The mechanisms controlling heat and mass transfer on frying of beefburgers. III. Mass transfer evolution during frying

An Integrated Model of Heat Transfer in Meat Products during Multistage Operations

This work focuses on the modelling of the heat transfer in the key processes during the manufacturing of salted-smoked loin pork, a traditional Danish product called "Hamburgerryg". Drying, smoking, steam-cooking, water-cooling, and air-cooling processes are important process steps in the production of "Hamburgerryg". A mathematical model that describes the heat transfer during these processes was developed. A current model formulation, multiple unit operations, and the transfer between these unit operations were considered and described by an equation that combines boundary conditions. The model governing and boundary equations were solved using the finite element method (COMSOL Multi-physics® version 5.6). The product temperature profile during the processes was predicted as a function of position and time in the loin. The model was validated using measured temperature profiles from industrial production, and a good agreement between the measured and simulated temperature profiles was obtained. Additionally, the effects of the position (in the heating, cooking, and cooling chamber) on the temperature profile were also investigated. The obtained model can be used as a simulation tool to predict the temperature profile (particularly cold and hot spots) for entire processes and this can aid in the digitization of food processes by providing a more accurate and efficient means of temperature control.

Effect of vegetable oil hydrogel emulsion as a fat substitute on the physicochemical properties, fatty acid profile, and color stability of modified atmospheric packaged buffalo burgers

Buffalo burgers were prepared with 50% or 100% buffalo backfat substitution using walnut, and peanut oil emulsion gels (EGs) blended with chia flour. Burgers were stored at 2 °C in modified atmosphere packaging for 12 days. The fat replacement decreased total fat by 26% and increased ash by 34%. Hardness and chewiness decreased with increasing the fat replacement; however, it did not affect springiness and cohesiveness values. Burger reformulations led to an increase in cooking yield (10%). Walnut oil EGs increased PUFA level up to 458%. Both oils enhanced PUFA/SFA and ω-6/ω-3 ratios and atherogenic and thrombogenic indices. Concerning color attribute, about 66% reduction was observed in redness values during the storage period of 12 days. Moreover, the sensory scores for all attributes, i.e., appearance, odor, flavor, and juiciness, were in the acceptable range of five or above in the reformulated burgers. In conclusion, 50% fat substitution using walnut and peanut oil EGs improved the nutritional profile of buffalo burgers without compromising the technological and sensory characteristics.

Effect of Potato Dietary Fiber on the Quality, Microstructure, and Thermal Stability of Chicken Patty

A total of 150 chicken patties containing different concentrations of potato dietary fiber (PDF) (0.0−4.0%) (30 for every treatment) with three replicates were used to access the influence of PDF on their quality, microstructure, and thermal stability. PDF improved the quality of chicken patty, including significantly inhibiting dimensional change and improving water- and fat-binding properties and textural properties (p < 0.05). Moreover, PDF promoted a more homogeneous and dense meat−protein network structure to be formed. The results of thermal stability showed that PDF did not affect the thermal denaturation of proteins (p > 0.05). The samples with PDF (<3.0%) did not have a significant negative effect on sensory properties of chicken patty; meanwhile, there were more abundant nutrients and a lower energy value in samples with PDF compared with the control. Therefore, PDF could be a promising ingredient to improve the properties of chicken patties, which was related to the amount of PDF added and performed best at 3.0% level.

Quality of Beef Burgers Formulated with Fat Substitute in a Form of Freeze-Dried Hydrogel Enriched with Açai Oil

The growing number of people at high risk of cardiovascular disease development contributed to both changes in diets by consumers and the reformulation of food products by food producers. Cardiovascular diseases are caused by the i.a. consumption of meat that contains animal fat rich in saturated fatty acids (SFA). The use of fat substitutes in meat seems to be a promising tool for the reduction of cardiovascular disease occurrence. In the presented study, beef fat was replaced at 0 (CO), 25 (S-25%), 50 (S-50%), 75 (S-75%), and 100% (S-100%) by a fat substitute in a form of a lyophilized hydrogel emulsion enriched with encapsulated açai oil. The chemical (TBARS, volatile compound profile, fatty acid profile, pH), and physical (TPA, consumer rating, L*a*b* color, cooking loss) analyses were performed on raw and grilled burgers subjected to storage at cold conditions (4 °C) in days 0 and 7. Burgers formulated with hydrogels had a higher content of polyunsaturated fatty acids (PUFAs) of about 32% (p < 0.05) and reduced SFAs by 22%. Reformulation of the burger resulted in lower nutritional indices of the atherogenicity index (AI) (0.8 for CO, 0.3 for S-100%, p < 0.05) and thrombogenicity index (TI) (1.8 for CO, 0.6 for S-100%, p < 0.05), as well as led to an increased h/H ratio (1.3 for CO, 3.9 for S-100%, p < 0.05). Furthermore the application of freeze-dried hydrogels reduced cooking loss. Moreover, consumers did not observe significant differences (p < 0.05) between the control and S-25% and S-50% burgers. Thus, the use of lyophilized hydrogels formulated with konjac flour and sodium alginate and enriched with encapsulated acai oil can be successfully applied as a fat substitute in beef burgers.

Effect of Purple Eggplant Flour on Physicochemical, Lipid Oxidation, and Sensory Properties of Low-Fat Beef Patties

This study examines the implications of PEF as an alternative fat replacer on nutritional composition, display storage stability, product quality, and its practical application for beef patties. Four different beef patties were formulated with 0, 2.5, 5.0, and 7.5% PEF. Addition of the PEF in beef patties resulted in a significant increase in moisture, ash, and total dietary fiber while decreasing protein and fat contents. The cooking yield, moisture, and fat retention of the PEF beef patties were significantly higher than the control patty. The tenderness and juiciness scores of the PEF beef patties were significantly increased compared to the control. The lightness and redness values of raw patties were superior to the control during storage time. The amounts of thiobarbituric acid-reactive substances (TBARS) were lower in PEF beef patties than the control patties during 7 days of storage at 4°C. These results suggested that PEF could be used as a natural antioxidant fat replacer in beef patties without losing sensory and visual quality. In addition, the utilization of PEF may improve nutritional values including dietary fiber and display storage stability in beef patties.

Effects of Adding Moringa oleifera Leaves Powder on the Nutritional Properties, Lipid Oxidation and Microbial Growth in Ground Beef during Cold Storage

The utilisation of Moringa oleifera leaves powder (MOLP) to improve the nutritional properties and inhibit lipid oxidation and the proliferation of microorganisms in ground beef during cold storage was examined. The effects of 0.2, 0.4, 0.6, and 0.8% MOLP on the nutritional properties (proximate composition, total phenolic and total flavonoid content), thiobarbituric acid reactive substances (TBARS), microbial composition, physicochemical characteristics (pH value, colour attributes, and cooking properties), and sensory analysis of ground beef were investigated. The findings showed that ash, protein, polyphenolic compounds, pH, colour, and microbial growth increased significantly, while moisture, fat content, and TBARS decreased significantly, with an increase in the concentration of MOLP during cold storage. Moderate levels (0.2 and 0.4%) of MOLP did not affect the sensory attributes of stored ground beef. Evidently, MOLP can be utilised as a natural preservative in ground beef to improve the nutritional value and inhibit lipid oxidation.

Volatile and nonvolatile taste compounds and their correlation with umami and flavor characteristics of chicken nuggets added with milkfat and potato mash

This study investigated the chemical compounds and umami characteristics of chicken nuggets using spent meat (SM) enriched with milkfat (MF) and potato mash (PM). Four different spent nuggets (SNs) i.e. T1 (75% SM, 5% MF), T2 (70% SM, 8% MF, 2% PM), T3 (65% SM, 11% MF, 4% PM), and T4 (60% SM, 14% MF, 6% PM) were developed and compared with control using broiler chicken muscles (without MF and PM). Most abundant volatiles were trimethyldodecane, camphene, 5-ethyl-2,2,3-trimethylheptane, 3,6-dimethylundecane, 2,2,4-trimethylheptane, and α-pinene, and their intensities were highest for T2. Umami-taste characteristics were better explained by partial least squares regression (PLS-R) than other taste variables assessed by electronic tongue. T2 and T3 had higher 5'-nucleotides (GMP, AMP, ADP) and umami-taste amino acids (aspartic and glutamic acids) resulting in increased equivalent umami concentration than the control, T1, and T4. This study may be useful for the egg industries to utilize spent hens.

Multiphase porous media modelling: A novel approach to predicting food processing performance

The development of a physics-based model of food processing is essential to improve the quality of processed food and optimize energy consumption. Food materials, particularly plant-based food materials, are complex in nature as they are porous and have hygroscopic properties. A multiphase porous media model for simultaneous heat and mass transfer can provide a realistic understanding of transport processes and thus can help to optimize energy consumption and improve food quality. Although the development of a multiphase porous media model for food processing is a challenging task because of its complexity, many researchers have attempted it. The primary aim of this paper is to present a comprehensive review of the multiphase models available in the literature for different methods of food processing, such as drying, frying, cooking, baking, heating, and roasting. A critical review of the parameters that should be considered for multiphase modelling is presented which includes input parameters, material properties, simulation techniques and the hypotheses. A discussion on the general trends in outcomes, such as moisture saturation, temperature profile, pressure variation, and evaporation patterns, is also presented. The paper concludes by considering key issues in the existing multiphase models and future directions for development of multiphase models.

Combined heat transfer and kinetic models to predict cooking loss during heat treatment of beef meat

A heat transfer model was used to simulate the temperature in 3 dimensions inside the meat. This model was combined with a first-order kinetic models to predict cooking losses. Identification of the parameters of the kinetic models and first validations were performed in a water bath. Afterwards, the performance of the combined model was determined in a fan-assisted oven under different air/steam conditions. Accurate knowledge of the heat transfer coefficient values and consideration of the retraction of the meat pieces are needed for the prediction of meat temperature. This is important since the temperature at the center of the product is often used to determine the cooking time. The combined model was also able to predict cooking losses from meat pieces of different sizes and subjected to different air/steam conditions. It was found that under the studied conditions, most of the water loss comes from the juice expelled by protein denaturation and contraction and not from evaporation.

Microstructure, texture and colour development during crust formation on whole muscle chicken fillets

1. The development of crust during a 22-min period was evaluated in an oven, and in previously cooked-in-bag products (no crust) placed in an oven for 10 min. The oven-roasted products started to develop a thin (2-4 μm) crust layer after 4 min. At that point, the colour of the fillets turned white but no browning was observed. As roasting time increased, crust thickness and shear force increased, the product turned brown and eventually black at certain spots. 2. Light microscopy revealed the shrinking of muscle fibres close to the surface, as they also lost water. At a certain point, tears between the different layers started to appear. The inner muscle fibres also progressively shrank and the spaces between them increased. Microscopy of cook-in-bag products revealed no crust formation during heating. Upon moving to the oven, crust started to form but was much faster compared with the other products. 3. Cook-in-the-bag samples showed a higher rate of cook loss during the first 12 min (to internal 70°C) compared with oven heating. This could have been due to the fast heating rate in water and/or no crust formation. 4. White colour was fully formed on water-cooked fillets within 2 min (L* = 83), while it was gradually forming on oven-roasted samples (max L* of 79 after 12 min). 5. Shear force measurements showed an increase in both treatments up to 18 min, with a decrease thereafter (when dry crust started to crack).

In situ imaging highlights local structural changes during heating: the case of meat

Understanding and monitoring deformation and water content changes in meat during cooking is of prime importance. We show the possibilities offered by nuclear magnetic resonance imaging (MRI) for the in situ dynamic measurement of deformation fields and water content mapping during beef heating from 20 to 75 °C. MRIs were acquired during heating, and image registration was used to calculate the deformation field. The temperature distribution in the sample was simulated numerically to link structural modifications and water transfer to temperature values. During heating, proton density decreases because of a magnetic susceptibility drop with temperature and water expulsion due to muscle contraction. A positive relationship was found between local cumulative deformation and water content. This new approach makes it possible to identify the deformation field and water transfer simultaneously and to trace thermal history to build heuristic models linking these parameters.