This study was conducted at dog slaughterhouses in Parakou, Borgou Department (Figure 1), and at the Central Laboratory for Food Safety of the Beninese Food Safety Agency (LCSSA/ABSSA) in Cotonou. Sensory and technological analyses were performed at the Quality and Safety of Agro-Food Products Unit (LARAEQ), University of Parakou.

Borgou Department is located in northeastern Benin between 8˚52' and 10˚25' North latitude and 2˚36' and 3˚41' East longitude, covering 25,856 km². The climate is Sudanese, with a dry season from November to May and a rainy season from June to October, with annual rainfall ranging from 900 to 1200 mm [13]. As in Alibori Department, the Harmattan winds blow from December to February.

Figure 1.Study area.

The study involved 30 indigenous dogs at 3 different age-types (12 months, 36 months, 60 months). Animals were classified into three age categories (12, 36, and 60 months) using information provided by animal owners and meat traders. The study protocol was conducted in accordance with the ethical principles governing the use of animal-derived biological materials for research. Ethical approval was obtained from the Institutional Research Ethics Committee of the University of Parakou/Faculty of Agronomy (Approval No.: 0067_-2025/UP-FA-DNSAA/CD/CDA). Prior to sample collection, authorization was obtained from the owners and operators of the slaughter sites where dogs were processed for human consumption. Because the study involved meat collected after routine slaughter and did not require additional handling or sacrifice of animals for experimental purposes, no intervention was performed on live animals. About the slaughtering process, dogs were bled and skinned according to the slaughtering diagram described by [3]. Carcasses were processed and thirty (30) composite samples of the Longissimus dorsi muscle were collected (10 per age-type) from the processed indigenous dogs for the meat quality analysis. During sampling, all personnel complied with standard biosafety procedures to minimize potential zoonotic risks. Disposable gloves, laboratory coats, face masks, and sterile sampling instruments were used throughout the collection process. Meat samples were individually packaged in sterile polyethylene bags, transported under refrigerated conditions (4˚C), and processed according to established laboratory biosafety guidelines.

The rheological and Technological attributes analyzed included color (CIE Lab*), drip loss, cooking loss, and water-holding capacity (WHC) and pH. Color was determined according to CIE Lab* standards: L* (lightness), a* (redness), b* (yellowness). Saturation (C) and hue (h) were calculated as C = (a∗² + b∗²)^1/2;

H* = 1/Tan(b*/a*). Five repetitions were conducted per sample. The water-holding capacity was determined as described by [3].

Drip loss was measured on post-mortem muscle samples, which were tied with wire and placed in Stomacher bags (without contact between meat and bag) at 4˚C for 24 hours. Drip loss was expressed as a percentage of initial weight [3].

Samples were then vacuum-sealed and cooked at 95˚C in a water bath for 60 minutes. After cooking, samples were cooled under running water, wiped, and weighed. Cooking loss was expressed as a percentage of initial weight [3][14]. Drip and cooking losses together represent the water holding capacity. The drip loss, the cooking loss and the water holding capacity were calculated by using the following formula:

pH was measured 24 hours post-slaughter using a HANNA portable pH meter with a muscle-specific probe on the Longissimus dorsi, with 3 repetitions per sample [3].

Proximate analyses were performed according to standard procedures of [15] and [3]. Dry matter content was determined by drying muscle at 105˚C until constant weight. Ash content was measured gravimetrically by incinerating 3 - 5 g of meat at 550˚C. Crude protein was determined via Kjeldahl method, converting nitrogen content (N) to protein. Fat content was determined according to [16] through HCl treatment, filtration, fat extraction, and calculation [3]. Two repetitions were performed per measurement.

Cooked meat samples from each age group were evaluated by a trained panel of 10 members. The samples were cut into uniform cubes and served sequentially on coded plates. The panel members evaluated five key sensory attributes of the meat [3]: tenderness, juiciness, taste, flavor intensity, and overall acceptability. These attributes were rated on a 1 - 5 scale.

Statistical analyses were conducted using SAS (2006). Means were calculated using PROC MEANS. The Proc GLM procedure of SAS Software was used for variance analysis. The significance of the effect of slaughtering age was evaluated by using the Student’s t-test.

The variation of the chemical composition of dog meat according to age is presented in Table 1. It appears that the dry matter and protein contents don’t vary significantly between 12, 36, and 60 months (p > 0.05). Indeed, the dry matter of dog meat of 12, 36 and 60 months olds varies between 38.9 and 39.5 g/100g. In contrast, fat content decreases significantly with age (p = 0.015), from 19.51% at 12 months to 18.83% at 60 months, indicating a progressive mobilization of lipid reserves or reduced fat accumulation in older animals. Ash content does not vary significantly with age (p = 0.522), reflecting a relatively constant mineral content. Overall, age has little influence on the chemical composition of meat, except for fat content, which tends to decrease with aging.

Table 1.Effect of age on proximate composition of dog meat.

*: p < 0.05.

The rheological and technological properties of dog meat at 12 months, 36 months and 60 months are given in Table 2. The pH values of the meat at the various ages are similar and vary between 6.48 and 6.52 (p = 0.851). In contrast, water losses differ significantly with the slaughtering age. The highest drip loss of the meat is recorded at 12 months (1.25%) to the respective values of 1.14% and 1.21% at 36 months and 60 months (p = 0.001). Cooking loss also decreases with age (25.86% at 12 months vs 24.71% at 60 months, p = 0.002), indicating lower water retention in older animals. Similarly, water holding capacity increases from 27.11% in young dogs of 12 months to 25.92% at 60 months (p = 0.001).

Rheologically, the luminance (L*) of the meat at 12 months (39.74) is significantly higher than the values found at 36 and 60 months (38.48 and 38.47, respectively, p < 0.001), indicating lighter meat in younger animals. Redness index (a*) and chroma (C*) increased with age (p < 0.01), reflecting more intense color in older dogs. The yellowness (b*) and the hue (H*) values also vary significantly with age with the more important values recorded at 60 months (p = 0.010). These results indicate that age of the animals significantly affects technological characteristics, particularly color (CIE, L*, a*, b*), drip loss, cooking loss and water holding capacity.

Table 2. Effect of age on rheological and processing properties of dog meat.

WHC: Water Holding Capacity. ***represents p < 0.001; **represents p < 0.01; *represents p < 0.05.

The effect of age on the organoleptic quality of dog meat is given in Table 3. Flavor intensity increases significantly with age, from 4.25 at 12 months to 4.69 at 60 months (p < 0.001). Texture is rated best at 36 months (4.70 versus 4.53 at 12 months and 4.33 at 60 months, p = 0.008), suggesting an optimal balance between tenderness and firmness at this age. Taste follows a similar trend, with a significant preference for meat from animals of 36-month-old (p = 0.004). Color or appearance is considered most attractive at 36 months (4.40 versus 4.10 and 4.13, p = 0.041). Finally, the highest overall acceptability is noted at 36 months (4.63, p < 0.001), confirming that this age represents the most favorable period for consumption according to the sensory criteria.

Table 3.Effect of age on sensory quality of dog meat.

***represents p < 0.001; **represents p < 0.01; *represents p < 0.05.

The proximate composition of dog meat shows little variation with age. Dry matter, protein, and ash contents remain relatively stable across age groups. However, fat content tends to decrease progressively as animals get older. This reduction in intramuscular fat with age may reflect altered lipid metabolism and lower fat deposition in older animals, a pattern previously reported in cattle meat quality [17]-[19] and in poultry meat [20][21]. Ash content remained stable across ages, indicating consistent mineral levels.

The proximate composition values obtained in the present study are generally close to those reported by [3], with the exception of fat content, which was considerably lower than 21 g/100g. In their study, these authors reported dry matter contents ranging from 38.87% to 39.11%, protein content of 19.02%, fat content of 21.1%, and ash content of 0.85%. The difference observed in fat content may be attributed to the type of muscle samples analyzed. [3] used composite samples from thigh, back, and shoulder muscles of two different dog genotypes, whereas in the present study, only the Longissimus dorsi muscle of the indigenous breed was analyzed.

According to [22], the decrease in intramuscular fat content with age can be explained by changes in energy metabolism and muscle physiology. Younger animals tend to deposit more intramuscular lipids as part of growth and energy storage, contributing to marbling. As animals mature, lipid deposition shifts toward subcutaneous and visceral depots, while muscle fibers become more metabolically active, mobilizing intramuscular lipids for maintenance and activity [22]. This redistribution leads to leaner meat in older animals [3][19]. Furthermore, the proximate composition of dog meat consumed in Nigeria, as reported by [7], indicated a water content of 69%, ash content of 1%, fat content of 6.01%, protein content of 21.19%, and carbohydrate content of 2.19%.

Although dog meat contains all macronutrients necessary for human nutrition, there is a risk of exposure to rabies and other zoonoses among processors and consumers of dog meat [10].

The rheological and technological traits of dog meat are influenced by age. pH values remain similar regardless of age, but water retention characteristics change, with drip loss, cooking loss, and water-holding capacity varying between younger and older animals. Meat color is also affected, with younger dogs showing lighter meat, while older ones develop a more intense and pronounced coloration. These age-related influences on the processing abilities of meat are consistent with previous reports on beef and rabbit by [23] and [24], on indigenous chickens of Benin [21]. These works indicate that animal age is a major factor affecting meat quality.

In the present study, pH values remained relatively stable with age, around 6.5, suggesting that post-mortem biochemical processes are largely independent of age. According to [3], dog meat presented a pH of 6.52, with color parameters including a red index of 15.35, a yellow index of 8.51, a chromaticity of 16.52, a luminance of 39.87, and a hue value of 28.91. Technological traits were characterized by drip losses of 1.21%, cooking losses of 25.11%, and a water retention capacity of 26.51%. The differences observed between these values and our findings may be attributed to the type of muscle samples analyzed. In their study, [3] used composite samples from thigh, back, and shoulder muscles of two different genotypes of dog, whereas in the present study, only the Longissimus dorsi muscles of indigenous dog breed were examined.

This finding aligns with previous studies on poultry and beef, where pH was relatively unaffected by age [19][20][24]. In contrast, significant age-related differences were observed in water-holding capacity, drip loss, and cooking loss. Younger dogs (12 months) exhibited higher drip loss (1.25%) and lower water retention (27.11%), whereas older dogs (60 months) showed lower drip loss (1.21%) and slightly better water-holding capacity (25.92%). This trend indicates that meat from older animals retains water more effectively, which can influence juiciness and processing yield. Similar effects of age on water on color (CIE L*, a*, b*) and retention and cooking losses have been reported in beef [19][25][26].

Color parameters were also affected by age. Luminance (L*) was higher in younger dogs (39.74), reflecting lighter-colored meat, while redness (a*) and chroma (C*) increased with age, indicating that meat becomes darker and more saturated in older animals. Yellowness (b*) and hue (H*) were less affected, although b* showed a significant increase with age. These findings suggest that meat color develops more intensity with age, consistent with observations in beef and poultry [20][26].

Proximate composition showed only minor age-related changes. Dry matter and protein contents decreased slightly with age, though not significantly, while fat content declined significantly (19.51% at 12 months vs. 18.83% at 60 months, p = 0.015). The proximate composition of the different dog meat samples under analysis herein is similar to the findings of [3].

Sensory evaluation revealed notable effects of age. Flavor intensity decreased with age (4.69 at 12 months vs. 4.25 at 60 months, p < 0.001), suggesting that younger animals produce meat with less pronounced aroma. Texture and taste were optimized at 36 months, showing a balance between tenderness and firmness, and the highest overall acceptability was observed at this intermediate age (4.63, p < 0.001). These results indicate that meat from very young or very old animals may be less preferred sensorially, a phenomenon also observed in poultry and rabbit studies.

Overall, age significantly influences the technological, chemical, and sensory properties of dog meat. Younger animals tend to produce lighter, more aromatic meat with higher fat content but lower water retention, while intermediate-aged animals (around 36 months) display optimal balance in texture, flavor, and overall acceptability. These findings highlight the importance of considering slaughter age in the production of dog meat to optimize both technological and sensory quality.

Sensory evaluation reveals that flavor intensity increases with age. Texture, taste, and overall acceptability are considered most favorable at an intermediate age of 36 months, suggesting that this stage offers the best balance of sensory qualities. This finding confirms that age is a major non-genetic factor influencing the various quality attributes of meat. Several studies have reported that fat content generally decreases with advancing age, reflecting a gradual mobilization of lipid reserves and reduced intramuscular fat deposition in older animals [19][22]. Younger animals typically exhibit higher intramuscular fat, which contributes to juiciness and flavor, whereas older animals produce leaner meat with lower marbling. The highest taste and overall acceptability scores observed at 36 months may be attributed to the interaction between lower moisture content and higher fat content in the muscle [3]. The greater flavor intensity observed in older animals as reported by [19] is likely associated with age-related hormonal activities and biochemical changes in muscle tissue, including increased concentrations of flavor precursors and intramuscular fat.