Understanding the Manufacturing and Uses of Sour Cream

Sour cream is a popular dairy product produced through the fermentation of high-pasteurized cream. This process begins by pasteurizing cream at high temperatures to eliminate harmful bacteria. The cream is then homogenized at a relatively low temperature (60-65°C). This temperature is preferred as it promotes the formation of fat clusters, which during the ripening phase, flocculate, thereby increasing the viscosity of the product and enhancing its texture.

Starter cultures play a crucial role in the fermentation process of sour cream. Aromatic starters, such as Lc. lactis subsp. lactis biovar. diacetylactis and L. mesenteroides subsp. cremoris, are typically used. These cultures are added to the cream, which is then incubated at a stable temperature of 22°C. During incubation, the cream develops titratable acidity, along with the desired body and texture. This incubation process usually takes about 10-12 hours to reach the optimal acidity levels.

Sour cream's versatility makes it a staple in various culinary applications. It is commonly used as a thickener in soups and hot sauces, adding a rich, creamy texture without curdling under heat. Additionally, it is a favorite accompaniment for warm entrees such as baked potatoes and burritos. For these uses, it is essential that sour cream remains viscous and does not separate into whey when placed on warm food, ensuring a consistent texture and taste.

The modern production of sour cream continues to balance traditional methods with technological advancements, ensuring a high-quality product that meets consumer expectations for flavor and consistency.
Understanding the Manufacturing and Uses of Sour Cream

Manufacturing of High-Fructose Corn Syrup

High-Fructose Corn Syrup (HFCS) is an extra sweet, inexpensive sweetener used mostly in soft drinks and fruit juices.

Corn is the primary source of high fructose corn syrup in the US. High fructose corn syrup is a liquid alternative sweetener to sucrose that is made from corn, the “king of crops”. It is a caloric sweetener, made from ordinary corn starch, which substitutes for sugar in a wide range of manufactured products.

Corn starch composed of glucose molecules of infinite length, consists of amylose and amylopectin and requires heat, caustic soda and/or hydrochloric acid plus the activity of three different enzymes to break it down into the simple sugars glucose and fructose present in HFCS.

The production of HFCS and corn wet milling are typically an integrated process. The wet milling process separates the corn kernel into its four principal components: the germ, hull, gluten, and starch. High fructose corn syrups, as well as other corn sweeteners, utilize the corn starch slurry produced by the wet milling process as their basic input.

An industrial enzyme, α-amylase produced from Bacillus spp., hydrolyzes corn starch to short chain dextrins and oligosaccharides. Bacterial α-amylases catalyze the hydrolysis of α-1,4 glucosidic linkages and act in a random but reproducible manner to reduce the polysaccharide molecular weight. Enzymatic liquefaction requires precise control of operating conditions like percentage of solids, temperature, time, pH and calcium level to ensure efficient hydrolysis, process economics and easier downstream processing operations.

A second enzyme, glucoamylase (also called amyloglucosidase),produced from fungi such as Apergillus, breaks dextrins and oligosaccharides to the simple sugar glucose.

A glucoamylase dosage is added to produce a maximum dextrose level in 1-4 days. Reaction time is inversely related to dose, so if a given dose yields maximum dextrose in 4 days, doubling or quadrupling the dose will reduce reaction time to 2 days or 1 day, respectively.

The product of these two enzymes is corn syrup also called glucose syrup. The third and relatively expensive enzyme used in the process is glucose isomerase (also called D-glucose ketoisomerase or D-xylose ketolisomerase),that converts glucose to fructose.

Fructose is superior to all nutritive sweeteners and humectants in controlling water in frozen system. Its water activity is low as compared to sucrose, sorbitol, dextrose, mannitol, etc. which makes it a better preservative.

Manufacturing of High-Fructose Corn Syrup 

Manufacturing process of raisins

Raisins are the second most important product of the grapevine wine, being the first. The quality of raisins depends on the size of the raisins berries, the uniformity and brilliance of the berry color, the condition of the berry surface, the texture of the skin and pulp in the berry, moisture content, chemical position and presence of decay, mold, yeast and foreign matter.

Raisins are produced from grapes by sun during and artificial drying. In the traditional drying method, grape bunches are spread over either the ground or on a platform or on wooden trays in a thin layer between the rows of grapes vines.

The trays are tilted to face the sun. After they are partially dried, the grape bunches are turned and allowed to dry to the point where no juice can be pressed out. The trays are then stacked, and the air drying is continued in the shade until moisture content of about 17% reached. After drying, the raisins are placed in sweat boxes to equilibrate, or to even out, the moisture that is present, and then they are packed in retail size containers or in larger containers to be sold to the bakery trade.

This method of drying is most cost-effective and takes approximately 8-10 days to produce dried products.

In artificial drying, grapes are first dipped in 0.25 – 1 % lye (sodium hydroxide) solution at 200 – 212 degree F for 2 – 5 sec to remove a natural wax that impedes drying and to check or crack the skin of the grape to facilitate drying

They are then washed, placed on trays, and treated with sulfur dioxide to prevent enzymatic and nonenzymatic browning during drying. Hence instead of having the dark brown color of raisins that normally be expected, the raisins will be of a light yellow color when dried.

Raisins are dried at temperatures not exceeding 165 degree F and at a low relative humidity. After the moisture content has been lowered to about 16 – 18%, the raisins are packaged in containers of various sizes to be sold at retail or for use by the food industry.

In California, light-colored raisins are produced mostly by the golden bleach process. First, Thompson Seedless grapes are sorted, then they are dipped to produce slight checking cracking of the skins, and they are cooled and washed in a spray of cold water. They are exposed to the fumes of burning sulfur in a sulfur house. After being sulfured, the grapes are dehydrated at a temperature of 140 to 160 degree F.
Manufacturing process of raisins

Production process of macaroni

Macaroni is made from durum or other wheat. The U.S standard for noodle requires the addition of 5.5 percent egg and egg yolk.

The production process for macaroni consist of adding water to semolina, farina, flour and other ingredients to form stiff dough with about 30 percent moisture. Semolina, which is generally used in the manufacture of macaroni, is the purified middlings of durum wheat. Farina is the purified middlings of hard wheat other than durum and is often blended with semolina in the manufacturers of macaroni products.

These ingredients are mixed together for a short period of time, unloading the dough to obtain a plastic, homogenous mass.The doughs are blended in continuous mixers where dry ingredient feeders and metering pumps deliver the correct ration of the recipe.

The dough then is extrude through a die into various shapes and forms under 1,500 – 2, 000 psi pressures at 130 – 140 °F. The purpose of extruder is to knead the semolina/water dough and deliver it uniformly to the die.

The wet macaroni products are then dried at 95 – 122 °F to 1o-12 percent moisture. Some of the chief macaroni products are as follows: Macaroni, spaghetti, egg noodles, elbow macaroni, elbow noodles, alphabets, numerals and shells.

Most macaroni products were made by a batch process. That is the semolina and water were weighed and combined in a mixer of about 300 lbs capacity.
Production process of macaroni

Lemon juice processing

An important crop in Italy and some other Mediterranean countries, the lemon is also grown commercially in the United States. The characteristic oval-shaped, yellow fruits, apart from their culinary use, are an important source of juice and flavouring for the soft drinks industry.

The main criteria for juice processing, on the other hand, are more straightforwardly that the fruit should be sound, of good quality, and of correct maturity. If the fruit producer has followed GAPs and the harvest and handling have been accomplished effectively, fruit arriving at the processing plant should be reasonably sanitary and of optimum quality, thus simplifying succeeding operations.

The following are the key manufacturing stages:
*Selection and preparation of raw material
*Juice extraction
*Filtration (optional)
*Batch preparation
*Pasteurization
*Filling and bottling

There are several methods to extract juice depending on the type of fruit used. The goal in juice manufacture is to remove as much of the desirable components from the fruit as possible without also extracting the undesirables.

Juice extraction equipment ranges from hand operated crushers to tonnes/hour mechanical extractors (Figure 6.5). With soft or comminuted fruit a cone screw expresser or paddle pulper fitted with appropriate screens serves to separate the juice from particulate matter.

In the separation of juice from its fruit, the traditional method has been to apply pressure to the mashed, or pulped, fruit in order to force the liquid portion through a cloth or some form of screen.

In the horizontal rotary press, mash is pumped into the press to partly fill the cylinder space. The piston then moves forward under hydraulic pressure to express the juice by consequently forcing it through the filter sleeves and along the channels in the drainage cores, to be fed through outlets in the specially designed plates for collection in a juice tank. The piston then withdraws whilst a second mash charge is received and the process repeats. During the pressing operation the endplate of the unit rotates with consequent meshing of the filter-lines, so that at the end of a pressing cycle the lines are loosely meshed together within the press-cake, or fruit pomace.

A thermal screw is a continuous system for both transporting and heating or cooling crushed fruit or whole small fruit. In a hot press regimen, the material passes directly from the crusher to the press holding tank via the screw, adjusted to deliver the crush at the proper temperature for enzyme activity, ~60ºC. In continuous pressing, the screw can even be slowed down enough to accomplish the holding time and then feed directly to the press (or to another feed/holding screw).

When the juice or pulp has been collected, it is necessary to prepare the batch according to the chosen recipe. This is very much a matter of choice and judgment, and must be done carefully to suit local tastes.

Clarification is an important processing step used by the lemon juice industry. Clarification is necessary in order to obtain a bright, clear product with low viscosity. Clarification of juice involves the use of bentonite gelatin and silica sol as fining agents.
Lemon juice processing

Manufacturing process of banana puree

The ripened bananas are peeled, traditionally by hand and more recently by using mechanical peelers.

Once the peels are separated the mashed bananas are passed through screens that vary in size and type, depending on whether or not a ‘deseeded puree’ is desired and are homogenized.

The next step, de-aeration, is one of the most important in determining the color of finished puree. During the aeration under vacuum, the air present in the puree is removed to a large extend.

After de-aeration, the puree is held under vacuum is a surge tank, form where it is metered into the aseptic process. For concentrated puree, a vacuum evaporation step is done at this point.

The sterile puree is finally cold sterilized. When canning banana puree, the puree is filled into cans with plastic film bag liners, sealed and stored (2-4 °C).

Production steps of processing
*Ripe banana
*Peel
*Homogenized
*De-aerated
*Vacuum Hold
*Aseptic process
*Concentration
*Aseptic filling

The major restriction in manufacturing banana puree is its tendency to brown rapidly. Procedures for overcoming the enzymatic browning involve:
*Heating the whole fruit to greater than 80 °C for 3 minutes to inactivate the polyphenol oxidase enzymes
*The ripe fruit is immediately processed
*The blanched puree for 30 seconds at ~90 °C with rapid cooling, can also be frozen in bulk

Banana puree is an important infant food. It is a good ingredient for bakery products and ice creams.

Banana puree also used as an ingredient for dairy dessert, bakery items, drinks, processed foods and sauces and as part of special diets in hospitals and nursing homes.
Manufacturing process of banana puree

Ice cream manufacturing

The details of the process vary from factory to factory according to the type of equipment and scale of manufacturer.

These are: mix preparation, which consists of dosing and mixing of the ingredients; pasteurization and homogenization; ageing; freezing and hardening.

Knowing a mix specification, mix calculations are performed to determine the amounts of desired ingredients needed to formulate the mix.

Mix processing begins with the assembly of the necessary ingredients in the desired amount.

In the next step is blending the ingredients. Mix blending can be performed at refrigeration temperatures 4 °C or at warmer temperatures 45 °C.

Freezing the mix is one of the most important operations in making ice cream, since the quality, palatability and yield of the finished product depend on proper freezing.

In the dynamic freezing step, cold, flavored ice cream mix enters the cylindrical freezer barrel and is chilled with a liquid refrigerant. The temperature of the mix entering the freezer is very important, 0 to -1 °C optimizing performance. The entry temperature of the mix should be constant to facilitate control of overrun and freezing rate.

At the end of freezing process, the ice cream is only partially frozen. The ice cream exiting the scrap-surface freezer is filled into packages, which are then sent through gardening step where additional ice is frozen and the cream becomes hard.
Ice cream manufacturing

Manufacture of cranberry sauce

Large amounts of cranberries are used to produce cranberries jelly and cranberry sauce, both retailed as canned products.

The forts can cranberry sauce was packed in Hanson, Massachusetts in 1919, about 100 years after cranberry cultivation began in North America.

In the manufacture of cranberry sauce, water, about twice, as much as fruit and about 0.3% of dispersed pectin are mixed together.

The mixture is then cooked to 102.2 ° C and evaporated in an open steam kettle to a soluble solids content of 65%. Citric acid solution is then added to bring the pH to 3.0 – 3.4.

Whole cranberry sauce should not be cooked to a point where it sets to a solid gel, but should flow slowly when poured into a dish.
Manufacture of cranberry sauce

Production of cottage cheese

Cottage cheese is a nutritious food product which when properly made and cared for, is valued highly by the consuming public.

In a vat, skim milk and a predetermined amount culture are added. The material is then heated, cooked and cured.

As soon as the desired acidity has developed, the curd is cut or broken and then cooked or heated until it is of the desired firmness.

Processing step of cottage cheese

The whey is drained and the curd is washed with water. The curds are washed 2-3 times with water to remove excess lactose and lactic acid, thereby stabilizing cord pH and to cool the curd.

The curd is mixed with a batch of dressing and is subsequently fed to the fillers. A popular type of cottage cheese is the mildly acid, large-grained product commonly known as low-acid rennet cottage cheese, or popcorn cheese or sweet curd cottage cheese.

The cooling/washing, drainage, creaming and packaging operations of commercial cottage cheese manufacture have undergone large-scale automation and semi-continuous multi-batch production is now normal practice.
Production of cottage cheese

Grape juice processing

In general grape juice production can be divided into four basic principal stages.
*Front end operation
*Juice extraction
*Juice clarification and refining
*Juice pasteurization and concentration

Grapes at the plant are first conveyed to a steamer which remove residual stems, leaves and petiole from fruit. After cleaning, grapes are crushed to facilitate juice extraction during the pressing step.

The crusher consists of several ruffled rotary rollers that break the berries while they are passing through. In most commercial operations, the continuous pressing method is used. Hot pressing is appropriate for deeply pigmented grape where maximum color extraction is desired.

Whereas, the immediate or cold press procedure is necessary to maintain the initial color of light colored grapes.

Additional enzyme treatment is required before the juiced is further processed For concentration it is necessary to complete the de-pectinization process to preclude gelation of the concentrate once produced.

For bottled juice, de-pectinization speeds and simplifies polish filtration and clarification prior to bottling.

Juice may be concentrated by evaporation or freeze concentration. It is desirable to heat the juice for as short a time as possible and to rapidly cook the product in order to minimize the effect on flavor, aroma and sugar concentration.
Grape juice processing

Manufacturing of mango flakes

Mango flakes are produced using drum-drying technology. The drum drying technique has been used for drying pulps or purees from fruits and vegetables. The drums were heated internally by steam under pressure. Spacing between the drums was adjusted to maintain the desired thickness of material deposited on the surfaces of the drum.

Drum drying of mango puree is an efficient, economical process for producing dried mango powder and flakes.

The production of drum dried mango flakes involves blending mango pulp with small amounts of wheat flour and sugar.

The material to be dried was fed into two counter-rotating drums. The homogenized mixture is dried during an atmospheric double drum dryer (50-60 psi).

As the drum rotated, water is evaporated from the thin layer of material on the surface and a scrapping blade is positioned to remove the dried material form the drum surface.  Flakes can be milled and screened into mango powder.

The important processing variables are drum speed, steam pressure, drum temperature, initial moisture content, and the spacing between drums.
Manufacturing of mango flakes

Tea processing

A cup of infusion of made tea is completely different from infusion of fresh tea flushes in color, taste and favor. These characteristics are developed during the manufacturing process after the harvesting of tea flushes.

Black tea is the major kind of tea consumed in the world. The traditional process for the manufacture of black tea may be broken down into stages called:
*Plucking or harvesting

*Withering – this process results in disrupting the cell structure of the leaves and initiation of the fermentation process.

*Leaf maceration or rolling. Rolling of tea leaves originally done manually, whereas nowadays is performed by machines.

*Fermentation

*Firing or drying. This process is to stop the fermentation and to reach the favorable moisture content to suppress microorganism growth.

*Sorting and packaging

The entire tea manufacturing process, from plucking through drying, is usually completed in 6 to 24 hours, depending on climatic conditions and the type of manufacturing equipment employed.

Green tea is made by a process similar to that used for black tea manufacturer except that the fermentation stage is drastically altered by steaming at high temperature the a flush prior to the maceration stage, causing the enzymes in the flush to be inactivated (de-enzyming or fixation).

The basic manufacturing processes of oolong tea include sunlight withering, light rolling, de-enzyming, rolling and drying. The plucking standard for Oolong tea is different from other kinds of tea. It is recommended that shoots with one bud and three to four leaves be plucked.
Tea processing 

Formulations and Processing

Formulations and Processing
For many food products, processing is an important way to preserve the product. However, for some food products, many self-preserving factors, such as the ingredients and their natural properties, play a role.

Three good examples of pickles, barbeque sauces and hard candies. Preserving pickles is not difficult of the end product is very sour (acidic) or tasty. Traditionally, barbeque success have a long shelf life because of the high content of sugar.

Most unwrapped hard candies keep a long time, assuming the environment is at room temperature and not very humid.

Most wrapped hard candies last even longer if the integrity of the wrappers is maintained.

For baked products (cookies, bread), measures against spoilage take second place to consumer acceptance of freshness.

So the objectives of processing vary with the products.

For a processed food products, it is assumed that the processor has a formula to manufacture the product.

In countries all over the world, small family owned food business usually start with home recipes for popular instead of a scientific formula. Most of us are aware of the similar humble beginnings of major corporations manufacturing cola (carbonated), soft drinks, cheeses, breakfast cereal and many others.

When this family business started, there was not much science or technology involved. When a company becomes big and has many employees, it starts hiring food scientists, food technologists, and food engineers to study the “recipe” and refine every aspect of it until the entire manufacturing process is based on sound scientific, technical and engineering principles. After that, all efforts are directed towards production.

Even now, somewhere, a person will start making “barbecue sauce” in his garage and selling it to his neighbors.

Although very few of these starters will succeeds, this trend will continue, in view of the free enterprise spirit of the West.

Although any person can start manufacturing food using a home recipe, the federal government in the United States has partially or total control over certain aspect of the manufacturing processes for food and beverage formulas.

This control automatically affects the recipe, formulas or specification of the products.

Although the word “control” here refers mainly to safety, it is understood that it will affect the formulations to some extent, especially critical factors such as temperature, pH, water activity and so on.
Formulations and Processing