Meat Flavor Jerrad Legako Graduate Student, Meat Science ANSC 3404 IMPORTANCE OF FLAVOR Consumer perception of meat quality • After appearance and tenderness flavor is most important • Specifically cooked meat flavor Flavor is a key factor for acceptance • Understanding flavor is therefore crucial – Analysis of flavor compounds (Machiels and Istasse) MEAT PALATABILITY Tenderness Juiciness Flavor Flavor often considered the most important when tenderness is acceptable Result of volatile compounds produced during cooking TASTE vs. FLAVOR • Taste refers to the five basic receptors: sweet, salty, sour, bitter and umami • Flavor is the perception of chemical compounds reacting with receptors in the oral and nasal cavities (aroma) in combination with taste Perception of Flavor (Taste and Aroma) Aroma Olfactory receptors Detected in nose Small, volatile, fat soluble molecules Anterior nares Posterior nares Taste Tongue Taste receptors Detected on tongue and in mouth Large, water soluble molecules (L. J. Farmer) TASTE • Salt and sour receptors are well understood while bitter and sweet receptors appear to be more complex. UMAMI •Umami [oo-MOM-ee], known as the fifth taste, is described as meaty and savory or delicious • derived from umai, the Japanese word for delicious • Glutamates – the salts of an amino acid - and other small molecules called nucleotides •Although umami has been known for quite awhile, recently umami receptors have been clearly identified so this is a bona fide fifth taste. 5 TASTES • Detection of these five tastes has been key to our survival throughout the ages • Sweet means energy-giving carbohydrates • Salt indicates essential minerals for life-sustaining cell functions and wound healing • Sour says to “proceed with caution,” since many foods sour as they deteriorate. • Umami signifies life-giving protein. • And bitter warns “spit it out, don’t touch it” because many natural toxins taste bitter FLAVOR CHEMISTRY What is flavor chemistry? A study of compounds which elicit a chemosensation or flavor sensation What produces flavor sensations? Chemical compounds reacting with receptors in the oral and nasal cavities Specifically ingested volatile compounds (Christen and Smith) FLAVOR CHEMISTRY Over 200 flavor compounds associated with cooked beef Sulferous and carbonyl compounds are predominate contributors Maillard reaction products • End products result from sugars and amino groups Lipid breakdown products • Higher concentrations may produce undesirable flavors (Calkins and Hodgen) MAIN FLAVOR FORMING REACTIONS Precursors Aroma compounds, e.g. Reducing sugars, nucleotides, Maillard reaction amino acids, peptides CH3 S S SH O Thiamine (L.J. Farmer) O O O S S O Thermal oxidation HEAT CH3 NH S S SH Thermal degradation O Lipids, fatty acids N CHO O CHO O O O CHO MAILLARD REACTION • Reducing sugar and free amino acid • Results in the production of H2O, • Therefore reaction does not occur with moist heat cookery reducing sugar + amine = brown pigments + flavors Flavor Compounds Formation by Maillard Reaction Reducing Sugars and -amino acids N-glycosylamine or N-fructosylamine 1-Amino-1-deoxy-2-ketose (Amadori intermediate) or 2-Amino-2-deoxy-1-aldose (Heynes intermediate) + H2 S NH3 Furans Thiophenes Pyrroles Reductones and Dehydroreductones Retroaldol Reaction Hydroxyacetone Hydroxyacetylaldehyde Acetoin Acetylaldehyde Glyoxal Pyruvaldehyde Glycerolaldehyde Heterocyclizaion Pyrazines Pyridines Oxazoles Thiazoles Pyrroles + Amino Strecker Acids degradation Strecker Aldehydes + CO2 + -aminoketone (Methional, NH3, H2S) FLAVOR COMPOUND ANALYSIS Volatile compounds must be extracted • Head space solid phase microextraction (HS-SPME) Separation of compounds may be done via gas chromatography (GC) Compounds may then be identified and sensory evaluated • Identified: purified standards and/or mass spectral library • Sensory evaluation: olfactometry (Frank and others) HS-SPME/GC-MS-Olfactory DISCUSSION Flavor is important to overall palatability of meat Flavor compounds may be studied by chemical and sensory evaluation Maillard reaction and lipid breakdown products are dependent on the type and condition of meat FACTORS AFFECTING MEAT FLAVOR Species Red meat species and poultry Breed Bos indicus vs Bos taurus? Sex Androstenone, skatole Diet Grain-fed vs. Grass-fed Age Young lamb vs. mutton Packaging MAP, over-wrap, vacuum FACTORS AFFECTING MEAT FLAVOR Fat Amount and type Muscle Location effect Aging Dry vs. wet Enhancement Brine solution containing salt Cooking method Dry vs. moist heat Degree of doneness Top 20 Beef Flavor Pairings in Newsstand Beef Recipes • Onion 60% • Garlic 55% • Tomato* 32% • Beef Broth/Stock/Bouillon* 25% • Wine (mainly red)* 20% • Cheese (mainly Parmesan, Cheddar, Blue)* 19% • Sugar 18% • Cream 18% • Bell Pepper 16% • Vinegar 16% • Thyme 15% • Parsley 14% • Cayenne 13% • Mushroom* 13% • Soy Sauce* 11% • Cumin 11% • Mustard 10% • Ginger 10% *indicates umami-rich ingredients • Bay Leaves 10% • Oregano 10% Beef and the Restaurant Scene Today’s Menu Special: Beef Flavored with… Onion Cheese* Mushroom* Wine* Garlic Pepper/Peppercorns Truffles* Peppers/Green Peppers Shallots Bacon* Barbecue Sauce* Horseradish Béarnaise Mustard *indicates umami-rich ingredients http://www.beefandvealculinary.com/beefflavorp airings.aspx