This study took chicken sausages as the research object, with chicken breast meat as the main raw material. Fat trim and chicken skin used in conventional formulations were eliminated to optimize the formula. The fat content of the product was reduced to below 3%, aiming to provide formula guidance for the preparation of low-fat and healthy smoked and cooked sausages.
1 Materials and Methods
1.1 Materials
Chicken breast meat, inulin, konjac gum, phosphate, soy protein isolate, culture media for microbiological tests, medium-speed qualitative filter paper, petroleum ether, hydrochloric acid, copper sulfate, potassium sulfate, sodium hydroxide
1.2 Instruments and Equipment
TGL-10B bench-top centrifuge; AL-204 electronic analytical balance; LT-BIX300M constant temperature and humidity incubator; HB-80L bowl cutter; XND-30 sausage stuffer; ZH-zKJ-500 packaging machine; DHG-9123A drying oven; KDN-812 Kjeldahl nitrogen analyzer
1.3 Methods
1.3.1 Optimization of Chicken Sausage Formula
(1) Effect of compound ratio of konjac powder and inulin on product quality
On the basis of 2% salt and seasonings, 1% soy protein isolate, 0.2% phosphate, 70% chicken breast meat and 20% ice water, compound mixtures of konjac powder and inulin with different compound ratios were added. The total addition level of the compound mixture was 6.8%. The selected compound ratios of konjac powder to inulin were 1:3, 1:4, 1:5, 1:6, 1:7 and 1:8. Chicken sausages were prepared through chopping, stuffing and cooking. Sensory score, water holding capacity and yield rate were used as evaluation indicators to determine the optimal compound ratio of inulin and konjac powder.
(2) Effect of addition level of compound mixture (konjac powder and inulin) on product quality
With 2% salt and seasonings, 1% soy protein isolate, 0.2% phosphate, chicken breast meat to ice water ratio of 7:2, and konjac powder:inulin ratio of 1:6, the addition levels of the compound mixture (inulin and konjac gum) were set at 4%, 5%, 6%, 7%, 8% and 9%. Chicken sausages were made by chopping, stuffing and cooking. Sensory score, water holding capacity and yield rate were adopted as evaluation indicators to determine the optimal addition amount of the compound mixture (inulin and konjac gum).
(3) Effect of soy protein isolate addition level on product quality
Under the conditions of 2% salt and seasonings, 0.2% phosphate, chicken breast meat to ice water ratio of 7:2, konjac powder:inulin ratio of 1:6 and compound mixture addition of 6%, soy protein isolate was added at levels of 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0%. Chicken sausages were produced via chopping, stuffing and cooking. Sensory score, water holding capacity and yield rate were used as evaluation indicators to determine the optimal addition level of soy protein isolate.
(4) Effect of ice water addition level on product quality
On the premise of 2% salt and seasonings, 0.2% phosphate and 6% compound mixture of konjac powder and inulin, ice water was added at 10%, 12%, 14%, 16%, 18% and 20%. Chicken sausages were prepared by chopping, stuffing and cooking. Sensory score, water holding capacity and yield rate were selected as evaluation indicators to determine the optimal ice water dosage.
(5) Determination of optimal formula for low-fat chicken sausages
To obtain the optimal formula of low-fat chicken sausages, an L₉(3⁴) orthogonal test was carried out with sensory score, water holding capacity and yield rate as evaluation indicators, and the test was performed in triplicate.
1.3.2 Processing Procedure and Key Operation Points of Chicken Breakfast Sausages
Processing procedure of chicken breakfast sausage: Chicken breast meat → pretreatment → chopping → stuffing → cooking → packaging → cooling.
Key operation points: Fresh skinless chicken breast meat without freezing after slaughter was used within 24 h. Visible fat was trimmed from chicken breast meat. The temperature during chopping was controlled below 10 °C. Each sausage segment was kept at 9–10 cm in length and 2 cm in diameter during stuffing. Cooking was performed at 90 °C for 25 min. After cooking, the product passed through a rapid cooling tunnel, and the core temperature was reduced to below 4 °C within 20 min.
1.3.3 Index Measurement
(1) Sensory evaluation
Blind scoring was adopted. Professional sensory panelists evaluated the flavor, odor, color, texture, mouthfeel and overall acceptability of chicken sausages prepared with different formulas and processes. After cooling cooked chicken sausages to room temperature, the samples were cut into cubes (1 cm × 1 cm × 1 cm). Hedonic scoring method was used for sensory assessment. A sensory panel of 10 members scored the samples according to a sensory scoring table formulated with reference to the specification for sensory evaluation of meat and meat products.
(2) Determination of water holding capacity (WHC)
The method described by Mittal and Barbut was used with minor modifications. Approximately 5 g of chicken sausage sample was accurately weighed, tightly wrapped with medium-speed qualitative filter paper and placed into a 50 mL centrifuge tube pre-lined with absorbent cotton at the bottom. The tube was centrifuged at 4800 r/min for 8 min. The mass of the chicken sausage sample after centrifugation was weighed. WHC was calculated as the percentage of the post-centrifugation mass relative to the initial mass.
(3) Determination of yield rate
The method of Whiting was referenced. Approximately 100 g of stuffed raw chicken sausage was accurately weighed, sealed in a plastic bag after air evacuation, and cooked at a specified temperature for a set duration. After cooking, the sample was cooled to room temperature, surface juice was gently wiped off with filter paper, and the sample was weighed again. Cooking loss was calculated as the percentage of mass difference before and after cooking relative to the mass before cooking.
(4) Shelf life test
Cooked chicken sausages were vacuum-packaged and incubated in a constant temperature and humidity chamber at 10 °C and 70% relative humidity. Total viable count, coliforms, Staphylococcus aureus, Salmonella spp. and Listeria monocytogenes were detected daily. Sensory changes including water separation and color variation were observed, and changes in flavor and mouthfeel were assessed. Total viable count was determined according to GB 4789.2-2016; coliforms were tested by the plate count method of GB 4789.3-2016; Staphylococcus aureus was determined by the plate method of GB 4789.10-2016; Salmonella spp. was detected in accordance with GB 4789.4-2016; Listeria monocytogenes was assayed following GB 4789.30-2016.
(5) Fat content determination
The fat content of low-fat chicken sausages was determined by the Soxhlet extraction method.
(6) Protein content determination
The protein content of low-fat chicken sausages was determined by the Kjeldahl method.
(7) Moisture content determination
The moisture content of low-fat chicken sausages was determined by the direct drying method.
2 Conclusions
The optimized processing formula of low-fat chicken sausages obtained in this study contained 72.3% chicken breast meat, 18% ice water, 6% compound mixture (konjac powder:inulin = 1:7), 1.5% soy protein isolate, 1.5% salt, 0.5% seasonings and 0.2% phosphate. Formula optimization significantly reduced the fat content of chicken sausages, achieving the target of less than 3%. Meanwhile, nutrient content was increased, quality properties were improved and the shelf life of the product was prolonged. This study on formula optimization of low-fat chicken sausages provides technical references for the development of other low-fat smoked and cooked sausages.
Helper Machinery Group Co., Ltd.
