Rheological Study of an Extruded Fish Diet with the Addition of Hydrolyzed Protein Flour

The extrusion of food for human and animal consumption is a unit operation that includes mixing, shearing, and force to the materials related to the rheological properties of the materials in the extruder. The present work aims to study the rheological behavior of an extruded fish diet incorporating hydrolyzed protein flour (HPF) processed by extrusion. The measurement was carried out online with a slit die rheometer, defining the rheological models and parameters that fit the process. During the extrusion process, the raw materials used were hydrolyzed protein flour, fish meal, and cassava starch. For the results, the evaluated treatments were adjusted to the Power Law, where an increase in the shear rate decreases the viscosity of the material, corresponding to a pseudoplastic behavior. The incorporation of hydrolyzed protein flour presented a significant effect on the value of n and Klp, increasing the viscosity with the increase in the percentage of inclusion of HPF. The models obtained for the prediction of the viscosity are adjusted to the system’s changes in shear rate, temperature, and humidity. The importance of the study lies in the fact that the diet developed can be applied to feed fish, and production is currently being scaled up to pilot plants for direct use by some producer communities.

Rheological Study of an Extruded Fish Diet with the Addition of Hydrolyzed Protein Meal

The extrusion of food for human and animal consumption is a unit operation that includes mixing, shearing and force to the materials related to the rheological properties of the materials in the extruder. The present work aims to study the rheological behavior of an extruded fish diet incorporating hydrolyzed protein flour processed by extrusion. The measurement was carried out online with a slit die rheometer, defining the rheological models and parameters that fit the process. During the extrusion process, the raw materials used were hydrolyzed protein meal, fish meal and cassava starch. For the results, the evaluated treatments were adjusted to the Power Law, where an increase in the shear rate decreases the viscosity of the material, corresponding to a pseudoplastic behavior. The incorporation of hydrolyzed protein flour presented a significant effect on the value of n and Klp, increasing the viscosity with the increase in the percentage of inclusion of HPH. The models obtained for the prediction of the viscosity are adjusted to the changes in shear rate, temperature and humidity of the system.

Department of Food Technology and Commodity Science, Regional Open Social Institute

It is proposed to use a mixture of milk protein concentrate and high-protein flour from sunflower meal, close in the content of essential amino acids to the “ideal” protein, and vitamin and mineral mixture “Kolos 8” in the recipe composition of muffins in order to increase their biological value. It has been found that when a single serving (100 g) of enriched muffin is consumed, 25% of the daily physiological protein requirement is satisfied. The range of fortified flour confectionery products has been expanded.

Improving the nutritional value of sugar cookies

The use of high-protein flour from sunflower meal pellets, vitamin and mineral mixture “Kolos-Forte” and liquid vegetable oil in the recipe composition of sugar cookies is proposed in order to increase their nutritional value. It has been found that when a single serving (100 g) of the developed sugar cookies is consumed, 16% of the daily physiological protein requirement is satisfied. The range of flour confectionery products of increased nutritional value has been expanded.

Strengthening of Porcine Plasma Protein Superabsorbent Materials through a Solubilization-Freeze-Drying Process

The replacement of common acrylic derivatives by biodegradable materials in the formulation of superabsorbent materials would lessen the associated environmental impact. Moreover, the use of by-products or biowastes from the food industry that are usually discarded would promote a desired circular economy. The present study deals with the development of superabsorbent materials based on a by-product from the meat industry, namely plasma protein, focusing on the effects of a freeze-drying stage before blending with glycerol and eventual injection molding. More specifically, this freeze-drying stage is carried out either directly on the protein flour or after its solubilization in deionized water (10% w/w). Superabsorbent materials obtained after this solubilization-freeze-drying process display higher Young’s modulus and tensile strength values, without affecting their water uptake capacity. As greater water uptake is commonly related to poorer mechanical properties, the proposed solubilization-freeze-drying process is a useful strategy for producing strengthened hydrophilic materials.

Changes in Protein Non-Covalent Bonds and Aggregate Size during Dough Formation

This research investigated changes in the amounts and sizes of monomeric proteins and protein aggregates during dough mixing, with a focus on the contribution of non-covalent bonds in the aggregation of gluten proteins. High protein flour (HF) and low protein flour (LF) were used in this study. As dough mixing progressed from flour to overmixed dough, the total amount of protein aggregates increased while the amount of monomeric protein decreased. Omega-gliadin was the major monomeric protein that decreased in quantity. Interestingly, the amount of larger-sized protein aggregates decreased and that of smaller-sized protein aggregates increased. The amount of gluten protein macro-polymer aggregated through strong non-covalent bonds decreased whereas aggregates formed with weaker non-covalent bonds increased. LF dough behaved similar to HF dough. Large-sized gluten protein aggregates disaggregated due to the weakening of non-covalent bonds and became smaller. Omega-gliadin was incorporated into gluten protein aggregates during dough mixing.

Assessing the Economic Viability of an Animal Byproduct Rendering Plant: Case Study of a Slaughterhouse in Greece

Continuous human population growth has led to increased livestock production and hence large quantities of animal byproducts. One of the oldest and most efficient animal byproducts processing techniques is rendering, which facilitates the recovery of resources in the form of fat and protein flour. The purpose of this study is to provide data for the feasibility of rendering as a treatment method. The case of a Greek slaughterhouse is presented, regarding its animal byproduct treatment process through rendering and incineration. Three different waste management scenarios are compared, with rendering proving to have a lower operational cost (€51.80/ton) compared to incineration (€74.10/ton), and rendering followed by incineration (€72.13/ton). The rendering process is then compared with other established animal byproduct treatment methods like composting and anaerobic digestion through the analytic hierarchy process, in terms of environmental, economic, and technological efficiency, with rendering (having a final score of 72%) proving once again superior compared to composting (with a score of 54%), and anaerobic digestion (with a score of 55%).

Effect of Different Ratios of Low Protein Flour to Oyster Mushroom (Pleurotus sajor-caju) Powder on the Physicochemical Properties and Sensory Acceptability of Edible Tablespoon

The aim of this study was to determine the effect of different ratios of low protein flour to oyster mushroom (Pleurotus sajor-caju) powder on the physicochemical properties and sensory acceptability of edible tablespoon. Fresh grey oyster mushroom was dried in a convection oven at temperature of 55.0˚C ± 2.0˚C for 20 h prior to the grinding process. The low protein flour (LPF) was then incorporated with oyster mushroom powder (OMP) at different ratios of 100:0, 96:4, 92:8, 88:12 and 84:16, before being with vegetable oil, sugar, egg white and water in formulating the edible tablespoon. The proximate analyses were carried out in triplicate for calorie content, colour profile, hardness value and morphological structure of edible tablespoon. This study revealed that with decreasing LPF and increasing OMP in the formulation, the ash content (1.24% to 1.92%), crude fat content (8.98% to 10.40%) and fiber content (0.13% to 1.24%) were observed to have increased as well as the hardness value (2042.03g to 2844.57g) and pore’s size of the morphological structure of edible tablespoon. However, the carbohydrate content (78.64% to 75.56%) significantly decreased (p>0.05) together with L* value (from 68.47 to 61.71) when the decrease was in the the percentage of LPF and an increase the percentage of OMP. The calorie content, moisture content and protein content of edible tablespoon were not significantly (p>0.05) affected by different ratios of LPF to OMP. The edible tablespoon formulated with up to 8% of OMP was accepted by the sensory panelists but further increase in OMP addition significantly decreased the degree of likeness in terms of colour, odour, taste and overall acceptability of edible tablespoon. This study suggested that oyster mushroom edible tablespoon could be potential alternative disposable cutlery which will help to reduce the use of huge amount of non-biodegradable materials for environmental conservation.