*2.7. Physicochemical Analysis*

Moisture, protein, fat and ash content of the cooked meat nugge<sup>t</sup> samples were determined by the procedures previously described by Association of O fficial Analytical Chemists AOAC [31]. The pH of sample was determined by combination electrode digital pH meter (Benchtop pH meter, BR Biochem, PHS-25CW, New Delhi, India). Briefly, 10 g of sample was homogenised with the help of tissue homogeniser (Omni International, Kennesaw GA, United States) for approximately a minute in 50 mL of distilled water. The homogenised sample was kept for 5 minutes and then mixed again by shaking rod. The pH value was recorded by immersing the electrode directly into the suspension.

The colour profile of thick slice of chicken nugge<sup>t</sup> or fresh chicken block was measured using Hunter Color Lab (Mini XE, Portable, HunterLab, Reston, VA, United States) to record Hunter L\*, a\*, and b\* values. The instrument was calibrated using light trap/black glass and white tile provided with the instrument. The instrument was directly put on the surface of meat block and reading was taken at three di fferent points. The textural properties of nuggets were evaluated using a texture analyser (Stable Micro System, Model TA. HDi, Surrey, UK). Texture profile analysis (TPA) was performed using central cores of five pieces of each sample (2 cm × 2 cm × 2 cm), which were compressed twice to 80% of the original height by a compression probe (P 75). A crosshead speed of 2 mm/s was used. The following parameters were determined; hardness (N/cm2), springiness (cm), cohesiveness, gumminess (N/cm2) and chewiness (N/cm).

Cooking yield of nuggets was determined by recording the weight of each meat block before and after cooking and expressed as percentage according to the following equation.

$$\text{Cooling yield} \left( \% \right) = \frac{\left( wt \text{ of cooled meat block} \right)}{wt \text{ of raw meat block}} \times 100 \tag{2}$$

Expressible water was estimated using the method of Das et al. [32] with slight modifications. Approximately 5 g of cooked sample was weighed and placed on 2 layers of Whatman no. 1 filter paper. The sample was placed at the bottom of 50 mL centrifuge tube and centrifuged at 1500 g (Remi, Mumbai, India) for 15 min. Immediately after centrifugation, meat samples were reweighed and the percentage of expressible water was calculated according to the following equation.

$$\text{Expressible water} \left( \% \right) = \frac{\text{(initial weight} - \text{final weight)}}{\text{initial weight}} \times 100\tag{3}$$

#### *2.8. Thiobarbituric Acid Reacting Substances (TBARS) Values*

The evaluation of lipid stability was performed by measuring TBARS values following the method proposed by Witte et al. [33]. The TBARS value was calculated as mg malonaldehyde (MDA) per kg of the sample by multiplying the absorbance value with a factor of 5.2.

#### *2.9. Sensory Evaluation of Chicken Nuggets*

Sensory evaluation of the control and treated chicken nuggets was used for various sensory attributes by trained and experienced panellists familiar with the characteristics of the meat product. Just before sensory evaluation, nugge<sup>t</sup> samples (C, T1 and T2) were warmed in a microwave oven for 20 s, coded and then served to evaluate for general appearance, colour, flavour, binding, texture, juiciness and overall acceptability using 8-point descriptive scale [34], where 8 = extremely desirable and 1 = extremely undesirable. Plain potable water was provided to rinse the mouth in between the samples.
