NFS 53 1st Edition Final Exam Study Guide Lecture 16 March 16 i Fruit and extraction 1 Fruit Juices a Pressing b Centrifuge c Pasteurization d Concentration i e apple cider 2 Fruit Oil a Cold pressing mechanically pressing the fruit or seeds b Expeller pressing squeezing fruits or seeds at high pressure c Chemical solvents removing oil from seeds with solvents i e Olive Oil Lecture 18 March 24 I Eggs a Types of eggs consumed i Chicken turkey duck quail turtle crocodile fish b Egg structure i c Why chickens i Chickens are indeterminate layers and will keep producing eggs indefinitely as long as they are taken away ii Can develop a system for egg production that trumps the simple biology of reproducing the chicken species iii 8 billon chicken eggs consumed in the United States d Parts of the egg i Chalazae 1 The chalazae are twisted cords of egg white that anchor the yolk to the egg itself 2 The air pocket always found in eggs is a product of two protective membranes pulling away from each other so that the growing chick can have air 3 The air pocket is an indicator of freshness larger is less fresh ii Egg Shell 1 Has been used for cooking in the past particularly in mixes used to clarify various hot liquids iii Egg Yolks 1 Contains 75 of the calories of the egg in the form of lipids as well as most vitamins and minerals iron thiamin Vitamin A 2 Color comes from plant derived xanthophylls color determined by what the chicken eats 3 Made up of tightly packed spheres iv Egg White Albumen 1 Mostly water 90 and protein 2 The proteins in the egg white are important for the versatility of cooking with eggs and determine egg structure both when raw and when cooked v Ovalbumin 1 Ovalbumin is the majority of the protein in eggs This protein gels easily and denatures easily when heated It also contributes to the overall flavor and texture of the eggs 2 The proteins have denatured and have coagulated resulting in a tighter protein network that blocks the light vi Ovomucin and Ovotransferrin 1 Ovomucin is the compound that keeps egg white thick and determines the quality of the egg from a commercial and culinary point of view 2 Ovotransferrin is a defensive protein that makes iron nonbioavailable but it also coagulates first and so determines the temperature at which eggs set e Egg cookery I i Protein coagulation 1 Similar to milk proteins 2 Coagulation is when proteins that do not interact for whatever reason are made to do so and form a solid mass where previously they had been disassociated 3 In milk this happens with casein either in the presence of acid or rennet chymosin or with lactoglobulin in the presence of heat and acid and the absence of casein it can bind to 4 Want to denature or unfold the globular proteins by physically or chemically breaking the bonds that hold them in their original compact folded shape 5 Want to concentrate the proteins enough allow them to interact and bond forming a network which on the macro scale is a solid mass 6 But in eggs the process is different than in milk we almost always want to avoid overcoagulation which for example makes scrambled eggs lumpy or even gritty with an unappealing surface moisture 7 It s all about the heat the heat a All of the parts of the egg coagulate below 212 F b parts of eggs coagulate at different temperatures yolks between 150 and 160 whites between 145 and 180 and the mixture around 165 ii Coagulation Control 1 Acids and salts encourage earlier but less complete coagulation 2 Acids lower the pH and thus neutralize the generally negativelycharged proteins in eggs 3 Salts do something similar with their disassociated ions again neutralizing the proteins 4 Proteins are less unfolded in each case and cannot unfold easily once coagulated this produces a more tender final product 5 Extra liquid sugar and fat delay coagulation and produce a more tender final product f Egg cookery II i Emulsification 1 Egg yolks are particularly rich sources of emulsifiers mostly lowdensity lipoproteins and phospholipids 2 This is due to the complex aggregations of proteins lipids and membrane forming compounds in egg yolks 3 Egg yolks can emulsify an astonishing amount of oil and water a single egg yolk can emulsify more than a dozen cups of oil 4 Salt makes egg yolk a far more effective emulsifier as it makes more of the substructure available to use for emulsification g Egg cookery III i Foams 1 Egg white foams are the most common and can be made just by whipping egg whites a The proteins in egg whites are unfolded by beating exposing portions that are nonopolar which are then attracted to the bubbles being introduced by beating b Once unfolded and concentrated at the surface of bubbles the proteins bond to each other forming a network that traps the bubbles and makes a stable foam c Acids and copper help stabilize the foam by preventing over bonding between proteins they both cause sulfide bonds between cysteine groups to be unable to form d Sugar makes foams more dense and stabilizes them by making the liquid between the air bubbles more viscous 2 Egg yolks a Require extra liquid to foam because most of the water in egg yolks is bound up and they re low water to begin with b Egg yolk proteins are more stable and do not denature with just mechanical force the foam must be heated to cause them to unfold and bond to each other c Thus classical egg yolk foams involve extra liquid and heating e g zabaglione ii Eggs emulsifying power in the proteins and fats help stabilize foams iii The ability of the proteins to coagulate and their abundance and sensitivity to mechanical force and heat sets the foams Lecture 19 March 26 I Meal preparation and USAD dietary guidelines a Executive summary i 2015 DGAC identifies that a healthy dietary pattern is higher in vegetables fruits whole grains low or non fat dairy seafood legumes and nuts moderate in alcohol lower in red and processed meat and low in sugar sweetened foods and drinks and refined grains ii Vegetables and fruit are the only characteristics of the diet that were consistently identified in every conclusion statement across the health outcomes Whole grains were identified slightly less consistently compared to vegetables and fruits but were identified in every conclusion with moderate to strong evidence iii Stronger Federal policies to help prevent household food insecurity and to help families to cope with food insecurity if it develops iv Food and nutrition assistance programs to take into