Maltodextrins are used in a wide array of foods, from canned fruits to snacks. Maltodextrins may also be an ingredient in the single-serve, table-top packet of some artificial sweeteners.
Corn syrups enriched with fructose are manufactured from syrups that have been treated to contain as much dextrose (glucose) as possible. Nearly all the glucose in these dextrose-rich corn syrups is transformed into fructose with enzymes. The fructose-enriched syrups are then blended with dextrose syrups. After blending, commercial fructose corn syrups contain either 42% or 55% fructose by weight.
The generic term high fructose corn syrup or its acronym HFCS is used in food and beverage ingredient statements.
The vast majority of the high fructose corn syrup containing 55% fructose is used to sweeten carbonated soft drinks and other flavored beverages. Minor amounts are used in frozen dairy products. Essentially all foods listing high fructose corn syrup as an ingredient contain the syrup with 42% fructose. The 95% fructose corn syrup is becoming more common in beverages, canned fruits, confectionery products and dessert syrups.
Crystalline fructose is produced by allowing the fructose to crystallize from a fructose-enriched corn syrup. The term crystalline fructose is listed in the ingredient statements of foods and beverages using this corn sweetener. It is important to understand that the crystalline fructose listed as an ingredient comes from cornstarch, not fruit.
Crystalline fructose can be used in the same foods as the high fructose corn syrups, or in any food that contains sugar.
Juice concentrates may be used to directly replace sugar. These syrups are made by first heating fruit juices to remove water, and then treating with enzymes and filtering to strip all characteristic color and natural flavor from the original juice. Because of their bland initial color and flavor, grapes and pears are the primary sources of the juice concentrates used as sugar replacers. Juice concentrates that replace sugar contain traces of sucrose, and variable amounts of fructose and glucose.
Juice concentrates are used in any foods where corn syrups have replaced sugar. They are particularly prominent in baked goods, jams and jellies, and frozen confections.
SUGAR ALCOHOLS
The common sugar alcohols sorbitol, mannitol, maltitol, erythritol, and hydrogenated starch hydrolysates are manufactured from cornstarch. Xylitol, another common sugar alcohol, is manufactured from such sources as corn cobs, sugar cane bagasse (stalk residue remaining after sugar extraction), or birch wood waste. Isomalt and lactitol are becoming more common and are manufactured from sucrose and whey, respectively. Isomalt and lactitol are commonly called bulk sweeteners because their sizes are nearly the same as sugar. Sugar alcohols are sometimes referred to as polyols, a generic term that represents a family of different products, not a unique single ingredient.
Although small amounts of sorbitol are present is some fruits, the commercial source of sorbitol is the dextrose (glucose) produced from cornstarch. Sorbitol is manufactured by hydrogenating (adding hydrogen) the recovered dextrose. While another name for sorbitol is glucitol (resembling glucose), sorbitol is the term used by the food industry. Sorbitol is about 60% as sweet as sucrose, and is considered to have 2.6 calories per gram.
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Sorbitol is used in hard and soft candies, flavored jam and jelly spreads, baked goods and baking mixes, chewing gum and cough drops.
Mannitol is widespread in nature, being present in the fruit, leaves and other parts of various plants. Strawberries, celery, onions, pumpkins and mushrooms are particularly good sources.
Commercially, mannitol is manufactured from fructose. Today, the source of fructose is cornstarch. Prior to the commercialization of starch hydrolysis, mannitol was produced from the fructose component of invert sugar. During hydrogenation (hydrogen addition), the fructose molecule rearranges to the sugar mannose. That is why this sugar alcohol is called mannitol. Mannitol is about 60% as sweet as sucrose, and is considered to have 1.6 calories per gram.
Mannitol is used in hard and soft candies, flavored jam and jelly spreads, confections and frostings, chewing gum and cough drops.
Maltitol is manufactured by hydrogenating maltose, the glucose-glucose disaccharide (two sugars) derived from cornstarch. The use of maltitol in food is approved in most countries including Canada, Europe, Australia, New Zealand and Japan.
Maltitol is about 90% as sweet as sugar. This feature makes it attractive to the food manufacturer as a one-for-one replacement of sugar.
Maltitol is used in the same food categories approved for sorbitol and mannitol.
The singular term hydrogenated starch hydrolysate is applied to a family of polyol products. Hydrogenated starch hydrolysates (HSH) are produced by the partial hydrolysis of starch corn being the most prominent and the subsequent hydrogenation the various starch fragments (dextrins). In practice, hydrogenated starch hydrolysate is used to describe products that contain more hydrogenated dextrins than sorbitol or maltitol.
This expansive term hydrogenated starch hydrolysate does not identify the primary polyol used in the food. However, if a HSH contains 50% or more sorbitol, for example, it can be labeled as sorbitol syrup. The same would also be true for the labeling of maltitol syrup.
Hydrogenated starch hydrolysates are 20% to 50% as sweet as sugar. HSH sweetness depends on its particular composition. For example, a HSH containing more maltitol would be sweeter than one containing more sorbitol.
Hydrogenated starch hydrolysates can be used in the same types of products that use the other common sugar alcohols. HSH products are generally blended with other sweeteners, both caloric and artificial.
Erythritol is the newest sugar alcohol to be manufactured from cornstarch. Unlike sorbitol, maltitol or hydrogenated starch hydrolysates, erythritol is produced by a fermentation process.
Erythritol is approximately 70% as sweet as sucrose, supplies about two-tenths of a calorie per gram, and has a mild cooling effect in the mouth. Erythritol is used mainly in confectionery and baked products, chewing gum and some beverages.
Xylitol has approximately the same sweetness as sugar. Xylitol provides the greatest cooling effect of any of the sugar alcohols. Xylitol has a pronounced mint flavor. These characteristics make xylitol the polyol of choice for sugar-free chewing gums, candies and chewable vitamins.
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The main application is foods formulated to meet the dietary needs of diabetics.
Isomalt is manufactured from sugar. The fructose portion of sugar is converted to equal amounts of sorbitol and mannitol. The glucose portion is unchanged. Thus, isomalt is a mixture of two disaccharides, glucose-sorbitol and glucose-mannitol.
Isomalt is about half as sweet as sugar and, unlike most polyols, produces no cooling effect in the mouth. Isomalt is considered to have 2 calories per gram.
Because the original glucose fructose bond remains, isomalt can be heated with no loss of sweetness or change in texture. While isomalt can provide nearly the bulk that sugar gives, baked products containing isomalt tend to be crispier and do not brown the same when heated.
Isomalt is used in hard and soft candies, chocolates, ice cream, jams and preserves, baked goods, fillings and fondants, chewing gum and cough drops. Isomalt may be mixed with an artificial sweetener to bring the level of sweetness up to what it would be if sugar were used.
Lactitol is manufactured from whey, the lactose (milk sugar) rich by-product of cheese making and processed dairy foods. Lactitol is slightly less than half as sweet as sugar and is considered to have 2 calories per gram.
Lactitol is used in a wide range of reduced-sugar or sugar-free foods, from baked goods and frozen dairy desserts to candies, chocolate confections and preserves. Lactitol is often mixed with artificial sweeteners.
In laboratory studies, lactitol has been shown to promote the growth of the two bacteria recognized to improve the health of the large intestine. As a result, the prebiotic potential of lactitol is sometimes highlighted for the foods using this sugar replacer.
SUGAR PRODUCTION AND THE MULTIPLE EFFECT EVAPORATOR
Sugar cane had been planted as early as 1750 near New Orleans, but with only limited success. By the 1790s, interest in sugar revived. Production rose steadily thereafter, and by 1830 Louisiana was producing over 33,000 tons of sugar annually.
Sugar cane is normally harvested in the fall. After cutting, the cane is milled to produce sugar cane juice. Originally animal power was used to grind the cane; by the 1830s, steam power began to replace animal power. In either case, the cane juice was boiled in four large open kettles arranged in a kettle train. Each kettle was of different size, and the kettles were arranged from the largest, which held up to five hundred gallons, to the smallest. The first kettle, the largest one, was called the grande, the next the flambeau, then the sirop, and finally, the smallest, the batterie.
Norbert Rillieuxs great innovation was his understanding of how latent heat could be used repeatedly in processing sugar. The result was his Multiple Effect Evaporator under Vacuum, which one expert, John Heitman in The Modernization of the Louisiana Sugar Industry, 1830-1910, called "the premier engineering achievement in nineteenth-century sugar technology."
Rillieux utilized the latent heat produced from evaporating sugar cane juice by employing a series of three or four closed evaporating pans in which vapor was piped out of each pan to heat the juice in the next, with the vapors in the end going to a condenser. At the same time, pressure in the system was reduced by pumps, which created partial vacuums and lowered the boiling point of the liquid. A description of the inventions design is given in Rillieuxs 1846 patent:
A series of vacuum pans, or partial vacuum pans, have been so combined together as to make use of the vapor of the evaporation of the juice in the first, to heat the juice in the second and the vapor from this to heat the juice in the third, which latter is in connection with a condenser, the degree of pressure in each successive one being lessThe number of sirup-pans may be increased or decreased at pleasure so long as the last of the series is in conjunction with the condenser.
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Rillieuxs invention allowed for the production of better quality sugar with less manpower and at reduced cost. One of the major economies was the conservation of fuel, because wood was needed to heat only the first chamber. Each successive chamber used the latent heat released by steam from the preceding chamber.
Sugar manufacturers around the world in Cuba, Mexico, France, and Egypt, as well as the United States, adopted Rillieuxs evaporator. Moreover, the device was not limited to sugar production but came to be recognized as the best method for lowering the temperature of all industrial evaporation and for saving large quantities of fuel. Multiple effect evaporation under vacuum is still used in sugar production as well as in the manufacture of condensed milk, soap, glue, and many other products.
The Rillieux evaporator was one of the earliest innovations in chemical engineering and remains the basis of all modern forms of industrial evaporation. He was successful because he understood the principles of thermodynamics and latent heat and applied that knowledge to the technical needs of the sugar industry.
SUGAR IN JELLIES AND PRESERVES
Gelling
Sugar is essential in the gelling process of jams, preserves and jellies to obtain the desired consistency and firmness. This gel-forming process is called gelationthe fruit juices are enmeshed in a network of fibers. Pectin, a natural component of fruits, has the ability to form this gel only in the presence of sugar and acid. Sugar is essential because it attracts and holds water during the gelling process. In addition, acid must be present in the proper proportions. This optimum acidity is a pH between 3.0 and 3.5. Some recipes include lemon juice or citric acid to achieve this proper acidity.
The amount of gel-forming pectin in a fruit varies with the ripeness (less ripe fruit has more pectin) and the variety (apples, cranberries and grapes are considerably richer in pectin than cherries and strawberries). In the case of a fruit too low in pectin, some commercial pectin may be added to produce the gelling, especially in jellies. In recipes that use commercial pectin, the proportions of sugar may be slightly higher or lower than the one part fruit to one part sugar ratio.
Preserving
Sugar prevents spoilage of jams, jellies, and preserves after the jar is opened. Properly prepared and packaged preserves and jellies are free from bacteria and yeast cells until the lid is opened and exposed to air. Once the jar is opened, sugar incapacitates any microorganisms by its ability to attract water. This is accomplished through osmosis (the process whereby water will flow from a weaker solution to a more concentrated solution when they are separated by a semi-permeable membrane). In the case of jellies and preserves, the water is withdrawn from these microorganisms toward the concentrated sugar syrup. The microorganisms become dehydrated and incapacitated, and are unable to multiply and bring about food spoilage. In jellies, jams and preserves, a concentrated sugar solution of at least 65% is necessary to perform this function. Since the sugar content naturally present in fruits and their juices is less than 65%, it is essential to add sugar to raise it to this concentration in jellies and preserves.
Color Retention
Sugar helps retain the color of the fruit through its capacity to attract and hold water. Sugar absorbs water more readily than other components, such as fruit, in preserves and jellies. Thus, sugar prevents the fruit from absorbing water which would cause its color to fade through dilution.
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EXTRACTION OF JUICE
The oldest method of extracting juice consists in subjecting the crushed fruit to pressure in such a manner that the fruit flesh remains behind in the press and the juice flows free. The fruit may be crushed by either grater or hammer mills which reduce the fruit to a coarse pulp from which the juice may be pressed readily. Certain fruits such as grapes yield juices of improved quality if they are heated before pressing.
The crushed fruit is wrapped in a heavy, coarsely woven press cloth to form a cheese. Pressure is commonly applied by a hydraulic press.
Crushing or heating followed by pressing are commonly used in the preparation of apple and grape juice and yield products relatively free from insoluble suspended matter. A somewhat different product results from utilization of a more recently developed type of press which is continuous in operation. In this type, a combined crushing and pressing action forces the fruit into contact with screens under comparatively gentle pressure. The most desirable machines, on the basis of flavor, color and vitamin retention in the juice, are those which reduce to a minimum the contact of juice with air. Another method for extraction of juice from fruit having a firm texture consists in passing the fruit through disintegrating machines which reduce it to a very fine pulp before pressing. Juice high in suspended solids results from this process. This method is used very successfully in preparing pineapple juice.
A specialized type of equipment is required for extracting citrus juices to avoid the inclusion in the juice of peel oils which give an undesired flavor.
After extraction, fruit juice is strained or screened when necessary to remove seeds and other objectionable solids which may present. Screens are preferably of the self-cleaning type such as rotating, inclined cylindrical screens, or vibrating screens.
WINE-MAKING
Wine- making was practiced in ancient Greece. It was dark and usually drunk with water. It was kept in casks, goatskins and stoppered with oil or a greasy rag; air was working on it all the time. The full maturing of wine had been impossible until the bottle and the cork were generally used. Wine reaches its maturity in about three years; retained longer it may not improve and may deteriorate. Hocks were indeed kept in cask for 20 years until the end of the 18th century and considered to improve.
The proper use of wine bottles and corks seems to have become common toward the end of the 17th century; another important change was the discovery by accident in 1775, that grapes left to rot on the vines produced a sweetness and bouquet unobtainable in any other way. In the middle of 1750s the Madeira shippers first began to fortify their wines by adding a proportion of brandy to them. By that time vineyards were planted in Latin America, in South Africa, in North Africa, in France, in England and other places.
Wine is the fermented juice of the grapes. It is one of the most ancient fermentative industries. It is based on the alcoholic fermentation. Wine is made from grapes of the various form. The two main types of wine are red (made from black grapes only) and white is in fact yellow in colour and may be made from either black or green grapes. Less important are the rose (pink) wines, usually made by leaving the grape juice, called must, in contact with the black skins for a very short space of time, enough to extract only a little of the colour.
The main stages of wine-making are the following ones: preparation of grape juice, fermenting it with yeast, racking and aging. The grapes are crushed, the juice is separated from the crushed grapes by pressing them. Thus, the grape must is produced. After clarification it is ready for fermenting. The main change in the grape juice fermentation is the conversion of glucose and fructose into alcohol and carbon dioxide. It is done with the aid of pure culture yeast. They are called wine yeasts. The grape juice fermentation is conducted at the temperature of +15-25 C for 14-24 days. After the fermentation is completed a young wine is produced. It is separated from the yeast sediment and is stored in wooden vats for maturing. During aging the wine is cleared, racked for several times. Different types of wines are aged for different periods: from some months till some years.
RAW MATERIALS
Raw materials for fermentative industries include those rich in sugar and those rich in cellulose. Among raw materials of the first group mention should be made on barley, oats, maize, rye, wheat and rice. As to the chemical constitution of the raw materials mentioned above they contain carbohydrates, proteins, fats and ashy elements. Carbohydrates, i.e. starch, sugars, dextrin-like substances and cellulose are of particular importance for fermentative industries. Nitrogenous substances are important constituents of the cereals. Among them proteins are of particular importance. They have a significant influence upon malting and brewing processes.
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Potatoes are used as raw materials for ethyl alcohol production.
Grapes and molasses are raw materials rich in sugars. Grapes are used in wine-making. Grape juice contains glucose, fructose and sucrose (over 32% of sugar). Molasses is a by-product of beet sugar production and is used as the main raw material for ethyl alcohol and bakers yeast production. Molasses is a dark brown thick liquid. Its main constituent is sucrose. It also contains invert sugar and nitrogen. Wood pulp is the raw material for hydrolytic production. There some auxiliary materials which sugar and starch dont contribute. These are spices, coloring matters, blending agents imparting a pleasant aroma, colour and taste to the liquor. Hop is one of them. It is used in brewing.
YEASTS
Yeasts were used in ancient times in wine-making, in brewing and in the alcohol production. Yeast is a round or oval plant. It consists of one cell. Yeasts form a number of enzymes affecting the process of fermentation. There are two main kinds of yeasts: true and false or pseudo-yeasts. True yeasts are subdivided into three types of yeasts: bottom yeasts, top yeasts and distillery yeasts. The first two are culture plants. Wine and brewers yeasts refer to the bottom yeasts; distillery yeasts and bakers yeasts and some brewers yeasts relate to the top yeasts. The difference between the top and the bottom yeasts is in rapid fermentation of the top yeasts.
The top yeasts are separated on the surface as a thick foam which remains till the end of fermentation. They precipitate in a thin layer on the bottom of the fermenting vat.
The characteristic feature of the bottom yeasts is that they settle down in a thick layer on the bottom of the fermenter.
There are different species of yeasts. The main species of the top yeasts used in alcohol production are those having a great power of attenuation and producing large amount of alcohol. The top yeasts used in bakers yeasts production should propagate quickly and have a great dough raising power and good keeping qualities.
The bottom yeasts used in brewing should be quite pure and have a flocculating capability. The top yeasts used in wine-making are capable of suppressing other microorganisms and give to wine its bouquet.
FAO'S SMALL-SCALE MODULAR SLAUGHTERHOUSE
The Animal Production and Health Division of the Food and Agriculture Organization of the United Nations (FAO) has developed a model project for village meat industry in which one of the main components is a smallscale modular slaughterhouse. The design incorporates the use of locally available construction materials and unsophisticated equipment. The slaughterhouse can be built in modules, adding units to the central slaughterhall for operations such as byproduct utilization, meat preservation, processing and butchering. Designs have also been prepared for the construction of a meat market in order to facilitate the integration of production, processing and marketing.
It is intended that from the basic nucleus a number of small-scale industries be developed consecutively, e.g. meat preservation by low-cost technologies, traditional tanning, handicrafts based on hides, skin, bone and horns, etc. The objective is to increase employment, in particular for rural women, create market outlets for livestock products and increase the income of small producers.
The project could become a focus for farmer organization and a centre of technical assistance for producers. The organization of small producers is indispensable to ensure their participation and for the success and continuity of the project.
FAO is promoting the establishment of slaughterhouses of this type in some rural areas because this would increase the availability and quality of meat, improve the utilization of by-products, avoid rural migration and increase employment. The slaughterhouses may, therefore, constitute a tool for rural development, increasing the income level in the countryside and villages, thus improving the living conditions of the rural communities.
Rural slaughterhouses can also facilitate veterinary control of livestock (ante-mortem inspection) and carcass meat (post-mortem inspection). Slaughtering can be organized to follow a determined daily or weekly time schedule for which compulsory veterinary controls can be arranged. In addition, adequate technical facilities for efficient meat inspection can be provided, i.e. vertical position of the carcasses and special platforms for the personnel. Special hooks or inspection tables can be provided for the inspection of internal organs.
The detailed design for a small-scale modular slaughterhouse was developed by FAO. It includes designs, specifications, and schedule of quantities for a slaughterhouse and meat market suitable for small communities.
Provision is made for slaughter of all species: cattle (or buffalo), sheep, goats and pigs, though because of space limitations, concurrent slaughter of different species is not possible. The abattoir capacity will be dependent on the mix of animals being slaughtered. Daily throughputs of approximately 10 large stock (e.g. cattle) or 50 small stock (sheep, goats or pigs) or a combination thereof could be achieved with this design.
The facilities are divided into modules which can be combined as required to suit a particular location.
The following modules are included:
Lairage
Slaughter floor
Chiller
Tripe room
Meat cutting and processing room
Solid waste and blood disposal
Hides and skin processing
Effluent disposal
Electric light and power
Water supply
Meat market
PRINCIPLES OF MEAT DRYING
Drying meat under natural temperatures, humidity and circulation of the air, including direct influence of sun rays, is the oldest method of meat preservation. It consists of a gradual dehydration of pieces of meat cut to a specific uniform shape that permits the equal and simultaneous drying of whole batches of meat.
Warm, dry air of a low humidity of about 30 percent and relatively small temperature differences between day and night are optimal conditions for meat drying. However, meat drying can also be carried out with good results under less favourable circumstances when basic hygienic and technological rules are observed. Intensity and duration of the drying process depend on air temperature, humidity and air circulation. Drying will be faster under high temperatures, low humidity and intensive air circulation.
Reducing the moisture content of the meat is achieved by evaporation of water from the peripheral zone of the meat to the surrounding air and the continuous migration of water from the deeper meat layers to the peripheral zone (Fig. 6).
There is a relatively high evaporation of water out of the meat during the first day of drying, after which it decreases continuously. After drying the meat for three or four days, weight losses of up to 60-70 percent can be observed, equivalent to the amount of water evaporated. Consequently, moisture losses can be monitored by controlling the weight of a batch during drying.
Continuous evaporation and weight losses during drying cause changes in the shape of the meat through shrinkage of the muscle and connective tissue. The meat pieces become smaller, thinner and to some degree wrinkled. The consistency also changes from soft to firm to hard.
In addition to these physical changes, there are also certain specific biochemical reactions with a strong impact on the organoleptic characteristics of the product. Meat used for drying in developing countries is usually derived from unchilled carcasses, and rapid ripening processes occur during the first stage of drying as the meat temperature continues to remain relatively high. For that reason the specific flavour of dried meat is completely different from the characteristic flavour of fresh meat.
Undersirable alterations may occur in dried meat when there is a high percentage of fatty tissue in the raw meat. The rather high temperatures during meat drying and storage cause intensive oxidation (rancidity) of the fat and an unpleasant rancid flavour which strongly influences the palatability of the product.
Meat drying is a complex process with many important steps, starting from the slaughtering of the animal, carcass iming, selection of the raw material, proper cutting and pre-treatment of the pieces to be dried and proper arrangement of drying facilities. In addition, the influence of unfavourable weather conditions must also be considered to avoid quality problems or production losses. The secret of correct meat drying lies in maintaining a balance between water evaporation on the meat surface and migration of water from the deeper layers.
In other words, care must be taken that meat surfaces do not become too dry while there is still a high moisture content inside the meat pieces. Dry surfaces inhibit the further evaporation of moisture, which may result in products not uniformly dried and in microbiological spoilage starting from the areas where the moisture content remains too high.
SMOKED DRIED MEAT
Smoking of meat is a technique in which meat is exposed directly to wood smoke which may be generated by a variety of methods. In smoke produced from wood there are various substances which contribute to the flavour and the appearance of the smoked meat product and which have a certain preserving effect on the product.
However, the preserving effect of common smoking is not very significant when storing the product without a cold chain. On the other hand, intensive or prolonged smoking may considerably increase the shelf-life of the product, but it also has an unfavourable effect on flavour. Whereas a light smoke aroma generally enhances the organoleptic properties of the product, intensive smoking has a negative influence on the quality, especially in the case of prolonged storage in which concentrated smoke compounds develop increasingly unpleasant tarry flavours.
