The aim of the study was to evaluate the impact of unconventional food resources on the quality of pig meat. 90 pigs of which 20 were slaughtered at 180 days old for meat quality evaluation. It came out from the study that the highest L* and b* were obtained in A0 commercial feed, while the highest a* was recorded in A3 (P < 0.05). From 45 minutes to 24 h post-mortem, the highest pork hue value was recorded in A2, whereas the highest chromaticity was found in A0. The pH 45 and pH 24 of Mld (Muscle Longissimus dorsi) were lower in control group than in experimental groups. The cooking loss and water-holding capacity of the meat from A4 were higher than those of other treatments. Luminance, redness, yellowness, chroma values and pH of the pork had increased during the post-mortem aging time for the both diet treatments while the hue value decreased (P < 0.05). Nutritionally, the protein content, the fat content, the dry matter content and the ash content varied respectively from 24.45% to 26.87%, 0.52% to 1.6%, 26% to 27.5% and 1.1% to 1.79% with the highest protein contents found in meat from unconventional feed A4 (P < 0.01) while the highest fat content (1.6%) was obtained from meat of the control group A0 (P < 0.001). The texture of the meat from the control group was better than those of experimental groups (P < 0.01). Overall, unconventional diet based on Azolla and Moringa improves technological and nutritional pork quality.
Meat is an important foodstuff and one of the most expensive components of human nutrition [
The study was conducted at the experimental farm of the Agronomic Science Faculty of the University of Abomey-Calavi located in Abomey-Calavi in Atlantic Department. Situated at latitude of 6˚27' North and at a longitude of 2˚21' East, the Commune of Abomey-Calavi covers an area of 650 km 2 with a population of 307,745 inhabitants [
A total of 90 pigs were divided in 5 groups constituted and used for the study. The first group was fed with a conventional commercial feed (A0). The four following groups were respectively fed with four different unconventional feeds (A1, A2, A3 and A4) containing Azolla, Moringa, rice bran, and different rates of chicken and fish viscera (
The pigs were fed with wet diets. After the study completion at 90 days, four pigs from each group were selected for the evaluation meat quality. The traits of meat quality were examined in Longissimus dorsi.
The pH was recorded at 45 minutes and 24 hours post mortem using a portable pH-meter HANNA. Drip loss was determined by the method used by Tougan et al. [
The colour of the meat was measured a slaughtering day and 24 hours post mortem with a Minolta Chromameter CR400 (Minolta Corporation, Ramsey, NJ, USA) after exposing the surface to the air for 1H 30 min at 4˚C. The average of triplicate measurements was recorded and the results were expressed as C.I.E (Commission Internationale de l’Eclairage) L*, a* and b*. The parameters L*, a* and b* represent lightness, redness and yellowness. From the a* and b* values, the hue (Hab) and the chroma (Cab) values were calculated. Hue , namely
Control diet | Experimental diets | ||||
---|---|---|---|---|---|
Foodstuffs (%) | A0 | A1 | A2 | A3 | A4 |
Maize | 29 | - | - | - | - |
Wheat bran | 24.65 | - | - | - | - |
Palm kernel cake | 32.5 | - | - | - | - |
Cotton seed cake | 5 | - | - | - | - |
Fish meal | 5 | - | - | - | - |
Shell | 1.5 | - | - | - | - |
C5 | 1.5 | - | - | - | - |
Phosphate | 0.5 | - | - | - | - |
Sulfate | 0.05 | - | - | - | - |
Salt | 0.3 | - | - | - | - |
Azolla meal | - | 40 | 40 | 40 | 40 |
Moringa meal | - | 25 | 25 | 25 | 25 |
Rice bran | - | 30 | 30 | 30 | 30 |
Chicken viscera | - | 0 | 1.5 | 3.5 | 5 |
Fish viscera | - | 5 | 3.5 | 1.5 | 0 |
Total | 100 | 100 | 100 | 100 | 100 |
the observable colour (e.g. red, blue, yellow), is an angular measurement calculated by the following equation: Hab = tan−1(b*/a*) [
Sensory analysis was performed on each dietary treatment with a panel of jury members from 12 randomly selected potential consumers. For the tasting, two groups of identical samples of 50 g of Longissimus dorsi muscle cuts were used. These pieces were boiled with water in a pot without seasoning and salt for 1 hour at 75˚C. After cooling to room temperature, the samples of cooked meat were cut into small identical cubes. Each judge received in a different colour trim a portion of each cutting counterpart belonging to each dietary treatment and completed a form of summary of the results of the tasting. Three repetitions were made for each cut dietary treatment. The judges evaluated the three important sensory characteristics of meat (tenderness, juiciness and flavour). These characteristics were rated on scales of 1 to 5. For tenderness, the scores 1, 2, 3, 4, and 5 correspond respectively to very hard, hard, acceptable, tender and very tender. As for juiciness, the scores 1, 2, 3, 4, and 5 correspond respectively very dry, dry, acceptable, soft and very soft. The intensity of flavour can obtain the score very low (1), low (2), acceptable (3), strong (4) and very strong (5).
The chemical composition was determined according to the standards used by Tougan et al. [
The data collected on the meat quality traits of the different group were analysed with the software SAS (Statistical Analysis System, 2006). For the analysis of variance, a fixed effects linear model was adjusted to the data and includes the fixed effects of the diet and post mortem aging time. The F test was used to determine the significance level of each effect in the model. Means were compared two by two by the Student’s t test.
The variation of technological quality of meat according to the diet and the post mortem (PM) aging time are given in
The pH values ranged from 5.54 to 5.38 for the control feed A0 but varied from 5.7 to 6.64 for the meat obtained from unconventional feeds. During the experiment, pH 45 (recorded at 45 minutes PM) and pH 24 (recorded at 24 hours PM) in the muscle Longissimus dorsi were lower in control group than in experimental groups. The pH values were significantly different among all of the five treatments (P < 0.05). The pH drop was rapid in the group fed with unconventional feeds.
The cooking loss and water-holding capacity of the meat from the treatment A4 were higher than those of other treatments. The loss of juices during cooking and water holding capacity were significantly different (P < 0.05), whereas no difference was observed for the drip loss (P > 0.05). The highest value of cooking loss (24.24%) was observed in meat from unconventional feed A3, while the higher drip loss (3.05%) was recorded in meat from the feed A4. Water holding capacity was of 22.85 for unconventional feeds to 20.5% for the control feed A0.
Luminance, redness, yellowness, chroma values and pH of the pork had increased during the post-mortem aging time (from 45 minutes to 24 hours) for the both diet treatments while the hue value decreased (P < 0.05).
Variables | Day | A0 | A1 | A2 | A3 | A4 | Diet | Effect of PM aging time | |||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Mean | ES | Mean | ES | Mean | ES | Mean | ES | Mean | ES | effect | |||
L* | J0 | 51.5 | 4 | 50.1 | 3.5 | 48.9 | 3.5 | 48.6 | 3.5 | 48.6 | 3.6 | NS | NS |
J1 | 52.7 | 2.6 | 52.2 | 2.4 | 52.7 | 5.3 | 52.3 | 2.4 | 51.5 | 3.3 | NS | ||
a* | J0 | 9.5 | 2.3 | 8.7 | 3.4 | 7 | 2.5 | 9.8 | 2.2 | 8.2 | 2.2 | *** | * |
J1 | 11.3 | 2 | 9.7 | 2.5 | 8.8 | 1.8 | 11.5 | 2.5 | 10.8 | 2.1 | *** | ||
b* | J0 | 8.6 | 3.2 | 6.5 | 2.5 | 6 | 1.7 | 7.9 | 2.5 | 6.7 | 1.9 | *** | * |
J1 | 11.5 | 1.4 | 9.6 | 2 | 10.2 | 1.7 | 11.1 | 2.2 | 10.8 | 2 | *** | ||
Hue H* | J0 | 0.2 | 0.03 | 0.17 | 0.04 | 0.21 | 0.05 | 0.15 | 0.03 | 0.18 | 0.03 | *** | * |
J1 | 0.2 | 0.02 | 0.16 | 0.04 | 0.17 | 0.04 | 0.14 | 0.03 | 0.14 | 0.02 | *** | ||
Chroma C* | J0 | 12.9 | 3.6 | 10.9 | 4.02 | 9.3 | 2.8 | 12.6 | 3.1 | 10.7 | 2.6 | *** | * |
J1 | 16.1 | 2.2 | 13.7 | 3 | 13.5 | 2.3 | 16 | 3. | 15.4 | 2.7 | *** | ||
pH | J0 | 5.5 | 0.5 | 6.6 | 0.5 | 5.8 | 0.6 | 6.7 | 0.3 | 6.5 | 0.4 | *** | * |
J1 | 5.4 | 0.2 | 5.9 | 0.2 | 5.6 | 0.3 | 5.7 | 0.24 | 5.6 | 0.3 | *** | ||
Cooking loss | 18.5 | 5.4 | 18 | 2.8 | 19.7 | 7.6 | 24.2 | 3.4 | 19.8 | 6 | *** | * | |
Drip loss | 2 | 0.8 | 2.2 | 1.3 | 2.3 | 1.9 | 2.2 | 1.2 | 3.05 | 1.5 | NS | * | |
WHC | 20.5 | 3.2 | 20.1 | 3.2 | 22.03 | 3.2 | 26.5 | 3.2 | 22.8 | 3.2 | *** | * |
WHC: Water-holding capacity. SE: Standard error.
Nutritionally, the protein content, the fat content, the dry matter content and the ash content varied respectively from 24.45% to 26.87%, 0.52% to 1.6%, 26% to 27.5% and 1.1% to 1.79% (
The highest protein contents were found in meat from unconventional feed A4 (P < 0.01) while the highest fat content (1.6%) was obtained from meat of the control group A0 (P < 0.001). Ash content was more important in meat from the unconventional fed A4 (P < 0.01). However, the meat the control group contained more dry matter than those of the experimental groups (P < 0.01).
For the sensory quality of the meat, no difference was found between flavor and juiciness of meat from control and experimental groups (P > 0.05). However, the texture of the meat from the control group was higher than those of the meat from experimental groups (P < 0.01) (
There are many factors which affect the quality of pig meat such as genetics associated factors, nutrition, rearing conditions, handling of animals during loading into vehicles, transportation, depot, stunning, slaughtering and cooling of the carcass [
High fibre in unconventional diets may inhibit the availability of iron which can limit pigment formation [
Attributes | A0 | A1 | A2 | A3 | A4 | RSD | ANOVA |
---|---|---|---|---|---|---|---|
Protein (g/100 g) | 24.5a | 24.5a | 25.2b | 25.9c | 26.8d | 0.7 | ** |
Fat (g/100 g) | 1.6a | 0.5b | 0.5b | 0.7c | 1d | 0.5 | *** |
Dry matter (g/100 g) | 27.5a | 27.3a | 26b | 27.4a | 27.3a | 0.8 | ** |
Ash (g/100 g) | 1a | 1.3b | 1.5c | 1.6cd | 1.8d | 0.4 | ** |
**: P < 0.01; ***: P < 0.001. The means of the same line followed by different letters differ significantly with the threshold of 5%. RSD: Residual standard deviation.
Variables | A0 | A1 | A2 | A3 | A4 | ANOVA | |||||
---|---|---|---|---|---|---|---|---|---|---|---|
Mean | ES | Mean | ES | Mean | ES | Mean | ES | Mean | ES | ||
Flavour | 2.7 | 0.8 | 2.2 | 1.1 | 2.3 | 0.7 | 2.5 | 1.3 | 2.5 | 1.08 | NS |
Juiciness | 2.8 | 0.7 | 2.6 | 0.9 | 2.9 | 0.9 | 3.1 | 0.8 | 3.1 | 0.8 | NS |
Texture | 2.5 | 0.9 | 1.3b | 0.5 | 2.1 | 0.8 | 3.1a | 1.08 | 3.1a | 0.8 | * |
*: P < 0.05; NS: Non-significant. The means of the same line followed by different letters differ significantly with the threshold of 5%.
to limit weight losses during its conservation and its transformation into cooked products. Therefore, it could be concluded that the unconventional feeds used in the current study improve technological properties in pig meat of Benin. The values of WHC found herein are below those found by Jukna and Jukna [
The nutritional value of pork found herein is better compared to the value reported by Rybarczyk et al. [
The protein and fat contents of pork derived from unconventional feed used in this study are better than those of pigs fed with the conventional diet. In addition the technological quality of the meat was not affected by the type of the diet. Therefore, it is possible to get good quality of pork by feeding the animals with unconventional local resources.
Research carried out in recent years emphasized that for consumers the sensory quality of culinary meat, which is determined mainly by level of intramuscular fat and other traits such as drip loss and the pH of the meat, is very important. The pH has a high influence on water holding capacity (WHC), which is closely related to product yield and pork quality [
The level of intramuscular fat depends on breed, portion of meat in the carcass, slaughter weight and nutrition of the animal during the growing period [
Concerning the implications of the feeding regime for pork quality traits, the results conclusively confirmed the results of Sundrum et al. [
In studies of Essén-Gustavsson [
The protein contents of pork found herein are higher than those obtained by Sundrum et al. [
Analysing the pig meat from unconventional and conventional feed, it can be concluded that unconventional meat is healthier with higher protein content and lower fat content. The feeding regime was the main source of variation for intramuscular fat content in the Longissimus dorsi muscle. Unconventional diet based on Azolla and Moringa can improve technological and nutritional pork quality.
The authors thank the “University of Abomey-Calavi” for their financial contribution and the Laboratory of Animal Biotechnology and Meat Technology of Polytechnic School of Abomey-Calavi for the technical supports.
Carine C.Hedji,Frédéric M.Houndonougbo,Ulbad P.Tougan,Marcel R. B.Houinato,Didier E.Fiogbe, (2015) Technological, Sensorial and Nutritional Meat Quality Traits from Pig Fed with Conventional and Unconventional Diets. Food and Nutrition Sciences,06,1514-1521. doi: 10.4236/fns.2015.616156