Development of chicken tender pops by utilizing pomegranate peel powder

Abstract Pomegranate peel powder (PPP) is a rich source of many bioactive components particularly polyphenols that are interlinked to various technological and functional properties. In the present study, chicken tender pops were developed with incorporation of PPP, and its effect on quality attributes and storage stability of the product were evaluated. The treatments were formulated using 0%, 3%, 6%, and 9% PPP in replacement of chicken. The physicochemical properties, texture profile, instrumental color, sensory attributes, and storage stability were assessed for 21 days at refrigeration temperature, at a regular interval of 7 days. The results indicated that the inclusion of PPP significantly (p < .05) increased the dietary fiber from 0.25% in T0 to 1.45% in T3 at Day 0 and WHC 43.60% ± 0.02 in T0 to 49.36% ± 0.02 in T3 at Day 0, whereas the moisture content significantly reduced from 60.05% ± 0.03 in T0 to 55.08% ± 0.01 in T3 at the start of the study. In addition, the values of TBARS were significantly (p < .05) reduced for treated samples 0.72 mg MDA/Kg in T3 as compared to control 1.17 mg MDA/Kg on the 21st day of storage, whereas a significant increase (p < .05) in TPC from 0.90 mg GAE/g to 3.87 mg GAE/g in T0 to T3 was observed at the start of the study. For TPA, a significant (p < .05) increase was noticed in hardness, chewiness, and gumminess, whereas cohesiveness and springiness showed a non‐significant (p > .05) change in treated samples in relation to control, and the instrumental color (L* and a*) decreased significantly. However, pH, crude fiber, fat, ash, and protein content showed non‐significant (p > .05) variations over time. The sensory evaluation suggested that chicken tender pops supplemented with 6% PPP (T2) presented high overall acceptability and balanced organoleptic properties. Hence, it can be concluded that PPP can be effectively utilized as a natural fiber source, antioxidant, and antimicrobial agent in novel functional foods.


| INTRODUC TI ON
Pomegranate (Punica granatum) is a spherical fruit that is a member of the Punicaceae family which was first cultivated in Iran and India and then spread throughout the Mediterranean basin (El Barnossi et al., 2021). Global pomegranate production is around 8.1 million tons, with a planting area of 835,950 hectares (Pienaar & Barends-Jones, 2021). The global pomegranate market is anticipated to grow from 208.9 million USD in 2020 to 322.9 million USD by 2026 (River Country, 2021). Pomegranate fruit comprises two parts, an edible part that is 50% of the fruit, and the other 50% is the peel (Rafraf et al., 2017). Pomegranate is a valuable fruit because of its nutritional components such as minerals, proteins, crude fibers, vitamins, alkaloids, organic acids, fatty acids, flavonoids, polyphenols, isoflavones, and pectin that are associated with various therapeutic and technological benefits (Pirzadeh et al., 2021;Rahmani et al., 2017;Viuda-Martos et al., 2010). It is usually consumed fresh or processed into different products such as juice, jam, oil, wine, or dietary supplements (Kahramanoglu & Usanmaz, 2016). However, the industrial processing of pomegranate produces enormous amounts of by-products, mainly peels (40%-50%) which are disposed of as waste without any valorization that jeopardizes the environment (Ali et al., 2019). On the other hand, Pomegranate peel can be valorized to produce pomegranate peel powder and peel extracts containing many functional biomolecules Singh et al., 2019).
These valorized products could be incorporated into the food chain to promote bio-economy and satisfy sustainable development principles (Ben-Othman et al., 2020;Sharayei et al., 2019).
Poultry consumption, particularly chicken meat, is associated with many positive health benefits and is considered more valuable than other meats because of its low energy value with high nutritional density (Bordoni & Danesi, 2017;Millen et al., 2014). In addition, it contains considerable amounts of long-chain n-3 polyunsaturated fatty acids, trace minerals (Fe and Zn), and B group vitamins, along with minute amounts of biotin, folic acid, pantothenic acid, and vitamin E (Barroeta, 2007). However, chicken meat lacks the dietary fiber essential to maintain human health by avoiding various ailments (Verma & Banerjee, 2010). Furthermore, using artificial preservatives to preserve the nutritional and quality attributes of meat products is associated with negative health effects such as allergy, asthma, cancer, hyperactivity, hypersensitivity, and neurological damage (Anand & Sati, 2013;Smaoui et al., 2019). Therefore, meat industries and researchers are focused on discovering natural substitutes to replace these synthetic additives with renewable biomass that is a natural safe source of many functional biomolecules (Pateiro et al., 2018;Žugčić et al., 2019).
The current study is aimed to develop a functional meat product (chicken tender pops) by effectively utilizing pomegranate peel powder and exploring its efficacy as a natural dietary fiber source, antioxidant, and antimicrobial agent. Furthermore, the effect of PPP incorporation on physiochemical characteristics, proximate composition, cooking characteristics, oxidative stability, instrumental color, texture profile, and sensory attributes of chicken tender pops was also assessed to predict the product's storage quality at refrigeration for 21 days.

| Procurement of raw materials
The pomegranate (Punica granatum) was procured from the local market of Lahore, Pakistan. The fresh boneless broiler chicken meat was purchased from the local Superstore in Lahore, Pakistan. The meat was packed in small bags of LDPE and held in a refrigerator at 4 ± 2°C for 6 h and later used to develop chicken tender pops.

| Preparation of pomegranate peel powder (PPP)
The PPP was prepared using the method of , with few modifications. Briefly, fresh pomegranates were washed thoroughly with distilled water to remove surface dust. The arils were separated from rinds and then cut into medium-sized pieces. Pomegranate peels (rind) were placed in a tray and dried using a hot-air oven DOF-230E (Bievopeak, Japan) at 50 ± 2°C for 48 hrs. Dried peels were cooled and ground enough to pass through a 20-mesh sieve to obtain a fine powder with uniform particle size. Pomegranate peel powder was transferred in zipped-lock high-density polyethylene bags and stored at room temperature 20 ± 3°C for physicochemical analysis and later used in product development.

| Physicochemical analysis of pomegranate peel powder (PPP)
Proximate analysis (moisture, fat, protein, ash, and crude fiber) was performed using standard protocols of AOAC (2005). The pH of PPP was determined using a pH meter described by .
Two gram of the sample was combined with 20 mL of methanol and left for 2 days to allow for maximum leaching to analyze the TPC of PPP. Folin-Ciocalteu reagent 1.5 mL was added into extract 0.5 mL and incubated at 25°C for 5 min. After incubation, 6% sodium carbonate 1.5 mL was added and incubated again for 90 min in a dark room. The absorbance of the resulting blue color mixture was measured at 725 nm, and the total phenolic content was articulated as mg GAE per 100 mL of a sample (Mahmoud et al., 2017).

| Manufacturing of chicken tender pops
Treatments of chicken tender pops were prepared using various concentrations of PPP replacing chicken meat. 0%, 3%, 6%, and 9% PPP were added to 80%, 77%, 74%, and 71% boneless meat, respectively, while other ingredients were added according to weight ratio (w/w) mentioned in Table 1. Boneless chicken breasts were washed with tap water, dried using a paper towel, and sliced into chunks of 8 g to 10 g. Chicken chunks were uniformly mixed with PPP, onion powder, garlic powder, black pepper, paprika, and iodized salt with the addition of chilled water according to the formulation mentioned in Table 1. After a marinating stay of 30 min, chunks were coated with flour and coarsely ground cornflakes. The functional chicken tender pops were packaged aerobically in low-density polyethylene (LDPE) boxes and stored in the refrigerator for 21 days. Physiochemical properties, proximate composition, cooking characteristics, oxidative stability, microbiological studies, texture profile, instrumental color, and sensory attributes of chicken tender pops were evaluated every 7 days up to 21 days. To determine sensory characteristics and cooking characteristics, the developed product was air fried using air fryer DWAF, 3013 (Dawlance, Pakistan) for 10 min at 200 ± 2°C.

| Determination of physiochemical parameters of chicken tender pops
The pH of chicken tender pops was estimated by the dipping probe of a digital pH meter (HANNA-instrument, USA) in a homogenized sample by following the method of Santhi et al. (2020). The waterholding capacity of samples was assessed as described by Rupasinghe et al. (2022), samples were placed between layers of filter paper and subjected to 10 kg weight for 5 min, and weight difference was expressed as WHC of samples.

| Determination of proximate composition
Moisture, fat, protein, ash, and crude fiber content of chicken tender pops were determined by following the standard protocols of AOAC, 2005. Chopped samples of chicken tender pops were oven dried at 100°C for 2 h, cooled in a desiccator, and moisture content was measured as weight loss. The solvent extraction method was used to determine fat content; methanol was used as a solvent.
Protein was assessed through the Kjeldahl method of digestion.
Samples were subjected to a muffle furnace at a temperature of 550°C for ashing. For crude fiber determination, defatted samples were digested using acid and base. After digestion, the leftover material was weighed and ashed. The crude fiber was calculated as the difference in sample weight.

| Determination of TPC and antioxidant activity (TBARS)
Folin-Ciocalteu method, as described by Firuzi et al. (2019), was used to determine the total phenolic content of the product with few modifications. 0.5 mL methanolic extract of the sample was mixed with 1.5 mL of Folin-Ciocalteu reagent and incubated at 25°C for 5 min. Afterward, 1.5 mL of sodium carbonate (6%) was added, and the sample was incubated in a dark room for about 90 min. The absorbance of the blue color mixture was taken at 725 nm, and total phenolic content was expressed as milligram gallic acid equivalents (GAE) per 100 mL of a sample. The assessment of TBARS was done to predict the lipid oxidation of the product. TBARS were measured using the method of Mashau et al. (2021) with few modifications, methanolic extracts of chicken tender pop samples were mixed with thiobarbituric acid, and centrifuged at 3000g for 15 min. Samples were heated at 95°C for 60 min in a water bath, followed by cooling at 25°C. The absorbance of samples was measured at 532 nm through the Tecan Sunrise spectrophotometer (Austria).

| Texture profile analysis
The instrumental texture profile (hardness, chewiness, springiness, gumminess, cohesiveness, and resilience) of chicken tender pops was evaluated using a Universal TA-XT plus texture analyzer (Stable Micro Systems, UK) and its propriety Exponent software, version V.5.1.1.0, as described by de Paiva et al. (2021). A slice of 1 × 1 cm was ligated from the treated samples of chicken tender TA B L E 1 Formulation of chicken tender pops.

| Instrumental color analysis
The instrumental color of chicken tender pops was determined using a Hunter lab calorimeter at 0, 7, 14, and 21 days of refrigerated storage. CIE L* (lightness), a* (redness), and b* (yellowness) of samples were measured (Shahamirian et al., 2019).

| Determination of cooking characteristics
Cooking yield and cooking loss expressed the overall cooking characteristics of samples. Samples were air fried for 10 min at 200°C and then cooled at room temperature 25 ± 5°C. The cooking yield and loss were measured as weight differences before and after frying chicken tender pop, following Sunantha and Saroat (2011) and El-Nashi et al. (2015).

| Microbiological evaluation
The microbiological analysis for each treatment was performed according to International Standards (APHA, 2001). Maximum recovery solution was prepared by adding 10 g of sample in 90 mL of peptone water in a sterile stomacher bag for 2 min of blending in the stomacher (IUL Instruments, Mod. 1986/470, Spain). After that, serial dilutions up to 10 −3 were prepared using 1 mL sample in 9 mL of peptone water. The samples were inoculated in particular culture media for enumeration of studied microorganisms: total vi-

| Sensory evaluation
Sensory evaluation of chicken tender pops was carried out by an untrained consumer panel of 20 individuals using a 9-point hedonic scale (score of 9 as excellent and 1 as extremely poor) at the Department of Food Sciences, University of the Punjab, Lahore, Pakistan. The items were air fried and served warm for a few minutes before sensory analysis. The samples were evaluated based on their general acceptability, juiciness, flavor, appearance, color, texture, and juiciness. Around 4.30 p.m., sensory evaluation was conducted in a setting with adequate lighting. The panelists offered potable water to rinse their mouths after each sample (Santhi et al., 2020).

| Statistical analysis
Acquired data were articulated as the mean values of three replicates, and standard deviations were analyzed statistically by evaluating variance using SPSS version 25.0. Two-way ANOVA and LSD's post hoc analysis were used for multiple comparisons. For all tests, p-values of (p < .05) were considered statistically significant.

| Physiochemical analysis of pomegranate peel powder
The physicochemical composition of PPP is illustrated in Table 2.
The percentage of moisture, crude fiber, fat, protein, and ash were 7.28 ± 1.50, 13.91 ± 0.02, 1.61 ± 0.08, 3.78 ± 0.14, and 3.63 ± 0.05, respectively. The results of our studies are in line with those of Kushwaha et al. (2013) and Rowayshed et al. (2013). According to our studies' results, pomegranate peel powder's pH was 4.86 ± 0.02, which was in near accordance with Jalal, Pal, Ahmad, et al. (2018). TPC in the methanolic extract of PPP was 23.59 ± 0.02 mg GAE/g, which is responsible for its excellent radical scavenging properties. Our findings are parallel to those of , who reported the TPC of methanol extract of PPP to be 24.00 mg GAE/g.

| Physiochemical parameters of chicken tender pops
The incorporation of pomegranate peel powder did not significantly change the pH of chicken tender pop as depicted in Table 3

| Proximate composition of chicken tender pops
The moisture content of chicken tender pops was significantly (p < .05) decreased by the addition of pomegranate peel powder ranging from 60.05 ± 0.03% to 55.08 ± 0.005%, attributed to the replacement of meat with dried peel powder. A considerable drop in moisture content was observed during storage associated with evaporation into surroundings, but this decrease was lower in treated samples, as elucidated in Table 4. Sharma and Yadav (2020) also reported reduced moisture content in chicken meat patties prepared with pomegranate peel powder. The fat content of chicken tender pops increased in a non-significant manner with the progression of the storage period due to the breakdown of lipoprotein into lipids and protein (El-Nashi et al., 2015).    Abbreviations: T 0 : Chicken tender pops with PPP; T 1 : Chicken tender pops with 3% PPP; T 2 : Chicken tender pops with 6% PPP; and T 3 : Chicken tender pops with 9% PPP.

F I G U R E 1
Effect of interaction between treatments and storage days for total phenolic content (mg of GAE/g) of chicken tender pops supplemented with different concentrations of pomegranate peel powder (PPP) during refrigerated storage at 4 ± 2°C for 21 days. Columns labeled with different letters are significantly different, p < .05 (n = 3). T 0 : control group; T 1 : 3% PPP; T 2 : 6% PPP; and T 3 : 9% PPP.
who evaluated the storage stability of garlic-fortified chicken bites.
The presence of little phenolic content (0.90 ± 0.055 mg GAE/g) in the control sample is attributed to spices used for seasoning.
TBARS were significantly (p < .05) increased for both control and treated samples throughout refrigerated storage. However, the increase in treated samples was significantly lower than the F I G U R E 2 Effect of interaction between treatments and storage days for TBARS (mg of MDA/Kg) of chicken tender pops supplemented with different concentrations of pomegranate peel powder (PPP) during refrigerated storage at 4 ± 2°C for 21 days. Columns labeled with different letters are significantly different, p < .05 (n = 3). T 0 : control group; T 1 : 3% PPP; T 2 : 6% PPP; and T 3 : 9% PPP.

TA B L E 5
Textural profile analysis of chicken tender pops supplemented with different concentrations of pomegranate peel powder during refrigerated storage at 4 ± 2°C for 21 days. Abbreviations: T 0 : Chicken tender pops with PPP; T 1 : Chicken tender pops with 3% PPP; T 2 : Chicken tender pops with 6% PPP; and T 3 : Chicken tender pops with 9% PPP.

F I G U R E 3
Effect of interaction between treatments and storage days for instrumental color (L*, a*, and b*) a, b, and c, respectively, of chicken tender pops supplemented with different concentrations of pomegranate peel powder (PPP) during refrigerated storage at 4 ± 2°C for 21 days. Columns labeled with different letters are significantly different, p < .05 (n = 3). T 0 : control group; T 1 : 3% PPP; T 2 : 6% PPP; and T 3 : 9% PPP.
control sample, as presented in Figure 2. Similarly, Vaithiyanathan et al. (2011) witnessed that dipping meat in a phenolic solution significantly (p < .05) reduced the TBARS of meat. However, the TBARS increased during the storage period, a consequence of lipid oxidation in muscle foods.

| Texture profile analysis of chicken tender pops
The influence of PPP inclusion on the textural parameters of chicken tender pops was scrutinized while refrigerated storage and elucidated in  (2020)  redness (a*), but it was more significant in the control sample than in treated samples (as illustrated in Figure 3b). The decline in a* is interlinked to the oxidation of myoglobin followed by accumulation of metmyoglobin that imparts a darker-brown color to meat products. Similar results were observed by , who added pomegranate seed extract to beef patties. However, more intense color was evident in control (3.14) than in treated samples 4.57, 4.69, and 4.78 at the end of storage, which can be attributed Abbreviations: T 0 : Chicken tender pops with PPP; T 1 : Chicken tender pops with 3% PPP; T 2 : Chicken tender pops with 6% PPP; and T 3 : Chicken tender pops with 9% PPP.

TA B L E 6
Cooking characteristics of chicken tender pops supplemented with different concentrations of pomegranate peel powder during refrigerated storage at 4 ± 2°C for 21 days.

F I G U R E 4
Effect of interaction between treatments and storage days for (a) total viable count (log cfu/g), (b) psychotropic count (log cfu/g); and c: coliform count (log cfu/g) of chicken tender pops supplemented with different concentrations of pomegranate peel powder (PPP) during refrigerated storage at 4 ± 2°C for 21 days. T 0 : control group; T 1 : 3% PPP; T 2 : 6% PPP; and T 3 : 9% PPP.
to the antioxidant potential of PPP. The addition of olive and grape pomace extracts to meat patties retained the intensity of red color in contrast to control sample (Andrés et al., 2017). The inclusion of PPP significantly (p < .05) reduced the yellowness (b*) in treated samples 12.15-12.37 than control 12.83. However, heterogeneous variation was observed for b* throughout the storage as depicted in Figure 3c.

| Cooking characteristics of chicken tender pops
Cooking yield and cooking loss of tender chicken pop prepared with 0%, 3%, 6%, and 9% pomegranate peel powder were assessed, and the results are elucidated in Table 6. There was a considerable increase in the cooking yield of the treated sample compared to the control sample. The upsurge in cooking yield is attributed to the water-retaining properties of pomegranate peel powder. Analogous effects were reported by Mashau et al. (2021) for the cooking yield of ground beef supplemented with moringa leaves powder. On the other hand, adding pomegranate peel powder reduced the cooking loss in developed products from 17.17% to 12.68%. According to El-Nashi et al. (2015), the reduction in cooking loss is attributed to the WHC of pomegranate peel powder. However, the advancement F I G U R E 5 Effect of interaction between treatments and storage days for sensory scores of texture, juiciness, flavor, tenderness, appearance, and overall acceptability of chicken tender pops supplemented with different concentrations of pomegranate peel powder (PPP) during refrigerated storage at 4 ± 2°C for 21 days. T 0 : control group; T 1 : 3% PPP; T 2 : 6% PPP; and T 3 : 9% PPP.
of storage resulted in a significant decrease in cooking yield and a significant increase in cooking loss.

| Microbiological studies of chicken tender pops
The effect of PPP supplementation on the microbiological safety of chicken tender pops during storage was investigated through the assessment of total viable count, psychotropic count, and coliform count along with Staphylococcus, Salmonella, and Listeria monocytogenes. The total viable count (TVC) for chicken tender pops significantly (p < .05) increased with the advancement of the storage period in all treatments as shown in Figure 4a. However, the increase in the TVC of treated samples was slightly less than that of the control sample. The TVC observed for the control sample was 2.54 ± 0.02 log cfu/g, whereas TVC for the treated sample (T3) was recorded as 1.33 ± 0.03 cfu/g. A similar trend was observed for the psychotropic count of chicken tender pops shown in Figure 4b

| Sensory evaluation
Sensory attributes (appearance, color, texture, flavor, juiciness, tenderness, and overall acceptability) of prepared treatments (T 0 , T 1 , T 2 , and T 3 ) containing different concentrations of pomegranate peel powder at different storage intervals are represented in Figure 5. Results indicated that the inclusion of pomegranate peel powder significantly improved the product's sensory attributes during storage with increased overall acceptability. However, in T 3 (9% PPP), darker red color was observed with a slight dryness with the progression of storage. In general, the best sensory scores were received by T 2 chicken tender pops containing 6% PPP. Hence, the panelists declared chicken tender pops with 6% pomegranate peel powder (T 2 ) as the best treatment for all organoleptic properties during the study period. The results for sensory evaluation of color and textural properties (juiciness and tenderness) can be correlated with instrumental color analysis and texture profile analysis.
Sensory scores for color were decreased as an increase in PPP concentration and results are analogous to L* and a* values which show increased darkness in product due to myoglobin oxidation and PPP color. Furthermore, instrumental texture analysis showed increased hardness and dryness because of moisture loss that will ultimately lower the juiciness and tenderness of the product.

| Heatmap and hierarchical analysis
A heatmap was generated to analyze all variables pertaining to storage time and pomegranate peel powder concentration ( Figure 6). In addition to data classification, a heatmap entails color comparison to make the findings more intrusive.

| Correlation and principal component analysis (PCA)
A regression analysis was performed to evaluate the correlation among the results of conducted assays on chicken tender pop samples supplemented with pomegranate peel powder shown in Figure 7. A significant positive correlation was observed between coliform count and fat. Similarly, the parameters hardness, chewiness, and gumminess were also observed to be positively correlated.
Correlation analysis revealed that all the sensorial attributes (color, appearance, tenderness, flavor, texture, juiciness, and overall acceptability) were significantly correlated with each other in a positive correlation. Water-holding capacity and cooking loss were also observed to be positively correlated. A comparatively neutral correlation was found between pH and organoleptic characters. Sensory properties were observed to be negatively correlated with coliform F I G U R E 8 Principal component analysis (PCA) of different parameters of chicken tender pops supplemented with pomegranate peel powder during 21 days of storage. count and psychotropic count. Crude fiber, hardness, and gumminess depicted a negative correlation with cohesiveness indicating an inverse relation. Total plate count and cooking yield were also observed to be in a negative correlation with cooking yield.
Principal component analysis (PCA) was characterized by reducing a large number of variables to a small number of comprehensive variables, accurately expressing the total amount of data.
Signal intensities are used in PCA to highlight the differences between the parameters that were taken into consideration. Figure 8 presents the results of the principal component analysis (

| CON CLUS ION
Incorporating pomegranate peel powder reduced the moisture content and significantly improved the product's water-holding capacity, ultimately enhancing the product's sensory attributes. Furthermore, the inclusion of PPP enhanced crude fiber content in treated samples compared to the control group. Significant elevation in total phenolic content indicated the potential of PPP to be used as a natural antioxidant. In contrast, reduced TBARS elucidated the positive impact of PPP on lipid auto-oxidation. Hardness, chewiness, and gumminess were considerably affected, whereas springiness and cohesiveness showed minor variations. In addition, PPP retarded pigment oxidation was indicated by retained red color during storage. The reduced microbial load validates the antimicrobial potential of PPP ascribed to the presence of polyphenols and flavonoids. Pomegranate peel powder significantly improves the sensory attributes, but up to a specific limit, as for our study, it was at 6%. Based on our study, it can be concluded that chicken products supplemented with PPP have improved nutritional and sensory profiles and can be naturally preserved for up to 3 weeks at refrigeration temperature. writing -review and editing (equal). Zujaja Umer: Formal analysis (equal); investigation (equal); methodology (equal); writing -review and editing (equal). Humphrey Garti: Conceptualization (equal); data curation (equal); formal analysis (equal); methodology (equal); writing -review and editing (equal).

ACK N OWLED G EM ENT
All the authors express deepest gratitude and appreciation to the Department of Food Sciences for their invaluable support during the research project. The resources, facilities, and expertise provided by the department were instrumental in the successful completion of this study.

FU N D I N G I N FO R M ATI O N
We did not receive any funding for this work.

CO N FLI C T O F I NTER E S T S TATEM ENT
The authors have no competing interest to declare.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author upon reasonable request.