FOS4114C Exam 2 Study Guide Texture International Standards Organization ISO sensory characteristics perceived largely by way of the senses of movement and touch Input from other senses especially vision and taste may sometimes contribute Texture is perceived by the sense of touch o Visual and auditory stimuli expectation o Tactile manipulation with hands fingers o Direct contact o Through utensils o Oral contact Lips tongue palate teeth Oral Food Management First bite Food cut by incisors Chewing Food transported by tongue Mastication with teeth Hard food particles bolus Swallowing Particle size and lubrication threshold Saltine cracker challenge 6 crackers in 1 min Texture Analyses Sensory test Instrumental measurement Empirical methods Imitative methods Fundamental methods Texture Characteristics Mechanical o Firmness o Adhesiveness o Cohesiveness o Viscosity o Springiness Geometrical o Size and shape related o Flakiness grittiness beady crystalline Compositional o Moisture and fat content o Juiciness Visual The primary means of measuring textural characteristics of food Subjective labor intensive o Smoothness Auditory o Crunchiness crackliness crispness Muscle Type and Meat Tenderness Tenderness o One of the most important aspects of quality o Cost 250 million annually due to lack of tenderness in beef cuts o Premium price for Guaranteed Tender Meat Factors the affect tenderness o Species o Breed Chicken vs beef Beef breed vs dairy breed o Management Steer vs bull o Sex Age Broiler vs hen Mature cow vs heifer Muscle Type o Support vs locomotion Size of muscle fibers affect tenderness of meat Small fibers tender meat Large long fibers tough meat o Filet mignon vs bottom round o Amount of connective tissue o Muscle location o Age older animals have more collagen cross linking Activity toughens muscles The older the animal the tougher it is has done more activity in its lifetime The younger the animal the tender it is has done less activity in its lifetime Rigor mortis Stiffness of death o Three phases Delay muscle contains sufficient ATP extensible Onset ATP no longer formed muscle less extensible Completion ATP depleted muscle inextensible o Resolution of rigor protein degradation Improving Meat Tenderness Meat aging Controlled refrigeration for days o 7 10 days for pork o Up to 4 weeks for beef Z line degradation o Desmin o alpha actinin Type III intermediate filament found near the Z line in sarcomeres f actin cross linking protein which is thought to anchor actinto a variety of intracellular structures bundling protein Cathepsin from lysosome o Cathepsin is a protease enzyme that degrades proteins Calpain o Protein that is calcium dependent o Break down structural proteins Mechanical tenderization o Blade tenderization Cooking tenderization o Moist heat o Pressure cooking o Disrupts connective tissue Enzymatic treatments to tenderize meat o Papain found in papaya o Bromelin found in pineapple o Ficin found in fig o Actinidin found in kiwi o Zingibain Ginger extract Measuring Meat tenderness Warner Bratzler shear o Dull v shaped blade o Cuts perpendicularly to the fiber direction Texture of Fruit and Vegetable Edible fruits and vegetables o Rich in weak non structural parenchyma cells Strength and texture is determined by o Mechanical property of cell wall o Internal turgor pressure o Intracellular adhesion Cell wall polysaccharides and texture Ripening related softening due to pectin degradation o Cellulose o Hemicellulose o Pectin o Endo polygalacturonase o Pectinmethylesterase o Firming agent o Ca2 Lignin polymerized phenolic compounds o Enzyme peroxidase o Polyphenol oxidase o Asparagus vegetable hardening o Low temperature decreases hardening rate Post harvest cutting handling and storage o Lignin formation Basic unit of xylem o Filled between polysaccharides Starch related texture o Crystalline amorphism o Granule disruption during heating o Starch gelatinization Starch and potato texture o High dry matter content o High amylose amylopectin ratio o Small cell size o Low sugar content Specific Gravity Total Solids 1 06 1 07 1 07 1 08 1 08 1 09 16 18 18 20 20 22 Crispiness Turgor Pressure the cell by osmosis Texture Soggy Waxy Mealy Optimum usage Boiling Mashing Baking frying o Turgor pressure pressure exerted on a plant cell wall by water passing into Osmotic influx of water into cell Key driver of cell expansion Slippage between cell wall polymers Hypertonic water goes out of cell Hypotonic water goes inside of the cell think hippo Isotonic water pressure remains equal both in and out of the cell o Crispness o Pressure on the tissue from the teeth increase hydrostatic pressure sudden fracturing of the plant structure crack propagation cell wall rupture juice release o Moisture lost low turgidity rubbery Heat induced softening o Disruption of cell membrane o Loss of turgor o Pectin solubility and degradation o Wall swelling o Cell separation Texture of Cereal Based Foods Glutinous rice vs rice o Rice 25 amylose 75 amylopectin o Glutinous rice up to 100 amylopectin Retrogradation recrystallization of gelatinized starch Bread staling o Loss of crumb crust moisture o Loss of crust crispness o Increase in crumbliness o Increase in crumb firmness moisture independent o Maximum staling rate at 4 degrees Celsius Gluten gliadin glutenin H2O work Gliadins o 30 40 wheat protein o Fluidity and extensibility Glutenins o 30 40 wheat protein o Cohesiveness elasticity firmness sponginess Relaxed and stretched gluten network Texture of bakery products o Moistness o Firmness Moist in crumb but dry in crust Bagel firm vs cake spongy o Cohesiveness o Springiness Factors affecting texture o Flour o Water o Fat Winter wheat vs spring wheat Moistness crumbliness Lubrication decreases gluten formation o Leavening agents Carbon dioxide Air cells Viscosity Viscosity resistance to flow due to internal friction o A flow property of materials o Which is more viscous mayonnaise or honey Honey is harder to stir Both are viscous Shear rate are similar in both Viscosity shear stress shear rate dynes sec cm2 shear stress shear rate dynes cm2 D sec 1 dynes sec cm2 F dynes A cm2 V cm sec Y cm 1 dynes sec cm2 1 poise 100 centipoises cp o Shear stress dynes cm2 F dynes A cm2 F the total force needed for motion Dyne the amount of force causes 1 gram mass to alter its speed by 1 cm sec A area of contact o Shear rate D D sec 1 V cm sec Y cm V speed of relative movement Y the distance between the layers