Physico-Chemical Changes of Frozen Chicken Burger Formulated with Some Spices and Herbs

The main objective of the present study was to examine the visibility of using natural spices and herbs (thyme, rosemary, sage, marjoram and black seeds) to help chicken burger industry to improve physical properties and extend the shelf life of chicken burger. Two concentrations of these spices (0.5 and 1%) were employed on chicken burger stored at 18°Cfor 6 months. Study indicated that, there were slight decreases in pH values, water holding capacity (W.H.C) and cooking yield in all treatments throughout the frozen storage period. Furthermore, during storage the drip loss, cooking loss and shrinkage was progressively increased by the extending of storage in all treatments. Meanwhile, treatments which had spices and herbs at levels 1% showed slight increase in pH values, water holding capacity (W.H.C) and cooking yield compared with control and treatments which had spices and herbs at level 0.5%. Also, the results appeared that control sample was recorded the highest percentage of drip loss, cooking loss and shrinkage than other treatments. Furthermore, the treatments containing spices and herbs at level 0.5% had higher drip loss, cooking loss and shrinkage than those treatments containing spices and herbs at level 1%.


Introduction
Poultry meat is widely accepted as a good source of high-quality protein. Chicken had some important physical properties. Water holding capacity and pH several methods have been applied to determine water holding capacity, such as the bag drip method or the filter paper co mpression method [1]. Water holding capacity is one of the most important qualitative characteristics of meat, it can affect the appearance of the product, its behavior on cooking and its juicy sensation on chewing [2].
During thawing of frozen meat the separation of drip is one of the problems facing the meat technologists. The drip separation causes loss in weight and in nutritive value since drip contains valuable nitrogenous compounds, minerals, and vitamins and might lead to the sensation of dryness and loss of juiciness [3].
Cooking loss, cooking yield and shrinkage considered the most important quality attributes of meat products for both consumers and meat products producers technologists [4]. The objective of the present study was investigate the feasibility of using selected natural spices and herbs for improving the physical properties and extending the shelf life of chicken burger during freezing storage.

Preparation of Chicken Burger
Fresh chicken burger samp les were prepared as described by [5]. All ingredients were minced twice, after mincing, the chicken mixture was shaped manually using a patty marker (stainless steel model "Form") to obtain round discs 10 cm diameter and 0.5 cm thickness. Burgers were packaged in polyethylene bags (in foam dishes).
• The Basal constituents of chicken burger were prepared as follows: The chilled minced chicken meat formu la included fat 71.5%, fresh onion (finely ground) 7.0%, whole egg (blended) 5.0%, bread crust powder 5.0%, rehydrated extruded soy 10.0% and sodium chloride 1.50%. These ingredients were mixed together, divided to eleven equal portions, the first portion was remained without any addition (control) and the ten reminder portions were individually mixed with t wo concentrations of each spices and herbs (0.5% and 1%) to g ive ten treat ments . All burgers treatments and control were freeze stored at -18±2℃ up to 6 months.

Physical Methods
Fresh chicken meat used in this study was analyzed immed iately upon receipt at the laboratory fo r physical analyses, as well as immediately after manufacturing (zero-time analyses), and then after 1, 2, 3, 4, 5 and 6 months of fro zen storage at -18±2℃. Water holding capacity (WHC) was measured using the method of [7] as fo llo ws: Minced chicken burger sample 0.3 g was placed on an ashless filter paper What man, No. 41 and placed between two glass plates, and pressed for 10 minutes by one kg weight, two zones were found on the filter paper, their surface areas were measured by a planimeter. The outer zone resulted from the water separated fro m the pressed tissues thus indicating the water holding capacity.

Drip Loss
Drip loss was measured by the difference between weight of comp lete frozen burger and weight of the same burger after thawing. The drip loss was calculated as the percentage of weight change [8].

Cooking Loss
Cooking loss of the prepared chicken burger was determined according to [9]. Cooking loss was calculated after grilling of chicken burger as follows: Raw sample weight -cooked sample weight % Cooking loss 100 Raw sample weight  

Statistical Analyses
The data obtained from three rep licats were analy zed by ANOVA using the SPSS statistical package program, and differences among the means were co mpared using the Duncan's Multiple Range test [11]. At a significance level of 0.05 was chosen.

pH Value
Measuring of pH value is an important because of its influence on many characteristics, including shelf-life, color, water hold ing capacity and texture of meat and meat products [12].
The pH value of different chicken burger treat ments during frozen storage at -18℃ up to 6 months were tabulated in Table (1). Fro m these data, it could be noticed that different chicken burger treat ments had less pH value than fresh chicken meat (pH 5.80). The decreasing in pH might be attributed to the ingredient used in the burger formu la as some of them have acidic effect. Moreover, addition of spices and herbs increased pH values of burger formula. These results were in agreement with [13].
During fro zen storage of d ifferent treat ments at -18℃ for 6 months, slight and not detectable decrease of pH values were observed. In this concern, [14] and [15] found that, the pH values of sausage decreased during storage time at -18℃ increased, and attributed this decrease to the breakdown of glycogen to produce lactic acid. [16] studied the influence of rosemary and sage extracts on deboned chicken meat (DCM) quality during refrigerated and fro zen storage, and they found that pH values of treated and untreated DCM decreased as the storage periods increased. [17] stated that the effect of various levels of rosemary or chinese mahogany on the quality of fresh chicken sausage during refrigerated storage, they observed that smaller pH reduction was observed for the samp les with more rosemary or Ch inese mahogany added. The pH reduction was probably due to the fact that some existing o xygen inside the package might trigger fat o xidation, thus resulting in the decrease of pH values.
Also, fro m the same of both spices and herbs to the basal chicken burger formu la led to no significantly increase in pH values during fro zen storage except in samp les formu lated with rosemary 0.5%, sage 0.5% and marjo ram 0.5%. Moreover, data showed that the control sample had the lowest value in pH with a significant difference than other treat ments in most cases. Also, the addition of spices and herbs at level 1% caused significant increase in pH value co mpared with the addition of spices and herbs at level 0.5% in some cases.

Water Hol ding Capaci ty (W.H.C)
The water holding capacity W.H.C of meat is defined as the ability of meat to hold fast to its own or added water during processing. It is considered as an important factor affects eating quality, tenderness, juiciness, thawing drip and cooking loss of meat [18]. This property is largely affected by the muscle protein and the level of pH value. Moreover, relationship between tenderness and the W.H.C of meat protein was reported by [7] and [19].
Water holding capacity of meat considered as one of the important measurements of quality attributes for determining the possibility of using this meat in manufacturing of meat product. The water holding capacity W.H.C of different chicken burger treat ments was determined by filter press method and calcu lated as percentage of bound water, are shown in Table (2).
The results indicated that although W.H.C of all treatments was convergent at zero t ime, the control samp le (basal burger formula without addition) showed decreased in W.H.C co mpared with other treat ments. Also, treatments which had spices and herbs at level 1% showed slight increase in W.H.C value co mpared with control and treatments which had spices and herbs at level 0.5%. In this concern, [15] found that the (W.H.C) of the cooked sausage samples increased as the concentration of cardamom vo latile oil and added emulsifiers increased. These results agree with the results obtained with shrinkage data.
Generally, with the progression of storage periods, the W.H.C had declined continuously with a significant statistical difference. The loss of W.H.C by freezing storage might be attributed to protein denaturation and losses in protein solubility. These findings were on line with those obtained by [20], [21], [13] and [22].
Moreover, data in Table (2) showed that the control sample showed significant decrease in W.H.C when compared with other treatments in all cases. Also, treatments of chicken burger contained spices and herbs at level 1% showed significant increase in W.H.C co mpared with samples contained spices and herbs at level 0.5% in most of cases. Furthermore, it could be noticed fro m Table (2) that, at the end of frozen storage periods no considerable changes were noticed between samp les. It could be concluded that, W.H.C was not considerably affected by spice.

Dri p Loss Percentages
Results in Tab le (3) cleared that the percentages of drip loss during freezing storage at -18℃ up to 6 months of different chicken burger treat ments.
Data in Tab le (3) shown that, the percentage of drip loss of all d ifferent chicken burger treatments progressively increased with a significant statistical difference by extending storage time, this might be parallel to the development of denaturation and aggregation of protein.
These results were in agreement with [23] and [13]. Also, the increase of drip loss percentage after storage periods of all samples might be attributed to the thaw rigor that might occurred if the meat which was fro zen before the adenosine triphosphate ( ATP ) has been fallen appreciably, this also might led to the increase of shrinkage at the first periods of storage. Similar results were obtained by [24].
Moreover, it could be noticed that the control sample was recorded the highest significant percentage of drip loss than other treatments in most cases except samples fo rmulated with rosemary at levels 0.5 and 1% after first month. Also, the treatments formu lated with spices and herbs at level 1% had lower significant percentages of drip loss compared with treatments formulated with spices and herbs at level 0.5% in some cases.

Cooking Loss Percentages
Cooking loss was measured by the difference between weight of fro zen chicken burger and weight of the same chicken burger after cooking [8].
The percentages of cooking loss of different chicken burger treat ments, during fro zen storage at -18℃up for 6 months are tabulated in Table (4).
The cooking loss of all samp les progressively significant increase as the period of storage increased. The highest increase observed after the first month of storage, the rate of increase in cooking loss after one month of storage was low and increased slowly till the sixth month of frozen storage at -18℃. These results were parallel to the drip loss due to the flu ids separated by cooking might included the fluids which probably separate by the thawing of the fro zen burger.
The progressive increases which were shown by extending storage time might be due to protein denaturation leading to deterioration of water hold ing capacity (W.H.C). These results are in agreement with [25] and [13]. Consequently, cooking loss results were on line with the changes in (W.H.C), the highest cooking loss corresponded with the lowest (W.H.C). Th is conclusion was previously emphasized by [21] who found that the cooking loss of sausage increased as the period of storage increased up to 90 days at -18℃. Furthermore, [26] reported that increasing of cooking loss during freezing storage is probably due to excessive fat separation and water released which occurred during cooking.
Moreover, the highest significant cooking loss was recorded for chicken burger formu la (as a control), when compared with other treatments in all cases. As well as, treatments containing spices and herbs at level 0.5% had significant higher cooking loss than those of treatments containing spices and herbs at level 1% in all of cases. DOI: 10.5923/j.fs.20120206.10         (*) = Significant difference between storage periods and treatments.
(a) = Significant difference between control and other treatments.
(SD)= Standard Deviation (a) = Significant difference between control and other treatments.

Cooking Yield Percentages
Results in Table (5) cleared that the percentages of cooking yield during frozen storage at -18℃ up to 6 months of different chicken burger treat ments.
Data represented in Table ( 5), indicated that with progression of storage periods, the cooking yield had declined continuously of all treat ments with a significant difference. In addition, the control sample showed a significant decrease in cooking y ield during fro zen storage when compared with other treat ments in all cases. Furthermore, the treatments containing spices and herbs at level 1% showed significant increase in cooking y ield when compared with treat ments containing spices and herbs at level 0.5% in all cases.
Generally, the cooking yield occurred in accordance with the changes of cooking loss and (W.H.C) during 6 months storage of chicken burger, the more cooking yield led to the less of cooking loss was found. With advancement of the time of storage, cooking loss progressively increased, while cooking yield decreased. Cooking yield was always higher and cooking loss lower for all t reatments. These results were on line with[27].

Shrinkage Percentages
The shrinkage was measured by difference between two diameters of burger before and after cooking. Moreover, it can be considered as one of important quality attributes measurements. The obtained results were shown in Tab le (6).
Fro m these results, it could be observed that the control sample showed significant increase in shrinkage compared with other treat ments. While, treat ments which had spices and herbs at level 0.5% showed significant h igher in shrinkage than treatments which had spices and herbs at level 1%. Also, fro m the same table, it could be observed that the shrinkage was progressively significant increased by the extending storage time in all treat ments. This might be attributed to excessive fat separation and water released which occurred during cooking and decreasing in water holding capacity (W.H.C). These results were on line with the results obtained with cooking loss and drip loss, but they were discrepant with the results of water holding capacity (W.H.C). Similar results were obtained with [13] and[27].

Conclusions
Results of the present study demonstrate the positive effects of spices and herbs, added with two concentrations to help chicken burger industry to improve physical properties and extend the shelf life of chicken burger during fro zen storage at (-18℃) for 180 days. The best results were obtained with the concentration of spices and herbs at level 1% to imp rove physical properties of chicken burger. Treat ments which had spices and herbs at levels 1% showed slight increase in pH values, water holding capacity (W.H.C) and cooking yield co mpared with control and treat ments which had spices and herbs at level 0.5%. Also, the results appeared that control sample was recorded the highest percentage of drip loss, cooking loss and shrinkage than other treatments. Furthermore, the treat ments containing spices and herbs at level 0.5% had higher drip loss, cooking loss and shrinkage than those treatments containing spices and herbs at level 1%. Physical properties is one of the technological characteristics to judge the quality and appearance of meat and poultry products so the determination is given an indicator to judge the quality of the products