LAB 6 Flashcards
(50 cards)
what are cereals or cereal grains?
edible seeds of plants belonging to the grass family
what are their nutrient content?
- rich in carbs, relatively low in fat, contains a fair amount of protein
the outer layers of the grain are rich in ____
B vitamins including folate
____ is concentrated in the germ
vitamin E
grains are also rich in ____
iron, phosphorus, magnesium and zinc
what is the main carb in grains?
starch organized in granules
- amylose
- amylopectin
amylose molecules are more tightly ordered and therefore require ___ to be pulled apart
higher temperatures, more water and more cooking time
amylopectin is a ______ that results in a ____ product when cooked
branched starch molecule
stickier
what happens when seeds are cooked in water?
the hull or outer shell is softened allowing starch granules to swell and starch molecules to separate from each other
the conversion of solid starch into a starch-water gel is referred to as ____ and improves ___
gelatinization
digestibility
what is also formed during cooking?
dextrin
what does gelatinization depend on?
depending on seed and starch there’s a temperature range of about 60-70C
how can you reduce cooking time? why?
pre-gelatinization or addition of disodium phosphate
-> they permit rapid rehydration but increase the tendency of the cereal to congeal
what happens after cooking/cooling below gelatinization temperature? what do we call this process?
starch molecules begin to reform in clusters with pockets of water in between causing starch granules to firm up once again
RETROGRADATION
why does long grain rice harden overnight in the fridge and short grain rice remains softer?
because long grain rice has a higher amylose content and amylose molecules bind closely together unlike amylopectin due to its branches
Barley is an excellent source of ____ and it is used for ____
soluble fibre, used in beer production
hulled barley includes ____ and is more _____ than pearled barley in terms of:
the bran
nutritious
- iron, madness, phosphorus, thiamine
what is cornmeal?
- coarsely ground corn
- it is usually de-germed to extend it’s shelf-life
- used to make polenta
what are different forms of oats?
- oat bran
- oat groats (whole kernels)
- rolled oats old-fashioned, quick-cooking or instant)
- steel-cut oats (from Ireland or Scotland; thinly sliced lengthwise)
what is removed from all rice grains? what influences the rice’s nutritional value?
- the outer inedible husk
- the extent of milling, which removes bran and germ
what white rice is the most nutritious? why?
- parboiled or converted rice
- bc it has been soaked and steamed under pressure before milling so that more nutrients are preserved
what determine the extent to which rice grains stick to each other?
the amount and type of starch they contain
what is the less sticky rice?
rice high in amylose (long chains) and low amylopectin (short branched chains) -> long grain rice
what type of rice hardens when cooled?
rice high in amylose bc the long amylose molecules bond tightly together
