Fichas
Experimental Food Science
Fichas del conjunto (41)
- 1Myosin*the most important
type of protein filament (long-highly charged) that acts as a motor protein with actin filaments to cause cell contraction
present in large quantity in lean muscle
high water holding capacity- polar amino acids - 2Fatty acidsare chains of hydrocarbons, containing one carboxylic acid end.
>the carbon-hydrogen bond is very energy-rich - 3SaturatedContaining no double bonds
>higher melting points
>more stable(less degradation)
>numerous health concerns
>abundant in terrestrial animals - 4UnsaturatedContaining at least one double bond
>lower melting points
>Abundant in plants/fish
>Vulnerable to the development of off-flavors
>a mix of health concerns + benefits - 5Omega -3 and Omega- 6mediate inflammation response
>pro and anti inflammatory
>ratio of 1:1 if ration is 15:1 could leave to cardiovascular,cancer, and inflammatory/autoimmune diseases. - 6Lipid Oxidation>Stability
>breakdown of unsaturated fatty acids=smaller molecules
>adds off flavors(volatile) to foods
>Major ongoing source of food-loss
>small fragments of carbon,hydrogen, and oxygen
>the more sat a fatty acid is, the more susceptible it is to oxidation - 7Antioxidants-ability to inhibit lipid oxidation + preserve foods.
-many exist - 8Triglycerides-predominant form of a fatty acids
-glycerol backbone + 3 fatty acids
-fatty acids can be the same or diff. - 9Disciplines within food scienceChemistry-microbiology-engineering-sensory science-nutrition-packaging
- 10Food Chemistrystudies food down to their molecular level, striving to understand the chemical explanation for all properties of food.
- 11interesterificationthe process of rearranging the fatty acids in a triglyceride
- 12Emulsificationare molecules that contain polar ends and non polar ends, allowing droplets of fat to remain dispersed in polar systems.
- 13Hydrogenation-it allows to convert liquid oil into plastic fats for production of margarine + shortenings
-addition of hydrogen to DBL bonds of unsat. faty acids in the presence of catalyst.
-Production of trans-fats - 14OlestraReal fatty acids attached to a sugar
-can't be digested = does not provide calories - 15Myoglobin>controls meat color (pigment)
>the more the darker the meat
>0.05(light) - 15.0 (darkest)
>consist of a typical amino acid protein chain and a non-protein heme molecule. - 16major factors that affect the pigment forms in meatfreshness
pH
Temperature
Oxygen pressure - 17Pink slime-Lean finely textured beef (LFTB)
-used as inexpensive filler to reduce overall fat content of ground beef.
-contains: boneless beef trimmings(rick in connective tissue) - 18Starch gel-fat free, thick gel substance
-used in a lot of foods - 19Defining colortwo ways:
-1 (physical truth):
-2 (matter of perception) - 20Color : Physical Truththe waves of light which populate the universe occur in a very large range of wavelengths= different molecules will absorb + reflect specific wavelengths of light"electromagnetic radiation"
- 21Color: A matter of perceptionour eyes perceive a small portion of the wavelength as a series of color
-interaction with the molecules with in a flower reflect light waves of approx. 600nm= our retina sees yellow - 22why do we perceive color?-identification of foods
-food ripeness
level of degradation
-nutritional contents
-color may be a true, natural indicator of food quality.
=perception of nutrient density =perception of food's value + desirability - 23foods that ripenfruits
*color is the most obvious (complex change as they approach maturity) - 24foods that don't aregrains, vegetables , meats
only degrade and show deterioration with age. - 25Ripeness: fruits can be divided into two groups according to the regulatory mechanisms underlying their ripening process:non-climacteric
climacteric - 26Non-climacteric fruit:-lack of ethylene-assoc. respiratory peak
-do not ripen after harvesting
ex: grapes,oranges,cherries
*maintain ripeness - 27Climacteric fruitripening-assoc. increase in respiration and in ethylene production, the phytohormone ethylene being the major trigger and coordinator of the ripening process
-ripen AFTER harvesting
ex: tomatoes,apples,pears,melons
*ripeness can be controlled -usually harvested prior to optimal ripeness - 28Ethylene"trigger" that stimulates ripeness
-administered to fruits to ripen before sale - 29natural colormay be extracted from different foods to suggest quality or desirability to consumers
- 30artificial colorscolors may be manufactured and placed into foods to suggest quality or desirability to consumers
-can be mixed to create many, many colors
-common starting material =petroleum - 31Natural colors in foodblues, purples, and reds
Greens
yellows, oranges, reds
Dark purple/red - 32anthocyaninsblues , purples and reds
-natural , water-soluble pigments widely distributed in plants
-appear purple or blue (or sometimes red) depending on pH
-Powerful antioxidants - 33Greens:chlorophyll
-fat-soluble
-source of vitamin K
-chlorophyll a and b are primary in plants
affecting factors: heating > loss of Mg > pheophytin - 34Enymes in Chlorophyllsremoves the phytol group ( deactivated by blanching)
- 35carotenoidsyellow foods contain lutein and zeaxanthin
red foods contain - lycopene - 36why color foods?correct natural variations in color
-enhance colors that occur naturally - 37cochinealwater soluble pigment carmine acid (carmine) is derived from the female insect.
-advantage of being stable when exposed to heat, light and oxygen. Uses include alcoholic beverages and processed meat products - 38chromatographyExtremely versatile and powerful family of techniques based upon the principle of separation
- 39spectroscopyoperates according to the same principle of observation as our eyes, but utilizes machinery for assessment
- 40Enzymes-are found in all living systems
-endogenous enzymes(operating within their natural source) contribute to aging ,degradation,spoilage of foods.
-enzymes from another source are of widespread use in the food industry for many purposes,processes and benefits
-biological tools
-proteins that operate as biological catalysts
-lowers activation energy of a reaction
necessary for many reactions - 41Enzymes in foodHigh fructose corn syrup- $1 billion
Aspartame - $850 million
Acrylamide - $300 million