Fermented Foods

[Guest guest]

Fermented Food Production

www.innvista.com

 

" In the last thirty years, scientists have discovered an entire

domain of life, one that may hold as much complexity and diversity as

that containing all plants, animals, and fungi. This before-unknown

domain, like that called bacteria, has no nuclei. It shows up in

unique niches, like the hot pools in Yellowstone, but also in great

abundance on the roots of plants -- that is, on those roots found in

organic, but not in chemically treated soils. Scientists are still

getting to the bottom of what Archaeal microbes on plant roots do,

but many suspect that they may mediate the flow of minerals and

nutrients and fend off pathogens. " (emphasis mine) (Lappé, p.288) " It

is not know what they [the archaea bacteria] are doing there, but

Goodman suspects that they are mediating the flow of minerals and

nutrients, especially nitrogen, warding off pathogens, coupling with

other microbes to create the unseen ecosystem that is the basis of

agriculture... The archaeal microbes were present in the organic soil

but not in the samples from the industrial ag land. We don't know

what the archaeal bacteria have to do with the health of crops, but

this simple result indicates we should " . (Manning).

 

Microbes and food have always had a love-hate relationship. Food

producers have learned to harness their power -- and sometimes for

good use. There is no doubt that organically grown fruits and

vegetables are superior in flavor. Now, despite arguments to the

contrary made by food manufacturers, they may well be more nutritious

for a variety of reasons. There are always studies available to prove

any point, especially one where chemically doused foods are more

nutritious. But then, like bacteria in the throes of death, food

manufacturers mount a valiant effort in trying to convince those near-

at-hand that what they say is valid. But, be that as it may, the

choice is ultimately made individually.

 

Bacteria are, to a great extent, resistant to the effects of

irradiation because of their ability to repair their damaged DNA.

Sometimes, however, their repair is faulty, and the new DNA becomes

abnormal, causing a new strain. Salmonella and Campylobacter are

easily removed by irridation, but other bacteria are more stubborn.

Some, like Clostridium botulinum and L. monocytogenes, have the

ability to survive the drying techniques of irridation by converting

themselves into tough, little spheres. Food irriadiation, however,

exposes an edible product to the equivalent of two and a half million

chest X-rays. How many nutrients are left after this bombardment is

anyone's guess, but, at least, most of the germs are gone. Most, not

all. Short term studies have shown the destruction of numerous

vitamins through this process as well as the formation of new

carcinogens. There is also the possible formation of mutant bacteria

and viruses. Since the USDA approved such a process in February of

2000, fast food chains, restaurants, school lunch programs, and

cafeterias are now using irradiated meat products without the public

knowledge.

 

The most common usage for bacteria in food preparation is with dairy

fermentations. Yogurt and cheeses have been made for centuries using

bacteria. The ancients may not have known exactly what kind of

bacteria that was needed or if what was needed was, indeed, bacteria.

All they knew was that the previous batch was required to make a new

one. Many people lack the ability to break down and absorb lactose,

the sugar molecule in milk. As a result, it enters the gut, producing

acid and gas, causing pain and diarrhea. Fermented milk products

metabolize lactose into lactic acid, which is more tolerable for many

people. The most common fermented milk product is yogurt. The

lactobacilli used in the making of many yogurts, however, may not be

the same type as found within the common flora of humans as there are

many different strains (see Probiotics). The following are some of

the bacteria used in the diary industry:

 

Acidophilus milk is made with Lactobacillus acidophilus.

 

Butter is made from pasteurized cream, to which a lactic acid starter

has been added. The starter contains, for example, Streptococcus

cremoris or S. lactis, but requires Lactobacillus diacetylactis to

give it its characteristic flavor and odor.

 

Cheese is often made with Streptococcus and Lactobacillus bacteria.

Fermentation lowers the pH, thus helping in the initial coagulation

of the milk protein, as well as giving characteristic flavors. In

such Swiss cheeses as Emmentaler and Gruyere, the typical flavor is

the result of the use of Propionibacterium. Cheese can be classified

within two groups -- ripened and unripened. Unripened cheeses consist

of cottage cheese, cream cheese, and Mozzarella, for example. These

are soft cheeses and are made by the lactic acid fermentation of

milk. Many different bacteria are used to produce the various

cheeses, but Lactococcus lactis and Leuconostoc cremoris are used

most often. Soft cheeses can take one to five months to ripen; hard

cheeses, three months to a year or more; and very hard cheeses, like

Parmesan, can take twelve to eighteen months. The blue veins found in

cheeses, like Stilton and Roquefort, are caused by growth Penicillium

roqueforti, which is deliberately added now to cheese. Originally, it

was found as a natural contaminant of the areas where it was made.

The holes in Swiss cheese are the result of Propionibacterium

shermanii. The surfaces of Camembert and Brie are innoculated with

Penicillium camembertii, which then develops in a skin on the

surface. Limburger is soaked in brine to encourage the growth of

Brevibacterium linens (it should come as no surprise that this is the

same bacteria isolated from smelly feet!)

 

Kefir includes many different microbes, including yeasts,

lactobacilli, lactococci, and leuconostocs. Depending on geographical

locations, the precise types of microbes will vary.

 

Yogurt usually requires the addition of Lactobacillus bulgaricus,

Lactococcus thermophilus, and/or Streptococcus thermophilus to the

milk.

 

Bacteria are not only used for fermentaion in the dairy industry, but

for use in other such food production as in the processing of coffee

and cocoa, the manufacturing of food additives, and other such

processes such as the making of xanthan gum and vinegar. Bacteria,

and most viruses do not tolerate acids. This is the reason that

vinegar retards the growth of most bacteria. The following is a list

of other foods where bacteria and other microbes are necessary for

the making of certain foodstuffs.

 

Vitamins are the most important non-prescription medications. Most

are economically made synthetically, but some are produced

biosynthetically, that is, partly from synthetics and partly from

bacteria. Such yeast extracts as Vegemite and Marmite are rich in B

vitamins. Microbes may be used to elaborate precursors in the making

of Vitamins A, C, and the B family. Using sugarbeet molasses as a

growth medium, Pseudomonas denitrificans is made to produce Vitamin

B12. Members of the genus Propionibacterium are also used to make

this vitamin. Although many bacteria and fungi produce riboflavin

(B2), the fungus Ashbya gossypii produces it in huge quantities.

 

MSG (monosodium glutamate) is manufactured by Corynebacterium

glutamicum, a cousin of the diptheria germ.

 

Citric acid used to be extracted primarily from lemons, but worldwide

demand for it forced the commercial industry to seek other sources.

The fungus, Aspergillus niger, when grown on sugarbeet molasses,

produces huge quantities of citric acid.

 

Glutamic acid requires Corynebacterium glutamicum for its formation.

Biotin is a cofactor essential for lipid synthesis in bacteria. By

growing C. glutamicum on limited amounts of biotin, it causes the

bacterial membrane to leak sufficient quantities of glutamic acid.

 

Lysine -- The bacterium, Brevibacterium flavum is used in the

industrial biosynthesis of lysine. Mutants no longer susceptible to

feedback inhibition have been isolated to be used industrially to

increase the yield of amino acids.

 

Baker's yeast (Saccharomyces cerevisiae) provides a variety of

enzymes that enable carbohydrates to be broken down producing

sufficient carbon dioxide to give bread its characteristic texture.

 

Beers, etc. -- Traditionally, the natural yeasts on grape skins

determine the quality of wine produced. These natural yeasts,

especially Saccharomyces cerevisiae (beer in Spanish is " cervesa " )

and Saccharomyces ellipsoideus, ferment the grapes to make wine. It

used to be a risky business leaving it up to nature to decide the

quality. Now winemaking has become a regulated science with the use

of these yeasts. Beers, lagers, and ales generally rely on the yeast

Saccharomyces cerevisiae, although lager yeasts will probably always

be known as Saccaromyces carlsbergensis.

 

Sauerkraut-making requires the bacteria Leuconostoc mesenteroides and

Lactobacillus brevis to ferment sugars that provide a variety of such

organic products as lactic acid, acetic acid, ethanol, and mannitol.

These bacteria are known as 'heterofermentative' bacteria. Later

a 'homofermentative' bacteria, Lactobacillus plantarum takes over,

producing only lactic acid. Later, Enterococcus faecalis and

Pediococcus cerevisiae assume the fermentation process if the salt

brine is not what it sould be.

 

Sourdough bread requires the help of a yeast, Saccharomyces exiguus,

along with lactobacilli, to provide its characteristic texture and

flavor.

 

Dill pickles are simply fermented cucumbers. Streptococci starts the

process of fermentation, but as the pH level falls, leuconostoc and

pediococcus species, as well as Lactobacillus plantarum continue the

process.

 

Olives are edible only after fermentation with Lactobacillus

plantarum and Lactobacillus mesenteroides.

 

Coffee and chocolate require Erwinia dissolvens, leuconostoc, and

lactobacillus species plus the yeasts of the genus Saccharomyces to

remove the tough outer coats. The microbes do not affect the taste of

coffee but are necessary to confer the characteristic taste to cocoa

and chocolate. The bacteria S. napoli and S. eastbourne often use

chocolate as a vector. It is thought that the chocolate provides

protection for the bacterium as it passes through the acidic

environment of the stomach. This was observed when higher incidents

of illness were reported in children.

 

Soy sauce is made from a mixture of soy beans and rice fermented by a

variety of bacteria and fungi. These include Lactobacillus

delbrueckii, Aspergillus oryzae, Aspergillus soyae, and Saccharomyces

rouxii.

 

Meat products, like salami and bologna sausages, require some

fermentation with Pediuococcus cerevisiae, Lactobacillus plantarum

and some members of the genus Bacillus. Country cured hams use fungi

of the genus Aspergillus and the genus Penicillium in their

fermentation process. Izushi (sushi), a Japanese delicacy made from a

mixture of fish, rice, and other vegetables is produced by

fermentation with lactobacilli.