Adipose tissue in meat

Adipose tissue

Specialized sites occur in tissues for lipid storage.
Most cells have similar metabolic pathways for synthesis of fat.
There are two types of fat
a)White –commonly present and also in very primitive animals.
b)Brown – rare in occurrence present in mitochondria and generates heat
Adipose tissue is 70-905 triglyceride and cholestrol is 100-200 mg/100g
About 70% of adipose is subcutaneous or inter- muscular.
Adipose may have an insulation function but this related to blood flow, not lipid r value.
Adipose tissue can withstand hypoxia.
It is organized into lobules or clusters of cells surrounded by connective tissue and is analogus
to perimysium.
Amount of connective tissue around a lobule depends on location . If deeper then the fat has
less matrix i.e. subcutaneous fat has more structure than kidney fat.
The fat depot distinctions may be unclear.

Functions of adipose tissue

It supplies energy.
Insulation.
Provides minor physical protection
Cholestrol storage and the percentage of the same changes with age.
Estrogen production from androstenedion

Composition of adipose tissue
The 90% of adipose tissue is tryglycerides. Triglycerides consist of one molecule of glycerol and three
molecules of fatty acids. The composition of tryglycerides for different fatty acids differs in various
species wise for example-

Fatty acid	Pigs ( in percent)	Cattle ( in percent )
i) Palmitic ii) Stearic iii) Oleic	27 15 40	28 25 41

Fatty acid composition of different animal fats (in percentage)

Acid	Lard	Beef	Mutton	Butter
Butyric Caproic Caprylic Capric Lauric Myristic Stearic Palmtic Arachidic Lauroleic Myristoleic Palmitoleic Oleic Linoleic Linolenic Arachidonic	0.7-1.1 12-16 26-32 0-0.3 2-5 41-51 3-14 0-1 0.4 - 0.3	0.0 - 0.2 2 - 8 14 - 29 24 - 33 0.4 - 1.3 0.4 - 0.6 1.9 - 2.7 39 - 50 0 - 5 0 - 0.5 0 - 0.5	1-4 25-32 20-28 36-47 3-5	3.0 1.0 1.5 3.0 3.5 12.0 13.0 38.0 1 0.4 1.5 3 28.5 1.0 0.5

Some characteristics of C4 - C22 straight - chain saturated fatty acids

Acid

Formula

Mol. Wt.

Melting Pt.( F)

Melting Pt. (C)

Butyric
Caproic
Caprylic
Capric
Lauric
Myristic
Palmitic
Stearic
Arachidic
Behenic

C3H7COOH
C5H11COOH
C7H15COOH
C9H19COOH
C11H23COOH
C13H27COOH
C15H31COOH
C17H35COOH
C19H39COOH
C21H43COOH

88.10
116.15
144.21
172.26
200.31
228.36
256.42
284.47
312.52 75
340.57

- 8.0
– 3.4
16.7
31.6
44.2
54.4
62.6
69.6
75.4
83.0

17.6
27.3
62.2
88.9
111.6
129.9
144.7
157.3
167.7
181.4

Lipid characteristics

Lipids donot mix with water and therefore are hydrophobic.
Lipids are composed of several types of fatty acids .
W6 are essential fatty acids.
Stearic acid is one fatty acid which is present in animal fat upto 15- 25 % and has a melting point of 72 C.
Oleic acid is fatty acid which is present upto 40% of animal fat.
Lipids require sterols for their transport and are steroid precursor.