QUALITY ATTRIBUTES OF CHICKEN BURGER FORMULATED WITH DIFFERENT LEVELS OF GIZZARD OR MECHANICAL DEBONED CHICKEN MEAT DURING FROZEN STORAGE

Abstract

The chicken burgers were formulated with 20, 40 and 60% levels of gizzard or mechanically deboned chicken meat (MDCM). The chemical, physicochemical, microbiological and sensory properties of chicken burgers were evaluated during storage at -18±1oC for 6 months. The chicken burgers formulated with gizzard had higher (p ≤ 0.05) moisture (70.56%), crude protein (17.23%), total ash (2.97%) and lower (p ≤ 0.05) total volatile nitrogen (14.46 mg/100g), thiobarbituric acid (0.54 mg malonaldehyde/kg sample), peroxide value (3.74 meq/kg fat ), pH (6.42), water holding capacity value (3.50 cm2/0.3g) and plasticity (3.11 cm2/0.3g) than chicken burgers formulated with MDCM. The crude protein and total ash contents of the chicken burgers were (p ≤ 0.05) decreased and crude fat, total volatile nitrogen, and thiobarbituric acid increased (p ≤ 0.05) by increasing the levels of gizzard or MDCM. Increasing the levels of gizzard in the chicken burgers led to reducing total bacterial count, psychrophilic bacteria and Staphylococcus aureus counts compared with control chicken burger. However, MDCM had an opposite trend. The sensory properties of the chicken burgers formulated with gizzard had rating scores described as like very much (7.52-8.05). However, chicken burgers formulated with MDCM had rating scores ranged between like moderately (6.80) and like very much (7.03-7.64). Although TVN, TBA, PV and microbial load of the chicken burgers increased and sensory properties decreased during the storage period, the chicken burger still had an acceptable quality. Key word: Chicken burger, chicken meat, gizzard, mechanical deboned chicken meat. INTRODUCTION Poultry meat is a very popular food commodity around the world and its consumption has increased over the last decades. In many countries some of the reasons for the popularity are the relatively low cost of production, low fat content and the high nutritional value of poultry meat (Chouliara et al., 2007). However, the poultry industry generates by-products which are generally underutilized, for example poultry liver, gizzard and mechanical deboned poultry meat. Gizzard is one of the principal edible by-products of poultry processing which is being marketed as variety meats along with dressed chicken. It forms nearly3% of dressed chicken (Charonpong and Chen 1980) and as such it is less preferred by the consumer due to its peculiar flavor and texture. Gizzard contains approximately 20% proteins (Kondaiah and Panda 1987 and Rao et al., 1994) and has potential for using in cost effective, convenient ready to eat chicken products. Mai M. El-Kordy, et al., 126 Mechanically deboned chicken meat (MDCM) is obtained by deboning or separation techniques of edible tissue on chicken bones. Generally, MDCM consist high amount of lipid and ash, when compared to fresh meat, and it also contains free heme groups because bone marrow and bone components are included in MDCM (Ockerman and Hansen, 2000). For these reasons, MDCM is vulnerable to oxidation and spoilage, and the addition of MDCM to meat products could have a negative effect on the sensory properties, mainly color, flavor, and texture (Pereira et al., 2011). Nevertheless, the inexpensive cost and nutritional value, to provide the effective use of animal resources, are main reasons why studies about the effects of MDCM on the quality characteristics of meat products are still underway. Perlo et al. (2006) reported that addition of washed MDCM up to 40% increased the fat content but decreased the protein content of chicken nuggets. Therefore the objective of this study was to formulatechicken burgerby replacing chicken meat with 20,40 and 60%of gizzard or MDCM. The proximate composition, chemical, physical, microbiological quality attributes and sensory properties of chicken burger immediately after preparation and during storage at -18±1oC for 6 months were evaluated. MATERIALS AND METHODS Materials Chicken meat Broiler carcasses (7-8 weeks age with average weight 1.5-2.0 kg) were purchased from the local market at Giza, Egypt. The chicken was slaughtered, allowed to bleed for 5 minutes, scalded for 2 min at 60 ̊C, plucked by hand, eviscerated, rinsed with tap water and deboned. On receipt at the laboratory, they were skinned, washed carefully then the chicken meat was stored at -18±1oC for 24 hours and then minced coarsely using a sterilized meat mincer before used in the formulation of chicken burgers. Fresh chicken gizzard Fresh chicken gizzard was obtained from El-Abed mall, Banha, qalyubia Governorate, Egypt. On receipt at the laboratory in the icebox, it was washed with cold tap water and stored at -18±1oC for 24 hours then minced coarsely using a sterilized meat mincer before used in the formulation of chicken burgers. Mechanically deboned chicken meat (MDCM): The frozen MDCM was purchased from Al-Kahera Slaughtering Company for poultry, Cairo, Egypt. Texturized soy: Texturized soy was obtained from the Food Technology Research Institute, Agricultural Research Center, Giza, Egypt. It was rehydrated by water at a ratio of 1:2 (w/v) and minced twice through 3 mm plate. Spices mixture The spices were purchased from the local market in Cairo, Egypt. The spices (60.0% fennel, 27.0% coriander, 3.0% Chinese cubeb, 3.0% white pepper, 3.0% clove, 2.0 % laurel leaf powder and 2.0 % cardamom.) were mixed together then ground to pass through a 60 mesh sieve and kept in a tight jar. Methods: Technological methods Preparation of chicken burgers: Fresh chicken burgers were prepared as described by Mikkelson (1993) and Abd EL-Qader (2004). The control chicken burger consisted of 71.50% minced chicken meat (included fat), 12.0% rehydrated texturized soy, 6.30% fresh eggs, 7.0% fresh onion, 1.50% salt, Quality attributes of chicken burger formulated with different levels of ............... 127 1.70% spices. The frozen chicken meat was cut into approximately 5 cm cubes and minced by using meat mincer. The other ingredients were added and mixed by using a laboratory blender (Hobart Kneading machine, Italy) together. After blending, the chicken mixture was shaped manually using a patty maker (stainless steel model "Form") to obtain round discs of 10 cm diameter and 0.50 cm thickness. The other chicken burgers were formulated by replacing chicken meat with 20, 40 and 60% levels of gizzard or MDCM. After the formulation of chicken burgers, it was aerobically packaged in the foam plates, wrapped with polyethylene film and stored at 18±1°C for 6 months. The samples were taken for analysis every month. Analytical methods Proximate composition: AOAC (2012) methods were used to determine moisture, crude fat, crude protein, and total ash contents of the chicken burger. Total carbohydrate content of the chicken burger was calculated by difference. Total volatile nitrogen (TVN): The TVN of the chicken burger was determined by the method described by Winton and Winton (1958). Thiobarbituric acid (TBA): The TBA of the chicken burger was determined according to the method described by Kirk and Sawyer (1991). The TBA values were expressed as mg malonaldehyde/ kg of sample. Peroxide value (PV): The PV of the chicken burger was determined by the titration method according to AOAC (2012) and expressed as meq/kg of fat. pH values: The pH values of the chicken burger were measured using a pH-meter (Jenway 3510 pH meter) at room temperature 25 ±1oC. Physical properties: Water Holding Capacity (WHC) and plasticity of the chicken burgers were measured according to the filter press method of Wierbicki and Deatherage (1958). Drip loss was measured by the difference between the weight of complete frozen burger and weight of the same burger after thawing. The drip loss was calculated as the percentage of weight change (AMSA 1995). Microbiological analysis Sample preparation: Ten grams of a representative and homogenized sample were mixed with 90 ml of sterile buffered 0.1% peptone water in a sterile blender, under sterile conditions, to give 1/10 dilution. Serial dilutions were prepared to be used for counting several types of bacteria and yeast and mold counts. Bacteriological methods: Total bacterial count (TBC), Staphylococcus aureus, psychrophilic bacteria and yeast and mold counts of the chicken burgers were determined by using Nutrient agar, Baird-parker agar, Nutrient agar, and Potato Dextrose agar media, respectively according to the procedures described by APHA (1976) and Difco Manual (1984). Incubations were carried out at 37oC/48 h for TBC; at 37°C /24h for Staphylococcus aureus, at 8oC/5days for psychrophilic bacteria and 25°C/5 day for yeasts and molds count. Salmonella: The presence or absence of salmonella of the chicken burger was determined according to the methods described by FAO (1979) using buffered peptone as a pre-enrichment, while tetrathionate broth was used as a Mai M. El-Kordy, et al., 128 selective enrichment broth and S-S agar was used as a selective plating media. Sensory evaluation: The thawed chicken burgers were grilled on a hot plate with little sunflower oil at 110oC for 4 minutes and left to cool at room temperature for 15 min. Sensory properties of cooked chicken burgers were carried out according to Mansour and Khalil (1999) by ten-trained panelists. Randomly coded samples were served to panelists individually. Five sensory attributes were evaluated (taste, odor, color, texture, and overall acceptability) using ten points hedonic scale for each trait where 9-10 = like extremely, 7-8 = like very much, 6 = like moderately, 5 = neither like nor dislike, 4 = dislike moderately, 3 = dislike very much and 1-2 = dislike extremely. Statistical analysis: Proximate composition of raw materials was analyzed by one-way analysis of variance. A completely randomized 2 (type of by-products) × 4 (replacement levels) × 7 (storage period) × 3 (replication) factorial design was used for chicken burger data. An analysis of variance was conducted using Costa