workshop 3 Flashcards
1
Q
factors affecting quality of frozen desserts (5)
A
- SUGAR: high concentration may be used because the sweeteness of frozen dessert is attenuated by cold temperature
- MILK SOLIDS: they are added to ice cream to give it more body and to promote a smooth texture.
- too many= sandy texture because lactose is relatively insoluble + easily precipitates into large crystals that can be felt by the tongue
* can be added on form of evaporated milk - FAT: creates a rich body and a smooth texture in frozen dessert
- too much= hard product - EMULSIFIERS: promotes smooth texture by incorporation of minute air bubbles and stabilize foam structure during storage
- common emulsifiers= mono + di-glycerides, egg yolk for its lecithin content - STABILIZERS: restrict crystal growth during storage
* guar gum and carrageenan - TEMPERATURE OF THE FREEZING TEMPERATURE:
- made by agitating the mixture at very low temp
- water forms ice crystals
- motion= kep ice crystal small + incorporate air
- coils or refrigerant in industry= use to withdraw heat from the mixture so it becomes cold enough for ice crystals to form
- temper. attain by the brine is affected by the ratio of ice to salt to water + size of salt crystals
2
Q
what is frozen desserts + different types
A
- it consists of ice crystals surrunded by sugar syrup
1. ice cream
2. ice milk (contains milk instead of cream)
3. imitation (mellorine= has vegetables fat substitued for milk fat and frozen tofu= tofu or soybean protein, high-fructose corn sweetener + corn oil)
4. water ices (granita)
5. sherbets and stiff-frozen (mousses, parfait)
** all large amount of whipped cream, gelatin or egg whites
3
Q
sugar production
A
- produiced from the juice extracted from sugar cans and sugar beets
1. juice is boiled down to a thick syrup to which tiny crystals are added and allowed to grow into larger sugar crystalls (cystallisation)
2. large crystals are refine into molasses, brown sugar + granulated white sugar - blackstrap molasses= residual obtained in the refining process (more nutrients like iron than white or brown sugar)
- icing sugar + powdered sugar = pulverized granulated whit sugar + corn or wheat starch to prevent caking
- honey: produce by bees who collect nectar from flowers (accumulate in their esophagus + mixes with saliva to form honey)
- maple syrup: by concentrating (40 times) the clear sap tapped from certain maple trees, contains K, include caramelization of fructose
4
Q
10 roles of sugar
A
- food preservation: inhibits microbial growth + keeps F and V firm
- industry: for osomotic dehydration so F,V and fish are dehydrated at room temp with sugar solution,removing water from food
- baked goods: re-crystallizes as water evaporates= crisp texture
- maillard reaction reaction: non-enzymatic non-oxidative browning resulting from a chemical reaction between reducing sugars glucose + fructose and nitrogen (protein) containing ingredients
- caramelization of fructose due to heat= contributes to browning + new flavors
- tenderizes baked goods: slow rate of gelatinization + gluten development
- slows moisture loss, extending shelf life
- breand making + brewing industries: influences rate of fermentation
- determines smoothness of candies
- frozen desserts: lowers freezing point of solution, ensuring smaller crystals + smoother product
5
Q
what are candies
A
def: it is a network of sugar crystals suspended in a supersaturated solution
* molecules in sugar syrup are attracted together + form crystals
- divide in crystalline and noncrystalline:
1. crystalline= fudge, fondant, panocha (contain very small sugar crystals not perceivable by tongue)
2. noncrystalline: chewy (caramel), hard (brittles), aerated (marshmallow): goal is to prevent formation of crystal
6
Q
4 factors affecting size of crystals in candies
A
- CRYSTAL INTERFERING AGENTS: smoother textur with smaller crystals
- interfere with rate of crystallization, speed at which nuclei grow into crystals
- ex: eggs white, butter, cream, milk, gelatin, cocoa, inverted sugar
* all provide fat, protein, air, dextrins and simple sugar that surrunded or coat crystals and impeded the growth
* accumulation of sugar in the pan should be dissolved : put the cover to create steam or use a brush dipped in hot water
* syrup= not stir during boiling - CONCENTRATION OF SUGAR SOLUTION:
- crystallization occurs if a sugar solution is supersaturatd with sucrose (the more it is, the faster it crystallizes)
- supersaturated= concentration of sugar dissolved is greater than normally would be at room temp.
2 ways to accomplished supersaturation:
1) heating a sugar solution above boiling point of water= large amount of sugar dissolve
2) slowly letting it cool without agitation
- when it cools: crystallization speeds up (molecules become closer) - TEMPERATURE:
- heating sugar solution to the good temp= critical because temp of the sugar syrup= index of its concentration
- super-saturation= rapid + small crystals
- concentration of sugar in sugar syrup = measure by measuring boiling point (it raises of 0.52C by every mole of sugar (342g fro sucrose)) dissolved in 1L of water. - AGITATION:
4 roles:
a) incorporates air
b) promotes formation of many crystal nuclei by redistributing impurities (delay cristal formation)
c) breaks up larger crystals
d) hastens crystallization
- begin AFTER CANDIES HAVE COOLED TO A CERTAIN TEMP and continue until crystallization is complete
- if beaten while still hot: form large crystals because of the rapid movement of molecules (they are far apart so less nuclei are formed and each one grows larger as temp. cools)
- if cools properly: forms small crystals= creamy texture
** contact with rough surface/seeding from dust/extra sugar crystals= too rapid crystallization- larger crystals
7
Q
what is inverted sugar
A
def: equimolar mixture of glucose + fructose that is formed when sucrose (table sugar) is heated in the presence of an acid or enzyme invertase
- interfering agent
- acids uses: cream of tartar, vingear, molasses
- dependant on cooking time (too long= too soft candy, too little= coarse and grainy product
8
Q
2 ways measure dodenss of candies
A
- temp of the syrup using a thermometer (chech accuracy in boiling water first)
- cold-water test= measure the consistency of syrup when dropped in cold water (a drop of syrup is made to fall off the edge of a spoon into glass of cold water)
9
Q
6 stages of a sugar syrup
A
- thread: syrup will not harden (bind agent for fruit pastes) (106-112C)
- soft ball: for soft but firm candy like fudge, fondant, creams, maple…
- firm ball: caramels (118=120C)
- hard ball: divinity, taffy, nougat, marshmallow
- soft crack: hard threads form; will form very hard candy; butterscotch, toffee (132-143C)
- hard crack: brittle threads form; brittle,
- light caramel (honey-golden in color)
- dark caramel (deep redish-amber in color) (177C)
- 8 each stage= associated with temp range
- ** needs to let the syrup cool to the proper temperature before agitation begins: THE TEMP. OF THE CANDY SOLUTION AT THE TIME OF BEATING IS THE MOST INFLUENCAL FACTOR IN CRYSTAL SIZE
10
Q
caramelization
A
def: nonenzymatic browning involving a nubr of reactions that occur when sugar is heated
- facilitated with acid
- organic acids= froms when sugar decomposed
ex: use baking soda to the caramelized sugar for peanut brittle= soda + acids reacts so produce CO2= holes in the brittle
- equipment; cast iron skillet + wooden spoon
2 methods for caramel
DRY AND WET METHOD: only use sugar (no water like the wet method)
- WET: not stirred until water is evaporated + look like layers of bubbles because if not= crystallize
to prevent crystals to stick:
- oiling the sides of the pot
- brushing the side with water
- covering pot for couple of minutes to let steam form
11
Q
coffee + goal of brewing
A
- good quality coffee= amber brown, clear of sediment, with a mild/brisk flavor
- goal of brewing: extract max amount of caffein +falvouring substances while minimizing amount of polyphenols (tannins)
2 ways to achieve goal of brewing:
1. water contact with the ground is limited
2. temp. not rise to boiling
different types:
- turkish cofee= strong + not respect the principles
- instant coffee= lacks the rich flavor of brewed coffee
- freeze drying coffee= improve flavors + cost..
12
Q
6 principles of coffee
A
- clean pot (create a bitter flavor during brewing)
- use correct ground for the different methods of brewing (too fine= too strong brew, too large= too weak
- medium strenght coffee: 15ml ground coffee/175ml eau
- coffee pot = filled 3/4 capacity for the best quality brew
- since coffee grounds absorb aroma from the brew= should be removed and discarded after the brew is prepared
- stroing fresh coffee in thermal carafe= preserves fresh taste ,storing in coffee maker= flavor deterioration
13
Q
tea (characteristics + different type)
A
- processing of tea leaves= affect the flavor
1. green tea: highly astringent + light in color
2. black tea: full-bodied flavor and darker color when leaves are fermented as black tea
3. oolong tea: partially fermented tea, flavor characteristics of both green and dark tea - over extracting tea leaves by prolonged steeping results in bitter beverage
- adding lemon juice= lighter color+ changes pH
14
Q
tea tasting
A
- slurping the liquid up into the mouth frm the surface of the spoon (O2 mixes with the liquor, help to brings the flavours to life)
- with tea in the mouth, should breathe out through the nose (keep mouth closed) = called retro-olfaction perception
then liquoir may be swallowed, allowed the taster to pay special attention to sensation on tongue
15
Q
tea descriptors (4)
A
For testing qualities = AROMA and ASTRINGENCY
1. AROMA: scent released form the leaf as a result of the brewing process
2 types:
- the fresh, clean or dull aspects that show style and quality of manufacture
- the floral, nutty or grassy descriptors correspond to the flavours that the palate will amplify
- ASTRNGENCY is a tactile taste felt as a dry, rough feeling in the mouth and contraction of tongue tissue. Involve formation of aggregated precipitates between tannins/polyphenols and proteins in salive
- tannins positively influences the tase of tea (as well as coffee, cocoa, wine, beer)
- tannins have a negative effect in immature fruit (bananas..) - COLOR: from pale gold to dark purple-black
- CLARITY: describes degree of transparency or purity
