Chemistry TESTING Services

Chestnut Labs food chemistry lab is well equipped with state-of-the-art technology to provide thorough proximate chemistry analysis for ingredients, and processed foods.

OUR LIST OF SERVICES INCLUDE:

ACID DEGREE VALUE

Acid degree value (ADV) has been used as an indicator of rancid off-flavor development in milk. In the ADV procedure, milk fat is extracted with heat, detergent, and centrifugation, and the FFA in the recovered fat is titrated. Milk with an ADV >1.00 meq/100 g of fat is considered slightly rancid.

Minimum Sample Size Requirements
35g
Reportable Units
ADV
Turn Around Time Minimums
6 days
Method
SMEDP

ALKALINITY OF ASH

The sample is ashed, then treated with 0.1N HCL, and back titrated with 0.1N NaOH to determine the amount of alkalinity.

Alkalinity of ash measures the basicity (alkalinity) of the ash obtained from a sample.

Minimum Sample Size Requirements
5g
Reportable Units
ml 0.1N HCL per 100 grams
Turn Around Time Minimums
6 days
Method
ADPI

ALLERGEN TESTS - (QUALITATIVE AND QUANTITATIVE) - MILK

Alert for allergen testing is a sandwich enzyme-linked immunosorbent assay. Milk is extracted from a sample by blending with a hot buffered salt solution. Extracted milk is added to antibody-coated wells where it binds to the antibody during incubation. Any unbound milk is washed away, and a second antibody, which is enzyme labeled, is added. The detector antibody binds to the already bound milk. After a second wash, substrate is added. Color develops as a result of the presence of bound detector antibody. Red stop reagent is added, and the color of the resulting solution is observed.

Minimum Sample Size Requirements
5g/ml or swab
Reportable Units
ppm
Turn Around Time Minimums
6 days
Method
Neogen Corp.

ALLERGEN TESTS - (QUALITATIVE AND QUANTITATIVE) - SOY

Soy Alert for allergen testing is a sandwich enzyme-linked immunosorbent assay. Soy is extracted from a sample by blending with a hot buffered salt solution. Extracted soy is added to antibody-coated wells where it binds to the antibody during incubation. Any unbound soy is washed away, and a second antibody, which is enzyme labeled, is added. The detector antibody binds to the already bound soy. After a second wash, substrate is added. Color develops as a result of the presence of bound detector antibody. Red stop reagent is added and the color of the resulting solution is observed.

Minimum Sample Size Requirements
5g/ml or swab
Reportable Units
ppm
Turn Around Time Minimums
6 days
Method
Neogen Corp.

ALLERGEN TESTS - (QUALITATIVE AND QUANTITATIVE) - EGG

Alert for allergen testing is a sandwich enzyme-linked immunosorbent assay. Egg is extracted from a sample by blending with a hot buffered salt solution. Extracted egg is added to antibody-coated wells where it binds to the antibody during incubation. Any unbound egg is washed away, and a second antibody, which is enzyme labeled, is added. The detector antibody binds to the already bound egg. After a second wash, substrate is added. Color develops as a result of the presence of bound detector antibody. Red stop reagent is added, and the color of the resulting solution is observed.

Minimum Sample Size Requirements
5g/ml or swab
Reportable Units
ppm
Turn Around Time Minimums
6 days
Method
Neogen Corp

ALLERGEN TESTS - (QUALITATIVE AND QUANTITATIVE) - PEANUT

Alert for allergen testing is a sandwich enzyme-linked immunosorbent assay. Peanut is extracted from a sample by blending with a hot buffered salt solution. Extracted peanut is added to antibody-coated wells where it binds to the antibody during incubation. Any unbound peanut is washed away, and a second antibody, which is enzyme labeled, is added. The detector antibody binds to the already bound peanut. After a second wash, substrate is added. Color develops as a result of the presence of bound detector antibody. Red stop reagent is added, and the color of the resulting solution is observed.

Minimum Sample Size Requirements
5g/ml or swab
Reportable Units
ppm
Turn Around Time Minimums
6 days
Method
Neogen Corp.

ALLERGEN TESTS - (QUALITATIVE AND QUANTITATIVE) - WHEAT/ GLIADEN

Alert for Allergen testing is sandwich enzyme-linked immunosorbent assay. Wheat/Gliaden is extracted from samples by blending with a hot buffered salt solution. Extracted gliaden is sampled and added to antibody-coated wells where it binds to the antibody during incubation. Any unbound gliaden is washed away and a second antibody, which is enzyme labeled, is added. The detector antibody binds to the already bound gliaden. After a second wash, substrate is added. Color develops as a result of the presence of bound detector antibody. Red stop reagent is added and the color of the resulting solution is observed.

Minimum Sample Size Requirements
5g/ml or swab
Reportable Units
ppm
Turn Around Time Minimums
6 days
Method
Neogen Corp.

ASH

Organic matter is burned off by igniting the sample at 550°C in an electric furnace. The remaining material is determined gravimetrically, and referred to as ash.

Ash is the inorganic residue remaining after the water and organic matter have been removed by heating in the presence of oxidizing agents, which provides a measure of the total amount of minerals within a food. Analytical techniques for providing information about the total mineral content are based on the fact that the minerals can be distinguished from all the other components (the matrix) within a food in some measurable way. The most widely used methods are based on the fact that minerals are not destroyed by heating, and that they have a low volatility compared to other food components. Ash contents of fresh foods rarely exceed 5%, although some processed foods can have ash contents as high as 12%.

Minimum Sample Size Requirements
5g
Reportable Units
%
Turn Around Time Minimums
6 days
Method
AOAC, SMEDP, AOCS

BULK DENSITY

Density is the measure of the weight per unit volume of solid or liquid samples. Bulk density measures the apparent density of powders, and particulates that to include the air voids in the bulk sample. Displacement density measures the density of the particles excluding void spaces.

Minimum Sample Size Requirements
100g for powder or 25g for liquids
Reportable Units
g/cc or g/ml
Turn Around Time Minimums
6 days
Method
IDF

CHLORIDE AS A PERCENT

This procedure employs the use of an ISE meter, and a chloride ion electrode to determine the amount of chloride present in a sample.

Minimum Sample Size Requirements
10g
Reportable Units
%
Turn Around Time Minimums
6 days
Method
AOAC, SMEDP, AOCS

EXTRANEOUS MATTER

The sample is prepared by adding 1000ml of a matrix specific solution. The sample is then mechanically agitate for one hour while on a hot plate. The product is then filtered, examined, and identified under a Widefield Stereoscopic Microscope.

Minimum Sample Size Requirements
225g
Reportable Units
Reports quantity and identity or description of matter.
Turn Around Time Minimums
6 days
Method
AOAC, SMEDP

FAT - Babcock

Sulfuric acid is added to a known weight of a sample to evolve the heat necessary to disintegrate all non-fat material, while at the same time releasing liquefied fat for volumetric measurement

Minimum Sample Size Requirements
25g
Reportable Units
% Fat
Turn Around Time Minimums
6 days
Method
SMEDP

FAT - MOJONIER

The fat is extracted by ether extraction, the ether is evaporated, and the dry fat is weighed and calculated.

Minimum Sample Size Requirements
5g
Reportable Units
% Fat
Turn Around Time Minimums
6 days
Method
AOAC, SMEDP

FAT - Free Fat

Applicable for the determination of free fat in most products.

Minimum Sample Size Requirements
30g
Reportable Units
% Free Fat
Turn Around Time Minimums
6 days
Method
Custom

FAT - ACID HYDROLYSIS

The sample is hydrolyzed with hydrochloric acid. The fat is extracted using ether and hexane. Then extract is filtered through a sodium sulfate column. The solvent is evaporated from the remaining extract, and the fat is dried, and weighed.

Minimum Sample Size Requirements
10g
Reportable Units
% Fat
Turn Around Time Minimums
6 days
Method
AOAC

FREE FATTY ACIDS

The method determines the free fatty acids existing in a sample by adding a specified amount of hot neutralized alcohol to a sample, and titrating it with standard sodium hydroxide and calculated as oleic acid.

Minimum Sample Size Requirements
Dependent on Product.
Reportable Units
%
Turn Around Time Minimums
6 days
Method
AOAC, AOCS

HEAVY METALS AS LEAD

Heavy metals can be toxic for humans when they are not metabolized by the body and accumulate in the soft tissues. Depending on the heavy metal in question, toxicity can occur at levels just above naturally occurring background levels, meaning that consumption of food with a high heavy metal concentration can cause acute or chronic poisoning. Poisoning can result in damaged or reduced mental and central nervous function as well as damage to blood composition, lungs, kidneys, liver, and other vital organs. Long-term exposure to heavy metals may result in slowly progressing physical, muscular, and neurological degenerative conditions as well as cancer.

The sample is digested with nitric acid, and sulfuric acid on a hot plate, then placed in a muffle furnace at 500° C. Dilute hydrochloric acid is added to the cooled sample, and taken to dryness on a hot plate. The pH is adjusted to remove iron impurities. The sample is filtered into a nessler tube, thioacetomide solution is added, and the color that develops is compared with that of lead standards.

Minimum Sample Size Requirements
5g
Reportable Units
Reported as <, or >5 ppm
Turn Around Time Minimums
6 days
Method
USP

INHIBATORY SUBSTANCES - BETA LACTAM - DELVOTEST P/ DELVOTEST P MINI

A nutrient tablet is added to an ampule containing Bacillus stearothermophilus var. calidolactus in a solid agar medium. A sample aliquot is added to the ampule which is incubated in a heat block at 64° + 1°C for 2-5 hrs. After incubation, the culture is observed for inhibition of growth as indicated by the color of the indicator in the medium.

Minimum Sample Size Requirements
Dependent on Product, 11g/ml
Reportable Units
Reported as “None Decected”, or “Detected.”
Turn Around Time Minimums
6 days
Method
SMEDP

LACTIC ACID (D AND L )- ENZYMATIC ANALYSIS

In the presence of D-lactate dehydrogenase (D-LDH), D-latic acid ( D-Lactate) is oxidized by pyruvate to nicotinamide-adenine dinucleotide. The oxidation of L-latic acid requires the presence of the enzyme L-lactate dehydrogenase. (1) D-Lactate + NAD D-LDH—>pyruvate + NADH + H (2) L-Lactate + NAD L-LDH—> pyruvate + NADH + H. The equilibrium of these reactions lies on the side of lactate. By trapping pyruvate in a subsequent reaction catalyzed to by the enzyme glutamate-pyruvate tranzaminase (GPT) in the presence of L-glutamate, the equilibrium can be displaced in facor of pyruvate and NADH. (3) Pyruvate + L-glutamate<–GPT–>L-alanine + 2-oxoglutarate. The amount of NADH formed in the aboce reactions is stoichiometric to the amount of D-lactic acid, and of the L-latic acid. The increase in NADH is determined by means of its light absorbance.

Minimum Sample Size Requirements
10g
Reportable Units
% Lactic Acid
Turn Around Time Minimums
6 days
Method
R-Biopharm

LACTOSE/D-GALACTOSE- ENZYMATIC ANALYSIS

Lactose is hydrolyzed to D-glucose and D-galactose in the presence of the enzyme ß-galactosidase and water. D-Galactose is oxidized by nicotinamide-adenine dinucleotide (NAD) to D-galactonic acid in the presence of the enzyme ß-galactosidase dehydrogenase. The amount of NADH formed in reaction is stoichiometric to the amount of lactose, and D-galactose respectively. The increase in NADH is measured by means of light absorbance.

Minimum Sample Size Requirements
5g
Reportable Units
% Lactose
Turn Around Time Minimums
6 days
Method
AOAC 984.15

LIPASE

Lipase is an enzyme that is used by the body to break down dietary fats into an absorable form. The heat treatment employed during the production of dry products should inactivate the lipase enzyme. Lipase is inactivated at 55°-60°C. Indoxylacetate is split by lipase into indigo and acetate. Indigo reacts with oxygen and turns blue. The presence of a blue color is an indication for the presence of lipase.

Minimum Sample Size Requirements
20g
Reportable Units
Reported as Positive or Negative.
Turn Around Time Minimums
6 days
Method
PURR

MINERAL ANALYSIS-ICP-OES

This process by which a sample is subjected to temperatures high enough to cause not only dissociation into atoms, but also causes significant amounts of collision excitation of the sample atoms to take place. Once the atoms or ions are in their excited states they can decay to lower states through thermal, or radiative energy transitions. the internsity of the light emitted at specific wave lengths is measured, and used to determine the concentrations of the elements of interest.

Minimum Sample Size Requirements
Dependent on Product
Reportable Units
ppm*, other units can be recorded as specified
Turn Around Time Minimums
6 days
Method
AOAC, ICP

MOISTURE - VACUUM OVEN

The sample is dried in a vacuum oven at 100° C to a constant weight.

Minimum Sample Size Requirements
5g/ml
Reportable Units
%
Turn Around Time Minimums
6 days
Method
OAC, SMEDP, AOCS

MOISTURE - FORCED AIR OVEN

A meat sample is blended into a homogenous sample, weighed, and placed in a forced air oven, cooled, and re-weighed. The weight loss is used for moisture determination.

Minimum Sample Size Requirements
5g/ml
Reportable Units
%
Turn Around Time Minimums
6 days
Method
AOAC, SMEDP

MOISTURE BALANCE

Applicable for the determination of mositure in food products.

Minimum Sample Size Requirements
Dependent on Product.
Reportable Units
%
Turn Around Time Minimums
6 days
Method
SMEDP

NITROGEN - TOTAL, KJELDAHL

Applicable for the determination of total nitrogen in most food products.

Minimum Sample Size Requirements
Dependent on Product from 1g to 15g.
Reportable Units
% Nitrogen
Turn Around Time Minimums
6 days
Method
AOAC

NITROGEN - NON-PROTEIN NITROGEN (NPN)

Protein is precipitated from milk by addition of trichloroacetic acid solution. Precipitated milk protein is removed by filtration. The filtrate contains the non protein nitrogen components of milk. Nitrogen content of protein precipitate is determined using the kjeldahl method.

Minimum Sample Size Requirements
5g
Reportable Units
% Non-Protein Nitrogen
Turn Around Time Minimums
6 days
Method
AOAC

NITROGEN - AMINO NITROGEN

This is a method used to determine the content of amino nitrogen in finished products.

Minimum Sample Size Requirements
5g
Reportable Units
% Amino Nitrogen
Turn Around Time Minimums
6 days
Method
AOAC

PARTICLE SIZE (ROTAP)

An automatic Ro-Tap sieve shaker is used to give an objective measure of particle size. Syloid 244FP flow agent is added as an aid to test for most products.

Minimum Sample Size Requirements
100g
Reportable Units
% retained on each sieve
Turn Around Time Minimums
6 days

PEROXIDE VALUE

The fat or oil sample is dissolved, and an excess amount of potassium iodide is added. Peroxides present oxidize a portion of the iodide forming iodine. The iodine is titrated with sodium thiosulfate, and the peroxide value is calculated.

Minimum Sample Size Requirements
50g
Reportable Units
meq/kg of fat
Turn Around Time Minimums
6 days
Method
AOAC, AOCS

PH

The sample solution is read to the nearest 0.1 pH unit using an appropriate pH meter and electrode.

Minimum Sample Size Requirements
10g
Reportable Units
pH units
Turn Around Time Minimums
6 days

PROTEIN BY KJELDAHL - TOTAL PROTEIN

The protein and other organic nitrogen in the sample is converted to ammonia by digesting the sample with sulfuric acid containing a catalyst mixture. The acid digest is made alkaline, and the ammonia is distilled, and titrated with standardized acid. The percent nitrogen is determined, and converted to protein using the appropriate factor value.

Minimum Sample Size Requirements
20g
Reportable Units
%
Turn Around Time Minimums
6 days
Method
AOAC

PROTEIN BY KJELDAHL - TRUE PROTEIN

Protein is precipitated from milk by addition of trichloroacetic acid solution. Precipitation must be done in kjeldahl flask or tube. Final concentration of TCA is 15%. The 15% TCA solution, which contains non-protein nitrogen components of the test sample, is separated from protein precipitate by filtration. Nitrogen content of protein precipitate is determined using the kjeldahl method.

Minimum Sample Size Requirements
20g
Reportable Units
% True Protein
Turn Around Time Minimums
6 days
Method
AOAC

PROTEIN BY KJELDAHL - CRUDE PROTEIN

Applicable for the determination of crude protein in food products.

Minimum Sample Size Requirements
5g
Reportable Units
%
Turn Around Time Minimums
6 days
Method
AOAC

PROTEIN BY KJELDAHL - CASEIN

A milk sample is tested for total protein content. Another portion of the same sample is adjusted to pH 4.6 to precipitate the casein, and the casein precipitate is removed by filtration. The filtrate contains whey protein, and non-protein nitrogen. The difference between the infrared protein test of the milk, and the filtrate gives the casein content of the original milk sample.

Minimum Sample Size Requirements
100ml
Reportable Units
%
Turn Around Time Minimums
6 days
Method
AOAC

SALT - POTENTIOMETRIC

The salt content is determined by titrimetry using a Mettler T-50 Titrator.

Minimum Sample Size Requirements
Dependent on Product from 5g to 35g.
Reportable Units
% salt
Turn Around Time Minimums
6 days
Method
AOAC

SCORCHED PARTICLES

Applicable for the determination of scorched particles in dairy products.

Minimum Sample Size Requirements
50g
Reportable Units
mg of scorched particles
Turn Around Time Minimums
6 days
Method
SMEDP

SEDIMENT

Applicable for the determination of sediment in food products

Minimum Sample Size Requirements
50g
Reportable Units
mg
Turn Around Time Minimums
6 days
Method
SMEDP

SOLUBILITY

A sample is resolublized in water, and centriduged into a graduated tube, and the amount of sediment is measured.

Minimum Sample Size Requirements
20g
Reportable Units
ml
Turn Around Time Minimums
6 days
Method
SMEDP

STARCH-QUALITATIVE

Applicable for the determination of starch in food products, pet foods, and feeds.

Minimum Sample Size Requirements
50g
Turn Around Time Minimums
6 days
Method
AOAC

TITRATABLE ACIDITY

Titratable acidity is valuable for measuring the extent of growth of acid-producing bacteria in dairy products.

Minimum Sample Size Requirements
Dependent on Product from 6.5g to 10g.
Reportable Units
%
Turn Around Time Minimums
6 days
Method
AOAC, ADPI

TOTAL SOLIDS- MOJONNIER

The sample is weighed into a tared pan, and the moisture is evaporated on a controlled hot plate. The pan containing the solids is then run through a heated vacuum oven, cooled, reweighed, and percent solids calculated.

Minimum Sample Size Requirements
5g
Reportable Units
% total solids
Turn Around Time Minimums
6 days
Method
SMEDP

TURBIDITY

This procedure is based on the comparison of the intensity of light scattered by the sample under defined conditions with the intensity of light scattered by a standard reference suspension under the same condition. The higher the intensity of scattered light, the higher the turbidity.

Minimum Sample Size Requirements
20ml
Reportable Units
NTU
Turn Around Time Minimums
6 days
Method
SMEWW

WATER ACTIVITY

The sample is placed in an HygroLab instrument. The instrument measures the head space humidity, and calculates the water activity (aw) of the sample. The water activity is an indicator of perish-ability.

Minimum Sample Size Requirements
5g
Reportable Units
aw units
Turn Around Time Minimums
6 days
Method
HygroLab 3

WHEY PROTEIN NITROGEN

Denatured whey proteins, and casein are separated from undenatured whey proteins by saturating the solution with salt, and filtering after the filtrate is acidified. A spectrophotometer is used to assay the extent of denaturation. This procedure should not be used to test for WPN for whey powders.

Minimum Sample Size Requirements
5g/ml
Reportable Units
mg of WPN/g
Turn Around Time Minimums
6 days
Method
ADPI

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