Natto

Natto is a Japanese product based on fermented whole soybeans. Generally the product is dark with a pungent and harsh character. It is eaten with boiled rice, as a seasoning or as a table condiment in the way of mustard. There are three types of natto in Japan. Itohiki-natto from Eastern Japan is produced by soaking washed soybean overnight to double its weight, steaming for 15 min and inoculating with Bacillus natto, which is a variant of Bacillus subtilis. Fermentation is allowed to proceed...

Yoghurt and Other Fermented Milk Products

Like cheese, yoghurt originated as a vehicle to preserve the nutrient value of milk. Through time, the product has evolved to a foodstuff richly diverse in flavour, texture and functional properties. Thus, the formulations may now incorporate components such as fruits, grains and nuts, as well as having a range of textures. Yoghurt is only one of a series of fermented dairy products (Table 11.1). Sour cream comprises cream (> 18 milk fat) fermented with specific lactic cultures, perhaps with...

Curd handling

The curd is separated from whey by settling and drainage through some form of perforated system. It is important to have efficient fusion of the curd particles and this is impacted by pH and by the physical properties of the curd. Fusion starts to occur when the pH has reached 5.8, and if the whey is removed before this, the cheese will feature openings. If fusion takes place in the presence of whey, the cheese will have a dense body. Sodium chloride may be introduced into the curd after the...

Mycoprotein

Although less high profile than it was 25-30 years ago, there is still interest in the cultivation of microbes specifically as foodstuffs, rather than as agents in the production of other products, which is how we have encountered them in this book. The term 'single cell protein' was coined to describe these products, which were based on diverse bacteria and yeasts, growing on a range of carbon sources (Table 17.1). Only one product has survived in substantial quantity to this day, Quorn . It...

The Science Underpinning Food Fermentations

Use the word 'biotechnology' nowadays and the vast majority of people will register an image of genetic alteration of organisms in the pursuit of new applications and products, many of them pharmaceutically relevant. Even the Merriam-Webster's Dictionary tells me that biotechnology is 'biological science when applied especially in genetic engineering and recombinant DNA technology'. Fortunately, the Oxford English Dictionary gives a rather more accurate definition as 'the branch of technology...

Problems with cider

Cider sickness, caused by infection through Zymomonas anaerobia is now very uncommon, as it is countered by the lower pHs lt 3.5 and reduced tendency to have residual sugar in the product. Symptoms include an aroma of banana skins and a white turbidity due to the acetaldehyde produced reacting with polyphenols to form insoluble complexes. Mousiness in cider is due to isomers of 2-acetyl or ethyl tetrahydropyridine Fig. 5.6 produced by lactic acid bacteria or Brettanomyces under aerobic...

Lactic acid bacteria

Throughout the centuries it has been the practice in various fermentation-based processes to add back a proportion of the previously produced food to the new batch, so-called back slopping. What of course this did was to seed the fermentation with the preferred micro-organism, and for many foodstuffs this organism is a lactic acid bacterium. Such bacteria are only weakly proteolytic and lipolytic, which means that they are quite 'mild' with respect to their tendency to produce pungent flavours....

Sake brewing

The brewing of sake retains much ritual and tradition. The Master Brewers the toji go about their tasks in the kura, brewing in the coldest months of the year. The toji are an elite breed of artisan that can trace their origins back to the Edo period. They develop their knowledge and stature over many years of practical experience, starting with the most menial of tasks and enduring long hours of heavy manual labour. The brewers lived in kura for all the 100 days of the brewing season in past...

Fortified Wines

Food, Fermentation and Micro-organisms Charles W. Bamforth Copyright 2005 by Blackwell Publishing Ltd Fortified wines are those in which fermented, partially fermented or unfermented grape must is enriched with wine-derived spirit. According to the European Union EU regulations, such liquor wines are those with an acquired alcohol content of 15-22 by volume and a total alcohol content of at least 17.5 by volume. The chief fortified wines are sherry originating in Spain, notably Jerez de la...

Info

Separate vessel where it was taken to boiling and then returned to the main mash, leading to an increase in temperature. This is a rather simplified version of the process, which traditionally involved several steps of progressive temperature increase. Temperature-programmed mashing. Although there are some adherents to the decoction-mashing protocol, most brewers nowadays employ the related but simpler temperature-programmed mashing. Again, the mashing is commenced at a relatively low...

Bibliography

London Chapman amp Hall. Atkinson, B. amp Mavituna, F. 1991 Biochemical Engineering and Biotechnology Handbook, 2nd edn. Basingstoke Macmillan. Berry, D.R., ed. 1988 Physiology of Industrial Fungi. Oxford Blackwell. Branen, A.L. amp Davidson, P.M., eds 1983 Antimicrobials in Foods. New York Marcel Dekker. Brown, C.M., Campbell, I. amp Priest, F.G. 1987 Introduction to Biotechnology. Oxford Blackwell Publishing. Caldwell, D.R. 1995 Microbial Physiology and...

Whey expulsion

Whey is expelled rapidly from the curd after it has been cut into small pieces. This will be further accelerated by an increase in temperature when the mix is agitated. Lactic acid bacteria trapped in the curd metabolise lactose to lactic acid and this diffuses from the curd. The rate at which this occurs, as well as the rate at which moisture and lactose are removed, have substantial impact on the nature of the finished cheese. Whey expulsion also has an impact on the release of calcium...

Inr

Whereas American bourbon and rye whiskies are put into new oak casks, Scotch, Irish and Canadian whiskies are filled into casks that have previously been employed for Bourbon or for sherry. For the most part they comprise 50 L butts. Whisky casks are either of American white oak which are used for Fino and Amontillado Sherries or Spanish Oak used for Oloroso Sherry . The bourbon casks used for Scotch whiskies must be filled at least once with bourbon and the...

Fermentation

Some blending of juices may occur prior to fermentation and additions made. In particular, there may be a blending with sugars or AJC, to arrive at a specific gravity of 1.08-1.1. The FAN level may be raised to 100 mgL-1 by the addition of ammonium sulphate or ammonium phosphate. Thiamine may be added, perhaps at 0.2 ppm, but this must be separate from the addition of sulphite as the latter will destroy it. Other B vitamins that are required are pantothenate 2.5 ppm , pyridoxine 1 ppm and...

Chemical synthesis of vinegar

Acetic acid can be produced by the catalytic oxidation of acetaldehyde, which in turn is produced by the catalytic hydration of acetylene or by the catalytic dehydrogenation of ethanol. The undesirable formic acid and formaldehyde are eliminated by distillation. The acetic acid is purified before diluting to 60-80 by volume to obtain the vinegar essence. This in turn is diluted to 4-5 in the generation of food grade 'vinegar'. Sugar, salt and colour may be added. In the United Kingdom, such a...

Vinegar making processes

Vinegar Generator

The slow Orleans process is employed for the manufacture of high-quality vinegars Fig. 9.1 . The starting liquor is held in large casks containing wood shavings or grape stalks that represent a large surface area on which the microbes can thrive. Acetification commences and after 8 days, the liquid is withdrawn and transferred to barrels so as to become half to two-thirds full. Fresh vinegar stock is introduced into the main cask to replace that which has been removed. Acidity reaches a maximum...

Rum

Rum primarily originated in the Caribbean, although the first references to liqueurs obtained from sugar cane are from India. Sugar cane was introduced to the Caribbean by Christopher Columbus in 1493. The chief producing countries are Barbados and Santo Domingo. Nowadays the coastal planes of Guyana Demerara are rich in estates producing sugar cane Saccharum officinarum . At harvest time the fields of sugar cane are set alight in order to sanitise the soil, the stems are scorched in this...

Nutritional needs

The four elements required by organisms in the largest quantity gram amounts are carbon, hydrogen, oxygen and nitrogen. This is because these are the elemental constituents of the key cellular components of carbohydrates Fig. 1.3 , lipids Fig. 1.4 , proteins Fig. 1.5 and nucleic acids Fig. 1.6 . Phosphorus and sulphur are also important in this regard. Calcium, magnesium, potassium, sodium and iron are demanded at the milligram level, while microgram amounts of copper, cobalt, zinc, manganese,...

Whiskey

Foreshot Middle Cut

Whisky spelled this way for Scotch, but as whiskey for Irish and other forms of the product is a distilled beverage made from cereals and normally matured in oak. It is subject to a great deal of legislation and custom. EU regulations state that it can be made from any cereal aided by starch-degrading enzymes with distillation to less than 94.8 ABV, with ensuing maturation in wooden casks of less than 700 L in volume for a period in excess of 3 years for sale at a strength in excess of 40 ABV....

Overview of malting and brewing

Micro Brewery Mash Tun

Brewer's yeast Saccharomyces can grow on sugar anaerobically by fermenting it to ethanol While malt and yeast contribute substantially to the character of beers, the quality of beer is at least as much a function of the water and, especially, of the hops used in its production. Barley starch supplies most of the sugars from which the alcohol is derived in the majority of the world's beers. Historically, this is because, unlike other cereals, barley retains its husk on threshing and this husk...

T

Cylindroconical Fermentor Principles

Discard 65 Hl yeast contaminated propagation yeast vessel 650 Hl fermentation vessel Fig. 2.24 Yeast propagation. After MacDonald et al 1984 . The sugar is 'dribbled in' and the end result is a far higher yield of biomass, perhaps four-fold more than is produced when the sugar is provided in a single batch at the start of fermentation. The majority of brewing yeasts are resistant to acid pH 2.0-2.2 and so the addition of phosphoric acid to attain this pH is very effective in killing bacteria...

Caramel

This is still produced to this day by burning sugar, but in very controlled ways. The principal products are produced by the polymerisation of glucose by dehydration. The process is catalysed by acids or bases and requires temperatures in excess of 120 C. In some markets, the word caramel is retained for materials that are produced in the absence of nitrogen-containing compounds and these products are used for flavouring value. Where N is present, then 'sugar colours' are produced and these are...

Nonenzymatic browning

These are chemical reactions that lead to a brown colour when food is heated. The relevant chemistry is known as the Maillard reaction, which actually comprises a sequence of reactions that occurs when reducing sugars are heated with compounds that contain a free amino group, for example, amino acids, proteins and amines Fig. 1.22, Table 1.7 . In reflection of the complexity of the chemistry, there are many reaction intermediates and products. As well as colour, Maillard reaction products have...

CuSO4 h2s CuS h2so4

Norisoprenoids

Certain inorganic precipitates can be thrown in wine, with tartrate being a key problem. This is avoided by cold treatment of the wine. Protein hazes are avoided by the use of chilling and bentonite. Maintaining wine in an anaerobic state and with 20-30 mgL-1 SO2 is generally sufficient to prevent spoilage by most bacteria and yeast. Furthermore, when fermented to dryness, most white wines are relatively resistant to spoilage. The use of other micro organisms in wine production Red wines...