Food Science Final Exam Review Guide

Food Science Final Exam Review Guide - Food Science Final...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Food Science Final Exam Review Guide Why is it that a small change in process temperature can have a large impact on required thermal process time? Meat, Fish, Poultry and Eggs o Trends in US Meat and Poultry Consumption Chicken has largest change in consumption o Nutritive Issues: Meats What do meats provide that plant foods don’t? Heme Iron More balanced proteins (Amino acid composition) What do meats NOT provide? Carbs Fiber o Composition of Lean Muscle Tissue Primarily Water (65 – 80%) Protein (17 – 23%) Lipid (5 – 15%) Ash (1 – 1.6%) o Muscle Structure Skeletal Muscle is largely collagen Muscle fibers = interspersed with connective tissue proteins: collagen and elastin Sarcomere = segment b/w 2 neighboring Z-lines; basic unit of muscle’s cross-striated myofibril Thin Filaments – Actin bounded by nebulin Thick Filaments – Myosin connected by titin Contraction and relaxation of sarcomere Collagen = connective tissue protein Most abundant protein in animal kingdom Single strand Triple coil Central glycines o Post-Slaughter changes in meat Reduction pH – 7 to 5.5 due to anaerobic glycolisis Lactic acid formation from glycogen Rigor Mortis – fiber contraction: 24 – 48 hrs Relaxation of Rigor – 2 to 9 days o P henomena occurring during aging of beef and other muscle foods Increased Tenderness
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Relaxation of rigor mortis Protein hydrolysis (collagen) Microbial surface growth Dehydration Some lipid oxidation o Grading of Beef Relationship b/w marbling (intra-muscle fat content), maturity of animal, and carcass quality grade o Shelf Life of Raw Chicken and Beef Off odor occurs first, then slime o Major Quality Factors in Fresh Meats Color Fresh meat color rxns Bacterial counts o Effect of storage temperature on growth of spoilage bacterial in ground beef shows that as the storage temperature decreases the spoilage detection 0 – 2 degrees Celsius storage has shelf life of about 5-6 days o Meat composition Beef Cut? o Sirloin, flank, chuck, round, ground… Grade? o USDA Prime vs. Choice Trimmed (of fat)? o Partially trimmed, untrimmed Raw vs. Cooked? How Cooked? o Broiled, Stewed, Roasted How do we account for the difference in the fat content of tenderloin vs. Top Sirloin?
Background image of page 2
How to account for protein and fat content b/w raw and broiled ground beef? Protein gain is due to loss of water Loss of fat depends on cooking method How do we account for the loss of fat in 80% lean 20% fat ground beef patties, broiled vs. 95% lean and 20% fat? o Red ” Meats vs. “White” Meats (same applies to poultry and fish) Red ” meats = high myoglobin content High myoglobin fibers o “Slow twitch” o Continuous operation o High oxygen demand o Processed Meats: Cured Meats Bacon, luncheon meats, ham, hot dogs, corned beef, etc. Key ingredients
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/12/2010 for the course FD SC 200 taught by Professor Hotchkiss,j./parker, during the Spring '09 term at Cornell.

Page1 / 22

Food Science Final Exam Review Guide - Food Science Final...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online