The Quality Characteristics of Camel Sausage Formulated with Different Levels of Whey Protein Powder

In this study camel sausage was formulated with different levels (1, 2, 3 and 4%) of whey protein powder (WPP). Raw and cooked sausage samples were evaluated for physical properties, cooking measurements, shrinkage, color parameters, emulsion capacity (EC) and emulsion stability (ES) and sensory attributes. Using whey protein powder increased pH value, moisture retention, emulsion capacity and emulsion stability while, the cooking loss and shrinkage were decreased. Camel sausages formulated with 4% whey protein powder (WPP) had higher emulsion stability and emulsion capacity, lower cooking loss, better color and more acceptable than other sausage samples. However addition of 4% whey protein powder can be improved the quality characteristics of camel sausages.

pH and emulsion properties pH of raw camel sausages was measured as described by Hood(1980). Five replicates were done for each treatment. Emulsifying capacity and emulsion stability of sausage were evaluated according to the method of Antipova et al. (2001). Three measurements were done for each treatment.
Cooking measurements and physical properties Sausages were roasted in a preheated oven for 10 min. All cooking measurements were carried out on five replicates of each treatment as reported by Naveena et al. (2006) as follows: Cooking loss (%):= (Uncooked sample weight) -(Cooked sample weight)/ (Uncooked sample weight) ×100 Cooking yield (%): = (Cooked sample weight) / (Uncooked sample weight) ×100 Moisture retention % was determined according to El-Magoli et al. (1996).Five replicates were done for each treatment. Moisture retention (%): = Cooking yield % × Moisture in cooked sample % /100 Moisture content was determined according to A.O.A.C (2000). Water holding capacity (W.H.C) and plasticity were measured using the method of Wierbicki and Deatherage (1958). Five replicates were done for each treatment. Data were presented as cm 2 as described by Russo et al. (1999).
Shrinkage measurements Raw and cooked samples were measured for width and length as described by Berry (1993) using the following equation: Reduction in width (%) = (Uncooked sample width) -(Cooked sample width) / (Uncooked sample width) ×100 Reduction in length (%) = (Uncooked sample length) -(Cooked sample length)/(Uncooked sample length) ×100 Dimensional shrinkage % was calculated using the following equation as reported by Murphy et al. (1975).
= [(Raw length -Cooked length) + (Raw width -Cooked width)] / (Raw length +Raw width) ×100 Color measurements Meat color was measured by Chroma meter (Konica Minolta, model CR 410, Japan) calibrated with a white plate and light trap supplied by the manufacturer. Color was expressed using the CIE L, a, and b color system (CIE, 1976). Five replicates were used per each treatment.
Sensory evaluation Camel sausage was subjected to organoleptic evaluation as described by A. M. S. A. (1995). Ten panelists of staff members of Food Sciences Department, Faculty of Agriculture, Ain-Shams University were scored appearance, texture, juiciness, flavor, tenderness and overall acceptability using a 9-point hedonic scale. The mean scores of the obtained results of organoleptic evaluation were then statistically analyzed.
Statistical analysis All data generated from each experiment were analyzed using statistical analysis system (SAS, 2000). Treatments were compared using the Duncan's multiple range test method for significant main effects at P < 0.05.

III.
RESULTS AND DISCUSSION pH value and emulsion properties From data shown in Table 2. It can be found that all sausage samples formulated with whey protein powder (WPP) had higher pH value compared to control one, but the difference between formulated sausage samples was slightly significant. (Yetim et al., 2006) showed slight but not significant (P > 0.05) increase in pH value of sausages with increasing whey substitution. Also, (Serdaroglu, 2006) reported that pH value of meatballs formulated with 2 or 4% whey protein (WP) were not significantly different at different levels of fat. The same results were obtained by Serdaroğlu and Özsümer (2003) they reported that no significant differences in pH values of batters or finished beef sausages formulated with different levels of whey protein and fat. Whey protein powder had a significant effect on emulsion capacity. Camel sausage formulated with whey protein had higher emulsion capacity than control one. In addition, emulsion capacity increased with the increasing of whey protein level. Data of pH value are consistency with the results of emulsion capacity % of camel sausage samples, which mean that emulsion capacity increased with the increasing of pH value and whey protein level. These results are coincided with (Kurt & Zorba, 2005) they reported that addition of whey protein significantly increased the protein concentration and emulsion capacity. Also, they concluded that pH value had much higher effect than protein concentration on emulsion capacity of different type of meats (beef, turkey and chicken).Sausages formulated with whey protein powder had the higher emulsion stability (ES) than control one. Camel sausages formulated with 2 or 4% WPP had the higher emulsion stability than the other sausage samples. These results are close to that obtained by Serdaroğlu and Özsümer (2003) they found that addition of WP increased the ES of beef sausage formulated with different fat levels. In addition Kurt & Zorba (2005) reported that using WP increased significantly the emulsion stability of different type of meats (beef, turkey& chicken). These may be due to that addition of whey protein powder increased fat binding in the meat system even at lower fat levels (El-Magoli et al., 1996) or the fact that whey proteins have a high capacity to bind water; i.e. high hydrophilic properties (Kocak & Aydemir, 1994).

International Journal of Environment, Agriculture and Biotechnology (IJEAB)
Cooking parameters and physical properties Data in Table 3.Showed that whey protein had a significant effect on the cooking loss of camel sausage. The lowest cooking loss was found in sausage formulated with 4% followed by sausage with 2% whey protein. No significant differences were found in sausages with 1% WPP and control. Sausage with 3% WPP had the highest cooking loss. These results are close to that obtained by Serdaroğlu (2006) which found that meatballs prepared with 2 or 4% whey protein were significantly higher for cooking yield at different fat levels. Also, Hale et al. (2002) found that beef patties containing textured whey protein had the lowest cooking loss than control one. In addition, Andiç et al. (2010) reported that addition WP improved the cooking yields of beef patties. They also found that patties formulated with 2% WP had the highest cooking yield. Sausage formulated with 1, 2 or 4% WPP had the highest moisture retention. Serdaroğlu (2006) found that addition of 2 or 4% whey protein to meatballs formulated with 5, 10, and 20 %fat significantly increased the moisture retention at each fat level. The same result was found by Andic et al.
(2010) they noticed that beef patties formulated with 1 or 2% whey protein had higher moisture retention than the other patties. protein powder as compared to control one. The highest score of plasticity was found in sausage sample formulated with 4% WPP. These results are close to that obtained by Abdolghafour & Saghir (2014) who found a significantly increase in water holding capacity (WHC) of buffalo sausage formulated with different levels of whey protein powder as compared with control one. The same results were found by Serdaroğlu and Özsümer (2003) they reported that addition of whey protein increased WHC of beef sausage formulated with different levels of fat. Results of WHC were coincided with the results of cooking loss of camel sausage. Therefore, it can be concluded that addition of whey protein powder increased the WHC which cause a significant decrease in cooking loss% Shrinkage measurements Results of the reduction in width, length and shrinkage % of camel sausages were given in Table 4. Sausage formulated with 2 or 4% WPP had the lowest reduction in width, no significant differences were found in other sausage groups. Also, it can be noticed that sausage formulated with 4%WPP and control samples had the lowest reduction in sausage length. A slight difference was found between other sausage samples. All sausage samples trend to shrink during cooking process. Sausage formulated with 4% WPP recorded the lowest shrinkage %, while sausages of 3% WPP had the highest shrinkage %. A difference between the other sausage samples was not significant. Kumar and Sharma (2003) found that the higher reduction in diameter was found in control and the lowest reduction found in lowfat patties formulated with 10 % milk co-precipitates. The gain in height of patties was increased with increasing level of incorporation amongst the low-fat products. The shrinkage percent was indirectly proportional to the level of incorporation of milk co-precipitates with maximum shrinkage in the control group and minimum in the low-fat patties with 10 % milk co-precipitates. Also, El-Magoli et al. (1996) found that addition of increasing levels of whey protein concentrate (WPC) to low fat beef patties resulted in a linear decrease in shrinkage.
Color measurements The effects of whey protein level on color attributes of fresh camel sausages were shown in Table 5. Sausages formulated with 4% WPP had the highest L* value followed by sausage with2%. No significant differences were found in other samples. The lowest a* value was found in control samples, slight differences were found between all sausage samples formulated with WPP at different levels. Control sample had the lowest b* value than sausages formulated with whey protein. These results are close to that obtained by Yetim et al.(2006) who found that sausages formulated with different level of liquid whey protein had higher L*,a* and b* values compared with control one. These results go in parallel to that obtained by Abdolghafour & Saghir (2014).
Sensory evaluation From data in Table 6. It can found that sausage formulated with 4% WPP recorded the highest score for appearance followed by sausage formulated with 1 and 3% WPP. A slight difference was found in other sausages sample.
Also, sausage with 4% WPP had the highest score for texture and no significant differences were found in the other sausage samples. The high score for juiciness was recorded in sausage formulated with 4% WPP followed by sausage with 3% WPP and no significant differences were found in the other sausage samples. Sausage formulated with 4% WPP was more tender, more flavor and more acceptable than all sausage samples. Generally, sausage formulated with 4% WPP had the highest score for all sensory attributes and no significant differences were recorded between the other sausage samples. These results are close to that found by El-Magoli et al. (1996) they reported that sensory analysis showed the 4% WPC level to be preferred over lower levels with respect to juiciness and overall acceptability. Serdaroğlu (2006) reported that panels were not able to detect the addition of WP in meatball samples. Also, Andic et al.(2010) they found no significant differences in appearance, interior color, juiciness and flavor scores of patties formulated with 1% and 2% WP. The same results were found by Abdolghafour & Saghir (2014).

IV.
CONCLUSION Addition of whey protein powder significantly improved the quality characteristics of camel sausage formulated with 4% WPP and showed the highest emulsion capacity and emulsion stability, in addition to the highest score of flavor, tenderness and overall acceptability. Whey protein powder (WPP) can be used in camel sausage formula to improve the quality characteristics of the product.