Application of Sensory and Consumer Science in optimization and exploration of debated food processing technologies: Smoke-flavoring of foods

The United Nations’ Food and Agriculture Organization emphasizes the urgent need for sustainable food production and equitable distribution to feed the global population by 2050. For people with sufficient access to food, it is expected that eating practices will need to shift due to e.g., changes in food distribution, raw material shortages, regulatory changes, cultural considerations, health factors, implementation of new foods and development of innovative and more efficient food processing technologies. Understanding people’s food choices is crucial for facilitating this shift. Consumers’ food choices are influenced by numerous factors. Some factors are food-internal, like sensory perception, while food-external stimuli include psychological and cognitive factors as well as culture, context, and practice. This thesis aimed to explore key internal and external factors influencing food choices using methods grounded in Sensory and Consumer Science. The optimization and exploration of the debated food processing technology, smoke-flavor processing, served as a case study to examine the effectiveness of different sensory and consumer methods to understand consumer choices and aid in product development and marketing. Food smoking is a long-standing tradition in Norway, used in the production of both everyday and traditional foods. Over the past decade, the European Union has encouraged the adoption of smoke-flavor processing as a safer and more environmentally friendly alternative to conventional smoking, which poses health risks due to polycyclic aromatic hydrocarbons. In Norway, the use of smoke-flavor processing has been a subject of ongoing debate. Some manufacturers have avoided this technology, anticipating high consumer skepticism. Recent scientific evaluations by the European Food Safety Authority (EFSA), EU’s independent agency responsible for providing scientific advice on risks within the food area, have identified health concerns associated with smoke-flavorings. As a result, EFSA recommended the withdrawal of previously approved smoke-flavorings, which have since been removed from the EU market. This work comprises a total of three papers. The initial two papers focused on the traditional Norwegian food product, cold-smoked salmon (smoked salmon) while the third paper focused on smoke-flavoring of foods in general. Previous studies have found that positive sensory perception is essential in accepting novel food technology. In Paper I, sensory characterization and consumer acceptance were employed to optimize the production of smoke-flavored salmon. The approach involved various sensory evaluation methods and panels with various levels of training and resulted in a product that did not significantly differ in consumer liking and closely matched conventionally smoked salmon in sensory characteristics. The results indicated that salty, smoky and natural flavors were important drivers for consumer liking. However, the findings in Paper I did not clarify what influenced consumer attitudes towards smoked salmon. Therefore, further investigation was conducted both quantitatively, through an online survey, and qualitatively, using focus group discussions (Paper II). The digital survey revealed that only 15% of Norwegian consumers were positively oriented towards smoke-flavoring of salmon. Negative attitudes were linked to perceptions of unnaturalness, violation of traditions (given the cultural significance of conventional smoking in Norwegian heritage) and expected changes in sensory quality and healthiness. Interestingly, consumer attitudes towards smoke-flavoring varied depending on the type of product. Smoke-flavoring was more accepted in the production of everyday foods compared to traditional foods like smoked salmon. A large-scale survey was conducted (Paper III) to further explore these and additional factors. The survey, conducted by 1003 Norwegian consumers, identified that 44% were negative, 36% neutral, and 20% positive towards smoke-flavor processing. Positive and neutral respondents were significantly less food-involved and food technology neophobic than the negative respondents. The negative respondents were concerned about the degree of processing and perceived naturalness. Among the negative respondents, two distinct subgroups emerged. One subgroup consisted of food-involved individuals who were concerned with traditional food and food production, and who exhibited personality traits such as being extroverted, imaginative, and friendly. The other subgroup was characterized by being older, more frequently retired, and living in rural areas. Together, the three papers examined the acceptance, barriers and drivers for acceptance, perception, and attitudes towards smoked salmon. They also explored the role of sociodemographics, traditions, food technology neophobia, smoke processing methods (conventional or smoke-flavoring), level of processing, naturalness, food involvement, and personality traits in shaping attitudes towards smoked foods. Although not all factors influencing food choices were examined, this work provides valuable insights into the many factors that affect consumer attitudes towards the novel food processing technology of smoke-flavoring. It is possible to segment consumers based on several of the examined factors. In this studies, consumers were grouped based on their attitudes towards the use of smoke-flavoring, focusing on the characteristics of the negative and neutral consumers who are unlikely to choose smoke-flavored products. By identifying the characteristics of these segments, information can be tailored to resonate with them, if the goal is to change their food choices or eating practices. The combination of methods employed in these three papers can be applied to other food-related areas, such as introducing novel food processing technologies or new foods. All the practical work in this thesis was conducted before the negative health effects of smoke-flavoring were identified and the approval of the previously approved smoke-flavors was withdrawn. This does not render the research irrelevant. On the contrary, this study may be valuable for future applications and for understanding the impact of regulatory changes on consumer attitudes and food choices

Norwegian Consumers’ Skepticism towards Smoke-Flavoring of Salmon—Is It for Real?

The aim of the present study was to explore Norwegian consumers’ attitudes toward smoke-flavoring of cold smoked salmon (CSS), by conducting a digital survey and focus group discussions. Some of the smoke-flavoring techniques, like atomized purified condensed smoke, is considered healthier than conventional smoking. Manufacturers of CSS are, however, hesitant to use all kinds of smoke-flavoring due to expected consumer skepticism. In the digital survey, the expected skepticism was confirmed (n = 487). Only 15% of the respondents were positively oriented toward smoke-flavoring of CSS. The selection criterion for the focus group discussion was based on the results from the survey and resulted in three attitude-oriented focus groups (negative, neutral, and positive). The negative focus group considered smoke-flavored CSS to be unnatural and out of the question to buy or eat. Unlike the negative focus group, the neutral group was curious to learn more and open to potential smoke-flavor benefits. However, credible information or science was crucial to influence CSS choice. Future studies may investigate whether the existent of this large group of curious neutral consumers (47% of the respondents) influence manufacturers (of CSS) skepticism or how various types of product information could steer consumer acceptance of smoke-flavoring of CSS.publishedVersio

Descriptive sensory methods

In recent years, the growing demand for cost efficiency within product development in the food Industry, have created a need for rapid descriptive sensory methods. Several new rapid methods have subsequently been developed. The overall aim of this thesis was to compare the two rapid methods Napping® and CATA, and compare them with the established method profiling (QDA). The thesis includes three studies. Study 1 compared Global and Partial Napping® with traditional profiling (QDA). In this study, the semi-trained panel at Sør-Trøndelag University College, Department of Food Technology, tested eight different types of strawberry yoghurt. Napping®, in particular Partial Napping®, was less time consuming and proved to give a better product description than profiling. In addition, consumer acceptance, of the same strawberry yoghurts, were examined and presented together with the profiling data in a Preference Map. In Study 2, CATA and Global Napping® were compared for consumer testing of five different brands of orange juice. CATA turned out to be easier for the consumers to understand and perform. Moreover, processing and interpretation of data and plot was easier using CATA than Napping®. The number of descriptive words created by use of Global Napping ® complicated interpretation of the plot. The final part, Study 3, compared CATA with profiling (QDA). In this study, the same semi-trained panel used in Study 1 profiled four varieties of vegetable juice whereas consumers performed CATA. The rapid method CATA provided similar product descriptions as profiling, as well as information about consumer acceptance and preferred usage. Profiling requires repeated tests and a trained sensory panel of professional assessors. The fact that untrained and unpaid consumers can perform Napping® and CATA as a single test, are advantages compared to traditional profiling. Profiling with a trained sensory panel, will sometimes give information that the rapid methods cannot provide. For instance, if small differences in one specific attribute is considered, or if shelf life of a product is tested. A trained sensory panel will also provide more precise and unambiguous product descriptions than a consumer panel. Hovedmålet i denne oppgaven ble formulert til bruk og vurdering av de beskrivende hurtigmetodene Napping® og CATA samt sammenligning med den etablerte sensoriske metoden profilering (QDA). Oppgavens første del, Studie 1, gikk ut på å sammenligne Global og Partial Napping® med profilering (QDA). Studie 2 gikk ut på å sammenligne CATA og Global Napping® når begge disse ble brukt til forbrukertesting av 5 ulike appelsinjuice. I Studie 3 ble CATA og profilering (QDA) sammenlignet.M-IM

Fra lærerstyrt undervisning til varierte læringsformer

Motivasjon er en av de viktigste faktorene for læring. Aktive og varierte læringsformer, samt bruk av formative og hyppige tilbakemeldinger er sentrale ingredienser for å skape motivasjon for læring. Dette var bakgrunnen for at emnet produktutvikling ved bachelorstudiet i matteknologi ved NTNU høsten 2015 ble lagt om fra å være et lærerstyrt teoretisk emne til å bli et emne som bruker aktiviserende og varierte læringsformer i kombinasjon med hyppige tilbakemeldinger fra lærere og medstudenter. Omleggingen var også basert på studentenes forventninger om en praktisk tilnærming til et emne i produktutvikling. Emnet fikk tittelen «Produktutvikling og sensorisk analyse - brygging av håndverksøl». Målet var å oppnå mer motiverte og engasjerte studenter, samt å forbedre studentenes akademiske prestasjoner. Undervisningsopplegget har elementer fra ulike didaktiske konsept; både problembasert læring, casemetoden, prosjektarbeid, forelesninger og arbeidslivsmedvirkning. Studentene har flere muntlige presentasjoner underveis i prosessen. Ølbrygging ble valgt som case fordi bryggeprosessen er tverrfaglig og krever at studentene bruker kunnskap ervervet i flere andre emner. Ølbrygging er en aktivitet som har oppnådd stor allmenninteresse de siste årene og kan av den grunn virke ekstra motiverende. Emneevalueringer basert på referansegruppemetodikk viste at studentene synes emnet ble engasjerende og at det praktiske arbeidet var appellerende og lærerikt. De hyppige direkte tilbakemeldingene ble trukket frem som positive. Mange av studentene rapporterte negative opplevelser knyttet til de muntlige fremføringene på forhånd, men endret mening etter gjennomføring. Læringsutbytte i emnet ble i gjennomsnitt skalert til 4,1 av maksimalt 5. De akademiske prestasjonene for de to kullene som har gjennomført emnet med studentaktivt undervisningsopplegg var signifikant bedre enn for de to forhenværende kullene. Erfaringene tyder på at studentene bør lære mer om gruppearbeid og hvordan konflikter i grupper skal håndteres. Lærerne opplevde at studentene viste eierskap til problemstillingen og at de viste høyt engasjement. Bruk av varierte og aktive læringsformer er motiverende, men også ressurskrevende for læreren.publishedVersionThis work is licensed under a Creative Commons Attribution 4.0 International License

Fra lærerstyrt undervisning til varierte læringsformer

Motivasjon er en av de viktigste faktorene for læring. Aktive og varierte læringsformer, samt bruk av formative og hyppige tilbakemeldinger er sentrale ingredienser for å skape motivasjon for læring. Dette var bakgrunnen for at emnet produktutvikling ved bachelorstudiet i matteknologi ved NTNU høsten 2015 ble lagt om fra å være et lærerstyrt teoretisk emne til å bli et emne som bruker aktiviserende og varierte læringsformer i kombinasjon med hyppige tilbakemeldinger fra lærere og medstudenter. Omleggingen var også basert på studentenes forventninger om en praktisk tilnærming til et emne i produktutvikling. Emnet fikk tittelen «Produktutvikling og sensorisk analyse - brygging av håndverksøl». Målet var å oppnå mer motiverte og engasjerte studenter, samt å forbedre studentenes akademiske prestasjoner. Undervisningsopplegget har elementer fra ulike didaktiske konsept; både problembasert læring, casemetoden, prosjektarbeid, forelesninger og arbeidslivsmedvirkning. Studentene har flere muntlige presentasjoner underveis i prosessen. Ølbrygging ble valgt som case fordi bryggeprosessen er tverrfaglig og krever at studentene bruker kunnskap ervervet i flere andre emner. Ølbrygging er en aktivitet som har oppnådd stor allmenninteresse de siste årene og kan av den grunn virke ekstra motiverende. Emneevalueringer basert på referansegruppemetodikk viste at studentene synes emnet ble engasjerende og at det praktiske arbeidet var appellerende og lærerikt. De hyppige direkte tilbakemeldingene ble trukket frem som positive. Mange av studentene rapporterte negative opplevelser knyttet til de muntlige fremføringene på forhånd, men endret mening etter gjennomføring. Læringsutbytte i emnet ble i gjennomsnitt skalert til 4,1 av maksimalt 5. De akademiske prestasjonene for de to kullene som har gjennomført emnet med studentaktivt undervisningsopplegg var signifikant bedre enn for de to forhenværende kullene. Erfaringene tyder på at studentene bør lære mer om gruppearbeid og hvordan konflikter i grupper skal håndteres. Lærerne opplevde at studentene viste eierskap til problemstillingen og at de viste høyt engasjement. Bruk av varierte og aktive læringsformer er motiverende, men også ressurskrevende for læreren

Sensory methodology in product optimization of coldsmoked Atlantic salmon (Salmo salar L.) processed withatomized purified condensed smoke

Atomized purified condensed smoke (PCS) is a smoke processing technique, producing fewer harmful substances during processing, than conventional smoking. Manufacturers of cold smoked salmon (CSS) are however skeptical to PCS due to expected decrease in perceptual quality. The aim of this study was to use sensory methodology (Check All That Apply [CATA], Descriptive Analysis [DA] and Napping®) in optimization of PCS processed CSS. A three-step experiment was performed using five unique PCS condensates and varying process parameters. In each step, PCS processed CSS were perceptually evaluated and compared with conventional CSS. In Step one, PCS processed CSS was compared to conventional CSS, initiating process changes prior to the next step. In Step two, conventional CSS, two new condensates and the altered CSS from Step one, were screened to choose two prototypes for Step three. In Step three, perceptual differences, consumer acceptance, and physiochemical parameters of the two PCS prototypes and conventional CSS were examined. Napping® was proven effective for sorting and describing samples, distinguishing the dry and smoky ones from the shiny, soft, and mild varieties. CATA with hedonic scaling successfully characterized samples and the ideal CSS, gave useful information about consumer acceptance, and identified salty, smokey and natural to be important drivers of liking. The two descriptive tests CATA and DA in Step three, processing yield and physiochemical parameters gave a complete prototype description and input for further development. By combining the results from sensory perception and the physicochemical measurements, the experiment succeeded to produce a promising PCS prototype with sensory quality and consumer acceptance similar to conventional CSS

Comparative evaluation on the quality and shelf life of Atlantic salmon (Salmo salar L.) filets using microwave and conventional pasteurization in combination with novel packaging methods

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Comparative evaluation on the quality and shelf life of Atlantic salmon (Salmo salar L.) filets using microwave and conventional pasteurization in combination with novel packaging methods

A comparative evaluation on the effect of carbon dioxide (CO2) on quality and shelf life of Atlantic salmon loins pasteurized with microwave and conventional technology was conducted. The experimental design allowed CO2 to enter the salmon muscle before (soluble gas stabilization [SGS] + vacuum) or after pasteurization (CO2 emitter + vacuum), whereas the control samples (vacuum only) were not presented for CO2. This setup resulted in six different groups; three heated with microwaves and three with conventional pasteurization. The core temperature of microwave samples was 58.8 ± 2.2 °C, whereas the surface temperature was equal to the oven temperature (62 °C) during conventional pasteurization and close to the core temperature during microwave pasteurization (57.6 ± 1.4 °C). Microwave‐heated samples showed higher microbial growth; decreased shelf life; and darker (lower L*‐value), more reddish (higher a*‐value), and yellowish (higher b*‐value) colors compared to conventional‐heated salmon. Lowest liquid loss (LL) was observed in salmon packaged with the CO2 emitter, whereas a SGS step prior to pasteurization did not affect the LL negatively as compared to samples packaged in vacuum only. Treatment with CO2, independent of the prestep using SGS or an emitter, resulted in increased shelf life. Protein denaturation, microbial growth, product color, product shelf life, and sensory properties of the salmon loin were significantly affected by the applied pasteurization method (microwave‐ or conventional pasteurization). However, the heat load was probably too high to detect differences resulting from the pretreatment using SGS or packaging with CO2 emitter

Effects of chemical leavening addition and drying time on the physicochemical characteristics and sensory properties of snack bars

The drying process plays a crucial role in the economic viability and shelf-life extension of snack bars. Additionally, the use of chemical leavening agents may contribute to improving the sensory characteristics of this food category. Therefore, this study aimed to evaluate the effects of different drying times (8 and 16 h) and the addition of chemical leavening (0 and 1 %) on the sensory properties and physicochemical characteristics of snack bars. The samples were analyzed for proximate composition, water activity, shear force, and sensory properties through a consumer panel using a Check-All-That-Apply (CATA) questionnaire and acceptance test. Drying time and the addition of chemical leavening agents significantly influenced the quality of the snack bars, particularly in terms of texture-related sensory attributes. Drying time mainly affected texture attributes, as longer drying increased hardness and dryness, while shorter drying resulted in softer products with higher acceptance. The addition of chemical leavening contributed to a darker roasted crust and more pronounced baking aroma but did not significantly improve overall acceptability, whereas samples without leavening were characterized by a cured ham flavor and a more rubbery texture. These findings demonstrate that processing parameters strongly influence texture and sensory perception, providing valuable insights for optimizing the formulation and processing of snack bars. Further research is necessary to enhance overall sensory acceptance, such as incorporating suitable flavoring agents

Influence of drying time and sugar content on the sensory profile of beef jerky

Abstract Beef jerky is widely consumed for its convenience, sensory appeal, and shelf stability. Reducing sugar content is a public health priority but presents technological and sensory challenges. Drying time also plays a crucial role due to its economic and sustainability impacts. This study evaluated the effects of different drying times (2, 3, 4, and 6 h) and sugar levels (0.5%, 1%, and 1.5%) on beef jerky’s sensory and physicochemical properties. Drying time significantly influenced product quality, affecting sensory attributes. Results showed that reducing added sugar did not compromise the sensory properties preferred by consumers. Moreover, optimizing both drying time and sugar content can improve production efficiency while maintaining consumer acceptance. These findings highlight the potential for healthier beef jerky with enhanced sustainability