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Have you ever eaten chicken meat that taste like rubber and tasteless? Well, literally, maybe? Sometimes, chicken meat can lose its tenderness and flavor and becomes hard to chew. It becomes tough and loses its appeal. Imagine overcooked, dry and tough chicken meat. One of the common methods used in every household to increase the flavor and texture is by marinating chicken with various concoctions.

Ever heard of marinating chicken in yogurt? curious? weird?

But fret not! We’re here to help you to test out this method.

In this simple test, we have studied

- How does marinating chicken in yogurt affects the flavor and texture

- The preservative effect of yogurt in chicken

Read on! Our result may surprise many… :D

To see how our test is done, click here.

To see the outcome of our test, click here.

To understand the theory behind this experiment, click here.

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Foundation of Experiments

The quality of chicken meat is largely attributed to flavor and texture. Flavor wise, juiciness is the important parameters and texture wise, tenderness is studied.

The tenderness factor.

Meat is muscle tissue, made up of water, protein, fat and carbohydrate. Muscle consists of muscle fibers held together in bundle by connective tissue. Tenderness of poultry meat depends upon the rate and extent of the chemical and physical changes occurring in the muscle as it becomes meat. When an animal dies, blood circulation stops, hence, there is no new supply of oxygen or nutrients to the muscles. This depletion causes muscles to run out of energy, and they contract and become stiff. This stiffening is called rigor mortis. Eventually, muscles become soft again, which means that they are tender when cooked (Maltin et al, 2003).

To understand rigor mortis in detail and how it affects tenderness of meat, you may click here.

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Post Mortem Factors That Affect Toughness or Tenderness of Meat

The most important factors affecting tenderness are cooking methods and heat.

The heat of cooking affects tenderness in two ways:

• Heat tenderizes connective tissue if moisture is present and cooking is slow.
• It toughens protein. Meat can turns tough and dry if cooked at excessively high heat for too long.

(Wayne Gisslen , 2004)

Because high heat toughen and shrinks protein and causes excessive moisture loss, low heat cooking should be the general practice. Among the cooking method preferred are low heat roasting, broiling and simmering. For this reason, our experiment is done by frying at 150 degree Celsius.

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Rigor Mortis

To know how muscle turns into meat, we must first understand what is rigor mortis.

When an animal dies, aerobic glycolysis stops since no oxygen is available. As the muscle attempts to maintain homeostasis, muscle glycogen is metabolised via anaerobic glycolysis, thus phosphorylating ADP to supply ATP.

Anaerobic glycolysis generates lactate that accumulates, lowering the intracellular pH, so that by 24 hours post mortem the pH has fallen to an ultimate pH of about 5.4–5.7.
Muscle is highly sensitive to both ATP and Ca2+, which are both involved in the contraction–relaxation process. Consequently, as ATP levels are reduced and Ca2+ levels rise, irreversible cross bridges form between myosin head and actin. This formation is associated with an increase in toughness.
It was also reported that meat with low ph is likely to be poorer eating quality as the enzymes involved in post mortem tenderization are inhibited by the acidification. (Maltin et al, 2003)

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Juiciness of meat

The Juiciness Factor

Juiciness is a very subjective measurement. One person’s definition of juiciness may differ from the other.

Three main factors affect the perception of juiciness:

- Internal fat – Fat makes meat juicy and we all know that. Lean meat taste drier and lack succulent than of marbled meat.

- Gelatin – Converted from connective tissue in muscle, it readily binds to water molecule and holds them in meat.

- Protein coagulation – as mentioned earlier, protein coagulates when cooked and looses water. The more it is cooked, the more it contracts and forces out the moisture. Also, extreme pH may cause protein coagulation too, which we will see later in our discussion of results ( Wayne Gisslen , 2004)

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Ingredients

1 x 500mL tub of yogurt








300gm Ritz crackers





Corn oil




corn flour

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Production of chicken nuggets -- Day 1

1) Wash chicken breasts thoroughly with running water to remove any unwanted material

2) Put the chicken breasts one at a time into a freezer bag so that they lie flat

3) Bash with a roller pin until the chicken is quite thin

4) Take it out and slide into few slices and repeat with other chicken breast.

5) Separate the chicken slices into 3 parts
The 1st part - chicken slices, unmarinated into freezer bag(control)
The 2nd part - chicken slices with water into freezer bag
The 3rd part - chicken slices with yogurt

6) Store all the 3 bags of chicken slices into chiller for one day

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