Brandy

Brandy is produced by distilling wine.The wine can be made from other fruits, but when made from grapes, white wines are used as the base. The most well known brandy is Cognac, made from the Cognac district of France. In the United States, brandy must conform to a standard of identity that describes the starting fruit or juice, the ethanol concentration, the duration of aging, and other compositional and manufacturing details. Most American beverage-type brandies contain less than 50 ethanol...

Fish sauce microbiology

While it is evident that microorganisms are present during the production of fermented fish sauces, it is not clear to what extent these organisms contribute to the finished product. The microbial population in raw, unsalted fish and shellfish is high in number and rich in diversity. Considering the fact that whole unevis-cerated fish (guts and all) are usually used to make fish sauces, the initial load of organisms is significant. In addition, the manufacturing environment is not aseptic, and...

Biotechnology and the Brewing Industry

For the first 5,000 years that humans made and consumed beer, little was known about the actual scientific principles involved in its manufacture. Beer making was an art, practiced by craftsmen. Only in the last 150 years have biochemists and microbiologists identified the relevant organisms and metabolic pathways involved in the beer fermentation. In the past ten years alone, the entire genome of Saccharomyces cerevisiae (albeit, a lab strain, not an actual brewing strain) has been sequenced,...

Beer Manufacturing Principles

Only four ingredients are necessary to make beer water, malt, hops, and yeast. Despite its ancient origins and long history, and this seemingly short list of ingredients, the manufacture of a quality beer remains a rather challenging task. In part, this is because beer making consists of several different and distinct processes that are not always easy to control. In addition, some steps taken to improve one aspect of the process for example, filtering the finished beer to enhance clarity may...

Beer Spoilage and the Origins of Modern Science

Most fermentation microbiology students are aware that cheese, sausage, and other fermented foods evolved, in part, because these products had unique and desirable sensory characteristics. Likewise, they might also appreciate the many pleasant attributes of malted and hopped beverages. However, it is important to recognize that, while our ancestors undoubtedly enjoyed beer for many of the same reasons as today's consumers,they also understood that beer, like other fermented foods, was somehow...

Viticulture and Grape Science

The starting material for most wines, as noted above, is grapes.The main wine grape grown in temperate zones throughout the world is Vitis vinifera. Another grape, Vitis labrusca, grows well in northern regions in the United States and is frequently used for Concord varieties. It is important to note that, despite the existence of only a few major grape species, there are many different grape cultivars grown throughout the world. For example, Cabernet Sauvi-gnon, Chardonnay, Gamay, Mission,...

Nitrogenous Compounds

Grapes contain both inorganic and organic sources of nitrogen.Total nitrogen concentrations in grapes (or musts) range from about 0.2 g L to 0.4 g L.The ammonium nitrogen is less than 0.1 g L. Despite their relatively low concentration in juice, the nitrogen content of most musts is generally adequate for rapid growth of yeasts. In fact, the primary role of nitrogen in wine appears to be as a nutrient source for the yeasts, rather than affecting any of the organoleptic or other properties of...

Saccharomyces

It can reasonably be argued that the yeasts belonging to the genus Saccharomyces are among the most important of all organisms used in fermented foods, perhaps more so than even the lactic acid bacteria.These yeasts are required, after all, for the production of beer, wine, and spirits (not to mention bread), products that have a combined, world-wide economic impact in the trillions of dollars. In addition, the main species, Saccharomyces cerevisiae, is widely used as a model organism in...

Koji and Tane Koji Manufacture

First, it is necessary to recognize there are many types of koji used in the Far East, and that each fermented food requires a specific type of koji.Thus, Japanese soy sauces generally use a koji that is different from the one used to make Chinese-style soy sauces, and both are different from the koji used for sake manufacture. Generally, koji can be referred to by its intended product (e.g., sake koji or shoyu koji) or by the substrate from which the koji is prepared (e.g., rice koji, barley...

Greekstyle

There are several significant differences between Greek-style and other olive types. First, these olives are naturally black when they are harvested, in contrast to California-style black olives that rely on oxidation to generate black pigments. Second, Greek-style olives are not lye-treated, giving them a more bitter flavor. Third, the fermentation is mediated not just by lactic acid bacteria, but also by yeast, non-lactic acid bacteria, and even fungi. Some of these non-lactic organisms...

Micrococcaceae Cultures

Most meat starter cultures available in the United States contain species belonging to two genera of lactic acid bacteria, Lactobacillus and Pediococcus. In Europe, a quite different type of starter culture has been used. Most of the cultures used for European or European-style fermented sausages contain not only lactic acid bacteria, but also totally unrelated organisms belonging to the family Micrococcaceae.These include species of coagulase-negative Staphylo-coccus, Micrococcus, and Kocuria....

Natto

Natto is another soybean-fermented product consumed mainly in Japan, but similar products are also produced in China, Thailand, and the Philippines. Per capita consumption in Japan is about 1.2 Kg per person per year or 3 g per day. Natto is used as a condiment or flavoring agent, usually for rice and vegetables or as an ingredient in sushi. Nutritionally, natto is comparable to other fermented soybean products. It contains 16 to 18 protein 45 on a dry basis , with good digestibility and...

Whey Utilization

As shown earlier in this chapter Figure 5-4 , water, in the form of whey, is released when milk is converted into cheese. In fact, the whey accounts for 90 of the original milk volume. The dilute nature of the whey about 92 to 94 water and low protein concentration lt 1 have historically contributed to the perception at least in the United States that whey has little economic value. However, in other parts of the world, whey is more widely used, especially in the manufacture of whey-derived...

Phenols Tannins and Pigments

Among the most important naturally occurring substances in grapes and musts are the phenolic and polyphenolic compounds. Some phenols can also be introduced into the wine following aging in wooden casks or via yeast and bacterial metabolism.These chemically diverse compounds contribute color, flavor, aroma, and mouth feel to the wine. They can also react with other grape components and can either improve or diminish wine quality. Finally, many of the phenolic compounds found in wine are thought...

Introduction

Perhaps no other fermented food starts with such a simple raw material and ends up with products having such an incredible diversity of color, flavor, texture, and appearance as does cheese. It is even more remarkable that milk, pale in color and bland in flavor, can be transformed into literally hundreds of different types of flavorful, colorful cheeses by manipulating just a few critical steps. How so many cheeses evolved from this simple process undoubtedly involved part trial and error,...

Trichinella In Fermented Meats

Antimicrobial barriers in fermented meats. Property Level, range, or function Box 6-3. Pathogens, Toxins, and the Safety of Fermented Sausage Continued The problem, however, is now more complicated, because it has been recognized recently that some pathogens appear to be tolerant even to multiple barriers. Some strains of E. coli O157 H7, for example, are much more tolerant to low pH and organic acids than are normal E. coli strains. Furthermore, L. monocytogenes is resistant to low...

The Flavor of Soy Sauce

Considering that most soy sauces contain up to 18 NaCl, the most immediate and obvious flavor one detects is saltiness. However, the flavor of soy sauce is far more complex than simply saltiness. In fact, the shoyu products listed in Table 12-2 all contain between 16 and 19 salt, yet their flavor profiles, and the concentrations of volatile flavor compounds, can vary considerably. Nearly 200 volatile flavor components have been identified in shoyu, using GC or GC MS analysis. Several of these,...

Types of Asian Fermented Foods

There are hundreds of different types of fermented foods produced in China, Japan, the Philippines, and throughout Asia Beuchat, 2001 . However, there are two general types of fermented foods that are associated with or are indigenous to Eastern or Asian cuisines those that are plant-based and those that are fish-based.The former are made using primarily soy and rice as substrates, but other grains and legumes are also used. For the most part, these soy-based fermentations have been...

Bibliography

Kunkee, C.S.Ough,V.L. Singleton, A.D. Webb. 1980. The Technology of Wine Making, 4th Ed.,Avi Publishing Company, Inc.,Westport, Connecticut. Bartowsky, E.J., and P.A. Henschke. 2004.The buttery' attribute of wine-diacetyl-desirability, spoilage and beyond. Int.J. Food Microbiol. 96 235-252. Boulton, R.B.,VL. Singleton, L.F. Bisson, and R.E. Kunkee. 1996. Principles and Practices of Winemak-ing. Chapman and Hall, New York, New York. Coates, C. 2000. An Encyclopedia...

Info

Bles, including radishes and cucumbers, can also be used, alone or mixed with cabbage. Other vegetables, spices, and flavoring agents are also commonly added to kimchi, depending on the particular type of kimchi being produced. Garlic, green onion, ginger, and red peppers are among the typical ingredients, but fish, shrimp, fruits, and nuts, can also be added. Kimchi, therefore, has a much more complex flavor and texture profile. However, kimchi has also been suggested to have unique...

Tempeh nutrition and safety

Among the most important changes that occur during the tempeh fermentation are those that affect the nutritional quality of tempeh. As noted above, the concentration of the major macronutrients i.e., protein, fat, and carbohydrates decreases as the soybeans are converted to tempeh, due to enzymatic hydrolysis. These changes may account, in part, for an improvement in nutritional quality. For example, it has been suggested that protein hydrolysis makes tempeh more digestible, compared to...

Manufacture of fermented olives

There are three main styles or types of table olives, based on their method of production Figure 7-7 . Spanish-style or green Spanish-style olives are treated with sodium hydroxide lye and fermented. Greek-style or naturally-black, ripe-style olives are not treated with lye, but are fermented. The fermentation for both types is mediated by the natural microflora, much like that for other fermented vegetables discussed below .The third type of olive is the ripe black- or green-style. They are...

Defects

Among the microbial defects that occur in pickles, the most common are bloaters and floaters Table 7-4 .The defect is caused by excessive gas pressure that subsequently results in internal cavity formation within the pickles. The CO2 gas is mainly produced by heterofermentative lactic acid bacteria some of which may produce CO2 via the malolactic fermentation , although coliforms and yeasts may also be responsible. Floaters and bloaters can still be used for some processed products i.e., relish...

Lactose-6-phosphate

The phosphotransferase system PTS in Gram positive bacteria. As shown in panel A, the PTS cascade is initiated by the cytoplasmic proteins Enzyme I EI and HPr. Phosphorylated HPr HPr P then transfers the phosphoryl group obtained originally from PEP to the substrate-specific Enzyme II complex. The latter consists of several proteins or domains, shown here as EIIA, EIIB, and EIIC. However, depending on the organism and the substrate, EII complexes may be organized differently, for...

Wine Manufacture Principles

Making wine, as far as the actual steps are concerned, looks to be a rather simple and straightforward process Figure 10-3 . Grapes are harvested and crushed, the crushed material or juice is fermented by yeasts and bacteria, the organisms and insoluble materials are removed, and the wine is aged and bottled. In reality, the process is far from easy, and each of these pre-fermentation, fermentation, and post-fermentation steps must be carefully executed if high-quality wine is to be...

Nonalcoholic beer

Low- or non-alcoholic beers were first produced in the United States more than eighty years ago during Prohibition , and have been available ever since. However, the relatively low demand for these products did not drive the industry to devote very much research effort into new technologies. Due to a marked increase in the consumer demand for low- or non-alcohol products, the technology for making these beers has improved dramatically in the last decade.The quality of these beers, not...

Factors Affecting Yeast Metabolism

S. cerevisiae has the genetic capacity to metabolize sugars via either the glycolytic or respiratory i.e., TCA pathways. Although oxygen availability affects expression of genes encoding enzymes of these two pathways and is, therefore, an important determinant of which way metabolism will occur, gene expression is also regulated by substrate availability. Although one might expect that in the presence of oxygen, metabolism would always be via the respiratory pathway, this is not the case. If...

Direct Lyophilized Milks Cultures

18,979,200 - 3.13 X 108 less than 1 xGiven the following assumptions Initial phage level 1 phage ml of milk Initial cell level 1,000,000 cells ml Phage latent period 40 minutes Cell generation time 40 minutes Average burst size 50 xGiven the following assumptions Initial phage level 1 phage ml of milk Initial cell level 1,000,000 cells ml Phage latent period 40 minutes Cell generation time 40 minutes Average burst size 50 In the past twenty years, however, the incidence of phage infections...

The Lactic Acid Bacteria

From the outset, it is important to recognize that the very term lactic acid bacteria has no official status in taxonomy and that it is really just a general term of convenience used to describe a group of functionally and genetically related bacteria. Still, the term carries rather significant meaning among microbiologists and others who study food fermentations, and, therefore, will be used freely in this text. Accordingly, the lactic acid bacteria are generally defined as a cluster of lactic...

Nh

Proteolysis during cheese ripening. The proteolytic system in lactococci starts with the hydrolysis of casein by a cell envelope-associated proteinase PrtP . The main products are oligopeptides, which are then transported across the cell membrane by the oligopeptide transport system Opp . Any free amino acids and di- and tripeptides in the milk are similarly transported by amino acid AA and di- and tripeptide transporters DtpT, DtpP , respectively. Once inside the cell, the...

Curd handling

Perhaps the most influential step during the cheese making process involves the means by which the curd is handled during and after the cooking and stirring steps. For many cheeses, the whey is removed when the desired acidity is reached, when the curd has been cooked for a sufficient length of time, or when it is sufficiently firm or dry. There are several means by which the curd is separated and the whey is removed. In traditional Cheddar cheese manufacture, the curds are simply pushed to the...

The Modern Beer Industry

Patent Pasteur 1873 Beer

Today, beer has one of the largest dollar values of all fermented food products, with U.S. retail sales in 2002 of more than 65 billion dollars. Box 9 1. Pasteur, the Origins of Microbiology, and Beer It is hard to imagine, given the current age of scientific specialization, that one person could have been as accomplished in so many fields as was Louis Pasteur in the latter half of the nineteenth century. He was trained as a chemist and, at the age of only 26, made important discoveries in...

Principles of Fermented Sausage Manufacture

There are actually only a few general steps involved in fermented sausage manufacture. First, the ingredients are selected, weighed, mixed, and stuffed into casings. Second, the stuffed sausages are held under conditions necessary to promote a fermentation. Third, the sausage is subjected to one or more postfermentation steps whose purpose is to affect flavor, texture, and preservation properties. These latter steps can range in duration from as little as one week in the case of moist or...

Strain improvement strategies

Since the beginning of beer making, all the way to the present, brewing strains have been used continuously, being passed down from batch to batch. These strains are highly adapted to wort and beer and are not very amenable to classical strain improvement strategies.That is, trying to select strains, either spontaneously or following mutagenesis, with improved fermentative, flavor-producing, or other relevant properties, is not an easy proposition. In addition, whereas laboratory strains are...

Recent Developments in the Beer Industry

The beer industry is one of the most competitive segments of the food and beverage indus-try.This competition has led to new technologies, new innovations, and new products. At the same time, there has been remarkable growth in the microbrewing industry, and a return to traditional or craft brewing practices. It is now possible to find nearly every type of beer at the local pub or retail outlet Box 9-8 . Thus, the beer industry, from the smallest to the largest brewer, continues to There are...

General Steps in Cheese Making

On a worldwide basis, there are probably thousands of different types of cheeses produced and consumed. As Charles De Gaulle, the former French president, famously lamented, there are hundreds of different cheeses made in France alone1. Anyone who has visited a fro-mageri in Paris or a formaggio in Milan or perhaps the National Cheese Emporium in England Box 5-3 , can certainly appreciate the incredible variety of cheeses that are available. How could there be so many Are the procedures for...

Proteolysis in cheese

It was long argued that milkfat was the primary constituent responsible for cheese flavor.While it is certainly true that many cheese flavors are either evolved from the lipid fraction or are soluble in the lipid phase, it is now generally accepted that, for most cheeses the main exception being the blue mold-type cheeses , it is the protein fraction that makes the more important overall contribution Table 5-2 . Cheeses made under controlled conditions in which proteoly-sis does not occur...

Flocculation

Flocculation Cells

Flocculation is the ability of yeast cells to agglomerate or adhere to one another in the form of clumps. When lager yeasts flocculate, the clumps have a density greater than that of the beer and settle to the bottom. Ale yeasts, in contrast, form clumps or flocs that entrap CO2 bubbles and have a lower density, and, therefore, rise to the surface. The ability of yeast cells to clump or flocculate, and the time at which flocculation occurs, are very important properties in beer manufacture. In...

Fermentors

The fermentation of the wort occurs in fer-mentor vessels of varying composition, size and configuration, and in either batch or continuous modes.Although most modern fermen-tors are now constructed of stainless steel, the traditional materials were wood, concrete, or copper. Size and shape depend on a number of considerations, but especially on whether the fermentation is top fermenting, as for ales, or bottom fermenting, as for lagers see below . For example, lager fermentation vessels are...

Propionic Acid In Hops

Hops Acids

In the final step prior to fermentation, the wort is pumped into a special heating tank called the brew kettle. It is here that the wort is boiled and other important reactions occur.Be-fore the wort is heated, however, one more essential beer ingredient, hops, is added to the wort. Hops are derived from the plant Homu-lus lupulus in the family, Cannabinaceae , and although they were not part of the original beer formula, they have been added to beer since the Middle Ages. Why hops came to be...

Waste Management in the Brewing Industry

Although waste management affects all segments of the fermented foods industry, the issue is particularly important in the brewing in-dustry.This is because beer manufacturing uses nearly a half-billion tons of grains each year and, although some components of that grain are fermented, much of the grain is left behind. These spent grains represent a considerable disposal problem. Currently, this material is used in one of several ways. It can be further processed and used as a specialty food...

Measure pH

Lawrence. 1976.The selection of starter strains for cheesemaking. N.Z.J. Dairy Sci. Tech. 11 16-20. Hynd,J. 1976.The use of concentrated single strain cheese starters in Scotland.J. Soc. Dairy Technol. 29 3945. O'Toole, D.K. 2004.The origin of single strain starter culture usage for commercial Cheddar cheesemaking. Int. J. Dairy Technol. 57 53-55. Richardson, G.H., G.L. Hong, and C.A. Ernstrom. 1980. Defined single strains of lactic streptococci in bulk culture for Cheddar...

Cheese with Eyes

Swiss cheese, the most famous of the eye-containing cheeses, is considered by experienced cheese makers to be the easiest cheese to make but the hardest cheese to make well. This is because the manufacture of high quality Swiss cheese, and proper eye development, in particular, depends on two rather independent processes. First, Swiss cheese requires excellent curd handling technique, such that conditions are correct for eyes to form. Second, there must be precise control over the...

Yeast Metabolism

The usual starting inoculum gives an initial yeast population of abut 5 X 106 cells per ml of wort. Depending on the activity of the yeast inoculum, a lag period of six to eighteen hours may occur. Although no increase in cell number is observed during the lag phase, metabolic activity is well under way. The yeasts are synthesizing sugar and amino acid transport systems, as well as enzymes necessary for their metabolism. As noted earlier, the wort is sparged with oxygen prior to pitching, thus...

Streptococcus

The genus Streptococcus contains many diverse species with a wide array of habitats. Included in this genus are human and animal pathogens, oral commensals, intestinal commensals, and one and only one species, Streptococcus thermophilus, that is used in the manufacture of fermented foods. In general, streptococci are non-motile, facultative anaerobes, with an obligate homofermentative metabolism. Since the mid-1980s,there have been several major taxonomical revisions within this genus. Some of...

Products and Consumption

In the United States, there are essentially only three fermented vegetable products that are produced and consumed on a large scale basis. These include sauerkraut, pickles, and olives. The raw materials for these products cabbage, cucumbers, and olives are high moisture foods, with little protein or fat except for olives , and just enough fermentable carbohydrate to support a fermentation Table 7-1 . Other fermented vegetables, such as peppers, cauliflower, and green tomatoes, are also...

Beer Defects

Despite the low pH, high ethanol content, and hop antimicrobials ordinarily present in beer, microorganisms are responsible for many but certainly not all of the defects that occur in beer. Chemical and physical defects are also common and can cause significant problems for brewers. However, preventing or minimizing entry and growth of microbial contaminants throughout the beer-making process is absolutely essential for consistent manufacture of high quality beer. This is no simple matter,...

Moldripening

Many of the European-style sausages are ripened by mold. These products are particularly popular in Hungary and Romania, as well as throughout the Mediterranean region. For many of these products, fungal growth can be extensive, with the mycelia covering the entire surface. Mold-fermented sausages are not nearly as common in the United States. However, there are some whole meat products, in particular, country-cured hams, that are fermented by yeasts and fungi and that are very popular in...

Ascospore

Ascospore Saccharomyces

Most lab strains form ascospores containing spores of opposite mating types, a and a. These spores can mate, hybridize, and form diploidal cells capable of budding or sporulating. In contrast, brewing yeasts generally only reproduce by budding. Figure 1. Yeast life cycle. Most lab strains form ascospores containing spores of opposite mating types, a and a. These spores can mate, hybridize, and form diploidal cells capable of budding or sporulating. In contrast,...

Cooking drying and smoking

Several different treatments and combinations of treatments can be applied at end of the fermentation. These include cooking, drying, and smoking. In the United States, fermented sausages are often cooked after fermentation, whereas, in Europe and elsewhere, raw sausages are the norm, and post-fermentation heating steps are rarely applied. In general, properly made dry, fermented, uncooked sausages, like salami and pepperoni, are still considered to be shelf-stable and ready-to-eat. Cooking,...

Fermentation and Metabolism Basics

Parts Aspergillus Sporangiospore

If one looks up fermentation in a biochemistry textbook, the definition that appears is usually something like this energy-yielding reactions in which an organic molecule is the electron acceptor . . . . Thus, in the lactic acid fermentation, pyruvic acid that is generated by the glycolytic pathway serves as the electron acceptor, forming lactic acid. Likewise, in the ethanolic pathway, acetaldehyde, formed by decarboxylation of pyruvate, is the electron recipient forming ethanol . So although...

Lactobacillus Casei

Lactobacillus Garicus

Although some strains of propionibacteria can ferment lactose, none is available during the time at which these bacteria are given the opportunity to grow i.e., several weeks after the primary lactose fermentation is complete . Instead, lactate is the only energy source available. Lactate fermentation occurs via the propionate pathway, which yields two moles of propionate, and one each of acetate and CO2 per three moles of lactate fermented. The cell nets one mole of ATP per...

Glucose6P

Trehalose metabolism by Saccharomyces cerevisiae. Structure of trehalose a-D-glucosyl-1 1-a-D-glucose is shown in the upper panel. Transport is mediated by a symport system, but synthesis from glucose-6-phosphate P may be the major route for trehalose accumulation lower panel . Trehalose not only alleviates stress, but it can also serve as a carbon source following its hydrolysis to glucose by the enzyme trehalase. of arginine and an increase in freeze tolerance and gassing power...

Preservation

Spoilage Bread Bacillus

Spoilage organisms of bread. Aspergillus niger Aspergillus glaucus Aspergillus flavus Penicillium sp. Rhizopus nigricans Mucor sp. Bacillus subtilus Bacillus licheniformis Bacillus mesentericus Given that biological spoilage of bread is caused primarily by molds, it is not surprising that preservation strategies have focused on controlling fungi, both in the production environment and in the finished product.As noted previously, mold and mold spores are present in flour and other raw...

Enzymatic Reactions Malting and Mashing

The first part of beer manufacture, the enzymatic steps, actually begins far from the brewing facility, in the malting houses that convert barley into malt. It is the malt that serves as the source of the amylases, proteinases, and other enzymes necessary for hydrolysis of large macromolecules, such as starch and protein. For most beers, the malt also serves as the substrates for those enzymes i.e., malt contains the starch and protein hydrolyzed by malt enzymes . In addition, malt is the...

H H pH C C C Hho

Structure of calcium propionate. How then, does calcium propionate exerts its anti-fungal activity Recall that weak organic acids can exist in either the acid undissociated or salt dissociated form Figure 2, upper panel . When the pH is equal to the pKa the dissociation constant of the acid, the concentration of undissociated and dissociated forms at equilibrium will be the same. When the pH is above the pKa, the equilibrium shifts to the salt or dissociated form. Conversely, when the...

End products

Although lactic acid is the major compound produced during the fermentation, other metabolic end products are also formed. Importantly, many of these products contribute to the overall flavor of sauerkraut. In particular, end products produced by Leuconostoc sp. and other heterofermentative lactic acid bacteria are essential for good-tasting sauerkraut.As much as 0.3 acetic acid and 0.5 ethanol can be present in the finished sauerkraut. In addition, these bacteria may also synthesize small...

Fermentation

Microbial Succession Sauerkraut

The sauerkraut fermentation has long been the subject of interest among food microbiologists as well as microbial ecologists. In fact, many of the biochemical and microbiological details of the sauerkraut fermentation were described as long ago as the 1930s. This interest has undoubtedly been due, in large part, to the very nature of the fermentation process, in that it involves several different naturally-occurring microorganisms acting as part of a complex ecosystem. Recent reports suggest...

Amylopectin crystalline

In fresh bread, amylose and amylopectin exist in amorphous or gelled forms. During storage, moisture is lost, the amylose and amylopectin retrograde, and crystalline forms appear, leading to firmness and staling. Adapted from Zobel and Kulp, 1996 and Lallemand Baking Update, Volume 1 Number 6. The commercially-available a-amylases used as anti-staling agents are derived from either bacterial or fungal sources. Most are produced by species of Bacillus and...

Bluemold Ripened Cheese

Although blue mold-ripened cheeses are made throughout the world, three specific types have achieved a significant measure of fame to warrant their own name and have DPO status . Roquefort, perhaps the most well-known of all blue cheeses, must be made according to a strict set of manufacturing requirements. For example, the milk must come from specially-bred sheep that have grazed in the Causses region of France. It is neither pasteurized, standardized, nor homogenized, and the cheese must...

Yogurt Flavor and Texture

The most dominant flavor of yogurt is sourness, due to lactic acid produced by the starter culture. Most yogurts contain between 0.8 and 1.0 lactic acid and have a pH below 4.6. In the absence of sweetener or added flavors, most consumers can detect sourness when the pH is below 5.0. Other organic acids, including formic and acetic, may also be produced by the culture, but at much lower concentrations, and they generally make only modest contributions to yogurt flavor. There are, however, other...

Current Issues in Cheese Technology

Given the important role of microorganisms in the manufacture of cheese, it should come as no surprise that among the most important issues faced by the cheese industry, most are microbiological in nature not withstanding yield, costs, and other economic issues . The key to making any high quality fermented food, including cheese, is to control the activities of the microbial starter culture and other organisms.This means ensuring that they grow when they are supposed to, that agents that would...

Bread Consumption

Bread Consumption Worldwide

Worldwide consumption of bread per person per year . Adapted from Association Internationale de la Boulangeri Industrielle www.aibi-online.org and Federation of Bakers www.bakersfederation. org , 2001-2002 statistics. Figure 8-2. Worldwide consumption of bread per person per year . Adapted from Association Internationale de la Boulangeri Industrielle www.aibi-online.org and Federation of Bakers www.bakersfederation. org , 2001-2002 statistics. several thousands of years earlier. The...

Liquid sponge process

The traditional methods of bread making, as described above for the straight dough and sponge and dough methods, require sufficient time for the initial or bulk fermentation to occur and for the dough to develop. In the past several decades, an emphasis on speed and economy of scale has led to newer methods of bread manufacture.These methods rely less on bulk fermentation and natural dough development, and more on mechanical dough development and a relatively short fermentation period. The...

Biological spoilage

Mucoid Ropy Texture Breads

Microbiological spoilage of bread is most often associated with fungi, and occurs when fungal mycelia are visible to the consumer. Some strains of Bacillus subtilis, Bacillus mesenteri-cus, and Bacillus licheniformis can spoil high-moisture breads via production of an extracellular capsule material that gives the infected bread a mucoid or ropy texture.There are also wild yeasts capable of causing flavor defects in bread after baking however, bacterial and yeast spoilage of bread is relatively...

Starter Cultures

The connection between wine fermentation and the development of the sugar fungus is not to be underestimated it is very probable that, by means of the development of the sugar fungus, fermentation is started. From A Preliminary Communication Concerning Experiments on Fermentation of Wine and Putrefaction by Theodor Schwann, 1837 as recounted by Barnett, 2003. The successful manufacture of all fermented products relies on the presence, growth, and metabolism of specific microorganisms. In...

The Modern Fermented Foods Industry

The fermented foods industry, like all other segments of the food processing industry, has changed dramatically in the past fifty years. Certainly, the average size of a typical production facility has increased several-fold, as has the rate at which raw materials are converted to finished product i.e., throughput . Although small, traditional-style facilities still exist, as is evident by the many microbreweries, small wineries, and artisanal-style bakery and cheese manufacturing operations,...

Sponge and dough process

The most commonly used method in the bread industry is the sponge and dough process. It is used by small, medium, and most large bakeries in the United States. The basic principle of this process relies on the use of a sponge, a partially concentrated portion of a flour-water dough that is allowed to ferment and then is mixed with the remaining dough ingredients. The main advantage of this method is it that it is tolerant to time. In other words, once the sponge is developed, it does not have...

Coagulation

In many cheese factories, chymosin is added to the milk immediately after or nearly at the same time as the culture is added. Some cheese makers allow a pre-ripening period to give the culture a brief opportunity to produce a small amount of acid and a slight lowering of the milk pH. Since chymosin is an acid protease its optimum activity on K-casein occurs at pH 5.5 , it will be more active as milk pH decreases.The solubility of calcium also increases as the pH decreases. Thus, with...

Straight dough process

Bread Manufacturing

The homemade, one-batch-at-a-time method described above is generally referred to as the straight method or straight dough process. Basically, the overall procedure outlined in Figure 8-9 involves mixing all of the ingredients and then allowing the dough to ferment for several hours with intermittent punching down . The developed dough is then divided, formed into round balls, given a brief intermediate proof, shaped into loaves, and placed in baking pans. Finally, after a final fermentation or...

Defects and spoilage

Olives are, generally, more susceptible to microbial spoilage than other fermented vegetables. Initially there is a diverse microflora present in raw olives and that flora is well maintained during the early stages of the fermentation. Reflective of this heterogenous mix, spoilage organisms include aerobic bacteria and fungi, facultative bacteria and yeasts, strict anaerobes, as well as sporeforming bacteria. If the lactic fermentation is delayed due to residual lye or limiting glucose, or if...

Mozzarella and Pasta Filata Cheese

As a recently as a generation ago, Mozzarella was still considered a mostly ethnic cheese, used primarily as an ingredient in Italian cui-sine.The popularity of this cheese it is now equal to that of Cheddar cheese among American consumers Figure 5-3 , is due to one product pizza. Of the more than 1.2 billion Kg 2.7 billion pounds of Mozzarella and related cheeses consumed each year, about 70 is used by the food service industry as an ingredient on pizza. And while Cheddar production has grown...

Heterofermentative pathway

Mig1 And Saccharomyces

The Leloir pathway in lactic acid bacteria. surface and has substrate-binding activity. The energy released from ATP hydrolysis drives transport. In general, ABC systems are used to transport amino acids, peptides, and osmopro-tectants. However, several ABC systems are involved in sugar transport, including the maltose ABC systems in L. plantarum and the oligosaccharide-multiple sugar transport system in L. acidophilus. As noted above, regulation of sugar metabolism in lactic acid...

Ferment

Adapted from Cheigh, 1999. Box 7-2. Health Properties of Kimchi Continued kimchi can certainly be ascribed to the combination of these desirable sensory characteristics, there are also nutritional reasons that contribute to the its widespread consumption. For example, kimchi contains appreciable amounts of ascorbic acid vitamin C , B vitamins, calcium, iron, potassium, dietary fiber, and naturally occurring antioxidants. It is also important to note that kimchi is...

Pediococcus

The pediococci are similar, in many respects, to other coccoid-shaped, obligate homofermenta-tive lactic acid bacteria, with one main excep-tion.When these bacteria divide, they do so in two planes and in right angles .Thus, tetrads are formed, which can be observed visually. Cells may appear as pairs and always spherical in shape , but chains are not formed, as they are for lactococci, streptococci, and leuconos-tocs. Pediococci, like other lactic acid bacteria, are facultative anaerobes, with...

Microbial taxonomy and methods of analysis

If microbiology began with Pasteur in the middle of the nineteenth century,then for the next 120 years, microbial classification was based primarily on phenotypic characteristics. Although many of these traits remain useful as diagnostic tools, by far, the most powerful means of classifying microorganisms is now via molecular techniques. Originally, routine tests were based on nucleic acid composition mol G C and DNA-DNA and DNA-RNA hybridization.The latter has long been considered the gold...

Microbial Defects Preservation and Food Safety

Given that cheese is made in a mostly open, non-sterile environment, using non-sterile raw materials, and is exposed to or held at non-lethal, non-inhibitory temperatures, it is not surprising that all sorts of microorganisms can gain entry in cheese. Although the combined effects of moderately low pH, moderately high salt concentrations, and low Eh provide a barrier against some microorganisms, there are others, including spoilage organisms, and in rare cases, pathogens, that can grow in the...

Spoilage and defects

Although chemical or physical reactions are occasionally responsible for sauerkraut spoilage, most defects are caused by microorganisms Table 7-4 . Defects are more likely to occur if the production conditions are not properly controlled, leading to deviations in the fermentation pattern. The two most common factors that influence the fermentation and that may lead to quality defects are temperature and salt. If, for example, the temperature is too high gt 30 C or if too much salt is added gt 3...

Defects and Spoilage of Fermented Meats

Defects of fermented meats can occur before, during, or after manufacturing. Like all fermented foods, the production of high quality products depends largely on the microbiological quality of the raw ingredients. Perhaps this is even more so for fermented sausage, since the starting material, meat, is raw and cannot be heat-processed to inactivate spoilage or other undesirable microorganisms. Thus, any organisms present in the raw meat will be present in the sausage batter and may even survive...

Other Cultured Dairy Products

The emphasis of this chapter has been on those products produced and consumed in the United States. However, there are hundreds of other products produced around the world that, although manufactured via similar processes, have unique and interesting features Table 4-4 .Villi, for example, is widely consumed in Finland is known for its high viscosity and musty flavor and aroma.The ropy texture is due to capsular EPS production by L. lactis subsp. lactis and L. lactis subsp. cremoris, and the...

Economic value

Fermented foods were the original members of the value-added category. Milk is milk, but add some culture and manipulate the mixture just right, age it for a time, and the result may be a fine cheese that fetches a price well above the combined costs of the raw materials, labor, and other expenses. Grapes are grapes, but if grown, harvested, and crushed in a particular environment and at under precise conditions, and the juice is allowed to ferment and mature in an optimized manner, some...

Cultured Buttermilk

Buttermilk is the fluid remaining after cream is churned into butter. It is a thin, watery liquid that is rarely consumed as a fluid drink. Because it is rich in phospholipids derived from the rupture of milk fat globules during churning , it has excellent functional properties and is an especially good source of natural emulsi-fiers. It is typically spray dried and used as an ingredient in processed food products. Cul tured buttermilk, in contrast, is made from skim or low-fat milk that is...

Acetobacter Gluconobacter and Gluconoacetobacter

The only Gram negative bacteria used in the manufacture of fermented foods are the acetic acid-producing rods belonging to the genera Acetobacter, Gluconobacter, and Gluconoace-tobacter in the Proteobacteria phylum, Family Acetobacteraceae . These bacteria are obligate aerobes, with a respiratory-only metabolism. They make acetic acid via oxidation of ethanol some species may also have the capacity to further oxidize acetic acid completely to CO2 and water. The acetic acid bacteria are...

Protective Properties of Cultures

It has long been suggested that lactic acid starter cultures were responsible for preservation effects beyond their acidification and pH-lowering effects. During growth in meat, they scavenge sugars and other nutrients faster than competitors, and they lower the oxidation-reduction potential Eh of the environment such that growth of aerobic organisms is inhibited. In the 1980s it was discovered that some of the strains used as meat starter cultures may provide additional preservation effects...

Processed and Cold Pack Cheese

Although cheese is the main ingredient, processed cheese or what many consumers mistakenly call American cheese is not a fermented food. However, because processed cheese is so popular in the United States and there is so much confusion regarding the differences between natural cheese and processed cheese Box 5-6 , it is worthwhile to describe the manufacture of processed cheese. Briefly, processed cheese is made by adding emulsifying salts to natural cheese, along with water and other dairy...

Brevibacterium celere

Phylogeny of Brevibacterium based on 16S rRNA sequence analysis. group contains the cutaneous species Propi-onibacterium acnes and Propionibacterium avidum, the organisms that cause acne. The dairy group consists of several species that are important in food fermentations, due to their use in the manufacture of Swiss-type cheeses. The most frequently used dairy species include Propionibacterium freuden-reichii subsp. shermanii, Propionibacterium freudenreichii subsp. freudenreichii,...

Factors Affecting Diacetyl Formation in Cultured Buttermilk

Even if the culture contains citrate-forming strains, diacetyl formation does not always occur in amounts necessary to impart the desired flavor. Several reasons may account for reduced citrate fermentation and diacetyl synthesis. First, there may simply not be enough citrate in the milk. Although milk contains, on average, about 0.15 citrate, this amount varies, depending largely on the diet of the cow. Therefore, sodium citrate is frequently added to the milk to provide a consistent source of...

Converting a liquid into a solid

Casein Micelle Structure

Water removal and the concentration of protein and fat occur via a combination of biochemical, biological, and physical-chemical events. Many of these events happen at nearly the same time and often have complex effects on one another. For example, exposure of cheese curds to both high temperature and low pH enhances removal of water from the curd a phenomenon known as syneresis . But if the temperature is too high, the microorganisms that produce the acid that lowers the pH will be...

Meat Starter Cultures

Once microbiologists began to study and identify the microorganisms present in fermented sausages in the 1940s, it became clear that lactic acid bacteria were the primary organisms responsible for the fermentation.This conclusion was based on the fact that the predominant organisms isolated from naturally fermented sausages were species of Lacto-bacillus .When the isolates were propagated and re-inoculated into fresh meat, a well-fermented sausage could be produced with all the expected...

Chymosinexpressing clone

Making recombinant chymosin see text for details . Box 5 2. Making Calf Chymosin in Fermentors Continued this case, chymosin are not secreted but instead are packaged inside the cell in the form of inclusion bodies.Thus,to retrieve the chymosin,the cells had to be collected and disrupted, either mechanically or chemically, to release the chymosin-containing inclusion bodies.The latter, then, had to be solubilized to liberate active chymosin. Nonetheless, despite these awkward and...

L Lactococcus lactis subsp hordniae

Phylogeny of Lactococcus based on 16S rRNA sequence analysis. First, they are readily isolated from raw milk in fact, it is difficult to find L. lactis subsp. cremoris anywhere but milk. Second, both species grow rapidly in milk, producing lactic acid and lowering the pH to below 4.5.Thus, they generally out-compete most potential competitors. Finally, the genes required for growth in milk are located on plasmids extrachromosomal DNA , indicating they were acquired recently...

Bifidobacterium

It is arguable whether species of Bifidobacterium should be considered involved in food fermentations. Although they have a fermentative metabolism, these bacteria are not used in the manufacture of any fermented food, nor are they even found in most raw food materials. Rather, bifidobacteria are added to certain foods, mostly milk and fermented dairy products, strictly for their probiotic functions. The intestinal tract is their primary habitat, and their elevated presence in the human...

Penicillium and Aspergillus

As previously mentioned, these molds are among the most common and widespread in foods. In the older literature, they were often referred to as Fungi Imperfecti, due to the absence of a sexual stage in their life cycle. Penicillium and Aspergillus are mainly of concern due to their role in food spoilage and as potential producers of mycotoxins however, some species of Penicillium and Aspergillus are also used to produce fermented foods. In fact, one of the most famous of all organisms used in...

Homofermentation

Lactic acid bacteria are obligate fermentors, and cannot obtain energy by oxidative or respiratory processes with the exception noted previously Box 2-1 . Technically, the precursor-product exchange systems, described below, provide an alternate way for these organisms to earn ATP credits by conserving the energy that would ordinarily be used to perform metabolic work. However, the substrate level phosphorylation reactions that occur during fermentation are by far the major means by which these...

Lyophilized or frozen cultures

Bulk vs. direct-to-vat culture preparation. and from infection by lytic bacteriophages see below . In general, bulk culture media are not that different from the fermentation media used by culture manufacturers for mass production of starter culture cells. They contain a basal medium consisting of a fermentable carbohydrate usually lactose, but glucose or sucrose can also be used and a nitrogen source usually proteins derived from milk or whey . Culture media are also supplemented...

Primer on Microbial Classification

For many readers, keeping track of the many genus, species, and subspecies names assigned to the organisms used in fermented foods can be a challenging task. However, knowing which organisms are used in specific fermented foods is rather essential to put it mildly to understanding the metabolic basis for how microbial fermentations occur. Therefore, prior to describing the different groups of microorganisms involved in food fermentations, it is first necessary to review the very nature of...

Kocuria Micrococcus and Staphylococcus

These closely related genera Phylum Firmi-cutes consist of Gram positive, catalase positive, non-motile, non-sporeforming, aerobic cocci. Only a few species are relevant to fermented foods, and their involvement is limited to the manufacture of fermented sausages although some may show up as inadvertent contaminants in cheese and other products . The main species include Kocuria varians formerly Micrococcus varians , Micrococcus lu-teus, Staphylococcus xylosus, and Staphylococcus carnosus. In...

The genera of lactic acid bacteria

Vagococcus Salmoninarum

According to current taxonomy, the lactic acid bacteria group consists of twelve genera Table 2-2 . All are in the phylum Firmicutes, Order, Lactobacillales. Based on 16S rRNA sequencing and other molecular techniques, the lactic acid bacteria can be grouped into a broad phy-logenetic cluster, positioned not far from other low G C Gram positive bacteria Figure 2-2 . Five sub-clusters are evident from this tree, including 1 a Streptococcus-Lactococcus branch Family Streptococcaceae , 2 a...

The three domains of life

Phylogenetic Tree Three Domains Life

According to modern taxonomy, life on this planet can be grouped into three branches or domains the Eukarya, the Bacteria, and the Archaea Figure 2-1 .This organization for classifying all living organisms was proposed and established in the 1980s by Carl Woese and is based on the relatedness of specific 16S rRNA sequences using a technique called oligonu-cleotide cataloging.This three-branch tree of life displaced the classical taxonomy that had recognized only two groups, eukaryotes and...

Fermented Foods From Art to Science

It is difficult for the twenty-first century reader to imagine that fermented foods, whose manufacture relies on the intricate and often subtle participation of microorganisms, could have been produced without even the slightest notion that living organisms were actually involved. The early manufacturers of fermented foods and beverages obviously could not have appreciated the actual science involved in their production, since it was only in the last 150 to 200 years that microorganisms and...