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High levels of meat consumption are increasingly being criticised for ethical, environmental, and social reasons. Plant-based meat substitutes have been with reservations identified as healthy sources of protein in comparison to meat. This alternative offers several social, environmental, and probably health benefits, and it may play a role in reducing meat consumption. However, there has been a lack of research on how specific meat substitute attributes can influence consumers to replace or partially replace meat in their diets. Research has demonstrated that, in many countries, consumers are highly attached to meat. They consider it to be an essential and integral element of their daily diet. For the consumers that are not interested in vegan or vegetarian alternatives to meat, so-called meathybrids could be a low-threshold option for a more sustainable food consumption behaviour. In meathybrids, only a fraction of the meat product (e.g., 20% to 50%) is replaced with plant-based proteins. In this paper, the results of an online survey with 500 German consumers are presented with a focus on preferences and attitudes relating to meathyrids. The results show that more than fifty percent of consumers substitute meat at least occasionally. Thus, approximately half of the respondents reveal an eligible consumption behaviour with respect to sustainability and healthiness to a certain degree. Regarding the determinants of choosing either meathybrid or meat, it becomes evident that the highest effect is exerted by the health perception. The healthier meathybrids are perceived, the higher is the choice probability. Thus, this egoistic motive seems to outperform altruistic motives, like animal welfare or environmental concerns, when it comes to choice for this new product category.
The increased consumption of reduced-fat or non-fat products leads to a reduced intake of fat-soluble bioactive substances, such as fat-soluble vitamins. Due to their natural role as transport systems for hydrophobic substances, casein micelles (CM) might depict a viable system. The structure of CM is characterized by a lipophilic core stabilized by an electric double layer-like structure. Modification allows accessibility of the core and, therefore, the inclusion of fat-soluble bioactive substances. Well-known modifications are pH reduction and use of rennet enzyme. A completely new procedure to modify CM structure is offered by pulsed electrical fields (PEF). The principle behind PEF is called electroporation and affects the electric double layer of CM so that it is interrupted. In this way, lipophilic substances can be incorporated into CM. In this work, we evaluated integration of β-carotene into native CM by an industry-compatible process to overcome disadvantages associated with the use of Na-caseinate and avoid great technical effort, e.g., due to treatment with high hydrostatic pressure. Our research has shown that PEF can be used for disintegration of CM and that significant amounts of β-carotene can be incorporated in CM. Furthermore, after disintegration using PEF, a combination of another PEF and thermal treatment was applied to restructure CM and trap significant amounts of β-carotene, permanently, ending up with an encapsulation efficiency of 78%.
The influence of oil content and droplet size of oil-in-water emulsions on the heat development in an ohmic heating system was investigated. The setup was run with constant power or voltage. Emulsions consisted of sunflower oil (10–50 wt%), aqua dest. (90–50 wt%) and whey protein isolate (1.25/ 2.5/ 3.75/ 5.0 and 6.25 wt%) Two different droplet size distributions were produced, large (d0.5 ≈ 2.0 μm) and small (d0.5 ≈ 0.3 μm), for each oil mass fraction. The emulsions were ohmically heated from 10 to 80 °C at a constant power of 3.0 kW and constant voltage of 15 V/cm. The electrical conductivity decreased with an increasing oil content, resulting in longer or shorter heating time for constant voltage or constant power input, respectively. The droplet size only affected the heating process at the highest oil content.
Industrial relevance
Emulsions occur in a wide range of food products (e.g. sauces, dressings, desserts) and have properties giving structure to the food system. Ohmic heating is an emerging thermal process with improved (e.g. faster or less energy required) heating characteristics. The influence of physical changes due to different droplet sizes are of interest because these might also affect the heating characteristic. In addition, the direct comparison of two different process regulations (constant power and constant voltage) indicate which set up is expedient to a successful heating process. This study aims to identify the influence of emulsion-induced structural changes and process changes on the heating rates, which is of interest for the food industry and the related machine building industry.
The study aimed for the analysis of the impact of pulsed electric field (PEF) pre-treatment on convection (CD) and microwave (MW-CD) assisted air drying. Drying kinetics acceleration and retention of bioactive compounds of PEF pre-treated carrots and apples has been demonstrated. Moreover, the direct and indirect environmental energy impacts of CD and MW-CD technologies with consideration of bioactive compounds preservation has been evaluated. PEF assisted CD and MW-CD demonstrated lower energy use, especially for indirect energy consumption, in the case of carotenoids preservation in dried carrots.