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What is the Germanic root meaning of the word "starch"?

The word starch is derived from a Germanic root word meaning "stiff", reflecting its role as a thickening or gelling agent in food preparation.

From greatest to least, how do common starches rank in their thickening ability?

Potato, waxy starches, tapioca, arrowroot, sorghum, cornstarch, rice, and wheat.

What is the major source of commercial starch in the United States, accounting for over 90% of production?

Corn (processed via wet milling to yield cornstarch).

What are the three main purposes starch serves in the food industry?

1. Thickening/gelling agent
   2. Edible films (e.g., protective coatings for gum)
   3. Sweetener source (dextrose and syrups).

What does "Dextrose Equivalent" (DE) measure?

The degree of conversion of starch to glucose (e.g., a DE of 50 means the syrup contains 50% dextrose).

What is the structural difference between amylose and amylopectin?

Amylose is a linear chain of glucose units linked by alpha-1,4 bonds.
Amylopectin is a highly branched chain linked by both alpha-1,4 and alpha-1,6 bonds.

How do amylose and amylopectin differ in their gelling properties?

Starches with high amylose levels tend to gel, whereas starches high in amylopectin are non-gelling but gummy.

What ratio of amylose and amylopectin is typically found in most starches?

Roughly 25% amylose and 75% amylopectin.

What are "waxy" starches?

Starches that consist entirely of amylopectin (0% amylose) and do not gel.

What is starch gelatinization?

The increase in volume, viscosity, and translucency of starch granules when they are heated in a liquid.

How does starch granule size affect its gelatinization temperature?

Larger starch granules (like potato starch) gelatinize at lower temperatures, while smaller granules (like wheat) require higher temperatures.

Why does heating starch beyond its gelatinization temperature decrease its viscosity?

Continued heating stresses the hydrogen bonds, causing the starch granules to rupture and break apart.

How does the presence of acid (pH below 4.0) affect a starch gel?

It decreases the viscosity of the starch gel by breaking down the starch chains.

How does sugar affect starch gelatinization?

Sugar competes with starch for water, which delays the onset of gelatinization and increases the required temperature.

How does fat affect gelatinization?

Fat delays gelatinization by coating the starch granules and preventing them from absorbing water.

What is gel formation (gelation)?

The process where a fluid starch paste (sol) cools and firms into a semi-solid paste (gel), dependent on the presence of amylose.

What is starch retrogradation?

A phenomenon during the cooling of gelled starch where amylose and amylopectin molecules realign and contract, sometimes forcing water out.

What is syneresis (weeping) in starch gels?

The seepage of water out of an aging gel due to the contraction of the gel network as amylose bonds tighten.

What is dextrinization?

The breakdown of starch molecules into smaller, sweeter-tasting dextrin molecules in the presence of dry heat, which reduces their thickening power.

What are instant or pregelatinized starches?

Starches that have already been cooked and dried, allowing them to expand and gel immediately when cold water is added without reheating.

What is the defining characteristic of resistant starches (RS)?

They resist digestion by enzymes in the small intestine and do not contribute calories.

Name the four types of resistant starch and their definitions.

RS1: Physically inaccessible (trapped in seeds/grains)
RS2: Ungelatinized (due to chemical configuration, e.g., green banana)
RS3: Retrograded (formed during heating and cooling)
RS4: Chemically modified.

What chemical modification creates "cross-linked starch" and what is its benefit?

Starch molecules are linked with cross-bridges, making the starch more heat-resistant and less likely to lose viscosity during cooking or canning.

What are the five "mother sauces" (grand or leading sauces) in cooking?

1. Béchamel (white)
   2. Espagnole (brown)
   3. Hollandaise
   4. Tomato
   5. Velouté

What is a roux and what are its three types?

A thickener made by cooking equal parts flour and fat.
The three types are white, blond, and brown roux.

How does cooking a roux longer to make it darker affect its thickening power?

It reduces its thickening power because heat breaks down the starch molecules.

What is a beurre manié?

A thickener made by blending equal parts of uncooked soft butter and flour into a paste, whisked in at the end of cooking.

What is a starch slurry?

A thickener made by gradually mixing cold liquid with starch (like cornstarch or flour) to prevent expansion before adding to a hot base.

What are the five steps involved in making gravy from pan drippings?

1. Degreasing
   2. Deglazing
   3. Reduction
   4. Straining
   5. Seasoning

How should dry starches be stored to prevent deterioration?

In airtight containers in a cool, dry place away from moisture, oxygen, light, and pests.

What are the five main components of an egg's structure?

1. Yolk
   2. Albumen (egg white)
   3. Shell membranes
   4. Air cell
   5. Shell

What percentage of the egg's weight does the yolk constitute, and what sits on its surface?

The yolk constitutes about 30% of the egg's weight; the pinhead-sized germinal disc sits on its surface.

What is the function of the chalazae in an egg?

They anchor the egg yolk in the center of the thick albumen and secure it to the vitelline membrane.

What are the two shell membranes and what is their function?

The inner and outer membranes, which press against the shell to protect the egg from bacterial invasion.

How is the air cell of an egg formed?

As a freshly laid egg cools, its contents contract, causing the inner shell membrane to separate from the outer shell membrane at the larger end.

What is the composition of an eggshell?

It is made of calcium carbonate (accounting for 12% of the egg's weight) and contains thousands of small pores for gas exchange.

What is the cuticle or bloom on an eggshell?

A protective waxy coating that seals the pores of the shell to defend against bacteria and moisture loss.

What is the primary protein in egg white, making up 54% of its protein content?

Ovalbumin, which denatures easily with heat.

What are the nutritional components of an average large egg?

About 75 kcalories, 7 grams of complete protein (4g from white, 3g from yolk), 5 grams of fat, and 186 mg of cholesterol.

Why is the iron in egg yolks not highly bioavailable?

It binds to phosvitin, an egg protein that inhibits iron absorption.

What are the USDA quality grades for eggs?

USDA Grade AA (best quality), USDA Grade A, and USDA Grade B (lowest quality, usually sold to food service).

What three methods are used to judge egg quality for grading?

1. Candling
   2. Measuring Haugh units
   3. Evaluating appearance (shell, white, yolk, air cell).

How are Haugh units measured to detect egg freshness?

By cracking the egg onto a flat surface and measuring the height of the thick albumen using a micrometer.

How does egg sizing differ from egg grading?

Sizing is not related to quality grading; it is based on the minimum weight per dozen eggs.

Name the weight classes for table eggs in the Philippines from heaviest to lightest.

Jumbo (>= 70g), Extra-Large (65-70g), Large (60-65g), Medium (55-60g), Small (50-55g), Pullets (45-50g), Peewee (40-45g), and No Weight (< 40g).

How do duck eggs compare to chicken eggs nutritionally?

Duck eggs are richer, containing more than triple the cholesterol (619 mg) and double the fat (10 g) of chicken eggs.

What is the natural emulsifying agent found in egg yolks?

Lecithin, which has one water-attracting end and one fat-attracting end to stabilize emulsions.

What causes egg whites to whip into a stable foam during beating?

Vigorous beating denatures the proteins, which unfold and rearrange to trap air, forming stable films around the air cells.

How does egg temperature affect foam volume when whipping egg whites?

Room-temperature eggs whip more easily and to a larger volume than cold eggs due to decreased surface tension.

What type of bowl is best for whipping egg whites and why?

Deep bowls with rounded bottoms (glass or copper) because they allow the beater to thoroughly pick up the whites. Avoid plastic, as residual grease ruins foams.

How do sugar and salt affect egg-white foams?

Sugar stabilizes the foam but delays whipping (add after soft peaks form).
Salt decreases both stability and volume.

At what temperatures do egg whites and egg yolks begin to coagulate?

Whites start coagulating at 140 degrees F (60 degrees C).
Yolks start coagulating at 144 degrees F (62 degrees C).

What causes the greenish-gray ring around the yolk of an overcooked hard-boiled egg?

Sulfur in the egg white combines with iron in the yolk to form ferrous sulfide under high heat.

What are the three methods for checking poached egg doneness and preventing spread?

Using fresh eggs, adding salt and/or vinegar to the water to speed coagulation, and cooking for 3 to 5 minutes.

How long should whole eggs stay fresh when refrigerated in their carton?

About 1 month (though recommended storage is 1 week).

Why can't you freeze a whole egg in its shell?

The expanding liquids inside the egg will cause the shell to crack.

Which starchy root crops are primarily used as dietary staples?

Cassava, white potatoes, and sweet potatoes.

What is the difference between the white and yellow varieties of cassava?

The white variety is a traditional staple crop.
The yellow variety is a hybrid containing high amounts of carotene (provitamin A).

How do white potatoes and sweet potatoes compare nutritionally?

White potatoes have more resistant starch, folate, iron, and potassium.
Sweet potatoes are much richer in vitamin A, vitamin C, and fiber.

Structurally, what is a potato tuber?

It is not a root, but rather the swollen end of an underground stem.

What is the difference between mealy and waxy potatoes?

Mealy potatoes (e.g., Russet) are high in starch and yield a fluffy texture.
Waxy potatoes are low in starch and hold their shape well when cooked.

What are the two primary production methods for cultivating taro?

"Upland" (dryland) and "wet" (wetland or flooded) production.

What substances in yams give a slimy, frothy quality to their juices?

Oxalate crystals and soap-like saponins.

What are some traditional Filipino culinary dishes made from root crops?

Nilupak and pichi-pichi (from cassava), and camote cue (from sweet potato).

What are the limiting amino acids in almost all root crop proteins?

Sulfur-containing amino acids (like methionine and cysteine).

Why should soaking potatoes in water to prevent browning be avoided if possible?

It leads to significant water-soluble nutrient loss.

What are the recommended storage conditions for potatoes?

In a dry, well-ventilated, cool place, but not refrigerated (refrigeration converts starch to sugar, affecting flavor and cooking).

What toxic compound is found in raw cassava, and how can sweet varieties be made safe?

Cyanide (hydrogen cyanide); sweet varieties are made safe by peeling and thorough cooking.

What toxic mold metabolites can contaminate sweet potatoes handling after harvest?

Ipomeamarone (a hepatotoxin) and 4-ipomeanol (a pulmonary toxin), produced due to fungal contamination by Ceratocystis fimbriata.

What is solanine and where is it found?

A toxic glycoalkaloid found in green or sprouted potatoes that causes gastrointestinal disturbances like vomiting and diarrhea.

What health hazard is associated with the calcium oxalate crystals in taro?

They cause severe skin irritation and itching on contact, and can precipitate calcium in the body, making it unavailable.

What toxic alkaloid is found in wild yams (but not cultivated ube), capable of causing paralysis?

Dioscorine (or dehydrodioscorine).