Jean Inman Study Guide Flashcards
(430 cards)
what is the water content of fruits and vegetables
75-93%
what is the cause of crispness (state of turgor) of fruits and vegetables
osmotic pressure of water filled vacuoles
what is the limiting amino acid in soybeans and its protein concentrates vs isolates
methionine protein concentrates =≥ 70%protein isolates =≥ 90% (isolates usually havehigher protein content)
list the ripening process
immature fruits contain theprecursorsubstance protopectin, which is converted to pectin and becomes more water-soluble as ripening proceeds.
pectin helps ripening fruits to remain firm and retain their shape
as a fruit becomes overripe, the pectin in it is broken down to simple sugars that are completely water-soluble is converted to pectic acid =overripefruitbecomes soft and begins to lose its shape.
describe pectin
pectin,any of a group of water-solublecarbohydratesubstances that are found in thecellwalls and intercellular tissues of certain plants.in the fruits of plants, pectin helps keep the walls ofadjacentcells joined together.
what accelerates ripening of fruits during storage?
ethylene gas
what temp should frozen fruit be stored at?
0 degrees F
what fruits ripen best at room temp?
avocado, banana, pear, tomato (dry fruits)
how can you delay aging in apples?
store in a controlled atmosphere (reduced oxygen)
why do fruits low in vitamin C darken rapidly when cut? how can you prevent this?
enzymatic action - to prevent dip in citrus juice, add sugar before freezing, heat to boiling
when sweetener is added to liquid of packing juice, what is the density of the syrup measured by?
a brix hydrometer expressed as % sucrose by weight
describe chlorophyll
green
insoluble in water
olive green in acid (pheophytin - d/t replacement of Mg w/ H+)
bright green in alkaline (chlorophyllin - formed when alkaline such as baking soda is added to veggies)
describe carotenoids
yellow/orange insoluble in water little color effect in acid or alkaline lycopene - red in tomato/watermelon overtone in aprictos (antioxidant/phytochemical)
what are 2 types of flavinoids
anthocyanins, anthoxanthis (flavones) - they are both soluble in water
describe anthocyanins
red, blue, purple
soluble in water
bright red in acid
bluish tone in alkaline
describe anthoxanthins
whitesoluble in watercolorless in acidyellow in alkaline
what provides the flavor in vegetables (3)
sugars, glutamic acid naturally found in young veggies and sulfur
what provides flavor in the followining vegetables: peas and corn, onions and cabbage and in young vegetables
peas and corn = sugarsonions and cabbage = sulfuryoung vegetables = glutamic acid (used to form MSG)
what is glutamic acid used in
MSG (form of salt)
what provides flavor is fruits (3 things)
acids, sugars, aromatic compounds (such as tannins - cause astringent feeling in mouth, underripe banana)
what are the 3 grades of fruits and vegetables and what are they used in?
Grade A (Fancy)= used in desserts andsaladsGrade B (Choice) = used in processed foodsGrade C (Standard) = used in puddings and pies
who is responsible for grading fruits and vegetables (fresh produce) and what are their grades?
USDAfancy, extra #1, extra #2, combination, #2
what is the green color under potatoes skin due too
chlorophyll that develops when potato is exposed to light during storage
potatoes contain what compound which is a natural toxicant
solanine; develops in a potato d/texposure to light, especially fluorescent lightstore potatoes in a dark place btw 50°F and 65°F