Foodstuffs and Play Role of Processing

By: Suharyanto


Characteristics of Foodstuffs
Foodstuffs: Plant based and Animal based
Animal foodstuffs properties:
• Shorter shelf life.
• Soft and flabby.
• The nature of each different type of product.
• Main source of fat and protein.
Animal food: Fish, Meat, Egg, Milk.


Damage to Foodstuffs
 Foodstuff based on durability:
 More durable: dried grains
 Medium: tubers
 Easily damage: vegetables and animal products
 Factors affecting damage:
 Temperature
 Moisture
 Oxygen
 pH
 Humidity
 Aw (Water Activity):
 Ratio of water vapor pressure of substance divided by the vapor pressure of pure water at the same temperature.
 Relative humidity divided by100.


Damage to Foodstuff can be:
 Physical.
 Chemical, ex: maillard reaction.
 Biological.
 Organoleptic:
 Color
 Odor
 Taste
 Flavor.


Processing, Preservation, Storage
 Processing: the process converting fresh foodstuff into finished or semi-finished products through addition, subtraction and / or mixing a few ingredients.
 Preservation: making fresh or processed foodstuff more durable.
 Storage: keeping fresh or processed foodstuff to make it more secure and durable.


Playrole of Processing
 Increase added value of products.
 Product diversivication.
 Increase nutrition.
 Increase shelf life.
 Increase palatability

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Posted in: Animal Product Technology

Nutritive Component of Egg

By: Suharyanto

Egg Structure and Composition

• Shell +10%
• Albumen + 60%
• Yolk + 30%
• Ratio of shell, albumen, yolk :
- Hen egg = 12,3% : 55,8% : 31,9%
- Duck egg = 12% : 52,6% : 35,4%


Nutrition Content

component % Water Protein Fat CHO
All 100 74.6 12.1 11.2 1.2
Albumen 58 88.0 10.1 0.2 0.8
Yolk 31 48.0 16.4 32.9 2.0


Physically, albumen consist of 4 layers:
• Outer layer 23,2%, mucin fiber
• Midle layer (albuminous sac) 57,3%, myelinous mucin
• Inner layer 16,9%, highly thick of fluids, rare mucin.
• Membrana kalazifera layer 2,7%, myelinous mucin sparating yolk and albumin. It functions as a hold of yolk.


Protein in Albumen:
• Ovalbumin
– Monomeric phosphoglycoprotein
– 54% in albumen
• Ovotransferrin
• Ovomucoid
• Lysozyme
• Ovomucin
• Globulin


Ovalbumen:
• 54%, the greatest
• It can be readily purified and crystallized
• It is a monomeric phosphoglycoprotein
• It has a molecular weight of 45,000
• It has pI of 4.7.
• Function:
– foaming and gelling;
– structure of baked products.


Ovotransferin:
• 12%, second largest
• Or Conalbumen
• It is a monomeric glycoprotein
• Function: binds metal/ion and discolorization.
• Denaturate at 60oC


Ovomucoid:
• 11%
• Contains 20-25% carbohydrates
• These carbohydrates contribute to ovomucoid stability againts tryptic hydrolysis
• Function: protease inhibitor, mainly tripsin.
• Physically is stable, but biologic activity is lost severe heat treatment, 100oC for 60 min.

Ovomucin:
• A Fibrous Protein.
• Characterized by a highly viscous gel-like nature.
• Not soluble in water, soluble in a salt dilution at pH 9 or above.
• Contains 30% carbohydrates.
• 2 types present in egg white:
– Insoluble, from gel fraction (whole thick white).
– Soluble, from liquid fraction (thin fraction).
• contributes to the thickness of the white (4 x more abundant than in yolk).
• Plays role in the foaminess of egg white.
• contributes to the stability of egg white foam.


Lyzozime:
• 8%.
Lysozyme: ability to hydrolyze a polysaccharide in the cell wall of some bacteria to prevent bacterial spoilage
others: ovoinhibitor, ovoflavoprotein, ovomicroglobulin, avidin (binds biotin, but is heat sensitive)


Yolk
• Proteins (16.4%):
 plasma (78%): livetins & LDL (protein content ~ 10%)
 granular fraction: phosvitin (16%, carrier of Fe), lipovitellins (70%) & LDL (12%)
• Water (48%)
• Lipids (32 to 34%)
 triglycerol (66%)
 phospholipid (28%) including lecithin
 (has remarkable emulsifying ability)
 cholesterol (3%, or 250 mg)
• The color of yolk depends on the presence of carotenoids.
 xanthophylls not carotene
 (Lutein and zeaxanthin)

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Posted in: Animal Product Technology

Composition and Properties of Meat Chemical

By: Suharyanto

Meat chemical composition comprises 56-72% water, 15-22% protein, 5-34% fat, and soluble non protein substances 3.5% including carbohydrates, organic salt, dissolved nitrogen substances, minerals and vitamins (Lawrie, 1991). Meanwhile, Aberle et al. (2001) state meat contains 70% water, 19% protein, 5% fat, 3.5% non-protein substances, and minerals and other materials 2.5%. However, Paleari et al. (2003) reported that each species has different chemical characteristics.

As a source of protein, meat protein is the second largest component after the water one. Muscle protein is divided into 3 groups based on their solubility properties; firstly, sarcoplasmic protein (30%), myofibrilar protein (55%) and stromal protein or muscle tissue (15%). Sarcoplasmic proteins are soluble in water and dilute salt solution contained in the sarcoplasmic. Myofibrilar protein is a protein-containing structures myofibril and are soluble in saline solution with a concentration of 1.5% or more. Stromal proteins are main constituent of connective tissue that is not soluble in salt solutions but soluble in alkali or acid treatment (Xiong, 2000).

Sarcoplasmic proteins include glyceraldehyde, aldose, enolase, creatine kinase, lactate dehydrogenase, pyruvate kinase, phosphorilase, myoglobin, calpain, chatepsin, extracellular proteins and membrane protein. Proteins are composed of myosin, actin, troponin, tropomyosin, M-protein, C-protein, Titin, Nebulin and Desmin. Myosin is the largest component in miofibril and dissolve into the solution with high ionic strength (greater than 0.3 M). Myosin has an important functional properties in meat, namely (a) is an enzyme with ATP-ase activity, (b) myosin form a complex with actin and (c) myosin form aggregate with each other to form filaments (Zayas, 1997; Xiong, 2000).

Stromal proteins include collagen, elastin and reticuline. This protein directly affects meat quality (Zayas, 1997) by:
1. Lowering the tenderness of meat and it depends on the number of stromal protein and the degree of cross-linking other stromal proteins.
2. Influencing meat emulsion capasity due to this protein is not soluble in water.
3. Lowering Water Binding Capacity of meat because of the low content of hydrophilic and charged amino acids.
4. Lowering meat nutritional value.

Muscle protein solubility is one of the factors influencing properties of water retention in the muscles and eventually affects meat quality. Physical and chemical bonding in muscle protein affects structural and texture muscle protein. There is a correlation between protein structure and solubility, and is related to tenderness or hardness of meat during processing and storage (Zayas, 1997).

Other chemical components that quite important in meat is fat. Although relatively few in amount, it is the 3rd largest chemical component in the flesh. Fat in meat has both beneficial and detrimental roles. One of the disadvantages is the oxidation. It affects meat processing.

Fat is an important energy source because of the amount of energy produced can be doubled from that generated by proteins and carbohydrates. Fat in meat is generally in triglycerides form. The composition of triglycerides significantly determines meat tenderness and roughness. Fatty acid composition in each species is different and it is also has different effect on fat properies in each species. Total saturated fatty acids in sheep, cattle and pigs respectively 53%, 45% and 40%, while the unsaturated fatty acids respectively were 47%, 55% and 60% (Warriss, 2000).

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Posted in: Animal Product Technology

Meat Texture

By: Suharyanto


Texture is a degree of meat fineness or coarseness. Texture measurement can be visually, touched or chewed. Although this is rather difficult determination, this trait is important for fresh meat because it is associated with some properties of fresh meat attributes, such as the status of rigor mortis, Water Holding Capacity (WHC) and others. Texture is usually associated with the hardness and structure of the meat. That is the level where the meat may have a shape and certain hardness and can affect meat quality.

Texture, hardness and structure of meat are influenced by several factors, including the WHC, rigor status, marbling fat, connective tissue content in meat and muscle bundle size. Meat with high WHC will have a stronger structure and a dry texture. Conversely, if WHC is low then flesh is soft, moist texture/ watery and toughness of meat is lost.

Meat in prerigor state has long sarcomere. When rigor, sarcomere shortened and peak rigor state, sarcomere lenght is very short. The short sarcomere indicates that sarcomerer contract to form the actomyosin or cross bridge bond. The formation of this bond, meat becomes harder and stronger.

The presence of fat marbling gives a soft texture. Low marbling content in meat marbling cause meat looks rough and dry. However, if excessive marbling produce meat with watery texture and it is also not good. Meat become soft and less rigid.
Besides a role in texture, marbling fat also influence the aroma and juiceness meat. Fat marbling will give the distinctive aroma of meat and usually preferred by consumers.

The proportion of high connective tissue that causes the coarse-textured meat and feels more hard and not soft.[]

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Posted in: Animal Product Technology

Fresh Meat Color

By: Suharyanto

The first indicator for consumers choose meat is meat color. The color of fresh meat is a typical red meat in accordance with their species.

The color of fresh meat is a total impression seen by the eye and is influenced by many conditions. The main contributor for meat color is meat pigment, myoglobin and hemoglobin. Thus, meat color shows manifestations of meat pigment captured by eyes due to light availability.

Myoglobin and hemoglobin is a protein-containing globin and heme ring with nucleus of ring binds ion Fe (iron). Level reddish or brownish in one type of meat is determined by the status of Fe ions. Fe ion in the reduced state (Fe2+) will be bright red flesh color. If the Fe ion in the oxidized state (Fe3+), meat becomes more brownish (metmyoglobin). Both states could change depending on the presence of oxygen, environmental conditions, treatment provided and so forth.[]

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Posted in: Animal Product Technology