Meat : Structure, Composition and Characteristics

GITAM INSTITUTE of SCIENCE, GITAM UNIVERSITYDepartment of Microbiology and Food Science & Technology

Name of The Student : Umesh Maskare Registration Number : 1223616116Course : M.Sc. Food Science and Technology

Year and Semester : 1st Year 2nd Semester Subject : Technology of Animal Foods

Unit and Topic : Unit – IV, Meat-Structure,Composition and Characteristics

Lecture-in-charge : Ch. PadmavatiDate : 06/06/2017

MEATSTRUCTURE, COMPOSITION

AND CHARACTERISTICS

MEAT• REFERS TO THE MUSCLES OF ANIMALS USED AS FOOD. INTERNAL ORGANS

OF ANIMALS USED AS FOOD IS ALSO INCLUDED IN THIS BROAD DEFINITION.• THE ANIMALS COMMONLY RAISED FOR MEAT WORLDWIDE ARE CATTLE,

SHEEP, PIG AND POULTRY WHICH IS DOMINATED BY CHICKEN.• OTHER MAMMALIAN SPECIES ARE ALSO USED AS FOOD IN VARIOUS PARTS OF

THE WORLD ACCORDING TO CULTURE AND AVAILABILITY.

PRODUCTION AND CONSUMPTION OF MEAT• THROUGHOUT THE HISTORY, MEAT HAS BEEN CONSIDERED A HIGH VALUE

FOOD. NUTRITION STUDIES INDEED SHOW THAT MEATS ARE HIGH GRADE PROTEIN SOURCES. THE LOW CONSUMPTION OF MEAT IN MANY COUNTRIES IN ASIA AND AFRICA WAS THEN CONSIDERED TO BE THE MALNUTRITION FOR THESE REGIONS.

• THE UNITED STATES IS THE LARGEST PRODUCER OF BEEF ( MORE THAN 19% OF THE WORLD'S BEEF) IN THE WORLD FOLLOWED BY BRAZIL & THE EUROPEAN UNION.

• THE UNITED STATES, BRAZIL AND THE EUROPEAN UNION PRODUCE ROUGHLY 49% OF THE WORLD'S BEEF.

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• BRAZIL PRODUCES ROUGHLY 16% OF THE WORLD'S BEEF.

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• CHINA PRODUCES NEARLY 12% OF THE WORLD'S BEEF.

TYPE OF MEAT

• RED MEAT EATEN COMES MAINLY FROM :

• CATTLE (BEEF) PIGS (PORK) SHEEP (LAMB)

STRUCTURE OF MEAT

• MEAT MUSCLE IS MADE UP OF BUNDLES OF MUSCLE FIBRES HELD TOGETHER BY CREAMY WHITE – CONNECTIVE TISSUE.• TENDONS JOIN THE MUSCLE (MADE UP OF BUNDLES OF MUSCLE FIBRES,

SURROUNDED BY CONNECTIVE TISSUE) TO THE BONES OF ANIMALS.

THIS IS WHAT MUSCLE FIBRE LOOKS LIKE:

CONNECTIVE TISSUE• MEAT ANIMAL’S BODY IS SUPPORTED BY BONES AND TENDONS. HELD

TOGETHER BY FIBROUS CONNECTIVE TISSUES.• MERGED INTO A LARGE MASS, THE TENDON AT THE TERMINI OF EACH

MUSCLES WHICH IS ANCHORED TO THE SKELETON. VEINS AND ARTERIES AS WELL AS LARGER NERVES ARE INSIDE THE PERIMYSIUM, WHILE CAPILLARIES AND THE SMALLER NERVES ARE IN THE ENDOMYSIUM.• CONTAINS TWO TYPES OF PROTEINS: COLLAGEN AND ELASTIN

COLLAGEN • EMBEDDED COLLAGEN FIBERS IS WHERE THE STRENGTH OF THE BONES CAME FROM (ALSO CALCIUM)• ELONGATED PROTEINS THAT FORM EXTREMELY STRONG BUT SMALL FIBRILS WHICH ASSOCIATE

TOGETHER TO FORM COLLAGEN FIBERS WHICH IN TURN FORM SHEETS OR CABLES THAT CAN BE EASILY DISTINGUISHED IN MEAT CUTS.• COLLAGENS ARE THE MOST ABUNDANT PROTEIN IN THE ANIMAL BODY AND IMPORTANT IN

DETERMINING THE TOUGHNESS OF THE MEAT.• COLLAGEN FIBERS SHRINK IN HOT WATER AND ARE CONVERTED TO GELATIN. AT AROUND 65°C, THE

HELICAL STRUCTURE OF COLLAGEN IS DISRUPTED AND THE CHAINS FALL INTO RANDOM ARRANGEMENT MAKING WAY FOR THE CONVERSION TO GELATIN. THIS CHANGE IS SIGNIFICANT IN THE TENDERIZATION OF MEAT CUTS WITH HIGH CONNECTIVE TISSUE CONTENT

ELASTIN

• ELASTIN HAS TRUE ELASTIC PROPERTIES COMPARED TO COLLAGEN WHICH DERIVES ITS ELASTICITY ONLY WHEN IT FORMS INTO CABLE-LIKE TENDONS.• ELASTIC PROPERTIES ARE NECESSARY IN THE TISSUES OF THE NECK, THE

ABDOMINAL/INTESTINAL WALL AND THE ARTERIAL SYSTEM.

FAT : LOCATION OF FAT • FAT CELLS ARE USUALLY LOCATED ABDOMINALLY,

UNDER THE SKIN AND WITHIN IN THE ENDOMYSIUM SURROUNDING MUSCLE FIBERS

MARBLING • WHEN FAT IS ASSOCIATED WITH THE MUSCLE FIBER

DUE TO ITS APPEARANCE IN THE MEAT AS WAVY LINES AND RESEMBLES THE APPEARANCE OF MARBLE.

MEAT COMPOSITION• PHYSICAL

• LEAN, FAT, BONE, CONNECTIVE TISSUE• PROPORTIONS CHANGE OVER TIME

• CHEMICAL

• 75% WATER

• 18% PROTEIN

• 2.5% FAT

• 1% ASH

• 1.2% CHO

• 2.3 % OTHER NON-PROTEIN SUBSTANCES ( NITROGENOUS COMPOUNDS, MINERALS, VITAMINS AND INORGANIC SUBSTANCES ETC) 

MEAT COMPOSITIONMEAT COMPOSITION VARIES WITH:- SPECIES OF ANIMAL SOURCE- SPECIES VARIATIONS DUE TO BREED, AGE AND SEX, DIET AND EXERCISE

CONDITIONS.- ANATOMICAL PLACEMENT OF THE MEAT IN FOCUS.

TYPICAL PERCENTAGE COMPOSITION OF SOME MEATS WITH MEDIUM AMOUNTS OF FAT

CHARACTERISTICS OF MEAT - MEAT PH• NORMAL PH IS 7.2 TO 7.4 WHICH IS REDUCED TO ABOUT PH 5.5 FOR RED

MEATS AND ABOUT PH 5.9 FOR POULTRY.• THE DROP IN PH IS ONE OF THE MOST IMPORTANT BIOCHEMICAL EVENTS IN

MEAT.WATER HOLDING CAPACITY • WHC IS THE ABILITY OF MEAT TO RETAIN ITS WATER DURING PROCESSING,

STORAGE, AND COOKING.• THE LOSS OF WATER HOLDING CAPACITY (WHC), IN TURN LEADS TO LOW

PRODUCT YIELD AND PORK QUALITY.

THE COLOR OF MEAT• DURING THE TIME MEAT IS STORED THE COLOUR CHANGES TO A DARKER BROWN-RED

BECAUSE OF THE FORMATION OF METMYOGLOBIN. • WHEN MEAT IS CUT AND EXPOSED TO OXYGEN IN THE AIR, IT TAKES ABOUT TWENTY

MINUTES FOR MYOGLOBIN TO CHANGE TO OXYMYOGLOBIN, WHICH IS BRIGHTER RED IN COLOUR. • AFTER SOME TIME, THE MEAT BECOMES A BROWNER COLOUR AGAIN AS METMYOGLOBIN IS

FORMED. • THESE COLOUR CHANGES DO NOT MAKE ANY DIFFERENCE TO THE TASTE OR TEXTURE

REFERENCES :• BASIC FOODS FOR FILIPINOS (3RD AND 4TH EDITION)• UNDERSTANDING FOODS BY AMY BROWN• PROFESSIONAL COOKING BY WAYNE GISLEN• HTTP://WWW.PETA.ORG/ACTION/10-SURPRISING-FACTS-CHICKENS/• HTTP://MAINSTREETMEATS.COM/HEALTH-FACTS-ABOUT-MEAT/• HTTP://WWW.MEDTERMS.COM/SCRIPT/MAIN/ART.ASP?ARTICLEKEY=38316