Sensory and Non-sensory Factors Behind the Liking and Choice of Healthy Food Products

A healthy and balanced diet can reduce health problems, such as overweight and metabolic syndrome. In general, people have a considerably good knowledge of what constitutes a healthy diet and how they could achieve it with their food choices. Besides, people argue that health is among their top five food choice motives. Nevertheless, the prevalence of overweight is increasing and other food choice motives, such as taste, seem to conflict with the health. Liking for food does not necessarily determine acceptance alone, thus several non-sensory factors, such as brand, country of origin and nutrition claim, can also influence. Moreover, consumers are individuals in how they prioritize sensory and nonsensory factors of foods, but e.g. increasing age, female gender and health concern have been connected to a more health-oriented dietary behaviour. To sum up, identifying different factors that can increase the liking and consumption of healthy food is essential in order to develop more attractive healthful food products. Adding vitamins, minerals, fibre or other ingredients to a food product can be used to enrich the nutritional quality of the products. However, this may be difficult in practice as regards the sensory quality and pleasantness of the foods. Generally, consumers are not willing to compromise on taste in food. On the other hand, consumers are very heterogeneous in their likings, and their personal values and attitudes may interact with preferences for specific sensory characteristics. The aims of this study were to investigate the effects of intrinsic product characteristics on sensory properties and hedonic responses; to determine the impact of few non-sensory factors; and to examine the interaction between sensory and non-sensory factors with consumers’ demographics, values and attitudes in liking of healthy model foods. The results showed that product composition influenced sensory quality and had an effect on hedonic responses. Adding flaxseed to bakery products showed a significant improvement in the nutritional quality without negative effects on sensory properties. On the other hand, the fortification of wellness beverages with vitamins and minerals may impart off-flavours. In general, sweetness of yoghurts, freshness of wellness beverages and low intensity of rye bread flavour appealed to consumers. Information about the domestic origin of yoghurts and claiming a specific function for wellness beverages enhanced liking. However, consumers who were more concerned about their health and considered natural content as an important food choice motive, rated sourer and less sweet yoghurts and wellness beverages as more pleasant. In addition, interest in health increased the consumption of rye breads and other whole grain breads among adolescents. The results showed that the optimal product quality in terms of intrinsic and extrinsic factors differs between individual consumers, and personal values and food choice motives can be connected to preferences for specific sensory characteristics of foods. This indicates that each food product needs to be considered in relation to its specific market niche, and to which segment of consumer will respond most positively to its characteristics.

Modelling of ultrasound assisted mixing in Newtonian and non-Newtonian liquids

The purpose of this work is to obtain a better understanding of behaviour of possible ultrasound appliance on fluid media mixing. The research is done in the regard to Newtonian and non-Newtonian fluids. The process of ultrasound appliance on liquids is modelled in COMSOL Multiphysics software. The influence of ultrasound using is introduced as waveform equation. Turbulence modelling is fulfilled by the k-ε model in Newtonian fluid. The modeling of ultrasound assisted mixing in non-Newtonian fluids is based on the power law. To verify modelling results two practical methods are used: Particle Image Velocimetry and measurements of mixing time. Particle Image Velocimetry allows capturing of velocity flow field continuously and presents detailed depiction of liquid dynamics. The second way of verification is the comparison of mixing time of homogeneity. Experimentally achievement of mixing time is done by conductivity measurements. In modelling part mixing time is achieved by special module of COMSOL Multiphysics – the transport of diluted species. Both practical and modelling parts show similar radial mechanism of fluid flow under ultrasound appliance – from the horn tip fluid moves to the bottom and along the walls goes back. Velocity profiles are similar in modelling and experimental part in the case of Newtonian fluid. In the case of non-Newtonian fluid velocity profiles do not agree. The development track of ultrasound-assisted mixing modelling is presented in the thesis.

Work and non-work : on work and meaning

I den politiska retoriken florerar debattinlägg om arbetslivet, och målsättningen är för det mesta att så många som möjligt ska arbeta så länge som möjligt. Att skapa jobb och minimera arbetslösheten ses som de främsta utmaningarna. På ett individuellt plan beskrivs arbete ofta som personligt självförverkligande eller som en nödvändig form av inkomst som kräver att livet struktureras enligt behovet av sysselsättning. I avhandlingen diskuteras hur de här till synes självklara rollerna som arbete spelar kan sägas neutralisera arbete. Med detta menas att kontroverser kring arbetets mening åsidosätts så att politiskt och etiskt grundläggande frågor om ett gott liv och mänskliga gemenskaper inte ges plats. Genom att gå i dialog med kritiska tänkare som Hannah Arendt, André Gorz, Kathi Weeks, Karl Marx och Richard Sennett diskuteras riskerna med att behandla arbete som en resurs, ett gemensamt samhällsprojekt eller individuellt självförverkligande. Vad är nödvändigt arbete? Vad innebär det att arbete är en vara? Vad är problemet med fragmentering av arbete? Det sägs ofta att arbete har blivit alltmer gränslöst – är detta något positivt eller negativt? Utifrån sådana frågor tar avhandlingen fasta på spänningar i arbetets roll i våra liv och i samhället. Genom att artikulera spänningar utmanas en neutralisering av arbetets etiskt och politiskt brännbara dimensioner. Avhandlingen syftar därmed till att lyfta fram ständigt pågående sätt att ifrågasätta och reflektera kring arbetets mening.