. According to US standards, ice cream must contain at least 10% milk fat, before the addition of bulky ingredients and must weigh a minimum of 4.5 pounds to the gallon. Ice cream made with less than 14% milk fat is weak-bodied coarse and icy.

Decreasing the fat content of ice cream decreases the creamy sensation and increases the intensities of flavors of skim milk powder and of corn syrup.

It also impacts on added flavors, since there are many flavor components that are fat soluble, which are released to the olfactory senses as fat melts.
Fat in ice cream

Monounsaturated fatty acids

Monounsaturated fatty acids are a fatty acid containing one point of unsaturation.

Plant sources that are rich in monounsaturated fatty acids include vegetables oils that are liquid at room temperature (eg, canola oil, olive oil, high oleic safflower and sunflower oil) and nuts.

When monounsaturated fat such as olive replaces started and trans fats in the diet, the risk of heart disease may be lessened.

Monounsaturated fat as in seafood, nuts, olive oil, canola and coconut oil, are considered the healthiest fats.

They are rich with fatty acids and important for normalizing prostaglandin levels. Studies suggest that diet rich in monounsaturated fats might be of benefits, especially for diabetes with insulin resistant.

A diet higher in monounsaturated fatty acid appeared to provide an advantage over a fiber-rich, high carbohydrates, low-fat diet on body fat distribution among diabetics.
Monounsaturated fatty acids

What are the health benefits of monounsaturated fat?

In monounsaturated fatty acids, only one double bond is found along the chain. Monounsaturated fatty acids are found in olive, canola, peanut and sesame oils. They are also found in avocados, peanuts and cashews. Monounsaturated fat is typically liquid in room temperature.

The fat in macadamia nut oil is 85 percent monounsaturated with a predominance of the heart-healthy oleic acid.

Oleic acid and also omega-3s lower triglyceride levels and raise HDL cholesterol, a very protective combination.

Cholesterol replacing saturated and trans-fats with monounsaturated fat such as olive oil may be effective dietary strategy to prevent heart disease.

Monounsaturated fats (omega-9s) are central to the Mediterranean diet that has been shown as the key factors in cardio-protection. Olive oil is a typical and quantitatively important food in Mediterranean countries, where the incidence cardiovascular heart disease was very low.

Monounsaturated fatty acids raise HDL levels even more than polyunsaturated fatty acids and also lower LDLs. In addition they prevent the oxidation of LDLs, which reduces the likelihood that LDLs will become part of atherosclerotic plaque.
What are the health benefits of monounsaturated fat?

Fat soluble vitamin

Vitamins fall into two broad categories: water soluble and fat soluble. This property determines the pattern of transport excretion and storage within the human body.

Vitamins A, D, E and K are lipid like molecules that are soluble in lipid materials. In general, the vitamins carried in the blood by protein carriers are stored in fat tissues, are needed in periodic doses and are more likely to be toxic when consumed in excess of need.

Intestinal cells absorb fat soluble vitamins along with dietary fat, the amount absorbed typically varies from 40 to 90 percent of the amount consumed; efficiency of absorption generally falls as the dietary intake rises above the body’s needs.

Once absorbed, these vitamins are stored in the liver and a fatty tissues until the body needs them.

Fat soluble vitamins play diverse roles in the body, Vitamin A and D may act somewhat like hormones, directing cells to convert one substance to another while vitamin flows throughout the body, preventing oxidative destruction of tissues. Vitamin K is necessary for blood to clot.
Fat soluble vitamin

Polyunsaturated fat in food

If a fat is polyunsaturated, there are two or more places among the carbon atoms of its fatty acids where there are fewer hydrogen atoms attached than in saturated fats.

Polyunsaturated fats are unstable and are also abundant in certain plant oils – particularly corn and soybean oils – as well as in seeds, whole grains and fatty types of fish like salmon and tuna.

Because of their instability polyunsaturated are highly susceptible to oxidization. Polyunsaturated oils are oxidized by frying, heating and exposure to light and air.

Some polyunsaturated fats are also known as essential fatty acids because human bodies need them but cannot make them from other nutrients.

Polyunsaturated fatty acids in the diet belong to either the (n-6) or (n-3) family. About 90% of all polyunsaturated fatty acid in the diet is linoleic acid, which is found in vegetable oils like sunflower oil, corn oil and soybean oil.

Foods containing high proportions of polyunsaturated fats are usually soft or oily. Polyunsaturated fats should not exceed 8% of total daily kcal.

Too much polyunsaturated fat can promote free-radical damage to cells, contributing to heart disease and cancer. When polyunsaturated oils turn rancid, they produce free radicals that attack the cholesterol, causing it to become oxidized as well. The result is that both the cholesterol and polyunsaturated fats in the lipoprotein become oxidized.
Polyunsaturated fat in food

Beef fat content

Fat is an essential component of meat for sensory perception of juiciness, flavor and texture, Fat in meat also supplies fatty acids that cannot be synthesized by humans.

However, regular consumption of red meat is associated, epidemiologically with increased risk of coronary heart disease, due to its fat composition.

Fat content can vary widely, according to the grade of meat and its cut. Several cuts of beef are lower in fat than an equal amount of some poultry choices.

Ground beef is a product with a high fat content; even extra lean ground beef gets more than 53 percent of its calories from fat and 21 percent from saturated fatty acid.

Fat especially in the form of marbling, melts during heating, thereby increasing the flavor and perceived tenderness of the meat.

According to research at the University of Missouri in 1985, beef lose mass when cooked, but the lean beef loses water and the regular beef loses fat and cholesterol.
Beef fat content

Fats

Fats
Fats are glyceryl ester of fatty acids. Fats, as do carbohydrates, contains the element of carbons, oxygen and hydrogen, but proportion of oxygen in fats is less, and it to be said that fats are fuel foods of more concentrated type than are carbohydrates.

Carbohydrates and fats are interchangeable as fuel foods, but it can be shown, by calorimetry, that fats produce more than twice the heat energy produced by carbohydrates.

One grams of fats yields 9 cal, while 1 gram of carbohydrates yields 4 cal. An additional advantage of fat from the view point of energy availability is that it stores well in large amount of adipose tissue. Thus fat, considered to be a reserve from of fuel for the body.

Paradoxically, this is not advantageous in affluent societies where the problem is not availability of food energy, but rather health hazard of obesity.

Fats may occur in foods as materials that are solid at room temperature or as oils that are liquid at room temperature.

Solid fat contain comparatively small amounts of fatty acids with two or more groups of adjacent carbons that are not fully saturated with hydrogen.
Fats

Glycogen

Glycogen
Glycogen is produced in the liver from glucose. And it is stored in the liver, as well as in the muscle where it is available for immediate use as energy.

Both liver and the muscles can store only a limited amount of glycogen; therefore, when an excess of carbohydrates is ingested, there will be a tendency to develop an excess of glycogen.

The excess carbohydrates will then be converted to fat and stored in body as fat.

The body maintains equilibrium between glucose, the energy-producing sugar, and glycogen, which can be converted to glucose as the glucose in the blood used up to produce energy.

The production of energy from glucose involves oxidation of sugar with the release of water and carbon dioxide, which are easily removed from the body.
Glycogen

Summary of Fats

Summary of Fats
Fats are comprised of fatty acids bound, in bundles of three, to glycerol.

• Fatty acids are either saturated, monounsaturated or polyunsaturated.
• Fats contains mixtures of all three types of fatty acids; the balance of the mix determines whether the fat is generally saturated (hard) or polyunsaturated (soft).
• Fats are insoluble in water and require special treatment for digestion and transport.
• In digestion, bile acids act as detergents to solubilize fats to aids digestion.
• In transport, the fatty material is surrounded by a coat of protein plus phospholipid. The full particle is a lipoprotein.
• The liver can convert carbohydrate to fat, which is exported from the liver as a lipoprotein.
• Certain polyunsaturated fatty acids are nutritionally essentially because:
  1. They are the precursors of the vitality important regulators of metabolism, the prostaglandins
  2. The body cannot make them from either carbohydrate or existing dietary fatty acids.
  
  Summary of Fats

Butter

Butter
Butter is one of the main fat products used as spreads. Both of these products are water in oil emulsions.

Butter usually contains about 80% fat. In England, butter must not contain more than 16% water.

Other constituents of butter include protein (1%), lactose (0.4%), mill ash (0.15%), and salt.

The natural color of butter is due to carotene and other fat soluble pigments.

The major proportion of the butter consumed in many countries is sweet cream butter. That is butter manufactured from fresh cream.

Lactic butter, which is more popular is some other countries is manufactured from cream which is first cultured to develop aromatic flavored compounds, e.g. diacetyl.

Both types of butter may be slated (up to 2% salt) depending on market requirements.

Production
Butter making is synonymous with churning of cream in batch or in continuous buttermakers, the latter having been established since the 1930s.

While both processes have been optimized over the years, batch churns are mainly used in smaller dairies and cheese factories (where the cream recovered from whey is churned into whey butter)and continuous plants are used in large scale operations productions 1 – 4 ton of butter.
Butter

The meaning of ‘shortenings’

The meaning of ‘shortenings’
Fats and fat products may consist of:

• Fat or oil
• Fat plus an emulsifying agent
• Fat emulsions such as butter and margarine
  

Fat products are used as shortenings, spreads, solid oil, cooking and frying fats and oils, and in the preparations of confectionery and icings.

The term shortening had its origin in the United States and referred to a preparation, originally developed from cottonseed oil, that was used to “shorten” the preparation time of shortbread and cakes. Shortenings consist entirely of fat and contain no moisture. The traditional shortening is lard.

Domestic shortenings generally fall into one of two categories – molded products (10% air) and liquid filled products (10 – 35% air). Molded products have goods cake making properties. Liquid-filled products are more expensive but are easier to use.

Shortenings are matured (tempered) by holding at an elevated temperature (25 – 30%) for up to 48 hr. This maturation causes a change in crystal structure such that when the product is cooled it has a plastic texture. This process is accomplished with scraped surface heat exchangers.

High ratio shortenings allow a higher ratio of sugar to flour to be used in cakes due to the emulsifying properties of the shortenings. Emulsifiers are usually mono – or diglycerides.
The meaning of ‘shortenings’

Fat Processing

Fat Processing
Plant Oils
The oils are usually removed from plant tissues by three methods. In the first method, cells containing oil are ruptured by heat and mechanical methods. In the past, cottonseeds free of lint were hulled, then flaked between rollers, and cooked with lived steam prior to hydraulic pressing to separate the oil. A second method, called screw pressing, involves heating the flakes or cracked meats, followed by passage through closed-fitting cages of screws to press out the oil. The third method involves solvent extraction using petroleum hydrocarbons at 60 – 70 degree Celsius. This method, which is a continuous one, has a capacity of processing of hundreds of tons of oil per day. The by-products of these methods are proteins, which are used in animal feeds.

Animal Fats
Animal fats are separated from fatty tissues by wet or dry rendering. In wet rendering, the fatty tissue is heated under steam pressure, thus rupturing the cells and liberating the fat. In dry rendering, the fatty tissue is heated in jacketed drums with agitation until the fats is released. Presently, centrifuges are used to separates the fat from water and protein.

Hydrogenation
Hydrogenation of unsaturated fats and oils increase their melting point and hardness, this process often used in the production of shortenings, which are generally defined as plastic materials made wholly from fats and oils. Hardness can be controlled by varying the ratio of solid to liquid glycerides. The shortenings are made by blending the desired oils and/or fats, deodorizing the mixture, chilling, and finally packaging.

Interesterification
When fats and oils are heated in the presence of certain catalysts, the fatty acids attached to glycerol rearrange in a process called interesterification. While vegetable oils are randomly distributed, animal fats generally are not. For example, at a level of 0.4% tin in standard hydroxide added to fat at 140 degree Celsius, then heated to 225 degree Celsius for 90 min in a vacuum, the distribution pattern of fatty acids will become random. In similar process, the melting point of soybean oil can be increased from -7 degree to +5.5 degree Celsius and its softening form -13 degree to -0.5 degree Celsius.

Interesterification is used in the industry to produced standard oils, which may be blended with others for use in the margarine and cooking fat trade. During interesterification, if the temperature is lowered, a certain amount of the higher melting triglycerides crystallize out. This has a dramatic effect on the remaining portion of liquid oil and alters the course of esterification. This is called directed interesterification.
Fat Processing

Composition of Cow’s Milk

Cow’s milk is made up of about 87% of water and 13% milk component or milk solids. The milk solids consist of a fat portion or butterfat accounting for 3.7% of the milk and a solids not fat portion, accounting for 8.9% of the milk.

SNF or solid no fat const sod three categories: lactose, minerals and proteins.

Cow’s milk is a nutrient dense food, providing a high concentration of nutrients in relation to its energy.

Milk also contains vitamins and other nutrients in small amounts, making it the most complete of foods. The young mammalians survive on it exclusively.

The principle proteins of milk are casein and whey proteins. These are high quality proteins, together containing, in varying amounts, all of the essential amino acids required for human growth and tissue maintenance.


Casein, is accounted for 77% of the protein component. These are bound tighter with calcium phosphate into particles known as micelles.

However, components of milk from different species vary, and occasionally the young of one species may be unable to tolerate the milk from another species, mainly because of differences in the lactose contained therein.

The fat content of milk from Ayrshire and Brown Swiss, and especially from Guernsey and Jersey breeds, is slightly higher than that from Holstein cows, but the latter breed generally produces much more milk than the others.
Composition of Cow’s Milk