Processing and Poultry Processing & Quality Evaluation

Question 1

Meat cuts and grading

Answer 1

• Common fresh meat cuts are tenderloin, sirloin, topside, silverside, rump, and parts of the neck and shoulder.

• The age of the animal influences the functional properties of beef.

• Meat from younger animals is suitable for products requiring high binding and water holding capacity.

• Meat from older animals is more suited for products undergoing a drying and fermentation process.

• Sufficient for small to medium-sized manufacturing operations.

• Beef fat and skin are usually not used as raw material for meat processing.

Question 2

Chicken cuts and grading

Answer 2

• Chicken meat is commonly processed into products such as frankfurters, hotdogs, hams, and breaded/fried nuggets.

• Chicken carcasses are typically cut into wings, legs, and breast.

• The breast includes a larger superficial muscle and a smaller profound muscle (filet).

Question 3

Types of meat products

Answer 3

1) Restructured
2) Comminuted
3) Emulsified

Question 4

Restructured Meat

Answer 4

Meat product that is partially or completely
disassembled and then reformed into the same
or a different form, resembling intact muscle

Question 5

Comminuted Meat

Answer 5

Meat product where the meat portion has been
broken down or ground into small particles, such
as minced or shredded meat

Question 6

Emulsified Meat

Answer 6

Finely comminuted sausage batters where fat
droplets are dispersed in an aqueous medium
containing soluble proteins, other soluble muscle
constituents, segments of muscle fibres, and
connective tissue fibres

Question 7

Categories of processed meat products

Answer 7

1. Fresh processed meat products
2. Cured meat cuts
3. Raw-cooked meat products
4. Precooked-cooked meat products
5. Raw-fermented sausages
6. Dried meat products

Question 8

Fresh processed meat products

Answer 8

• The products are meat mixes with animal fat, salt, and some non-meat ingredients for flavor and binding.

• They are not cooked before consumption, but heat-treated immediately before eating.

• Chicken nuggets are included but are pre-fried during production.

• Examples of products include hamburgers, sausages, kebab, and chicken nuggets.

Question 9

Cured meat cuts

Answer 9

• There are two types of cured meat cuts: cured-raw meats and cured-cooked meats. Both use nitrite to treat entire pieces of muscle meat.

• Cured-raw meats are not cooked and undergo curing, fermentation, and ripening in controlled conditions to make them palatable for raw
consumption. Examples include raw cured ham and beef.

• Cured-cooked meats undergo heat treatment after curing to make them palatable. Examples include cooked beef, ham, and bacon.

Question 10

Raw-cooked meat products

Answer 10

• The product is made by mixing raw muscle meat, fat, and non-meat ingredients.

• The resulting mixture is then portioned into sausages and cooked.

• The heat treatment causes the protein to coagulate, resulting in a firm-elastic texture for raw-cooked products.

Question 11

Principle of manufacture (Raw-cooked meat products)

Answer 11

1. Extract and dissolve solid muscle proteins
2. Establish a network structure of liquid or gelatinous muscle proteins
3. Stabilise the muscle protein network through heat coagulation
4. Cool products

Question 12

Precooked-cooked meat products

Answer 12

• Precooked-cooked meat products are made of lower-grade muscle trimmings, animal by-products, and non-meat ingredients.

• They undergo two heat treatments: the first precooks the raw materials, and the second cooks the finished product.

• These products stand out from others because they use a wide variety of ingredients.

• Examples include blood sausage and liver sausage.

Question 13

Raw-fermented sausages

Answer 13

• Raw-fermented sausages are uncooked meat
products made from a mixture of lean meats, fatty
tissues, salts, nitrite, sugars, spices, and other non-
meat ingredients.

• They are filled into casings and get their
characteristic properties through fermentation.

• They are not cooked during processing and are
typically consumed raw.

• They have a firm texture, red color, and distinct
flavor.

Question 14

Dried meat products

Answer 14

• Dried meat products are made by dehydrating or drying lean meat in natural or artificial conditions.

• The meat is cut into a uniform shape to ensure even drying.

• Dried meat has a longer shelf life than fresh meat but has different sensory and processing properties.

• Nutritional properties, especially protein content, remain unchanged through drying.

Question 15

Coated / breaded products

Answer 15

• Battered and breaded products are popular on the market and come in a variety of boneless and bone-in products.

• Battered and breaded products are made by coating meat with a cereal-based mixture like wheat flour.

Question 16

Processing steps

Answer 16

1) Forming
2) Pre-dusting
3) Battering
4) Breading

Question 17

Forming (Meat)

Answer 17

Forming involves shaping meat into desired shapes.

Question 18

Pre-dusting (Meat)

Answer 18

Pre-dusting is the process of coating meat with flour or breadcrumbs to help the batter stick to the surface.

Question 19

Battering (Meat)

Answer 19

Battering uses dry ingredients to coat the product and prepare it for the next layer of breading.

Different types of batters exist, such as adhesion, cohesion, and tempura batters.

Answer 20

Breading involves coating the product with cereal-based crumbs after the batter has been applied.

The breading is usually baked and ground into fine, medium, or large size crumbs.

Breading is used to create unique appearance, texture, and increase volume and weight of a product.

It is usually made from baked and ground cereal-based products.

The breading adheres to the product via the sticky batter, so it’s important to match the batter with the right breading.

Question 21

Types of breading

Answer 21

1) Flour
2) Home-style or American bread crumbs
3) Japanese-style crumbs (Panko)
4) Fresh crumbs
5) Mixture of/with seeds and grains

Question 22

Flour (Meat)

Answer 22

Simple, low-cost coating option, use rice flour or cornstarch

Question 23

Home-style or American bread crumbs

Answer 23

Dried bread, which can be made from various types of bread such as white, whole wheat

Question 24

Traditional/cracker-type crumbs

Answer 24

White or coloured bread crumbs, with minimal or no crust on the surface

Question 25

Japanese-style crumbs (Panko)

Answer 25

Made from bread without crusts, typically made from white bread, that is processed into flaky, coarse crumbs

Question 26

Fresh crumbs

Answer 26

It consists of soft crumbs resembling material coming out from the center of a bread loaf

Question 27

Mixture of/with seeds and grains

Answer 27

Contains natural seeds and whole grains, sesame seeds, pumpkin seeds, and corn flakes are among the popular materials

Question 28

Frying

Answer 28

• The final step in this process is heat treatment to stabilize the coatings on the meat surface.

• This short heat treatment in hot fat/oil (approx. +175°C) as part of the processing must be seen as a pre-treatment only and does not cook the product (par-fry/flash fry; less than 1 min).

• The final heat treatment is carried out by the consumer right before eating.

Question 29

Q U A L I T Y E V A L U A T I O N

Answer 29

1. Texture Evaluations
   a. Penetration and shear tests
   b. Texture Profile Analyses (TPA) and
   Compression Tests
   c. Tension/extension tests
2. Flavor of meat
   a) Sensory Analysis
   b) E-tongue
   c) E-nose
3. Water Holding Capacity
4. Fat Holding Capacity
   a) Monitoring meat sample behavior
   b) Pressure application
   c) Microstructure evaluation
   d) Chemical extraction
5. Color Evaluations

Question 30

Penetration and shear tests

Answer 30

• Tests like shear and penetration are used to evaluate the toughness of meat products.

• Shear tests use a blade/knife to cut the sample, while penetration tests use a flat/round probe.

• These values obtained are usually correlated with
sensory analysis, such as bite value.

• The Warner Bratzler shear (WB) test is one of the most common tests and measures peak force.

• Sample size, location within the muscle, fiber
orientation, and presence or absence of connective
tissue are critical for reliable results with the shear
device.

• WB values of ≤ 4.5 kg are considered good for deboned chicken breast meat sold to consumers

Question 31

Texture Profile Analyses (TPA) and Compression Tests

Answer 31

• TPA test is a popular method for testing various food products.

• It involves compressing a cylindrical sample twice to a predetermined deformation point.

• The main advantage of TPA is that one can assess many variates with a double compression cycle.

• The Texture Profile Analysis (TPA) test measures different properties of a food sample by compressing it twice to a predetermined deformation point.

• The test parameters used should be standardized to ensure comparability of results across laboratories.

Question 32

Food Regulations 1985 (Malaysian Act)

Answer 32

147 Manufactured meat

• Meat product prepared from meat, containing not less than 65% meat and not more than 30% fat.

• Meat burger, sausage, corned, cured, pickled, or salted meat.

• The final product cannot contain more than 200 ppm of total nitrate and nitrite calculated as sodium nitrite (in uncooked formed other than meat burger,
permitted preservative)

• Any phosphate in such a proportion that the total phosphorus content calculated as phosphorus pentoxide does not exceed 0.3 per cent;

Question 33

Non-meat ingredients

Answer 33

• Along with the main components meat and animal fat, a wide range of substances of nonmeat origin are used as ingredients in processed meat
products.

• Some of them are absolutely necessary, such as salt and spices.

• Others are used for specific products.

Question 34

One way of categorizing nonmeat ingredients is by source. They are either

Answer 34

i. chemical substances
ii. plant origin
iii. animal origin

Question 35

a) Chemical substances used as ingredients

Answer 35

• There are various chemical substances approved for the different kinds of food processing, but in
the specific case of meat processing the number of approved chemical substances is rather
limited in most countries.

Question 36

Examples of chemical substances used as ingredients

Answer 36

✓ Salt (for taste, impact on meat proteins, shelf-life)

✓ Nitrite (for curing colour, flavour, shelf-life)

✓ Ascorbic acid (to accelerate curing reaction)

✓ Phosphates (for protein structuring and water binding)

✓ Chemical preservatives (for shelf-life)

✓ Antioxidants (for flavour and shelf-life)

✓ Monosodium glutamate MSG (for enhancement of flavour)

✓ Food colouring substances (synthetic and of plant origin)

Question 37

b) Non-meat ingredients of animal origin

Answer 37

• Ingredients of animal origin are not commonly applied but may be useful for specific meat preparations.

• They all have functional properties, in particular improvement of water binding and prevention of fat
separation during heat treatment.

Question 38

Meat extender of non-meat ingredients of animal origin

Answer 38

i. Milk caseinate (90% protein; used in small quantities (2%); have functional water and fat binding properties)

ii. Whole milk or non-fat dried milk (=skim milk) (sometimes used in meat preparations as a protein
extender)

iii. Gelatin (binding properties and meat extender)

iv. Blood plasma (predominantly binding properties)

v. Eggs (extender and binding ingredient for meat pieces)

vi. Transglutaminase - natural substance in animal organisms, but now microbial origin. (exclusively binding properties)

Question 39

c) Ingredients of plant origin

Answer 39

• Another group of predominantly functional substances of plant origin with high protein content are used as binders to increase water binding and fat retention, in particular in intensively heat treated products.

• The most commonly used substances are;

i. isolated soy protein (90% protein) and
ii. wheat gluten (80% protein)

Question 40

Meat extenders of plant origin

Answer 40

• A third group of ingredients of plant origin are used as meat extenders (if rich in proteins) or fillers (if rich in carbohydrates) for meat product and sausage formulations.

• The purpose is to replace expensive meat for lower- or medium-grade products by cheaper ingredients of plant origin for cost reduction and volume increase.

• Extenders are distinguished from fillers by their high protein content, compared to the high carbohydrate content of fillers.

Question 41

Meat extenders / Plant products with high protein content are

Answer 41

i. Soy flour (50% protein)
ii. Soy concentrate (70% protein)
iii. Other food legumes (beans, peas, lentils)

Question 42

Fillers

Answer 42

Carbohydrate products with low protein content.

Apart from cost reduction and adding to volume, some flours and starches belonging to this group of fillers also act to some extend as binders.

This property serves important functions such as
increasing water binding for more juiciness or fat binding for improved texture.

Question 43

Examples of filler

Answer 43

i. Cereal flours from wheat, rice and corn

ii. Starches from wheat, rice, corn, potato and cassava

iii. Breadcrumbs

iv. Roots and tubers, e.g. cassava, sweet potato

v. Vegetable and fruits, e.g. onions, carrots, green vegetables, bananas

vi. Polysaccharides (Hydrocolloids)

Carrageenan

Question 44

Tension/extension tests

Answer 44

• Tension/extension tests evaluate the binding strength of meat slices and gelled protein systems.

• The test involves pulling the sample apart, and muscle fiber orientation is important.

• Muscle fibers pulled along their longitudinal axis.

• Good binding products required an average pulling
force of 3.0 Newtons, while poor binding slices had a
value of 1.4 Newtons.

Question 45

2. Flavour of meat

Answer 45

• Changes in reducing sugars, free amino acids, and
nucleotides during cooking affect meat flavor.

• Glutamic acid, inosine monophosphate, and
potassium ions contribute to umami and salty
tastes in cooked chicken.

• Ribose is important in increasing a roasted and
chicken aroma in cooked poultry meat.

• Key compounds for poultry meat include
furanthiols and disulfides, sulfur-containing
compounds, aldehydes, ketones and lactones,
heterocyclic compounds, and others.

• These compounds combine to provide the typical
aroma of a cooked chicken.

Question 46

Sensory analysis

Answer 46

• Sensory analysis studies how ingredients, processing, and preparation techniques affect food perception.

• The evaluation includes taste, smell, touch, sight, and hearing.

• Specially trained sensory professionals work in quality control, product development, and texture and flavor research.

• It is quantitative, collecting numerical data to establish relationships between product characteristics and perception.

Question 47

Sensory tests can be generally divided into:

Answer 47

a. Descriptive analysis – investigates how products differ in specific sensory characteristics

b. Difference testing – investigates if products are perceptibly different in any way

c. Affective testing – investigates how well products are liked and which are preferred

Question 48

E-tongue

Answer 48

• It comprises a set of sensors reacting when
immersed in chemical solutions, consisting of an
electrochemical cell (sensor array), a measurement module, and a pattern recognition system.

• The e-tongue has shown acceptable correlations
with human panellists’ organoleptic results and
exhibits higher sensitivity than the human tongue.

• It finds applications in various meat analysis
categories, including process monitoring, freshness evaluation, shelf-life investigation, authenticity assessment, and quality control studies.

Question 49

E-nose

Answer 49

• It converts sensory information into electrical
signals through an array of gas sensors and artificial
intelligence algorithms.

• Semiconductor metal oxides, commonly used for
their affordability and high sensitivity, are suitable
for assessing meat and fish freshness.

• In spoilage monitoring, e-nose technology detects
odour changes associated with food decomposition
by enzymes and bacteria.

• It distinguishes between different meat types,
assesses dietary supplementation impacts, and
monitors meat production processes.

Question 50

3. Water holding capacity

Answer 50

• Lean meat contains about 75% water held within muscle fibers and their associated components.

• Moisture in further processed products usually ranges from 55-80% and protein from 10-18%.

• Protein’s water holding capacity (WHC) is important for increased yield in both fresh meat cuts and further processed products.

• WHC is influenced by factors such as rigor conditions, processing conditions, and additives.

Question 51

Measuring Water Holding
Capacity (WHC)

Answer 51

• WHC measurement is important for predicting food/meat behavior in various applications.

• Different methods for measuring WHC exist, including monitoring meat sample behavior, pressure application, microstructure evaluation, and optical sensors.

a) Meat sample behavior - a sample of meat is placed in a closed plastic bag to evaluate WHC during storage, or placed in a closed jar/test
tube and heated to the desired temperature to evaluate WHC during cooking.

b) Pressure application - an external force is applied to a meat sample by a press or centrifuge to extract a certain volume of water. The released moisture is commonly collected on a pre-weighed, dehumidified filter paper.

Question 52

4. Fat holding capacity

Answer 52

• In whole muscle and ground products, fat is usually trapped within adipose tissue cells in
the connective tissue network.

• The myofibrillar and sarcoplasmic proteins, mainly myosin and/or actomyosin, are responsible for the fat-holding properties of comminuted meat products by forming an interfacial film around the fat droplets.

• Various methods to predict fat holding capacity in processed products have been developed, including monitoring meat sample behavior, pressure application, microstructure evaluation, emulsion capacity testing, chemical extraction, and optical
sensors.

Question 53

Measuring fat holding capacity

Answer 53

A. Monitoring meat sample behavior:
B. Pressure application
C. Microstructure evaluation
D. Chemical extraction

Question 54

A. Monitoring meat sample behavior:

Answer 54

• One common method is monitoring the fat and
moisture losses that occur while cooking meat samples.

• This can be done using small batches of meat samples in test tubes or monitoring exudates during cooking of a ground meat product.

• Monitoring can reveal the advantages/disadvantages of using certain meats, processing parameters, and different ingredients.

• The cooking test is easy to perform and does not
require sophisticated equipment.

Question 55

B. Pressure application

Answer 55

• Different methods can be employed such as
low/high centrifugation and hydraulic press.

• Olsson and Tornberg (1991) compared fat holding
capacity in hamburger patties using cooking test
and net test.

• Fat losses increased linearly with fat content in both tests.

• However, fat losses were significantly higher in the
net test due to centrifugal force applied after
cooking.

• High gravity forces are not commonly used by the
industry to check raw meats but are useful in

Question 56

C. Microstructure evaluation

Answer 56

• Microstructure evaluations are used to study fresh and cooked meats.
• Light microscopy pictures show the distribution of fat clusters within the raw product

Question 57

D. Chemical extraction

Answer 57

• Chemical extraction is used to estimate fat holding by removing fat that is not well held within the product and can escape during conventional processing (e.g., cooking).

• Unbound fat portion is usually the fat that is not surrounded by a cellular membrane structure in whole muscle and ground products or fat that is not properly surrounded by an interfacial protein film in finely comminuted products.

• Andersson et al. (2000) used hexane to extract unbound fat from hamburgers and emulsion sausages.

• The results showed that the hamburgers lost more fat than the sausages.

Question 58

5. Color evaluations