Male Layer-Type Birds (Lohmann Brown Classic Hybrid) as a Meat Source for Chicken Pâtés

Abstract

The valorisation of underutilized male layer-type chickens offers a sustainable and ethically aligned opportunity for the poultry industry. This study evaluated the feasibility of male layer-type chicken meat in the production of chicken pâtés and compared the effects of different meat sources—commercial broiler (CP), and 5 (5wP) and 9-week-old (9wP) male layer-type chickens—on product quality during refrigerated storage using the general linear model with the Tukey–Kramer post-hoc test. Pâtés made from 5wP meat exhibited the most favourable technological properties, including the lowest (p < 0.05) total expressible fluid (TEF), highest (p < 0.05) water retention (TEF_Water), and lowest (p < 0.05) fat content (TEF_Fat) than CP and 9wP indicating superior emulsion stability. The 5wP pâtés also presented the lowest (p < 0.05) TBARS values on day 1, along with reduced colour deterioration (ΔE) over 7 days of storage. CP samples demonstrated the greatest (p < 0.05) hardness, cohesiveness, and gumminess, but lower (p < 0.05) springiness and resilience compared to 5wP and 9wP, yielding softer and elastic pâtés. Overall, pâtés formulated with 5wP can be a promising option for the development of value-added poultry products. The incorporation of male layer-type chicken meat into commercial formulations will encourage further research of their market potential.

1. Introduction

The world poultry industry is primarily divided into two sectors: broilers raised for meat production and laying hens for egg production [1]. Broiler meat is characterized by high nutritional value, relatively tender texture, and pleasant taste, making it highly preferred by consumers [2]. The growing global demand for chicken meat has intensified large-scale broiler production [3]. This growth is primarily due to the broilers’ rapid growth cycle, allowing them to reach market weight within 5 to 6 weeks, thereby optimizing production efficiency and reducing costs [4].

Globally, egg-laying hens are culled and processed for meat once they surpass their peak productive period at the end of their laying cycle [5]. The meat from spent hens exhibits high nutritional value, comparable to broiler chickens, representing a rich source of complete proteins [3]. In commercial poultry production, male chicks from egg-laying breeds are not utilized for meat production due to their slow growth rates and lack of desirable carcass traits [6,7]. As a result, these chicks are typically culled immediately after sex determination. This long-standing practice has faced ethical scrutiny, particularly within the European Union, prompting regulatory interventions, including a ban on the culling of male chicks [8,9].

In response to legislative changes within the European Union prohibiting the culling of male chicks, various alternative strategies have been investigated [9,10,11,12]. One promising approach is rearing the male chickens from egg-laying breeds for meat production [12,13,14,15], offering a sustainable utilization of these birds in the poultry industry. Previous investigations suggested a superior quality of meat from male chicks from egg-laying breeds compared to male broilers [16,17]. Comparative analyses have reported a positive consumer perception regarding the meat quality from male laying hens [12,18], as well as the concern about the management of newly hatched male chicks. To prevent the hatching of male chicks, consumers often favour pre-sexing techniques, followed by the adoption of dual-purpose breeds suitable for both egg and meat production [12,13,14,19]. However, the production costs of raising male laying hens, compared to broiler breeds, is yet a challenge to the market success [20].

Poultry pâtés are a popular food product consumed worldwide, appreciated for their taste, nutritional value, and convenience [21,22]. The origins of pâté date back to the Middle Ages, when it was traditionally made from minced meat and fat, suitable for spreading on bread and for direct consumption. Nowadays, despite the variety of recipes, the pâtés are divided into two categories depending on the primary raw material—meat or liver pâtés [21,23,24]. Both types have specific characteristics, such as price, proximate composition, technological, and sensory properties [25]. From a health perspective, poultry products are lower in saturated fat content and rich in polyunsaturated fatty acids (PUFA), which provide several health benefits [23,26]. However, the high content of unsaturated fatty acids increases the product’s susceptibility to oxidation [27], as well as changing its quality parameters [28].

From this perspective, the main hypothesis of this study will try to answer the question: are the male layer-type birds (Lohmann Brown Classic Hybrid) a sustainable meat source for the production of chicken pâtés? Therefore, the present study aims to investigate the proximate composition and technological properties of pâtés produced using meat from male laying hens compared to those produced from broiler chickens, contributing to the development of sustainable and high-quality poultry-based products.

2. Materials and Methods

2.1. Raw Materials

Three different chicken meat sources were utilized in this study: (1): chicken meat from conventional raised broiler (Gallus gallus) purchased from a commercial market (control pâté; CP); (2) meat from 5-week-old male layer-type chickens (5wP); and (3) meat from 9-week-old male layer-type chickens (9wP). The male layer-type chickens were derived from Lohman Brown Classic hybrid breed reared at the experimental poultry farm of the Institute of Animal Science-Kostinbrod, Bulgaria, and slaughtered in a certified poultry abattoir [14]. All additional ingredients were bought from the market. Poultry carcasses with an average weight of 1.42 ± 0.11 kg (CP; n = 7 carcasses); 0.19 ± 0.03 kg (5wP; n = 52 carcasses), and 0.79 ± 0.07kg (9wP; n = 13 carcasses) were utilized in the preparation of the pâtés. For each pâtés formulation, 10 kg of meat from CP, 5wP, and 9wP were utilized, along with pork back fat and poultry liver. The meat was frozen and subsequently thawed to a temperature range of 0–4 °C before processing.

2.2. Recipe and Formulation

The control and experimental pâtés were produced in three separate batches following the process outlined in the flow diagram (Figure 1). Briefly, the three different poultry meat sources were obtained from the whole thawed poultry carcasses, including skin, after undergoing boiling for 1 h, subsequent cooling, and deboning.

Pâté emulsions were prepared using a cutter machine in a two-step process. Initially, the boiled and deboned poultry meat (54.20%) and liver (10.00%) were finely chopped with table salt (1.55%), tripolyphosphates (0.15%), and flaky ice (12.70%). In the second step, pork back fat (20.00%), milk protein powder (0.85%), and wheat flour (0.35%) were incorporated, followed by the addition of black pepper (0.16%) and nutmeg (0.04%). The cutting process continued until a homogeneous emulsion was achieved, with no visible particles. The emulsions were stuffed into polyamide casings and sealed with metal clips. The pâtés were steam-boiled at 80–85 °C until reaching an internal temperature of 72 °C, then cooled with running water and stored under refrigeration at 0–4 °C for up to 7 days.

2.3. Sampling

For colour and texture profile analyses (TPAs), the pâtés were sliced into 15 mm-thick portions. Approximately 1 kg of remaining pâtés were then homogenized for further analysis [29].

2.4. Emulsion Stability

A centrifuge tube (height = 106 mm, diameter = 38 mm) was filled with 40 g of raw pâté emulsion immediately after preparation. The tubes were then placed in a water bath at 72 °C for 30 min. Following heating, the tubes were centrifuged at 5200 rpm (4226 G) for 90 s. After centrifugation, the supernatant was separated and weighed to determine the total expressible fluid (TEF). Subsequently, the tubes were dried at 103 °C overnight and reweighed [30]. The percentage of TEF, along with the water and fat fraction in TEF, was calculated using the following equations:

TEF, % = (mass of supernatant/mass of sample) × 100

(1)

TEF_Water, % = (mass of supernatant − mass of supernatant after drying)/mass of supernatant) × 100

(2)

TEF_Fat, % = 100 − TEF_Water

(3)

2.5. Proximate Composition Analyses of Pâtés

Total nitrogen was determined by the Kjeldahl method according to AOAC 984.13-1994 [31], and protein content was calculated using the nitrogen-protein conversion factor of 6.25. Fat content was determined through extraction with diethyl ether using a Soxhlet apparatus [32]. Water content was assessed by the gravimetric method after drying the samples at 104 °C overnight [33]. Total ash (mineral) content was determined by incineration at temperatures ranging from 400–600 °C [34].

2.6. pH and Intrumental Colour Determination of Pâtés

The pH value of the pâtés was measured using a portable Hanna pH meter, HI99163 (Hanna Instruments, Smithfield, RI, USA), equipped with a meat-specific probe (FCO99). The instrument was pre-calibrated with certified buffer solutions with pH 4.04 and 6.86 (Popova et al., 2024) [20]. Measurements were conducted at three different points on each sample.

The instrumental colour of pâtés was determined using a Konica Minolta CR-410 colorimeter (Konica Minolta Holding, Inc., New York, NY, USA) equipped with a 50 mm aperture, illuminant D65, and a 2° standard observer. The colorimeter was calibrated with a standard white plate. The colour of the pâtés was determined on the 1st and 7th day of refrigerated storage. CIE lightness (L*), redness (a*), and yellowness (b*) values were measured at three different locations on the oxygen exposure surfaces of the pâté slices [35]. The total colour change or Delta E (ΔE) was calculated during storage using the following Equation (4) according to King et al. [35]:

ΔE = (ΔL*^2 + Δa*^2 + Δb*^2)^1/2

(4)

2.7. Texture Profile Analysis (TPA) of Pâtés

The texture profile analysis was performed in the pâté slices (15 mm thick and 60 mm in diameter) using a TX-700 analyser equipped with a 25 kg load cell (Lamy Rheology, Champagne au Mont d’Or, France). The test was conducted using a double compression method with a ½ spherical probe (30 mm of diameter), to compress 70% of the initial height with a compression rate of 1 mm/s and a 5-s delay between compressions. Data were processed using Rheotex software version 2.55 (Lamy Rheology, Champagne au Mont d’Or, France). Textural parameters derived from force and area measurements were determined as described by Estevez et al. [36]. Hardness (N/cm²) was defined as the maximum force required to compress the sample, corresponding to the peak force during the first compression cycle. Springiness (cm) referred to the extent to which the sample recovered its height between the end of the first compression and the beginning of the second. Cohesiveness was calculated as the ratio of the area under the first compression curve (A1) to that under the second compression curve (A2), representing the sample’s ability to withstand deformation before rupture. Gumminess (N/cm²) was obtained by multiplying hardness by cohesiveness and represented the force necessary to disintegrate a semisolid sample to a state ready for swallowing. Finally, chewiness (N·s) was defined as the work required to chew a solid sample until it reached a swallowable consistency, calculated as gumminess multiplied by springiness. The procedure for each pâté was repeated 9 times.

2.8. Hydrolytic and Oxidative Changes in Lipid Fraction of Pâtés

Total lipid extraction was performed as described by Bligh and Dyer [37]. One part of pâté was homogenized with three parts (w:v) of a chloroform/methanol mixture (2:1, v:v). The mixture was stored overnight under refrigeration to ensure thorough lipid solubilization. Subsequently, the liquid phase was filtered through cotton, and the chloroform layer was evaporated under vacuum at 30–40 °C. The extracted lipids were then stored at −20 °C until further analyses.

The extent of lipid hydrolysis was evaluated by quantifying the free fatty acid (FFA) using Equation (5). The acid value was determined by titrimetric analysis in accordance with EN ISO 660:2020 [38], as outlined by Prasad and Sivamani [39].

FFA, % Oleic acid = Acid value × 0.504

(5)

The quantification of hydroperoxides, which represent the primary products of lipid oxidation (peroxide value; PV, expressed as meq O₂/kg fat), was performed according to Shantha and Decker [40] with modifications proposed by Popova et al. [20]. Concurrently, secondary lipid oxidation products were assessed as a 2-thiobarbituric acid reactive substance (TBARS), following the protocol of Botsoglu et al. [41] with modifications by Popova et al. [20]. Both assays were performed using a double-beam UV-VIS spectrophotometer (Camspec M 550, Camspec Ltd., Leeds, UK).

The fatty acid profile was determined following the transmethylation of the extracted fat with 2% H₂SO₄ in methanol (CH₃OH) at 50 °C. Analysis was carried out using a gas chromatographic system (Trace GC Ultra, Thermo Fisher Scientific Inc., Waltham, MA, USA) equipped with a flame ionization detector (FID), in accordance with ISO 12966-4:2015 [42]. The chromatographic conditions were as follows: the initial oven temperature was set at 140 °C (held for 5 min), followed by an increase of 4 °C/min to 240 °C (held for 3 min). Both the injector and detector were maintained at 250 °C.

2.9. Data Analyses

All statistical analyses were carried out to assess the effects of the factors “meat source” and “storage time” as well as their interaction using the PROC GLM procedure in SAS version 9.4 (SAS Institute Inc., Cary, NC, USA). Least Square Means were compared using Tukey–Kramer post hoc test, and differences were considered statistically significant at p ≤ 0.05. The results are presented as Least Squares Means. Pearson’s correlation analysis was employed to examine the relationships among the measured parameters throughout the entire experimental period [43]. The correlation coefficient (r) was interpreted as follows: 1 ≥ r > 0 indicates a positive correlation; r = 0 denotes no correlation; and 0 ≥ r > −1 represents a negative correlation. Pearson’s correlation strength was categorized as follows: 0.00–0.10 (negligible); 0.10–0.39 (weak); 0.40–0.69 (moderate); 0.70–0.89 (strong); and 0.90–1.00 (very strong).

3. Results

3.1. Emulsion Stability

Meat source significantly influenced (p ≤ 0.0007) the emulsion stability of the pâté, as observed in the total expressible fluid (TEF) values (

Table 1. Emulsion stability of chicken pâtés elaborated with conventional raised broiler chickens (control; CP), 5-week-old male layer-type chickens (5wP), and 9-week-old male layer-type chickens (9wP).

Parameters	CP	5wP	9wP	RMSE *	p-Value
TEF, %	14.35 b	13.16 c	15.58 a	0.365139	0.0007
TEFWater, %	83.48 b	85.56 a	83.02 c	0.175214	<0.0001
TEFFat, %	16.52 b	14.44 c	16.98 a	0.175214	<0.0001

^a,b,c Indicate significant differences between samples (p < 0.05). * RMSE—Root Mean Squared Error.

). Among the samples, 5wP exhibited the lowest TEF values (p ≤ 0.0007), followed by CP and 9wP. Additionally, 5wP exhibited the highest proportion (p < 0.0001) of water in TEF (TEF_Water) and the lowest fat content (p < 0.0001) in TEF (TEF_Fat), whereas the highest percentage (p < 0.0001) of fat and the lowest percentage of water were observed in 9wP.

3.2. Proximate Composition of Pâtés

The meat source did not influence (p ≥ 0.05) the proximate composition of the pâtés, including the amount of protein, fat, water, and ash (

Table 2. Proximate composition of chicken pâtés elaborated with conventional raised broiler chickens (control; CP), 5-week-old male layer-type chickens (5wP), and 9-week-old male layer-type chickens (9wP).

Parameters	CP	5wP	9wP	RMSE *	p-Value
Moisture, %	57.74 a	58.89 a	58.28 a	2.913406	0.8916
Ash, %	0.76 a	0.51 a	0.86 a	0.126183	0.0549
Proteins, %	16.70 a	16.40 a	16.60 a	0.828358	0.9028
Fats, %	20.10 a	20.50 a	20.90 a	1.023502	0.6507
Carbohydrates, %	4.70 a	3.70 a	3.26 a	0.612545	0.0772

^a Indicate insignificant differences between samples (p ≥ 0.05). * RMSE—Root Mean Squared Error.

).

3.3. pH and Instrumental Colour Characteristics of Pâtés

The pH value of pâtés was significantly influenced (p ≤ 0.0008) by the meat source and storage time (

Table 3. Values of pH and instrumental colour (L*, a*, and b*) of chicken pâtés elaborated with conventional raised broiler chickens (control; CP), 5-week-old male layer-type chickens (5wP), and 9-week-old male layer-type chickens (9wP) during 7 days of refrigerated storage.

Parameters	CP	5wP	9wP	RMSE *	p-Value
					M	S	M × S
pH, 1st day	6.52 e	6.61 c	6.57 d	0.009428	<0.0001	<0.0001	0.0008
pH, 7th day	6.65 b	6.72 a	6.65 b
L*, 1st day	69.32 ax	65.16 bx	65.71 bx	0.406537	<0.0001	0.8782	0.9387
L*, 7th day	69.34 ax	65.18 bx	65.58 bx
a*, 1st day	10.15 cx	11.60 ax	11.34 bx	0.161727	<0.0001	0.0184	0.9443
a*, 7th day	9.91 by	11.42 ax	11.13 ax
b*, 1st day	11.43 ab	10.97 b	11.25 ab	0.218632	0.0038	0.1544	0.0425
b*, 7th day	11.79 a	11.35 ab	10.99 b
ΔE	0.43	0.42	0.36

^a,b,c,d,e Indicate significant differences between samples. ^x,y Indicate significant differences during storage. * RMSE—Root Mean Squared Error; M = meat source; S = storage period.

). The lowest pH value was observed in CP (p ≤ 0.05), whereas the highest pH (p ≤ 0.05) was observed in 5wP. There was an increase in the pH values (p ≤ 0.05) of all pâtés over the 7 days of refrigerated storage.

All instrumental colour parameters of the pâtés were significantly influenced (p < 0.0001) by the chicken meat source (Table 3). The CP exhibited the highest L* than 5wP and 9wP, whereas no significant (p ≥ 0.05) changes in L* were observed during the 7-day storage in all samples.

Regarding a*, 5wP and 9wP exhibited higher (p < 0.0001) a* values than CP (Table 2). During storage, there was a decrease (p ≤ 0.05) in the a* value of CP, whereas similar (p ≥ 0.05) a* values were observed in 5wP and 9wP.

Regarding b* values, 5wP exhibited the lowest values compared (p < 0.0001) to 9wP and CP on the first day of storage (Table 3). However, there were no changes (p ≥ 0.05) in the b* values of all pátês over the 7 days of storage.

Delta E expresses the total colour change of a sample and was calculated using the differences between the 7th and 1st day of storage in CP, 5wP, and 9wP. Greater Delta E reflects greater changes in overall colour, which was observed in CP, followed by 5wP and 9wP.

3.4. Texture Profile Analysis (TPA) of Pâtés

All texture profile parameters were influenced (p ≤ 0.05) by the meat source (

Table 4. Hardness, cohesiveness, springiness, gumminess, and resilience of chicken pâtés elaborated with conventional raised broiler chickens (control; CP), 5-week-old male layer-type chickens (5wP), and 9-week-old male layer-type chickens (9wP) over 7 days of refrigerated storage.

Parameters	CP	5wP	9wP	RMSE *	p-Values
					M	S	M × S
Hardness, 1st day (N)	5.38 ay	4.62 by	3.99 cy	0.310416	<0.0001	<0.0001	0.4491
Hardness, 7th day (N)	6.30 ax	5.30 bx	4.56 cx
Cohesiveness, 1st day	0.47 a	0.38 b	0.44 a	0.023452	<0.0001	0.2866	0.0279
Cohesiveness, 7th day	0.46 a	0.42 ab	0.43 a
Springiness, 1st day	0.50 b	0.57 b	0.60 b	0.234325	0.0001	<0.0001	0.0002
Springiness, 7th day	0.67 b	1.63 a	0.80 b
Gumminess, 1st day (N)	2.40 ay	1.84 aby	1.78 by	0.604078	0.0357	0.0165	0.2485
Gumminess, 7th day (N)	2.81 ax	2.93 ax	1.98 bx
Resilience, 1st day	0.09 ax	0.05 bx	0.06 bx	0.004655	<0.0001	0.0006	0.1066
Resilience, 7th day	0.08 ay	0.05 bx	0.05 by

^a,b,c Indicate significant differences between samples (p < 0.05). ^x,y Indicate significant differences during storage (p < 0.05). * RMSE–Root Mean Squared Error; M = meat source; S = storage period.

). On the 1st and 7th day of storage, CP exhibited the greatest (p < 0.0001) hardness, followed by 5wP and 9wP. CP exhibited a greater cohesiveness (p ≤ 0.05) than 5wP and 9wP on days 1 and 7. Additionally, CP exhibited the lowest (p ≤ 0.0001) springiness compared to 5wP and 9wP on the first day of storage, whereas no significant differences (p ≥ 0.05) were observed between 5wP and 9wP (Table 4).

Regarding gumminess, pâtés from CP exhibited the greatest (p < 0.0001) gumminess, followed by 9wP and 5wP (Table 4). Resilience of all three pâtés was influenced (p < 0.0001) by the meat source (Table 4). CP demonstrated the greatest (p ≤ 0.05) resilience, compared to 5wP and 9wP on both the 1st and 7th days of refrigerated storage. During storage, all pâtés exhibited an increase (p < 0.05) in hardness, springiness, and gumminess. However, no significant changes (p ≥ 0.05) were observed in cohesiveness over the 7 days of storage.

3.5. Oxidatative Changes in Pâtés During Storage

The content of free fatty acids (FFAs; % oleic acid) was influenced (p ≤ 0.0106) by meat × storage interaction. CP exhibited a decrease (p ≤ 0.05) in FFA, whereas similar (p ≥ 0.05) results were observed in 5wP and 9wP on the 1st and 7th day of storage (

Table 5. Values of free fatty acids (FFAs), primary lipid oxidation products (PV), and lipid oxidation (TBARS) of chicken pâtés elaborated with conventional raised broiler chickens (control; CP), 5-week-old male layer-type chickens (5wP), and 9-week-old male layer-type chickens (9wP) over 7 days of refrigerated storage.

Parameters	CP	5wP	9wP	RMSE *	p-Values
					M	S	M × S
FFA, 1st day (% Oleic acid)	0.16 a	0.17 a	0.17 a	0.007716	0.0013	0.1731	0.0106
FFA, 7th day (% Oleic acid)	0.14 b	0.17 a	0.18 a
PV, 1st day (meq O2/kg fat)	3.23 ax	3.44 ax	3.42 ax	0.170569	0.8133	<0.0001	0.2268
PV, 7th day (meq O2/kg fat)	1.80 ay	1.72 ay	1.66 ay
TBARS, 1st day (mg MDA/kg)	2.05 cd	1.75 d	3.21 b	0.174032	<0.0001	<0.0001	<0.0001
TBARS, 7th day (mg MDA/kg)	1.34 e	2.44 c	5.08 a

^a,b,c,d,e Indicate significant differences between samples (p < 0.05). ^x,y Indicate significant differences during storage (p < 0.05). * RMSE–Root Mean Squared Error; M = meat source; S = storage period.

).

Regarding primary lipid oxidation products (PV), the three pâté formulations exhibited a similar (p ≥ 0.05) peroxide value (PV) on days 1 and 7 of storage (Table 5). During storage, there was a decrease (p ≤ 0.05) in PV in all pâté formulations from day 1 to 7 of storage.

TBARS was influenced (p < 0.0001) by both the meat source and storage time (Table 5). Pâtés from 5wP exhibited the lowest (p < 0.0001) TBARS, followed by CP and 9wP on day 1. On day 7, CP exhibited the lowest (p < 0.0001) TBARS, followed by 5wP and 9wP. During storage, there was a decrease (p < 0.0001) in TBARS in CP, whereas an increase in TBARS was observed in 5wP and 9wP (p < 0.0001) over the 7 days of storage.

3.6. Fatty Acid Profile of Pâtés

Table 6. Fatty acid profile of chicken pâtés elaborated with conventional raised broiler chickens (control; CP), 5-week-old male layer-type chickens (5wP), and 9-week-old male layer-type chickens (9wP) over 7 days of refrigerated storage.

Fatty Acid, %	CP 1st day	5wP 1st day	9wP 1st day	CP 7th day	5wP 7th day	9wP 7th day	RMSE *	p-Values
								M	S	M × S
C 6:0	0.1 c	0.1 c	0.1 c	0.4 a	0.3 b	0.3 b	0.216667	<0.0001	<0.0001	<0.0001
C 8:0	N.F.	0.1 b	N.F.	0.2 a	0.1 b	0.1 b	0.002415	<0.0001	<0.0001	<0.0001
C 10:0	N.F.	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.003000	<0.0001	<0.0001	<0.0001
C 12:0	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.003606	1.0000	1.0000	1.0000
C 14:0	1.2 bc	1.3 b	1.3 b	1.1 c	1.8 a	1.3 b	0.048484	<0.0001	<0.0001	<0.0001
C 15:0	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.003786	1.0000	1.0000	1.0000
C 15:1	N.F.	N.F.	N.F.	0.1 a	0.1 a	0.1 a	0.002345	1.0000	<0.0001	1.0000
C 16:0	21.7 bx	23.0 ax	23.5 ax	21.6 bx	23.1 ax	23.0 ax	0.696649	0.0035	0.6210	0.7545
C 16:1	2.2 bx	2.5 ax	2.5 ax	2.2 bx	2.4 ay	2.4 ay	0.042695	<0.0001	0.0062	0.1045
C 17:0	0.3 b	0.4 a	0.3 b	0.4 a	0.4 a	0.4 a	0.009678	<0.0001	<0.0001	<0.0001
C 17:1	0.3 b	0.4 a	0.3 b	0.4 a	0.4 a	0.4 a	0.011540	<0.0001	<0.0001	<0.0001
C 18:0	10.2 bc	10.5 ab	9.7 c	10.2 bc	11.1 a	10.9 ab	0.280923	0.0066	0.0007	0.0104
C 18:1	46.7 a	47.2 a	46.1 a	46.3 a	46.3 a	45.9 a	1.336086	0.6243	0.4427	0.8974
C 18:2 Trans	0.1 a	N.F.	0.1 a	N.F.	N.F.	N.F.	0.002380	<0.0001	<0.0001	<0.0001
C 18:2	13.8 ax	10.8 cx	12.3 bx	13.7 ay	10.3 cy	11.6 by	0.388433	<0.0001	0.0356	0.4220
C 18:3 n-6	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.002309	1.0000	1.0000	1.0000
C 18:3 n-3	0.5 c	0.5 c	0.7 a	0.5 c	0.6 b	0.7 a	0.015449	<0.0001	0.0006	0.0001
C 20:0	0.2 ax	0.2 ax	0.1 bx	0.2 ax	0.2 ax	0.1 bx	0.005686	<0.0001	1.0000	1.0000
C 20:1	1.2 b	1.3 a	1.3 a	1.1 c	1.2 b	1.1 c	0.033643	0.0009	<0.0001	0.0365
C 20:2	0.5 a	0.5 a	0.5 a	0.5 a	0.5 a	0.5 a	0.016753	1.0000	1.0000	1.0000
C 20:3 n-6	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.003000	1.0000	1.0000	1.0000
C 20:4	0.3 b	0.4 a	0.4 a	0.3 b	0.3 b	0.3 b	0.011518	<0.0001	<0.0001	<0.0001
C 20:3 n-3	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.003028	1.0000	1.0000	1.0000
C 20:5	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	N.F.	0.002739	<0.0001	<0.0001	<0.0001
C 24:0	N.F.	N.F.	N.F.	N.F.	0.1 b	0.2 a	0.004163	<0.0001	<0.0001	<0.0001
C 24:1	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.1 a	0.003440	1.0000	1.0000	1.0000
SFA	33.9 by	35.9 ay	35.3 ay	34.4 bx	37.4 ax	36.6 ax	0.562670	<0.0001	0.0014	0.3016
USFA	66.1 ax	64.1 bx	64.7 abx	65.6 ax	62.6 bx	63.4 abx	1.358902	0.0212	0.1116	0.7999
MUFA	50.5 a	51.5 a	50.3 a	50.2 a	50.5 a	50.0 a	1.068031	0.3836	0.3103	0.8098
PUFA	15.6 a	12.6 d	14.4 b	15.4 a	12.1 d	13.4 c	0.230146	<0.0001	0.0002	0.0324

^a,b,c,d Indicate significant differences between samples (p < 0.05). ^x,y Indicate significant differences during storage (p < 0.05).* RMSE–Root Mean Squared Error; M = meat source; S = storage period.

presents the fatty acid composition of the pâtés stored for 7 days. The main fatty acids observed were C16:0 (palmitic acid), C18:0 (stearic acid), C18:1 (oleic acid), C20:1 (eicosenoic acid), and C18:2 (linoleic acid). Among the saturated fatty acids, C16:0 ranged from 21.6% to 23.5% (p ≤ 0.0035) and remained stable (p ≥ 0.6210) during storage in all samples. The CP exhibited the lowest content of C16:0 and C17:0. On the other hand, the content of C18:0 remained stable in CP, while it increased in 5wP and 9wP over the 7 days of storage (p ≤ 0.01049). Regarding the monounsaturated fatty acids (MUFAs), C18:1 exhibited the highest concentration, ranging from 45.9% to 47.2%, and exhibited similar values in all pâtés over the 7 days of storage (p ≥ 0.05).

Among the polyunsaturated fatty acids (PUFAs), C18:2 was detected in 10.3% to 13.7% (p < 0.0001), with a slight decrease in CP over time in all pâtés (p ≤ 0.0356). PUFAs are more prone to lipid oxidation, and the observed decrease may indicate an increase in lipid oxidation in the pâtés. On the other hand, 5wP and 9wP exhibited a decrease in C18:2 over the 7 days of storage, which could be attributed to the intrinsic fatty acid composition of the layer-type chicken [44]. Saturated fatty acids were influenced by meat source (p < 0.0001) and storage time (p ≤ 0.0014), while unsaturated only by the meat source (p ≤ 0.0212). There was a meat source x storage interaction in the polyunsaturated fatty acid (PUFA; p ≤ 0.0324) (Table 6).

CP exhibited the lower (p ≤ 0.05) content of saturated fatty acids (SFAs) and the greater (p ≤ 0.05) content of unsaturated fatty acids (USFAs) and polyunsaturated fatty acids (PUFAs) than their 5wP and 9wP counterparts, both on day 1 and 7. In the same time, monounsaturated fatty acid (MUFA) content was similar in all pâtés on day 1 and 7 (p ≥ 0.05).

During 7-day storage, all three pâtés exhibited an increase (p ≤ 0.0014) in SFAs, and a decrease (p ≤ 0.0014) in PUFAs.

3.7. Correlation Analysis

Strong positive correlations (Figure 2) were observed between the following parameters: TEF and SFAs (r > 0.88), pH and a* (r > 0.85), L* and b* (r > 0.99), hardness and gumminess (r > 0.96), hardness and MUFAs (r > 0.90), cohesiveness and resilience (r > 0.91), gumminess and USFAs (r > 0.95), resilience and MUFAs (r ≤ 1.00), PV and TBARS (r > 0.99), USFAs and PUFAs (r > 0.94).

On the other hand, strong negative correlations (Figure 2) were identified between the following: TEF and USFAs (r > −0.88), TEF and PUFAs (r > −0.99), pH and L* (r > −0.81), L* and a* (r > −1.00), a* and b* (r > −0.97), pH and cohesiveness (r > −0.98), hardness and FFA (r > −0.97), cohesiveness and springiness (r > −0.96), PV and USFAs (r > −0.99), FFAs and MUFAs (r > −0.98), TBARS and USFAs (r ≥ −1.00), TBARS and PUFAs (r > −0.93), SFAs and USFAs (r > −1.00), SFAs and PUFAs (r > −0.94).

4. Discussion

4.1. Emulsion Stability

The meat source had a significant impact on the emulsion stability of the pâtés, as reflected by total expressible fluid (TEF) measurements (Table 1). Among the formulations, 5wP presented the lowest TEF values, followed by CP and 9wP. Additionally, 5wP exhibited the greatest proportion of water (TEF_Water) and the lowest proportion of fat (TEF_Fat) within the expressible fluid, suggesting superior water and fat binding capabilities, possibly due to better functional protein characteristics or a more favourable fatty acid profile. Conversely, 9wP exhibited the highest fat and lowest water content in the TEF, which could be attributed to less organized protein networks, lower protein solubility, or differences in muscle fibre structure related to the animal’s age or muscle maturation status.

The observed differences in emulsion stability could be explained by a combination of factors, including the degree of protein denaturation caused by precooking [45,46], variations in the expression of myosin heavy chain isoforms during muscle development [47], and the fatty acid composition of the meat [28].

Heat-induced protein denaturation likely impaired the extractability of myofibrillar proteins, while differences in muscle maturation between broilers and male layer chickens influenced the initial functional properties of the tissue. Additionally, a high proportion of saturated fatty acids favours the emulsion formation, whereas high levels of unsaturated fatty acids is associated with reduced emulsion stability, as evidenced by the strong correlations found between TEF and the fatty acid profile: TEF and SFAs (r > 0.88), TEF and USFAs (r > −0.88), and TEF and PUFAs (r > −0.99) [45,46]. Myofibrillar proteins, such as myosin and actin, are the most abundant in poultry muscles and evolve with animal age, influencing protein extractability [47]. According to Doherty et al. [48], the soluble protein composition of chicken skeletal muscle undergoes dynamic changes throughout muscle development when broilers initiate the expression of adult myosin heavy chain (MHC) isoforms earlier than male layer chickens [49].

4.2. Proximate Composition

In the present study, no significant differences were observed in the proximate composition of the pâtés from CP, 5wP, and 9wP. The pâtés exhibited an average of 16.5% protein, 20.5% fat, 4% carbohydrates, 58.0% moisture, and less than 1% ash/minerals (Table 2), which agrees with the composition of poultry pâtés reported previously [23,24]. Additionally, the observed similarity in the proximate composition indicates that meat from male layer-type chickens at 5 and 9 weeks of age is comparable to conventional broiler meat for pâté production [3,13].

4.3. pH and Instrumental Colour Characteristics

Regarding pH, pâtés from CP exhibited the lowest pH value, while 5wP showed the highest pH among the samples. A significant increase in pH was observed in all samples after 7 days of refrigerated storage. The observed changes in pH may be attributed to an increased stabilization of the emulsion, as moving further from the isoelectric point of muscle proteins (pH 5.4–5.6), enhancing water-binding capacity, and colour saturation [46].

Meat protein solubility is closely associated with pH, a relationship that is particularly important in processed products, such as pâtés, where pH directly influences emulsion stability [26,50].

Regarding the pâtés’ colour, CP overall exhibited the higher lightness (L*) and lower redness (a*), indicating a paler colour, whereas 5wP and 9wP exhibited lower lightness (L*) and greater redness (a*) than their CP counterparts, indicating a redder–darker colour. Redness (a*) is primarily influenced by myoglobin concentration and its oxidative state. In this regard, the greater a* values in 5wP and 9wP may be attributed to a greater myoglobin concentration [4,51]. Muscles from older animals are darker in colour due to the increased levels of myoglobin with age [51]. Additionally, the observed differences in a* values could also be associated with the differences in the pátês pH. Lower pH values (as observed in CP) can lead to a greater extent of myoglobin denaturation, increasing light scattering and meat paleness (high L* and low a*) [52].

During storage, there was a decrease in a* values of the pâtés from CP, whereas a* values of 5wP and 9wP remained stable for 7 days. The decrease in a* in CP over time may be due to pH-induced myoglobin oxidation [52,53], resulting in the discoloration of the pâtés. Total colour change (ΔE) was more pronounced in CP, followed by 5wP and 9wP, indicating that CP exhibited more discoloration than its 5wP and 9wP counterparts over the 7 days of storage [46].

4.4. Texture Profile Analysis (TPA)

CP exhibited greater hardness, cohesiveness, gumminess, and lower springiness than 5wP and 9wP, indicating a firmer, denser, and less elastic pátê, probably due to stronger protein–protein interactions, reduced moisture retention, and emulsion destabilization during storage. For pâté-type products, the decrease in hardness, gumminess, and chewiness (as observed in 5wP and 9wP) is generally preferred. Softer texture or lower hardness could improve the spreadability and enhance the sensory acceptance [50]. Estevez et al. [54] reported that lower hardness values are associated with better emulsion stability, which is consistent with the lower TEF observed in 5wP pâtés. Additionally, the secondary textural parameters, gumminess and chewiness, exhibited trends similar to hardness, as they directly depend on it. In addition, the low hardness, cohesiveness, gumminess, and resilience observed in 5wP and 9wP could be attributed to their high pH and SFA content compared to CP, both of which can influence the stability of the emulsion and texture [45,46].

Over the 7 days of refrigerated storage, hardness, springiness, and gumminess significantly increased in all pâté samples. Several factors could contribute to this increase in hardness, including lipid and/or protein polymerization and moisture loss during storage [54]. Increases in hardness during storage have previously been reported in liver pâtés and other emulsion-type foods [55], and are often linked to emulsion destabilization, characterized by the separation of water and fat from the protein matrix.

Texture can be affected by many factors, such as protein/fat/water ratio, pH, emulsion stability, and fatty acid profile [21,28,50,56].

4.5. Oxidatative Changes Pâtés During Storage

Pâtés from 5wP exhibited the lowest TBARS values, followed by CP and 9wP. During refrigerated storage, TBARS levels decreased in CP, whereas they increased in both 5wP and 9wP over the 7-day period.

The low TBARS in 5wP can be associated with the higher SFA compared to the CP. The correlation between TBARS values and fatty acid profiles highlights the influence of lipid composition on oxidative stability. Pâtés with higher initial PUFA content, such as CP, are more prone to lipid oxidation due to the greater susceptibility of polyunsaturated fatty acids to peroxidation [27,57]. On the other hand, the high TBARS in 9wP can be associated with the decrease in endogenous antioxidants with animal age. Kim et al. [58] found that the skeletal muscles of adult chickens decrease antioxidant ability compared to the muscles from younger ones. This can also explain the intermediate TBARS values observed in CP and its subsequent decrease during storage. It is important to highlight that the CP pâtés were elaborated from fast-growing broiler breeds, which could have led to an early decrease in muscle endogenous antioxidant ability. This, combined with the high content of PUFA could have enhanced lipid oxidation on day 1. On the other hand, the decrease in TBARS during storage can be due to the high reactivity of MDA and its capability to form complexes with proteins via carbonyl–amine reactions [27].

According to Latoch et al. [56], thermally processed meat products usually exhibit TBARS levels up to 4 mg MDA/kg of product. In our study, only 9wP on the 7th day of storage (5.08 mg MDA/kg product) exceeded this threshold. CP exhibited the lowest TBARS. However, the observed decrease in TBARS during storage suggests that the initial phase of lipid oxidation may have already passed, with protein oxidation now predominating [27,57].

5. Conclusions

This study demonstrates that meat from male layer-type chickens can serve as a viable and high-quality raw material for producing value-added poultry pâtés, supporting the sustainable use of underutilized poultry resources in light of evolving ethical and regulatory frameworks. Among the formulations evaluated, pâtés made from 5-week-old male chicken (5wP) demonstrated superior technological and oxidative stability, as indicated by their lower total expressible fluid (TEF), higher water retention (TEF_Water), and lower fat release (TEF_Fat). These results suggest improved emulsion stability, possibly due to favourable protein functionality or fat composition. The 5wP samples also exhibited the lowest TBARS values on day 1 and showed greater colour stability (lower ΔE) compared to CP, reinforcing their oxidative advantage.

Texture profile analysis revealed that the CP samples had the highest hardness, cohesiveness, and gumminess, but the lowest springiness and resilience, while 5wP and 9wP offered softer and more elastic textures. Colour measurements further distinguished the samples: 5wP and 9wP pâtés were darker and redder (higher a*, lower L*) than those from CP, with less discoloration over storage. Although pH increased in all samples during storage, 5wP consistently maintained the highest values. Overall, the 5wP pâtés emerged as a promising formulation, combining favourable technological traits, colour stability, and oxidative resistance. Future work should explore product diversification and processing innovations to expand the use of male layer-type chickens in the food industry.