Inverse method to sequentially estimate temperature-dependent thermal conductivity of cherry pomace during nonisothermal heating

Performance and meat quality of broiler chickens fed with the addition of dried fruit pomace

The aim of the study was to evaluate the addition to feed of 3% of dried pomace from apples (AP), cherries (CH), and strawberries (ST) on the production results and meat quality of broiler chickens. Birds fed only the standard mixture for broiler chickens were the control group (CO). On d 42, a lower body weight of broiler chickens from group ST was noted compared to birds from group CO at P = 0.032. When feed conversion per 1 kg of weight gain and loss of broiler chickens was assessed, no differences between groups were shown (P ˃ 0.05). The leg muscles of AP and CH broiler chickens had less drip loss compared to the control group at P = 0.036. For other quality parameters of breast and leg muscles, no differences between groups were noted (P ˃ 0.05). It was found that the addition of dried apple and cherry pomace to the feed in the amount of 3% did not adversely affect the production results and the quality of broiler chicken meat. On the other hand, the addition to feed of dried pomace from strawberries reduced the final body weight of experimental birds. The most interesting additive turned out to be dried cherry pomace, because it improved slaughter efficiency, contributed to reducing drip loss of leg muscles, and influenced the lower level of crude fat in the breast muscles. However, further research should be carried out on the optimal concentration of CH in the diet of fattening chickens in order to achieve the most beneficial results.

Optimal Design of Complementary Experiments for Parameter Estimation at Elevated Temperature of Food Processing

Simultaneous estimation of thermal properties can be challenging, especially when the parameters are temperature-dependent. Previous research has shown that by using a complementary experiment, temperature-dependent thermal conductivity can be estimated using a single experiment. The objective of this study was to optimize the complementary experiments that can facilitate the simultaneous estimation of temperature-dependent thermal conductivity and volumetric heat capacity. A theoretical study was conducted with two experiments in a single trial with the sample being kept in a cylindrical sample holder, which had a thin film heater in the center. The first part of the experiment was conducted by keeping the external surface temperature at 50 °C for 300 s and allowing the center temperature to equilibrate with the boundary temperature. Then, the second part of the experiment followed, where the thin film heater was supplied with electrical power to increase the center temperate to 140 °C. Several heating profiles were studied to maximize the information obtained from the complementary experiments, and the best one was the power profile with a sinusoidal function. All four parameters of sweet potato puree temperature-dependent thermal conductivity (0.509 to 0.629 W/mK at 25 °C and 140 °C, respectively) and volumetric heat capacity (3.617 × 106 to 4.180 × 106 J/m3K at 25 °C and 140 °C, respectively) were estimated with low standard errors.

Dynamic Thermal Properties Estimation Using Sensitivity Coefficients for Rapid Heating Process

Thermal conductivity determination of food at temperatures > 100 °C still remains a challenge. The objective of this study was to determine the temperature-dependent thermal conductivity of food using rapid heating (TPCell). The experiments were designed based on scaled sensitivity coefficient (SSC), and the estimated thermal conductivity of potato puree was compared between the constant temperature heating at 121.10 °C (R12B10T1) and the rapid heating (R22B10T1). Temperature-dependent thermal conductivity models along with a constant conductivity were used for estimation. R22B10T1 experiment using the k model provided reliable measurements as compared to R12B10T1 with thermal conductivity values from 0.463 ± 0.011 W m⁻¹ K⁻¹ to 0.450 ± 0.016 W m⁻¹ K⁻¹ for 25–140 °C and root mean squares error (RMSE) of 1.441. In the R12B10T1 experiment, the analysis showed the correlation of residuals, which made the estimation less reliable. The thermal conductivity values were in the range of 0.444 ± 0.012 W m⁻¹ K⁻¹ to 0.510 ± 0.034 W m⁻¹ K⁻¹ for 20–120 °C estimated using the k model. Temperature-dependent models (linear and k models) provided a better estimate than the single parameter thermal conductivity determination with low RMSE for both types of experiments. SSC can provide insight in designing dynamic experiments for the determination of thermal conductivity coefficient.

Sour Cherry By-products: Compositions, Functional Properties and Recovery Potentials - A Review

Sour (tart) cherry is an industrial fruit where a considerable amount of by-products remain after processing. Sour cherry by-products consist of pomace (skin and flesh) and seeds (pit, stone) which remain after the fruit juice and IQF processes. Sour cherry pomace is characterized with a high content of phenolic compounds and the seed constitutes a high oil yield with beneficial effects on human health because of their antioxidant, antimicrobial, and anti-inflammatory properties. There has been a great interest in sour cherry by-products due to the increasing production rate of sour cherry worldwide and the increasing efforts on seeking bioactive compounds from natural sources as functional food. Thus, there have been a number of studies regarding the sour cherry pomace and sour cherry seed, especially in the last five years. The present review summarizes the chemical, biological, functional, and technological properties of the sour cherry pomace and sour cherry seed with their current and potential applications.

Propriedades físicas e reológicas de produtos à base de frutas

Resumo Em vista da crescente demanda da população por questões relacionadas à saúde, nutrição e bem-estar, o mercado alimentício tem se preocupado em aumentar a inserção de ingredientes mais saudáveis como as frutas, por exemplo, visando atender à nova demanda do consumidor. A otimização de um processo é dependente da presença de dados precisos que permitam o dimensionamento correto dos equipamentos. O objetivo deste trabalho foi caracterizar amostras comerciais de produtos à base de frutas e avaliar as propriedades termofísicas (densidade, calor específico, difusividade térmica e condutividade térmica) e reológicas (viscosidade aparente e energia de ativação), visando à adequação a modelos teóricos. Os resultados foram ajustados a modelos matemáticos apresentando erros relativos entre 0,2% e 50%, sendo o modelo de ajuste da densidade o mais preciso (erro máximo de 1,7%). O comportamento reológico das amostras teve melhor ajuste ao modelo Lei da Potência (R2 > 0,96) e a viscosidade relacionou-se bem com a temperatura, segundo a equação de Arrhenius (R2 > 0,90).