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ChemWell
Automated
Food & Beverage Process Control
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Shown: Amm-500 (250 tests)
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Ammonia UniTab Reagent (=AMM):
An enzymatic test kit for
determination of ammonia
in grape juice, fermenting wine, and
other liquid samples. Contains
enzymes, substrates and buffer components in tablet form and as aqueous
solutions and suspensions.
Each reagent tablet
is dissolved in 5 mL
of deionized water, permitting the user to prepare only as much working reagent
as required for daily use. One drop of Trigger (start) reagent is
sufficient to initiate the reaction. This reagent is linear to
approximately 180 mg/L. Ask about our "Extended Range AMM" reagent kit,
linear to 350 mg/L (with sensitivity to 10 mg/L)
Yeast Assimilable
Nitrogen compounds in juice are made up of Ammonia Nitrogen + Primary Amino
Nitrogen.
Typical
total YAN compounds range from 40 – 560, expressed in mg Primary Amino
Nitrogen mg/L. Lower limits of 35 mg/L L-Arginine and 50 – 70 mg/L Total
Nitrogen (YAN) have been recommended.
Scroll down, to see our Primary Amino Nitrogen (PAN) UniTab
Reagent kit.
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Yeast and M-L Bacteria require
available nitrogen for effective fermentation.
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Nitrogen status of must is monitored
to ensure sufficient Nitrogen sources to sustain yeast and lactic bacteria
fermentation. Nitrogen content of grape juice may be supplemented, e.g. with
diammonium phosphate (DAP.)
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Low Ammonia Nitrogen
& PAN levels have been associated with sluggish fermentation and sensory
imperfections.
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Routine and excessive nitrogen
supplementation should be avoided, since residual nitrogen supports the growth
of unwanted wine spoilage organisms such as Brettanomyces, Lactic Acid Bacteria,
Acetobacter, etc.
Available in
30-Test, 75-Test,
250-Test kit sizes.
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ChemWell
Automated
Food & Beverage Process Control
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Shown:
GF-150 (75 tests)
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D-Glucose/Fructose UniTab
Reagent (=GF):
An enzymatic
test kit for determination of total D-glucose plus D-fructose (reducing sugars)
in grape juice,
fermenting wine, and other
samples.
Contains enzymes, substrates and buffer components in tablet
form;
each reagent tablet is dissolved in 5 mL
of deionized water, permitting the user to prepare only as much working reagent
as required for daily use. One drop of Trigger (start
enzymes Hexokinase and PGI)) reagent is
sufficient to initiate the reaction. The D-Fructose Standard, provided
in addition to the D-Glucose Standard, is of particular benefit in monitoring
the (slower) PGI mediated reaction.
Reducing sugars are the
predominant soluble components of soft fruits, with sucrose in low amounts.
D-Glucose and D-fructose are the predominant reducing sugars in grape and other
fruit juices. The ratio of glucose to fructose in mature grapes is "1", but
ranges from 0.74 - 1.12 according to variety, maturity and fermentation
conditions. In 'stuck fermentations', D-Fructose often predominates, since
D-Glucose is the preferred energy source for yeast.
Available in 30-Test, 75-Test, 250-Test kit sizes.
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ChemWell
Automated
Food & Beverage Process Control
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Shown: LMA-150 (75 tests)
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L-Malic Acid Unitab Reagent
(=LMA):
An enzymatic test kit for determination of L-malic acid
in grape juice, fermenting wine, and
other liquid samples and
other samples. Contains enzymes, substrates and buffer components in tablet
form and as aqueous solutions and suspensions.
Each reagent tablet is dissolved
in 5 mL of Malic Acid Buffer,
permitting the user
to prepare only as much working reagent as required for daily use.
One drop of Trigger
(start enzymes Malate Dehydrogenase and GOT)) reagent is
sufficient to initiate the reaction. ) reagent is sufficient to initiate the reaction.
L-malic acid is present in
grapes, apples and other fruit and vegetables. In grape juice, its concentration
drops from (as high as) 8 to perhaps 1 g/L in grape must as the ripening process
proceeds; L-Malic levels, along with sugar concentration, are typically used to
gauge ripeness for wine production. Up to 30% of the malic acid may be consumed
by yeast fermentation. A secondary fermentation is typical in wine; L-malic acid
is converted to L-lactic acid and carbon dioxide by lactic bacteria. Mali-lactic
fermentation can be prevented by filtration and increased sulfite.
Available in 30-Test, 75-Test, 250-Test kit sizes.
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ChemWell
Automated
Food & Beverage Process Control
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Click to enlarge
Shown: PAN-150 (75 tests)
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Primary Amino Nitrogen UniTab
Reagent (=PAN): A test kit
for determining primary amino nitrogen compounds (NOPA) in
grape juice, fermenting wine, and other liquid samples.
Contains buffered
N-Acetyl-l-cysteine
(NAC) tablets, ophthaldialdehyde
(OPA), and
Nitrogen Standard Solution.
Each tablet is dissolved in 5 mL
of deionized water, permitting the user to prepare only as much working reagent
as required for daily use. This "fast blanking" method only requires working reagent
(the blank reagent solution is no longer required). This procedure is based on a published method
from UC Davis.
Yeast Assimilable
Nitrogen compounds in juice are made up of Ammonia Nitrogen + Primary Amino
Nitrogen.
Typical
total YAN compounds range from 40 – 560, expressed in mg Primary Amino
Nitrogen mg/L. Lower limits of 35 mg/L L-Arginine and 50 – 70 mg/L Total
Nitrogen (YAN) have been recommended.
Scroll up, to
see our Ammonia UniTab Reagent kit.
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Yeast and M-L Bacteria require
available nitrogen for effective fermentation.
-
Nitrogen status of must is monitored
to ensure sufficient Nitrogen sources to sustain yeast and lactic bacteria
fermentation. Nitrogen content of grape juice may be supplemented, e.g. with
diammonium phosphate (DAP.)
-
Low Ammonia Nitrogen
& PAN levels have been associated with sluggish fermentation and sensory
imperfections.
-
Routine and excessive nitrogen
supplementation should be avoided, since residual nitrogen supports the growth
of unwanted wine spoilage organisms such as Brettanomyces, Lactic Acid Bacteria,
Acetobacter, etc.
Available in 30-Test, 75-Test, 250-Test kit sizes.
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Shown: URAA-150 (75 tests)
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Urea/Ammonia/L-Arginine
UniTab Reagent Kit (=URAA):
A test for sequentially
determining ammonia, urea, and L-Arginine in grape juice, fermenting wine,
and other liquid samples.
Each reagent tablet
is dissolved in 5 mL
of deionized water, permitting the user to prepare only as much working reagent
as required for daily use. One drop of Trigger (start) reagent is
sufficient to initiate each reaction.
For a description of the role of
Urea, Ammonia, and L-Arginine (and other Primary Amino Acids) in fermentation,
refer to the URAM and YAN-arg reagent kits below.
Available in 30-Test, 75-Test kit sizes.
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Shown:
URAM-150 (75 tests)
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Urea / Ammonia
UniTab Reagent Kit (=URAM): A test for sequentially determining
ammonia and urea in grape juice, fermenting wine, and other liquid samples.
Each reagent tablet
is dissolved in 5 mL
of deionized water, permitting the user to prepare only as much working reagent
as required for daily use. One drop of Trigger (start) reagent is
sufficient to initiate each reaction.
Yeast require available nitrogen for
effective fermentation. Low Ammonia levels have been associated with
sluggish fermentation and sensory imperfections. Nitrogen status of must is
monitored to ensure sufficient Nitrogen sources to sustain yeast and lactic
bacteria fermentation. Nitrogen content of grape juice may be
supplemented, e.g. with diammonium phosphate (DAP.) Neither routine nor
excessive nitrogen supplementation is recommended. Yeast intracellular urea
is excreted and may be only partially reutilized during fermentation.
Residual urea can spontaneously react with ethanol to form ethyl carbamide,
and should be maintained at low levels in table wine and sherry.
In addition
to Ammonia Nitrogen & Urea Nitrogen, yeast assimilate nitrogen from amino
acids (i.e. Primary Amino Nitrogen compounds) in juice. Scroll up, to
see our Primary Amino Nitrogen (PAN) UniTab Reagent kits.
Available in 30-Test, 75-Test kit sizes.
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Winemakers monitor
Nitrogen Status because:
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Yeast and M-L Bacteria require
available nitrogen for effective fermentation.
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Nitrogen status of must is
monitored to ensure sufficient Nitrogen sources to sustain yeast and lactic
bacteria fermentation. Nitrogen content of grape juice may be supplemented,
e.g. with diammonium phosphate (DAP.)
-
Low Ammonia Nitrogen & PAN levels have been
associated with sluggish fermentation and sensory imperfections.
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Routine and excessive nitrogen supplementation should be avoided, since
residual nitrogen supports the growth of unwanted wine spoilage organisms
such as Brettanomyces, Lactic Acid Bacteria, Acetobacter, etc
L-Arginine determination is critically important
as a potential source of EC formation.
Arginine determination is
monitored to:
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Ensure sufficient Nitrogen sources to sustain yeast
and lactic bacteria fermentation
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L-Arginine spontaneously reacts with ethanol to form ethyl carbamide
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L-Arginine should be maintained at low levels in table
wine and sherry The accepted
limit is < 1000 mg/L. This minimizes the content of ethyl carbamate (EC), a potential carcinogen.
A rough estimate of YANC may be obtained
from Ammonia and L-Arginine values obtrained with the Unitech 'YAN-arg
Reagent Kit'. First one must calculate (or estimate) the approximate
fraction of PAN represented by L-Arginine (=%ARG) in a vineyards or region;
then:
(estimated) total Yeast Assimilable
Nitrogen Compounds (YANC) = Ammonia Nitrogen + ([PAN] / [%ARG]).
Typical
total YAN compounds range from 40 – 560, expressed in mg Primary Amino
Nitrogen mg/L. Lower limits of 35 mg/L L-Arginine and 50 – 70 mg/L Total
Nitrogen (YAN) have been recommended. An
accurate determination of total
Yeast Assimilable Nitrogen Compounds (YANC) is calculated from the sum
of Ammonia Nitrogen plus Primary Amino Nitrogen. Scroll up, to see our
Primary Amino Nitrogen (PAN) UniTab Reagent kits.
Available in 30-Test, 75-Test, 250-Test kit sizes.
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ChemWell
Automated
Food & Beverage Process Control
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Click to enlarge
Shown: AA-F150 (75 tests)
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Acetic Acid UniFlex Reagent
(=AA-F):
An enzymatic test kit
for determination of acetic acid in foods, beverages and other samples.
Contains ready to use aqueous buffer, MDH/Citrate synthase enzyme suspension,
ACS enzyme diluent, and acetic acid standard. Also contains in dry form Acetyl
Co-A Synthetase, which is dissolved in ACS enzyme diluent, and Coenzyme powder,
which is dissolve in deionized water.
Features:
1.
Reconstituted Coenzyme Solution and Acetyl Co-A Synthetase Solutions have
extended shelf life. Both are stable for 3 months following dissolution.
2.
The Flex CalculatorTM, which automatically calculates acetic
acid content in G/L based on the acetic acid ΔABS and extinction coefficient
equations. The user simply enters A0,A1, and A2
values into the Flex CalculatorTM spreadsheet. The Calculator
assists in estimating free acetic acid by providing a plot to facilitate the
extrapolation of A2 absorbance values at the time of ACS enzyme
addition.
Available in 30-Test, 75-Test, 250-Test kit sizes.
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You can download a copy of the
Flex CalculatorTM spreadsheet
here.
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ChemWell
Automated
Food & Beverage Process Control
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Click to enlarge
Shown: GLU F-150
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D-Glucose, UniFLEX Reagent
(=GLU F):
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ChemWell
Automated
Food & Beverage Process Control
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Shown: GF-F150 (75 tests)
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D-Glucose/Fructose UniFlex Reagent
(=GF-F):
An enzymatic test kit
for determination of both D-glucose and D-fructose (reducing sugars) in foods,
beverages and other samples.
Contains read-to-use Buffer solution and two enzyme suspensions (Hexokinase/G6PDH and PGI), permitting independent determinations of D-glucose and D-fructose.
Also contains D-fructose
and D-glucose standards. The Fructose Standard is of particular benefit in
monitoring the (slower) PGI mediated reaction.
Reducing sugars are the
predominant soluble components of soft fruits, with sucrose in low amounts.
D-Glucose and D-fructose are the predominant reducing sugars in grape and other
fruit juices. The ratio of glucose to fructose in mature grapes is "1", but
ranges from 0.74 - 1.12 according to variety, maturity and fermentation
conditions. In 'stuck fermentations', D-Fructose often predominates, since
D-Glucose is the preferred energy source for yeast.
Available in 30-Test, 75-Test, 250-Test kit sizes.
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ChemWell
Automated
Food & Beverage Process Control
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D-Lactic Acid
UniFlex Reagent (=DLA-F):
An enzymatic test kit for the determination of D-lactic acid
in wine and
other liquid samples and
other samples.
Contains
buffer, NAD Substrate, enzymes, and standard as ready-to-use aqueous solutions and suspensions.
Lactic acid is found in very low concentration in grapes.
Between 0.1 – 0.4 G/L of lactic acid is typically
found in wine (absent mali-lactic fermentation.)
Infrequently, and in the presence of high residual sugar and
pH, ubiquitous lactic bacteria (typically of Leuconostoc,
Pediococcus, or Lactobacillus genera) are involved in wine
spoilage; significant amounts of D-Lactic acid and acetic acid
can be produced by metabolism of sugars, glycerol, tartaric or
citric acid in the wine. D-Lactic acid and detrimental
by-products of lactic bacterial action can be largely prevented
by filtration and increased sulfite concentration.
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ChemWell
Automated
Food & Beverage Process Control
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D/L-Lactic Acid
UniFlex Reagent (=DL-LA-F):
An enzymatic test kit for the sequential determination of L-lactic and D-lactic acid
in grape juice, fermenting wine, and
other liquid samples and
other samples.
Contains
buffer, NAD Substrate, enzymes, and standard as ready-to-use aqueous solutions and suspensions.
Lactic acid is found in very low concentration in grapes.
Between 0.1 – 0.4 G/L of lactic acid is typically
found in wine (absent mali-lactic fermentation.) A small
proportion of this (typically L-lactic acid) is produced by
yeast during primary fermentation, while larger quantities of
L-Lactic acid may be produced by the metabolism of L-malic acid
by lactic bacteria during secondary fermentation. Infrequently,
and in the presence of high residual sugar and pH, ubiquitous
lactic bacteria (typically of Leuconostoc, Pediococcus, or
Lactobacillus genera) are involved in wine spoilage;
significant amounts of D-Lactic acid and acetic acid can be
produced by metabolism of sugars, glycerol, tartaric or citric
acid in the wine. D-Lactic acid and detrimental
by-products of lactic bacterial action can be largely prevented
by filtration and increased sulfite concentration.
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ChemWell
Automated
Food & Beverage Process Control
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L-Lactic Acid
UniFlex Reagent (=LLA-F):
An enzymatic test kit for determination of L-lactic acid
in grape juice, fermenting wine, and
other liquid samples and
other samples.
Contains
buffer, NAD Substrate, enzymes, and standard as ready-to-use aqueous solutions and suspensions.
Lactic acid is found in very low concentration in grapes.
Between 0.1 – 0.4 G/L of lactic acid is typically
found in wine. A small proportion of this (typically L-lactic
acid) is produced by yeast during primary fermentation, while
larger quantities of L-Lactic acid may be produced by the
metabolism of L-malic acid by lactic bacteria during secondary
fermentation.
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ChemWell
Automated
Food & Beverage Process Control
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Click to enlarge
Shown: LMA-F500 (250 tests)
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L-Malic Acid UniFlex Reagent
(=LMA-F):
An enzymatic test kit
for determination of L-malic acid in foods, beverages and other samples.
Contains read-to-use Buffer, NAD Subtstrate solution, two enzyme suspensions
(Malate
Dehydrogenase and GOT), as well as a L-Malic Acid Standard.
L-malic acid is present in
grapes, apples and other fruit and vegetables. In grape juice, its concentration
drops from (as high as) 8 to perhaps 1 g/L in grape must as the ripening process
proceeds; L-Malic levels, along with sugar concentration, are typically used to
gauge ripeness for wine production. Up to 30% of the malic acid may be consumed
by yeast fermentation. A secondary fermentation is typical in wine; L-malic acid
is converted to L-lactic acid and carbon dioxide by lactic bacteria. Mali-lactic
fermentation can be prevented by filtration and increased sulfite.
Available in 30-Test, 75-Test, 250-Test kit sizes.
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Shown: TA-F60 (30 tests)
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Tartaric Acid
UniFlex Reagent Kit (=TA-F): -
for
the determination of tartaric acid in wine and other liquid samples. In the
presence of tartaric acid, the reagent forms an orange/red color which is
read photometrically.Contains
Tartaric Acid "Reagent A" and NaOH "Reagent B". A Tartaric Acid
Standard at 3G/L is also provided.
Available in 30-Test, 75-Test, and 250-Test kit sizes.
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Shown: PHEN-F60 (30 tests)
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Total Phenols
UniFlex Reagent Kit (=PHEN-F):
Total Phenol FLEX-REAGENT is intended for
determination of total phenols and polyphenols in wine, tea and other
non-protein liquid samples.This
reagent is a colorimetric oxidation/reduction method for phenolic compounds.
This Folin-Ciocalteu method is sensitive, quantitative and relatively
independent of the degree of polymerization (e.g. mono-, di- or trimer), and
is generally preferred over other analyses of wine phenols.
Phenolics in wine include tannins,
anthocyanins, polymeric pigments
and monomeric phenols (e.g. caffeic acid,
caftaric acid, catechins, quercetin, kaempherol, and gallic acid)
and are responsible for wine color, bitterness, and astringency. Color
and flavor profiles of finished wine are affected by grape selection and
winemaking techniques. Total
phenol content, as well as color and hue data, can provide valuable
information for optimizing these processes.
Available in 30-Test, 75-Test kit sizes.
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