Determination of Moisture Levels, Protein and Water Absorption of Chicken Giblets

Abstract

This study aimed at evaluating the levels of moisture, protein, water to protein ratio, and water absorption during chilling of chicken giblets (heart, liver, and gizzard) to set legal limits of water absorption during this process. The survey was conducted in the southern Brazil, the largest broiler-producing region of this country. Giblets (heart, liver, and gizzard) were collected fresh from the processing line after evisceration and at the exit of the chiller after the immersion process from two processing plants. One of the plants (PP1) processes small chickens (1,100g live weight) and PP2 processes chickens with 2,800g live weight. In total, 448 samples were collected. Laboratory tests were performed in duplicate for each parameter measured. The results show that moisture levels of fresh giblets were higher in the gizzard, followed by the liver and the heart, whereas in chilled giblets, the gizzard still maintained the highest moisture level, but was followed by the heart and then the liver. Both in fresh and chilled samples, the liver presented the highest protein content, followed by the gizzard and the heart. Water to protein ratios were higher in chilled than in fresh samples, and was highest in the heart, followed by the gizzard and the liver. After immersion in the chiller, the heart presented the highest water absorption rate (6.59%), which was significantly higher compared with those of the liver (4.16%) and the gizzard (4.51%). Considering that the water absorption rates obtained both in fresh and chilled chicken giblets were below 8.00%, the following upper limits of water absorption are suggested for chicken giblet processing in Brazil: 7.0% for the heart, and 5.0% for the gizzard and the liver.

Utilização De Algoritmos De Aprendizagem De Máquina Para Predição De Absorção De Água Nas Carcaças De Frango / Use of Machine Learning Algorithms for Water Absorption Prediction in Chicken Carcasses

“…Estudos acerca do índice de absorção de água das carcaças de frango apontam, principalmente, o chiller de resfriamento e suas variáveis como foco de estudo sobre as influências no resultado final (Scaratti et al, 2016). A grande dificuldade é determinar matematicamente um modelo que possa simular as saídas conforme as variáveis de entrada do processo (Carciofi & Laurindo, 2007;Martins et al, 2011).…”

Water absorption process capability analysis by chicken carcasses during precooling

“…The chicken carcasses are immersed and transported in a mixture of water and ice, being cooled from approximately 40 °C to 4 °C (measured at the center of the pectoralis muscle) at the exit of the equipment (Carciofi & Laurindo, 2007;Carciofi & Laurindo, 2010;Rodrigues et al, 2015). Ot is during this stage that water absorption occurs through the chicken carcasses (Scaratti et al, 2016).…”