Glycerin Production: Processes and Methods

Glycerin, also called glycerol, is most commonly obtained by breaking down fats and oils through a process known as hydrolysis. This technique involves the decomposition of triglycerides, which are compounds formed from glycerin and fatty acids, into their base components: glycerin and fatty acids.

The key stages in glycerin production include:

Hydrolysis: Fats and oils, typically sourced from plants like soybeans or palm, or from animal fats like tallow, are subjected to hydrolysis. This step separates the triglycerides into glycerin and fatty acids.

Purification: The crude glycerin that results from hydrolysis contains various impurities. It undergoes purification steps, such as filtration and chemical treatments, to remove contaminants.

Distillation: After purification, the glycerin is distilled to enhance its concentration and purity. Distillation ensures that the glycerin meets the quality standards necessary for a variety of applications.

Decolorization: In the final stage, the glycerin may undergo decolorization to remove any remaining color impurities, resulting in a transparent, colorless liquid.

In addition to hydrolysis, glycerin can also be produced through the transesterification of triglycerides, a process commonly used in biodiesel production. This involves reacting triglycerides with an alcohol, like methanol, to yield glycerin and methyl esters, the latter being the biodiesel.

Another method for glycerin production involves the fermentation of sugars or starches, though this approach is less frequently used due to its lower efficiency and higher costs.
Glycerin Production: Processes and Methods

Canned meat

Canning is probably the most efficient meat preservation method. It ensures the destruction of pathogens and spoilage microorganisms and allows foods to be easily handled and transported.

Canned meats are immediately ready to serve and can be taken on outdoor trip, contrary to frozen foods that have to be thawed out first. Animals and insects cannot force their way through a can or the jar, so the safeguarding of food is easier.

The factors involved in the selection and sourcing of meat raw materials for canning have much in common with those involved in the choice of meats for other manufacturing purposes and indeed, for the supply of meat for retail sale.

The most important of these factors, along with process, are the identity of the meat (species form which it has been derived), its composition (fat content, collagen content, etc), its quality and its microbiological condition.

Perishable or pasteurization canned meats are cooked to an internal temperature of a least 150 °F, as required by federal inspection regulations. This result in canned products being frees from any public health hazard but does not result in complete destruction of all microbial contaminants.
Canned meat

Rice cleaning process

Modern rice mills perform the milling process mechanically, starting with cleaning the field-run grain and ending with milled rice which has been sorted into grades.

Cleaning is a material separation process. The objective is to separate undesirable foreign materials from the paddy and leave a cleaned paddy for storage and process. The paddy procured from the farmer may be dried, if necessary and stored in storage bins, and then it is cleaned with the help of paddy cleaners.

The removal of impurities from grain is essential to protect the subsequent milling machinery from unusual wear and tear as well as to improve the quality of the final product.

Rough cleaning precedes drying, which is usually done in upright continuous flow dryers with a concurrent flow of heated air. After cooling, the dried rice is cleaned by various separation methods to give rough rice or “paddy”.

The cleaning process involves
*scalping to remove sticks, mud lumps, etc
*bearding to remove the awns, culms and leaves
*monitoring or cleaning to remove sterile florets and any remaining foreign matter.
Rice cleaning process

Olives oil processing: Cold Pressing

After olives are harvested and cleaned within 72 hrs they must be crushed and made into a pulp. After that point, the pulp is cold pressed in the absence of light and oxygen and the oil expelled and bottled in opaque glass bottles.

In olive oil processing, cold pressed means that the olives or the press are not heated or treated with hot water. The maximum allowed temperature for extra virgin oil is 25 °C. Heat would give a higher yield of oil during the pressing, but would compromise the quality and flavor.

Cold press is very important for the first pressing of extra virgin olive oil. A cold press retains all the nutrient benefits of the raw fruit. Using this method 90% of the oil is extracted from the olives.

An olive oil extracted from the first cold press of unripe green olives, characterized by having a high level of astringency. Good quality oil is fragrant with a fine taste, free of sharpness and acridity.
Olives oil processing: Cold Pressing

Separating fat from milk

Most milk plants separate milk for standardization or the obtain cream for bottling purpose and skim milk for butter milk and cottage cheese.

A layer of cream will form on the top of fresh milk, as it comes from cow, if it is allowed to stand for twenty or thirty minutes. This known as gravity creaming and it was very important prior to the invention of the cream separator. For many years it was customary to heat milk to 85 to 95 °F separation, because at this temperature the difference in density between the fat and skim milk is greatest and results in the most efficient separation of fat from skim milk.

Cream is separated form milk in a cream separator. Cream separator is a heavy metal bowl spinning at a very high speed which sediments the skim milk phase of incoming milk toward the wall of the bowl and displaces the cream inward along the centre of the bowl.

The cream and skim milk can then be recombined in desired ratios to obtain low-fat, light and whole milk with 1%, 2% and 3.25% fat respectively. This standardization usually is performed in a continuous manner.
Separating fat from milk

Cleaning in place (CIP)

Today, in many food industries, cleaning in place (CIP) is not only a cleaning method but a strategic decision built into the design of the plant and its individual parts.

Among the advantages of CIP:
*Permit on-site cleaning
*Substantial increases in processing capacity
*Reduced losses through the application of CIP cleanable automated vales and highly automated process
*Minimizes downtime
*Improved quality of all products and significant improvement in perishable products
*Reduced labor for both processing and cleaning

An additional advantage is that the cleaning agent/solvent quantities necessary for CIP is less than for conventional cleaning.

Basically CIP is a hydrodynamic cleaning process where rinsing, cleaning and sanitizing fluids circulate along with the path of the products and provide the detergency as well as the mechanical action needed for the removal of soil, without dismantling the line.

It is an economical method of maintaining the processing line at peak performance and extending it operating life. It is recommend that regular CIP cleaning is included in the preventive maintenance program to maximize processing performance and minimize the system operating costs and overall maintenance cost.

With its controlled, monitored, documented and reliably reproducible cleaning result, CIP fulfills the GMP (good manufacturing practices) requirements.
Cleaning in place (CIP)

Canned pineapple processing

Four cultivars account for the majority of pineapples used for canning: Cayenne, Singapore, Queen and Red Spanish.

Good-quality canned fruit is only attained when the fruit is just ripe, and every step is taken to process with least possible delay.

Harvested pineapples are unloaded from bulk bins at the cannery and, each pineapple is washed and graded for size to determine where the fruit will be sent.

The pineapple is then sent through a Ginaca machine that has been adjusted for a proper fruit size. This machine is entirely automatic and removes the inedible portion of the fruit from the edible parts.  This machine removes the shell, cores the fruit, and trims about 1.3 cm of the bottom and 1.9 cm at the top, greatly simplifying these operations. The final operation of the Ginaca machine removes the core from the centre of the fruit.

The rest of the pineapple is sent to be crushed into juiced and/or processed into livestock feed. Meanwhile, the fruit cylinder is inspected and hand trimmed to remove any defects or eyes, which may have escaped the first operation.

The fruit is then cut into slices, chunks, tidbits or crushed pieces or is pressed onto juice depending on its processing line destination.

Pineapple slices are usually graded and manually packed in cans. Sugar s added to the final product, which ensures certain homogeneity. Slices that have been cut either too thick or too thin, and broken pieces not good enough for canning as slices, are used in crushed pineapple or juice.

The cans are then sealed and cooked at 211 ° F for 11 minutes in a pasteurization process.

Notes:
*Slices or spiral slices or whole slices or rings: uniformly cut circular slices or rings cut across the axis of the peeled, cored pineapple cylinders.

*Tidbits: reasonably uniform, wedge-shaped sectors cut from slices or portion thereof, predominantly from 8 to 13 mm thick.

*Chunks: short, thick pieces cut from thick slices and/or form peeled cored pineapple and predominantly more than 12 mm in both thickness and width, and less than 38 mm in length.

*Ginaca machine is named after the man who invented it.
Canned pineapple processing

Vegetable processing

It is necessary to process green vegetables to preserve them for a year-round food source.  The most common commercial method of preservation is canning.  Canning is regarded to be a universal and economical method in food processing.

The principles of canning were first enunciated by Nicholas Appert in 1810, after many years of experiment and are essentially unchanged. For this process, the vegetables are cleaned, grading, heat blanching, peeling and coring, cut, packed into cans, sealed and heated to sufficiently high temperature (in the order of 240 ° F) to destroy spoilage and disease causing microorganisms. It follows by cooling, labeling and packing.

It is important for the food processor to control pH of the water added to the vegetable prior to canning. The vegetable may be canned whole, diced, pureed as juice and so on.

Vegetables are usually packed in liquid. Canner’s brine, a weak solution of sugar and salt, is ordinarily used for vegetables.
Vegetable processing

Process and uses of canned blueberries

Fresh ripe blueberries may spoil of left out at room temperature for a day or more, but they will keep for 2 or 3 days if stored without washing in a covered container in the refrigerator. Canned blueberries can be light or heavy syrup packed or water packed.

Blueberries can be canned, mostly used for pie fillings, are cleaned and inspected, placed in cans, and the cans are then filled with water or with a 10-30% sugar solution to cover the head space.

The open cans are the exhausted or heated in free-flowing steam for 10 minutes, and finally sealed and heat process at about 93-95 °C with 25-30 minutes holding time.

The packing syrup from canned or frozen berries usually has picked up much of the color and flavor form the fruit. Hence, it may be used as a flavoring or a syrup for ice-cream sodas and sundaes, milk shake, mixed drinks, pancakes and waffles.

Compared with other fruits, canned blueberries are an excellent source of iron, fair sources of vitamin A, about average in protein fat and calcium and low in phosphorus.

Canned blueberries packed in water are low in calories and carbohydrates because they contain only about two-thirds the levels of the nutrients that are supplied by the raw fruit.
Process and uses of canned blueberries

The reasons of hydrogenation process

Hydrogenation is a major type of chemical process. Hydrogenation of triglyceride oils may be defined as the reaction of the carbon-carbon double bonds of the fatty acids with hydrogen. The reaction is carried out in the presence of a catalyst, to form a solid or semi-solid mixture.

Consequently the fatty acid become saturated and thus, less prone to oxidation and attain a high melting point.

The first patent for the hydrogenation process was by William Norman in 1903. The process has affected the whole food industry because the lipid by-product from the manufacture of high-protein feeds from soybeans, cottonseeds, etc.

The hydrogenation process is an important tool for the edible fats and oils processor. With hydrogenation, liquid oils can be converted into plastic or hard fats more suitable for a particular food product.

The purpose to hydrogenate fat or oil:
*To change the physical form for product functionality improvement
*To improve oxidative stability

It is a complex process, requiring the right catalyst type and quantity, the right combination of process conditions and the optimum processing time, reflecting upstream and downstream, capacity; it is mass transfer limited.

Hydrogenation is used to convert liquid oils to semi-solid plastic fats that are suitable for margarine, shortening and specialty products.
The reasons of hydrogenation process

Processing of Honey

Processing of Honey
The processing of honey may be very simple e.g. in the case of a hobby operation, or extremely complex involving a great deal of technology tailored to each individual honey type.

Most processing however is concerned with liquefying and straining (or filtering) honey.

Both of these operations usually require some application of heat to the honey. The heat has the dual effect of removing crystallization in natural honey, and to reduce the viscosity.

Both of these things are required to provide a product that can be cleaned and further processed for creamed honey or just filled into jars as liquid honey.
Processing of Honey

Canning of fish

Canning is a method of storing food in airtight containers in a way that destroys potentially harmful microorganisms such as bacteria.

Most canned fish products are composed of ingredients that result in finished product with pH above 4.6 and water activity greater than 0.85.

These characteristics result in canned fish products being considered ‘low-acid canned food’. Canned fish have a shelf life of one year while frozen, oily fish should be used within two months.

Processing of Fish Canning 

Canned fish is conventionally covered with a liquid such as brine, vegetables oil tomato sauce or other sauces.

The canning process depends on the size of the fish. Small fish species such as sardines and pilchards are generally canned whole, with only the heads and tails removed. These whole-fish products are cooked in the can after it has been filled with brine or oil.

Canned fish is that it’s already cooked and ready for many easy dishes such as fish cakes, quiche, loaf, salads, sandwiches and appetizers.
Canning of fish

Ingredients for making fondants

Fondant, a mixture do sucrose, corn syrup and water, is a simple candy. Fondant used extensively in the candy and baking industry, the additive used is invert sugar.

When making fondant, accurately measuring the ingredients is important because changing their ratios greatly affects the texture of the fondant.

Ingredients: ½ cup softened butter, ½ cup corn syrup, ½ teaspoon salt, 1 teaspoon vanilla extract and 2 cups confectioner’s sugar (shifted).

The process of making fondant consists of cooking a mixture of the ingredients, cooling to 38° C to 54 ° C, then agitating it until it crystallizes.

In the baking industry, fondant is used in the preparation of high quality icings. It imparts humectants qualities to the icings, but at the same time, it provides a highly desirable sheen or luster to the finished products.

Adding flavoring to fondant can help make an otherwise bland icing a little more palatable. Adding color to it makes the cake more vibrant and visually interesting.
Ingredients for making fondants

Drum dryer operation

The drum dryer is a continuous contact dryer widely used in the food industry for drying products initially in liquid form.

It is highly flexible equipment consists of one or two horizontally mounted hollow cylinders made of high-grade casts iron or stainless steel, a supporting, a product feeding system, a scrapper and auxiliaries.

The variety of feed arrangements available ensures that solution, suspension and pastes with a wide range of viscosities can be dried.

In drum drying, a thick film of feedstock is applied to the external surface of a heated drum which rotates slowly about its horizontal axis.

The feed can be pre-concentrated and preheated to reduce the drying load but there is a limit to the feed concentration beyond which the sheet may not form well.

In operation steam at temperature up to 200 °C heats the inner surface do the drum. The moist material is uniformly applied in a thin layer (0.5 - 2mm) onto the outer drum surface.

The layer of material remains attached to the drum for about 80% of a revolution drum which time moisture evaporates and leaves behind a layer of solids, which is subsequently removed from the drum surface by a scrapper or doctor knife.

There are many types of drum dryer available:
*Atmospheric double drum dryers
*Atmospheric single drum dryers
*Atmospheric twin drum dryers
*Enclosed drum dryers
*Vacuum Double drum dryers

The single-drum comprises only one roll. A double drum dryer comprises two rolls, which rotate toward each other at the top.

By using the drum dryer, the products have a good porosity and hence good rehydration due to boiling evaporation.

Drum dryers also can dry viscous foods, such as pastes and gelatinized or cooked starch, which cannot be easily dried with other methods.
Drum dryer operation

Coffee process of roasting

Green beans smell green earthy, so they must be heat treated in a process called roasting to bring about their truly delightful aroma.

Coffee beans are usually roasted in large batch dryers which spin and heat them evenly at temperatures that reach 550° F. In the USA continuous roasting of beans is the common method, using fluidization of beans in a perforated cylinder with a horizontal airstream.

The process consists of roughly three stages lasting about six minutes altogether: begin roasting, end roasting, quenching. During roasting heat is transferred by contact of the beans with the walls of the roasting apparatus or by hot air or combusted gases.

The bean is warmed intensely to drive off free and bound moisture which constitute about 12% of initial weight. During the roasting process, about 20 percent of the water content of the green beans evaporates and carbon dioxide escaped. They are accompanied by some carbon monoxide and organic volatiles.

The bean’s starch content is converted to sugar. The volatiles oils and acids that gave coffee its tempting aroma and delicious flavor are developed during the roasting process.

The roasting process is terminated at the desired flavor, indicated by the darkness of color.

When the desired degree of roast is reached, the beans have to be cooled down rapidly by water quenching or cold air in order to stop further changes in color, flavor and volume. Normally the product is discharged into an air cooler for rapid cooling to 104° F.
Coffee process of roasting

Heating in food processing

Heat Processing
The development of the modern eating process started in France during the first decade of the 1800s by Nicholas Appert who preserved foods in sealed glass jars in boiling water

In 1819, William Underwood of the United States started the first canning factory in Baltimore.

But to preserve foods in boiling water took too long, requiring about 6 hours, so salt was added to the water bath which increased the boiling temperature, thereby shortening the processing time.

However salt corroded the cans so the next innovation was to heat in steam under pressure. The higher the pressure, the higher the temperature and the shorter the processing time.

These early pressure chambers evolved into the modern retort.
Heat Processing

What is happening during baking?

Baking is a complex food process with many ingredient and process interactions. Most bakery items are made of the same ingredients: flour, water, sugar, eggs, leavening agents and fat.

The transition from raw materials to baked product is most often referred as being a change from foam to a sponge.

Browning reactions, gelatinization of starch, and denaturation of protein are some of the key biochemical processes involved in baking.

The activity of baking includes takes like mixing the batter, preheating the oven, putting the pan in the oven and taking the cake out of the oven at the right time.

Baking begin with its most elementary ingredient: wheat flour. Its special properties allow bakers to produce an astonishing array of products from pastry to cakes and cookies.

When mixing, batters and dough trap pockets of air as paddles and whips push through them. With continued mixing, large air pockets are reduced in size to many more smaller ones, providing the ‘nuclei’ that expand during baking into full-sized air cells.

A gluten structure of wheat allows dough to hold steam or expanding air bubbles, so that yeasted dough can rise and puff pastry can puff.

Salt does not only help regulate yeast fermentation but also strengthen gluten and makes it more elastic. 

Solid fats mixed into a dough or batter trap air, water and some leavening gases. When the fats, melt, these gases are released and the water turns to steam, both of which contribute to leavening.

Different fats have different melting points, but most fats used in baking melt between 32 ° and 55° C. Gases released early in baking are more likely to escape because the structure isn’t set enough to trap all of them.
What is happening during baking?

Roasting

Roasting is often used when preparing succulent meats such as ham roast, crown roast, tenderloins, turkey and rubs.

Roasting is often associated with festive times such as holidays or special occasions.

It is a dry heat method. No water is used, and the meat is not covered, so steam can escape. In principle, roasting meats is a simple procedure. The prepared cut meat is placed in an oven at a selected temperature and it is removed when done.

During roasting a crust is formed on the surface, which preserves the internal part from too sudden or violent a degree of heat and also prevents the draining away of its juice.

Historically, roasting meant cooking meat over an open fire. As time evolved, and the concept developed, meat was impaled onto a spit that turned over the flame.

The Brits perfected this technique in the 18th century one of their culinary claims to fame. Salt added to the surface of meat just before roasting will penetrate the meat only a fraction of an inch during cooking.

The same is true of the flavors of the herbs, spices and aromatics.
Roasting

Process of Milk Pasteurization

Process of Milk Pasteurization
Pasteurization, named after Louis Pasteur (1622-1895), its originator, was originally used to treat wine and beer, but soon came into use to treat milk as well, when it found that heating milk for a short time to below its boiling point killed microorganisms.

Pasteurization destroys 100 percent of pathogenic bacteria, yeasts and molds and 95 to 99 percent of other, nonpathogenic bacteria.

The process of pasteurization also inactivated many of the enzymes that cause the off-flavors of rancidity.

In the United States pasteurization was championed by Alice Catherine Evans (1881-1975), a microbiologists who worked for the US department of Agriculture.

Evans suffered from a disease known as brucellosis (undulant fever) and in 1918 she discovered that brucella, the bacterium that caused her disease, could be found in cow’s milk.

Scientists eventually determined that brucella was not the only milk borne bacterium. Milk can harbor other bacteria – such as E. coli, salmonella, and listeria – which can cause harmful and even life threatening infectious in the young, the old, pregnant women and the infirm.

Indeed, unpasteurized cow’s milk was a very common cause of tuberculosis, typhoid fever and salmonellosis.

Evans advocated on behalf of pasteurization for years after her discovery. Finally in the 1930s, milk pasteurization became mandatory under US law.

The advantages to be derived from pasteurization vary with the conditions under which the milk is produced and the efficiency with which the work is conducted.

If the milk comes from dairies where disease and uncleanliness prevail, pasteurization will prolong the keeping quality of the milk and also materially lessen the danger from disease germs.

If on the other hand, healthfulness and cleanliness receive the exacting attention which prevails on certified dairy farms, nothing can be gained by subjected milk to the pasteurizing process.
Process of Milk Pasteurization

Processing of Butter

Processing of Butter
Butter is produced by concentrating the milk found in cream, either through churning (causing the fat to flocculate) or through centrifugal processing.

Much of butter manufactured today derives from whey cream. Whey cream has a more pronounced flavor than that of fresh cream and its use is thus favored in lower quality, more flavorful grades of butter. However, it is also commonly used in the production of Grade AA butter.

Butter is often flavored with lactic acid, cultures, diacetyl, or started distillate.

Butter processing begins with the clarification and separation of milk. Cream with a concentration of 30 to 45 percent milkfat (depending on the method of churning) is then pasteurized and cooled.

For vat pasteurization the cream is normally pasteurized at 74 degree Celsius for 30 minutes; for the high temperature short time method cream is pasteurized at 85 degree Celsius for 15 seconds.

These pasteurization temperature are higher than those for fluid milk because of the higher fat content of the cream, and to help lengthen butter’s shelf life.

The cream is not homogenized since that would make churning more difficult.

After the cream is cooled, it is pumped into a conventional churn where it may be mixed with anotto yellow coloring. The cream is then churned until butter granules are formed.

The butter milk is drained and washed from the butter granules, salt is added and the butter is worked to a smooth, creamy consistency.

The butter is then packaged by a print machine, which mold it into sticks, wraps it, and packages it.
Processing of Butter