CULINARY Spectroscopy: The CHEMISTRY of Texas BBQ

0rEsthetically Engineered Edibles

Dr. Jerry DeMennaFUN-SCIence Academics, Chem-Chek Labs & EDU-CHEM Innovations

ChemEd 2007, Denton, TXWednesday, 1 August 2007

Chem-Chek Laboratories

CONCEPT:Cooking is nothing more than Organic REACTION Chemistry using Reagents that are EDIBLE (usually):

pH Adjustment (acidity / alkalinity)Neutralization (elimination)Esterification (structure change)Dehydration (loss of water)Pyrolysis (charring/carmelization)Condensation (new molecules)Distillation (loss of volatiles)

All of these will cause “new” compounds to be synthesized!

Chem-Chek Laboratories

CONCEPTS: (con’t)

The COMPOSITION of the FOODS in general

are based on the FINAL PRODUCTS of

these Synthetic Reactions, and the

QUALITY is a function of the YIELD of the

DESIRED End-Product! Proteins,

Carbohydrates and Fats are the Raw

Materials; but there are MILLIONS of By-

Products that determine the MANY Flavors & Aromas!

Chem-Chek Laboratories

MEASUREMENTS & TESTING:

“Classic” Chefs, like Julia Child, James Beard and even Emeril Lagasse use their “SENSES” (smell,

taste, sight) to gauge to Quality of their cooking. For others, there are more Scientific ways to accurately MEASURE the effects of Cooking processes. These Instrumental techniques:

Analytical Spectroscopy,

Chromatography and Electro-Chemistry

Chem-Chek Laboratories

MEASUREMENTS & TESTING: Tools of the Trade

Analytical Spectroscopy------------------------------------------

These are based on OPTICAL Characteristics of a “BULK” (whole) Sample in either the Ultra-Violet (UV), Visible (VIS) or Infra-Red

(IR) regions of the Electromagnetic Spectrum

Spectroscopy - IR, UV-VIS & Fluor:

Give “PEAKS” that correspond to certain types & parts of MOLECULES.Infra-Red SPECTROSCOPY =The “FINGERPRINTER”!…

… provides an EXACT Identification (“Qualitative”) of ANY type of Molecular

“Functional Group”UV-VIS & Fluor Spectrophotometry

=The “INNER VISION” Technique!…

… provides "Quantitative" details of the Types of BONDS & Concentrations in the Molecule

RESULTS: IR “Spectrum”

shows PEAKS to IDENTIFY & MEASURE Food Content for -

FAT, PROTEIN, “Carbs”, WATER

and more!

Chem-Chek Laboratories

MEASUREMENTS & TESTING: (con’t)Analytical

Chromatography----------------------------------------------

-These are based on

PHYSICAL Characteristics of a “SEPARATED” Sample (Boiling Point, Polarity,

Viscosity, Solubility, pH, Conductivity, Molecular

Weight, Vapor Pressure) by GAS (GC) or LIQUID (HPLC)

Chromatography & GC-Mass Spectroscopy (GC-MS)

Chromatography - Gas or Liquid: Separates MOLECULES based on the

“Structure” & “Polarity” (like a magnet) of the MoleculeEXAMPLE - Natural PARAFFINIC Hydrocarbons:

Straight and Branched Hydro-Carbons (Mineral Oil)Alcohols (Ethanol / Whiskey, Booze, Hooch, "Shine", Sterno),

Esters (Ethyl Acetate / Nail Polish Remover), Ketones (Acetone), Aromatics (Xylene / “Wite-Out”),

Olefinic (unsaturated) Chains & Rings & Side-Groups… Oh, MY!

"Billions & billions... " Carl Sagan, circa 1980

RESULTS:Cheap Gas

Standard-GC run:

70 peaks ID’d in

330 mins

…. PHEW!!

Chem-Chek Laboratories

MEASUREMENTS & TESTING: (con’t)Analytical Electro-Chemistry------------------------------------------------

These are based on IONIC Characteristics of an Aqueous “SOLUBLE” Sample (Hydrogen Ion

[pH], total "free" Ions [conductivity / voltage] and "Capacitance" [amperometry / current])

using Electro-Chemical "Meters" & Sensors (pH, I-C, ReDOX, ASV, ISE)

Electro-Chemistry - pH, ISE, mV / ReDOX:

Measures specific IONS based on the type of "Sensor" or Electrode w/ a semi-Pemeable Membrane to Detect, Separate, Reduce or

Oxidize those Ions.EXAMPLE – Acidity & Ionic Strength of Apple Cider:

Basic Titration of Acetic Acid (mono-protic... single transition) " Malic & Citric Acids (di-protic... two transitions)

Re-Dox Titration of Ascorbic Acid (Vitamin-C)Ionic Strength of Electrolyte Drinks (conductivity)RESULTS:

Titration Curve & mV Data

points

IUPAC Nomenclature for Cooks:Protein Pyrolysis and Synthetic

Peptide Hydrolysis with Cellulosic Esterification, Acid Carboxylate

Neutralization, Ion Transport & Moist Membrane Osmotic Phase Extraction

=Newark, NJ

Boise, ID

Covington, KY

NYC, NY

Somewhere in SD

INGREDIENTS for BBQMetry:

[1] Direct & Radiant Thermal Energy (a good Charcoal Grill)[2] Protein Substrate (Amino-Acid based Beef)[3] Organic Reactant Mixtures (BBQ Sauce or Rubs)[4] Hi-Temp Synthetic Chemist (Cook)

Barbeque: Definitions of an Italian Brooklyn... (with apologies in advance to Grillmeisters from TX,TN, NC, AL, SC, Upstate NY, the Dakotas and elsewhere...)

* Carolina-style BBQ is typically based on PORK and uses an "Acid" type Marinade or Sauce.

Disclaimer = Above information is a summary of feedback from Academic and Industrial Professionals Nationwide with sufficient

burnt Arm hairs to qualify as Experts in this case. Opinions to the contrary may vary... so don't blame the Messenger (me!) for errors.

Barbeque: Definitions of an Italian Brooklyn... (with apologies in advance to Grillmeisters from TX,TN, NC, AL, SC, Upstate NY, the Dakotas and elsewhere...)

* Texas-style BBQ is classically made with BEEF (brisket) & a "Sugar" based Sauce or Dry RUB.

Barbeque: (con't) (following Folk-lore from numerous collaborating, yet sometimes conflicting Sources... see Disclaimer!)

* NC, SC & TN "Acidic" BBQ was created to mask the unpleasant Smell & Taste of STALE (read "rotting") PORK. The Acids would "neutralize" the Amines formed as the Meat Protein HYDROLYZED... same principle as using Lemon on Fish.* TX "Sweet" BBQ was developed for BEEF that was not properly "aged" to mask the SOUR ("gamey") Taste by the more "potent" SWEET Taste on the tongue.

Hypothesized REACTION Mechanisms: Controlling FactorsACIDIC: The Carboxylic ACIDS from the Vinegar, Tomato Sauce and Apple (fruit) Juices neutralize the AMINE products from Enzymatic Hydrolysis & Atmospheric Oxidative of the Meat PROTEINS (Amino Acids) to form SALTS.

They will also "sequester" Organic HYDROXYL Species in the Meat FATS (Cholesterol, Mono- & Di-Glycerides) to form new Molecules.

Hypothesized REACTION Mechanisms: ACIDIC: (con't)MEAT Proteins are made up of assorted

Amino Acids ("Poly Amides") that undergo many Reactions at room

temperature & exposure to Oxygen... forming "free" Amines (bad smelling... thus bad tasting) that are ALKALINE in

nature & reactivity.

Typical ACIDIC BBQ Sauces have ~7% assorted Organic ACIDS by weight (that’s a LOT!). So when you combine Organic

Acids and Amines under most any condition... you will quickly form AMINE SALTS... that have no Flavor or Aroma.

R-C=O | NH + R-C=0 | OH make R-C=O | NC=O-R + H-OH

Hypothesized REACTION Mechanisms: ACIDIC: (con't)MEAT Fats are composed of Tri-Glycerides

(not necessarily bad). There’s also Mono- & Di-Glycerides (not necessarily

good) and free Cholesterol (almost always bad in excess!), which are

ALKALINE components, having HYDROXYL (Alcohol) groups on their

molecules.

As noted these types of BBQ Sauces have a high concentration of Free CARBOXYLIC ACIDS. So when you

combine Organic Acids and Alcohols under high heat…..

You get an ESTER & Water (steam)!

R-OH +R-C=0 | OH

make

R-C=O | O-R +H-OH

Hypothesized REACTION Mechanisms: Controlling FactorsBASIC: These Sauces have a wide variety of low-MW SUGARS and simple STARCHES. These Carbohydrates have a "poly-Hydroxy" structure that can also react with the MEAT Amino Acids... which are AMPHOTERIC (they can be either Acidic or Alkaline).Alkaline environments also promote the HYDROLYSIS of the Triglycerides completely into Free FATTY ACIDS and GLYCERINE.

Hypothesized REACTION Mechanisms: BASIC: (con't)The MEAT Protein Amino Acid groups act as

ACIDS under these conditions and will form GLYCOPROTEINS... which are naturally found in

Albumin (Eggs), Casein (Milk) and Collagen (Muscle Fibers and Brittany Spears Lips).

Hydrolysis and Oxidation form many complex Peptide "fragments" (mini-Proteins), "free"

Amino Acids and individual Amines... and all these Molecules can react with Carbohydrates

under HEAT and associated DEHYDRATION.

Hypothesized REACTION Mechanisms: BASIC: (con't)The standard TRI-GLYCERIDE Structure of any

natural Fat or Oil can be HYDROLYZED under Alkaline conditions to form Free FATTY ACIDS and

Free GLYCERINE... which actually ADD to the Juiciness and Flavor or the BBQ'd MEAT.

Example: Extra-Virgin Olive Oil has ~5% Free FATTY ACIDS & has a superior FLAVOR to plain Olive Oil!

Hypothesized REACTION Mechanisms: Controlling FactorsDRY RUBS: The composition of most DRY RUB Seasonings include a variety of HERBS (Oregano, Thyme, Cumin), CHILI PEPPERS (Chipotle, Cayenne... and, yes, Paprika), GARLIC & ONION, maybe some HICKORY SMOKE... and almost always... SUGAR... be it Molasses, Sorghum or Brown.

As ORGANIC Reagents... these materials exhibit a variety of POLARITIES, SOLUBILITIES & either Hydro-Phobic or Hydro-Philic characteristic.

Hypothesized REACTION Mechanisms:

DRY RUBS: (con't)"MEAT" is very complex CHEMICALLY, but the MORPHOLOGY of Meat is fairly simple:

Polar, High-Ionic strength Muscle Fiber with ~70% Water content will ABSORB Hydro-Philic

components in the RUB Spices... ... while the Low-Moisture, Low-Polarity Fatty Tissue ("marbling") will EXTRACT the Hydro-Phobic compounds... such as the Herbal Oils.

Letting the Meat STAND for ~4-8 hours coated with a BBQ RUB will let the Flavors soak several

centimeters into the surface of the Meat.

SAMPLE PREPARATION PROCEDURE: Reaction Rate Constant / Equilibria

SAMPLE PREPARATION PROCEDURE: Reaction Rate Constant / Equilibria

MARINATION =

OSMOTIC PRESSURE & PHASE EXTRACTION: Sufficient TIME must be allowed for the Active Compounds to be EXTRACTED from the Sauce or Rub and penetrate into the Hydro-Philic (muscle) and Hydro-Phobic (fat) PHASES on the Meat.Under preferred hygienic kitchen conditions... ~6-12 hours "reaction" under refrigeration has been found to be the optimum time for best Flavor.

SAMPLE PREPARATION PROCEDURE: Reaction Rate Constant / Equilibria

"Hmmm... BBQ...".Homer Simpson, circa 1995

SAMPLE PREPARATION PROCEDURE: Reaction Rate Constant / Equilibria

SEARING =

SURFACE PYROLYSIS, CARBONIZATION of PROTEINS & CARAMELIZATION of SUGARS:

Thermodynamic conditions SEAR the surface of the MEAT and SEAL in the Juices and Flavor components from Marination or Seasoning.Rapid, high-temperature PYROLYSIS of the Meat @ ~550-650oC will Denature the Proteins & Caramelize the Carbohydrates to "lock in" the Juices and Flavors.

SAMPLE PREPARATION PROCEDURE: Reaction Rate Constant / Equilibria

COOKING = .

CONVECTION & REFLECTIVE RADIANT HEATING to "STEAM" the Internal MEAT Structure: .

After "sealing" the Surface of MEAT... the gentler "cooking"process at lower heatallows the internal temperature of MEATto rise to safety limits (to kill Microbes)

ANALYTICAL DATA: Samples of NIST-Traceable MEAT "Standard" ($9.99/lb Shell Steaks) were taken BEFORE the Marinating / Seasoning processes & then AFTER the final Grilling / Cooking steps.

Collection of the Samples was done immediately after the Grilling, and were flash-frozen to prevent further decomposition.

The following Instrumental Tests were made to compare the Scientifically measurable FLAVOR & NUTRITIONAL composition of the 3 types of BBQ:

ANALYTICAL DATA: (con't)

* IR Spectroscopy for Moisture & High-MW Protein* HPLC-GPC for Med-MW Protein & Peptides* UV-Fluorescence for low-MW Soluble Amino Acids* GC-FID for Fatty Acid content (F.A.M.E.)* GC-MS for Cholesterol and its Esters in Meat* pH for Acidity / Alkalinity of BBQ Sauces / Rubs* Conductivity for Ionic Strength of Sauces / Rubs* Atomic Absorption for Iron Content in Meat Extracts* Refractive Index for Sugars in BBQ Sauces / Rubs and Residual Content in final Grilled Meat* Brinell Hardness for relative Tenderness

ANALYTICAL DATA: (con't)MEAT Samples were prepared as 2% Emulsions in DI Water using a Food Processor. Aliquots were treated with HCl for Iron Content. Dry Rub was prepared as a 5% Suspension in DI Water for

testing

CONCLUSIONS: The WINNER is.... NC-SC / Acid TX / Sugar DRY RUBJuiciness B- A+ A- (moisture)Tenderness C+ A B+Flavor (Sol. AA) C A A-Total FAT A B+ B-Total PROTEIN A B- B+Cholesterol C A BIron B- A BSO... enjoy a nice, pH balanced Texas BBQ once in a while & squeeze some Quaker Oats somewhere in

your day!

CONCLUSIONS: No limits…..

LIFE is a giant, long-term LEARNING Process… but you CAN make it an enjoyable, rewarding and fulfilling experience! Think

OUTSIDE the Box...

… with the right

TOOLS…

you can MEASURE

the Universe!