Erstellt von Veronica Castro
vor mehr als 6 Jahre
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Frage | Antworten |
Myosin | *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 |
Fatty acids | are chains of hydrocarbons, containing one carboxylic acid end. >the carbon-hydrogen bond is very energy-rich |
Saturated | Containing no double bonds >higher melting points >more stable(less degradation) >numerous health concerns >abundant in terrestrial animals |
Unsaturated | Containing 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 |
Omega -3 and Omega- 6 | mediate inflammation response >pro and anti inflammatory >ratio of 1:1 if ration is 15:1 could leave to cardiovascular,cancer, and inflammatory/autoimmune diseases. |
Lipid 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 |
Antioxidants | -ability to inhibit lipid oxidation + preserve foods. -many exist |
Triglycerides | -predominant form of a fatty acids -glycerol backbone + 3 fatty acids -fatty acids can be the same or diff. |
Disciplines within food science | Chemistry-microbiology-engineering-sensory science-nutrition-packaging |
Food Chemistry | studies food down to their molecular level, striving to understand the chemical explanation for all properties of food. |
interesterification | the process of rearranging the fatty acids in a triglyceride |
Emulsification | are molecules that contain polar ends and non polar ends, allowing droplets of fat to remain dispersed in polar systems. |
Hydrogenation | -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 |
Olestra | Real fatty acids attached to a sugar -can't be digested = does not provide calories |
Myoglobin | >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. |
major factors that affect the pigment forms in meat | freshness pH Temperature Oxygen pressure |
Pink 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) |
Starch gel | -fat free, thick gel substance -used in a lot of foods |
Defining color | two ways: -1 (physical truth): -2 (matter of perception) |
Color : Physical Truth | the 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" |
Color: A matter of perception | our 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 |
why 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 |
foods that ripen | fruits *color is the most obvious (complex change as they approach maturity) |
foods that don't are | grains, vegetables , meats only degrade and show deterioration with age. |
Ripeness: fruits can be divided into two groups according to the regulatory mechanisms underlying their ripening process: | non-climacteric climacteric |
Non-climacteric fruit: | -lack of ethylene-assoc. respiratory peak -do not ripen after harvesting ex: grapes,oranges,cherries *maintain ripeness |
Climacteric fruit | ripening-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 |
Ethylene | "trigger" that stimulates ripeness -administered to fruits to ripen before sale |
natural color | may be extracted from different foods to suggest quality or desirability to consumers |
artificial colors | colors 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 |
Natural colors in food | blues, purples, and reds Greens yellows, oranges, reds Dark purple/red |
anthocyanins | blues , purples and reds -natural , water-soluble pigments widely distributed in plants -appear purple or blue (or sometimes red) depending on pH -Powerful antioxidants |
Greens: | chlorophyll -fat-soluble -source of vitamin K -chlorophyll a and b are primary in plants affecting factors: heating > loss of Mg > pheophytin |
Enymes in Chlorophylls | removes the phytol group ( deactivated by blanching) |
carotenoids | yellow foods contain lutein and zeaxanthin red foods contain - lycopene |
why color foods? | correct natural variations in color -enhance colors that occur naturally |
cochineal | water 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 |
chromatography | Extremely versatile and powerful family of techniques based upon the principle of separation |
spectroscopy | operates according to the same principle of observation as our eyes, but utilizes machinery for assessment |
Enzymes | -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 |
Enzymes in food | High fructose corn syrup- $1 billion Aspartame - $850 million Acrylamide - $300 million |
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