EXAM_3 Flashcards
Vinegar production probably started developing soon after
wine manufacturing began
The word Vinegar comes from from vin aigre (French); meaning
Sour wine;
A spoilage problem became one of the most widely used ingredients in foods
World-wide production of Vinegar
1 million liters/year
Vinegar was probably first developed as a means to:
preserve non-fermented, perishable foods, such as meats and vegetables.
The first biologically-produced preservative was
Vinegar
______ functions in pickling and flavor and is also used as a topical disinfectant, a cleaning agent, and as an industrial chemical
Vinegar
______ is found in hundres of processed foods; Salad dressings, mayonnaise, mustard, ketchup, bread and bakery products, picked foods, canned foods, and marinades and sauces
Vinegar
There is no U.S. standard of identity for _______, but there are guidelines
Vinegar
The guidelines for Vinegar in the U.S. are:
- Must be made from an ethanol-containing solution. (Most common starting materials are grape and rice wine, fermented grain and malt mashes, and fermented apple cider; distilled ethanol also permitted)
- Must have resulted from the “acetous fermentation”
- Must contain at least 4% acetic acid or at least 40 grains with the pH between 2.0 and 3.5
In making vinegar the most common starting materials for ethanol solutions are:
- grape and rice wine
- fermented grain and malt mashes
- fermented apple cider;
- distilled ethanol also permitted
The name of the vinegar is determined by:
the raw material
The predominate flavor in vinegar is the ____
acetate; source and ingredients also add flavors
The Two-step manufacturing process for Vinegar is:
- An ethanolic, anaerobic fermentation performed by yeasts
2. Acetogenic, aerobic process carried out by acetic acid bacteria
The genera of bacteria that can produce acetic acid as its primary metabolic end-product via oxidation of ethanol in the production of vinegar are:
Acetobacter
Gluconobacter
Gluconacetobacter (recently named)
Acidomonas
Acetobacter, Gluconobacter, Gluconacetobacter (recently named), and Acidomonas are all
gram-negative, obligately aerobic bacteria
Acetic acid bacteria are widely distributed in
plant materials rich in sugars (and alcohol-containing solutions)
Acetic acid bacteria commonly share environments with
ethanol-producing yeasts
Generally, Acetobacter grows better on _____ than _____ while, Gluconobacter grows better on _____ than _____
Ethanol, Glucose
Glucose, Ethanol
Generally, Acetobacter grows better on ethanol than glucose while Gluconobacter grows better on glucose than ethanol.
Acetobacter aceti long is considered
the primary industrial vinegar producer
Many vinegar fermentations use ______ or ______ cultures
mixed or wild cultures
In vinegar metabolism is
an incomplete oxidation
In vinegar metabolism oxidation isn’t down to ___ and ____ like the Krebs Cycle
CO2 and H2O
In vinegar metabolism ethanol is oxidized to
acetic acid; that’s it
The two main steps of metabolism in vinegar are
- Ethanol (CH3CH2OH) oxidized to acetaldehyde (CH3COH).
2. Acetaldehyde oxidized to acetic acid (CH3COOH).
In the production of vinegar both the substrate and product are _____, so there is a _____ of competitors in the process
toxic; lack
In vinegar acetic acid bacteria ______ ______ low pH and high levels of acetic acid
remarkably tolerate
To prevent further oxidation of acetic acid to breakdown products vinegar fermentation have historically been conducted in a
semi-continuous mode with a minimum amount of ethanol always present (EtOH represses synthesis of Krebs Cycle enzymes that would oxidize acetate).
(Vinegar) Spontaneous mutations of Acetobacter strains have caused _____ in several important functions
defects
(Vinegar) Acetobacter strain mutants have lost ability to
oxidize EtOH, tolerate acetic acid, and form surface films.
Most industrial strains of Acetobacter contain plasmids, but most plasmids are
cryptic
Methods for producing vinegar:
- Open vat method
- Trickling generator process
- Submerged fermentation process
In the production of vinegar the open vat process relies on _______________________ in vats, barrels, jars, or trays.
surface growth of acetic acid bacteria (AAB)
The _______ process was probably the first method developed to make vinegar
open vat process
In the open vat process of vinegar making the ___ only grow at the surface
AAB
In the open vat process of vinegar making a ____________________ forms on the surface
polysaccharide-containing film or pellicle
In the open vat process of vinegar making intact ______ is important; can take _________ to _____
pellicle
several weeks
months
Intact pellicle is important; can take several weeks to months.
The Orleans style open vat process for vinegar uses:
- Wooden barrels used; 60 to 70% full.
2. A pipe from outside top to inside bottom; air holes drilled along sides plugged with cheesecloth.
When complete the Orleans style open vat process for vinegar removes ________ and is __________
about two-thirds of the volume and is recharged to do again.
In the Orleans style open vat process for vinegar the film or pellicle is __________
Not disrupted
Balsamic vinegar is done using the ______________ process
The Orleans style open vat process
The Orleans style open vat process takes at least
2 to 3 weeks
What is the trickling generator process?
The presence and availability of oxygen and the surface area represented by the air-liquid interface critically affect production of acetic acid.
Optimizing the diffusion or transport of oxygen to the AAB cell surface.
Observations of Dutchman, Hermann Boerhaave, formed the basis for ____________
trickling generator processes
When and where was the trickling generator process first used?
1820s in Europe
What kind of vats were used for trickling generator processes in Europe during the 1820s
Used vats with inert packing materials, such as curled wood shavings, wood staves, or corn cobs.
I.e., Immobilized cells
The packing materials used in the trickling generator processes during the 1820s increased _______________
the surface area and degree of aeration
