Beer and Consumer Response Using Biometrics: Associations Assessment of Beer Compounds and Elicited Emotions

Consumer insights into the at-home liking of commercial beers: Integrating nonvolatile and volatile flavor chemometrics

Consumer acceptability of beers is influenced by product formulation and processing conditions, which impart unique sensory profiles. This study used multivariate techniques to evaluate at-home consumer sensory acceptability of six commercial beers considering their style, fermentation type, and chemical composition. Samples included top-fermented beers (American India Pale Ale and Stout) and bottom-fermented beers (Pilsner, zero-alcohol Pilsner, Vienna Lager, and Munich Dunkel). Beer consumers (n = 50) conducted sensory hedonic, check-all-that-apply (CATA) and just-about-right (JAR) tests. Chemometric variables included iso-alpha-acids, hordenine, and volatile aromatic compounds, quantified by chromatographic methods, whereas bitterness units (IBU) were determined spectrophotometrically. Lager beers had higher acceptability than top-fermented beer (p < .05) for all attributes. Light-colored beers and medium-height foams had the highest liking scores for visual sensory attributes. Higher concentrations of bitter-tasting molecules, hordenine, and acidity decreased the liking scores of top-fermented (Ale) beers, as a sensory penalty analysis suggested. In contrast, the most favored beers (Pilsners and Munich Dunkel) contained higher fusel alcohol esters linked to fruity aromatic notes. Although a low conversion rate of fatty acids into fruity esters was noted in nonalcoholic Pilsner, its overall liking score was not statistically different from the alcoholic version. However, consumers perceived the nonalcoholic Pilsner as less bitter than its alcoholic counterpart even when IBUs were nonsignificantly different. This study emphasized the significance of understanding beer chemometrics to comprehend consumer acceptability, highlighting the crucial role of bitter molecules. Hence, hordenine, acidity, and volatile contents provided additional and valuable insights into consumer preferences.

Review of technology advances to assess rice quality traits and consumer perception

The increase in rice consumption and demand for high-quality rice is impacted by the growth of socioeconomic status in developing countries and consumer awareness of the health benefits of rice consumption. The latter aspects drive the need for rapid, low-cost, and reliable quality assessment methods to produce high-quality rice according to consumer preference. This is important to ensure the sustainability of the rice value chain and, therefore, accelerate the rice industry toward digital agriculture. This review article focuses on the measurements of the physicochemical and sensory quality of rice, including new and emerging technology advances, particularly in the development of low-cost, non-destructive, and rapid digital sensing techniques to assess rice quality traits and consumer perceptions. In addition, the prospects for potential applications of emerging technologies (i.e., sensors, computer vision, machine learning, and artificial intelligence) to assess rice quality and consumer preferences are discussed. The integration of these technologies shows promising potential in the forthcoming to be adopted by the rice industry to assess rice quality traits and consumer preferences at a lower cost, shorter time, and more objectively compared to the traditional approaches.

Effects of Different Beer Compounds on Biometrically Assessed Emotional Responses in Consumers

The study of emotional responses from consumers toward beer products is an important digital tool to obtain novel information about the acceptability of beers and their optimal physicochemical composition. This research proposed the use of biometrics to assess emotional responses from Mexican beer consumers while tasting top- and bottom-fermented samples. Furthermore, a novel emotional validation assessment using proven evoking images for neutral, negative, and positive emotions was proposed. The results showed that emotional responses obtained from self-reported emoticons and biometrics are correlated to the specific emotions evoked by the visual, aroma, and taste aspects of beers. Consumers preferred bottom-fermentation beers and disliked the wheat-based and higher-bitterness samples. Chemical compounds and concentrations were in accordance to previously reported research for similar beer styles. However, the levels of hordenine were not high enough to evoke positive emotions in the biometric assessment, which opens additional research opportunities to assess higher concentrations of this alkaloid to increase the happiness perception of low or non-alcoholic beers.

Effect of UV Filters during the Application of Pulsed Light to Reduce Lactobacillus brevis Contamination and 3-Methylbut-2-ene-1-thiol Formation While Preserving the Physicochemical Attributes of Blonde Ale and Centennial Red Ale Beers

Pulsed light (PL) is a novel, non-thermal technology being used to control the microbial spoilage of foods and beverages. Adverse sensory changes, commonly characterized as "lightstruck", can occur in beers when exposed to the UV portion of PL due to the formation of 3-methylbut-2-ene-1-thiol (3-MBT) upon the photodegradation of iso-α-acids. This study is the first to investigate the effect of different portions of the PL spectrum on UV-sensitive beers (light-colored blonde ale and dark-colored centennial red ale) using clear and bronze-tinted UV filters. PL treatments with its entire spectrum, including the ultraviolet portion of the spectrum, resulted in up to 4.2 and 2.4 log reductions of L. brevis in the blonde ale and centennial red ale beers, respectively, but also resulted in the formation of 3-MBT and small but significant changes in physicochemical properties including color, bitterness, pH, and total soluble solids. The application of UV filters effectively maintained 3-MBT below the limit of quantification but significantly reduced microbial deactivation to 1.2 and 1.0 log reductions of L. brevis at 8.9 J/cm² fluence with a clear filter. Further optimization of the filter wavelengths is considered necessary to fully apply PL for beer processing and possibly other light-sensitive foods and beverages.

Consumer Studies: Beyond Acceptability—A Case Study with Beer

Beer is one of the most consumed alcoholic beverages in the world; its consumption and preference are evolving from traditional industrial beers of low complexity to novel craft beers with diverse flavour profiles. In such a competitive industry and considering the complexity of consumer behaviour, improvement and innovation become necessary. Consequently, consumer science, which is responsible for identifying the motivation behind customer preferences through their attitudes, perception and behaviour, has implemented strategies ranging from simple hedonic measurements to several innovative and emerging methodologies for a deeper understanding of the variables that affect the product experience: sensory, affective and cognitive. In this context, we offer a review inspired by previous research that explores some of the quantitative and qualitative methods used in consumer studies related to beer consumption, ranging from traditional approaches (acceptability, purchase intention, preference, etc.) to techniques that go beyond acceptability and allow a different understanding of aspects of consumer perception and behaviour (segmentation, expectations, emotions, representation, etc.). Also, innovative applications (contexts, immersive technologies and virtual reality, implicit measures, etc.) and current trends related to consumer science (Internet, social media, pairing, product experience, etc.) are addressed.

Combined chemoenzymatic strategy for sustainable continuous synthesis of the natural product hordenine

To improve sustainability, safety and cost-efficiency of synthetic methodologies, biocatalysis can be a helpful ally. In this work, a novel chemoenzymatic stategy ensures the rapid synthesis of hordenine, a valuable phenolic phytochemical under mild working conditions. In a two-step cascade, the immobilized tyrosine decarboxylase from Lactobacillus brevis (LbTDC) is here coupled with the chemical reductive amination of tyramine. Starting from the abundant and cost-effective amino acid l-tyrosine, the complete conversion to hordenine is achieved in less than 5 minutes residence time in a fully-automated continuous flow system. Compared to the metal-catalyzed N,N-dimethylation of tyramine, this biocatalytic approach reduces the process environmental impact and improves its STY to 2.68 g L^-1 h^-1.

Novel Techniques to Measure the Sensory, Emotional, and Physiological Responses of Consumers toward Foods

Sensory science is an evolving field that has been incorporating technologies from different disciplines [...].

Sunroot snack bar: Optimization, characterization, consumer perception, and storage stability assessment

This study reports the evolution of phenolics, inulin content, proximate composition, hardness, and sensory characteristics of an inulin-rich healthy snack bar (The Sunroot Snack Bar) over 90 days of storage in refrigerated and room temperature storage. A response surface methodology (RSM) with a central composite rotatable design was first employed for optimizing the concentrations of sunroot, potato, and oats. The optimum selected concentrations of sunroot, potato, and oat were 53.99, 37.88, and 5 g, respectively, and a quadratic model was found to yield the best fit. Analysis of variance revealed that a higher sunroot content resulted in more firmness of the bar and higher overall acceptability in sensory trials. Sunroot snack bar samples without flavor (control), sunroot snack bar with cheese flavor (S1), and sunroot snack bar with olive flavor (S2) were then tested for sensory, chemical, phytochemicals, and microbial contents among control, S1, and S2 samples over a 90-day shelf-life study. Results showed no significant (p < .05) changes in these contents on addition of flavor. An increase in microbial load and the appearance of a bitter taste after 30 days of fresh sunroot storage were observed. No microbial growth was observed in all sunroot snack bar samples during storage at 4°C, while some microbial growth was observed at 25°C for 90 days. It was inferred that the high-quality shelf life of the sunroot bar was 90 days at 4°C, which was shortened to a month if the bars were preserved at 25°C. There was a significant phenolic and inulin content loss at 25°C compared with 4°C in total phenolic component. Based on the results of sensory evaluation, online questionnaire of customer experience, and cost analysis, this study successfully used sunroot tubers for the production of snack bars as a promising new raw material, which was introduced healthily with a suitable price for such product compared with other products in the market.

Reading Food Experiences from the Face: Effects of Familiarity and Branding of Soy Sauce on Facial Expressions and Video-Based RPPG Heart Rate

Food experiences are not only driven by the food's intrinsic properties, such as its taste, texture, and aroma, but also by extrinsic properties such as visual brand information and the consumers' previous experiences with the foods. Recent developments in automated facial expression analysis and heart rate detection based on skin color changes (remote photoplethysmography or RPPG) allow for the monitoring of food experiences based on video images of the face. RPPG offers the possibility of large-scale non-laboratory and web-based testing of food products. In this study, results from the video-based analysis were compared to the more conventional tests (scores of valence and arousal using Emojis and photoplethysmography heart rate (PPG)). Forty participants with varying degrees of familiarity with soy sauce were presented with samples of rice and three commercial soy sauces with and without brand information. The results showed that (1) liking and arousal were affected primarily by the specific tastes, but not by branding and familiarity. In contrast, facial expressions were affected by branding and familiarity, and to a lesser degree by specific tastes. (2) RPPG heart rate and PPG both showed effects of branding and familiarity. However, RPPG heart rate needs further development because it underestimated the heart rate compared to PPG and was less sensitive to changes over time and with activity (viewing of brand information and tasting). In conclusion, this study suggests that recording of facial expressions and heart rates may no longer be limited to laboratories but can be done remotely using video images, which offers opportunities for large-scale testing in consumer science.

Exploring the Effects of Immersive Virtual Reality Environments on Sensory Perception of Beef Steaks and Chocolate

Virtual reality (VR) technology is emerging as a tool for simulating different eating environments to better understand consumer sensory response to food. This research explored the impact of different environmental contexts on participants' hedonic ratings of two different food products: beef steaks, and milk chocolate, using VR as the context-enhancing technology. Two separate studies were conducted. For beef, two different contextual conditions were compared: traditional sensory booths and a VR restaurant. For chocolate, data were generated under three different contextual conditions: traditional sensory booths, VR Irish countryside; VR busy city (Dublin, Ireland). All VR experiences were 360-degree video based. Consumer level of engagement in the different contextual settings was also investigated. The results showed that VR had a significant effect on participants' hedonic responses to the food products. Beef was rated significantly higher in terms of liking for all sensory attributes when consumed in the VR restaurant. While for chocolate, the VR countryside context generated significantly higher hedonic scores for flavour and overall liking in comparison to the sensory booth. Taken together, both studies demonstrate how specific contextual settings can impact participants' sensory response to food products, when compared to a traditional sensory laboratory condition.

Silicon supplementation improves the nutritional and sensory characteristics of lentil seeds obtained from drought-stressed plants

BACKGROUND

Lentil is an important nutritionally rich pulse crop in the world. Despite having a prominent role in human health and nutrition, it is very unfortunate that global lentil production is adversely limited by drought stress, causing a huge decline in yield and productivity. Drought stress can also affect the nutritional profile of seeds. Silicon (Si) is an essential element for plants and a general component of the human diet found mainly in plant-based foods. This study investigated the effects of Si on nutritional and sensory properties of seeds obtained from lentil plants grown in an Si-supplied drought-stressed environment.

RESULTS

Significant enhancements in the concentration of nutrients (protein, carbohydrate, dietary fibre, Si) and antioxidants (ascorbate, phenol, flavonoids, total antioxidants) were found in seeds. Significant reductions in antinutrients (trypsin inhibitor, phytic acid, tannin) were also recorded. A novel sensory analysis was implemented in this study to evaluate the unconscious and conscious responses of consumers. Biometrics were integrated with a traditional sensory questionnaire to gather consumers responses. Significant positive correlations (R = 0.6-1) were observed between sensory responses and nutritional properties of seeds. Seeds from Si-treated drought-stressed plants showed higher acceptability scores among consumers.

CONCLUSION

The results demonstrated that Si supplementation can improve the nutritional and sensory properties of seeds. This study offers an innovative approach in sensory analysis coupled with biometrics to accurately assess a consumer's preference towards tested samples. In the future, the results of this study will help in making a predictive model for sensory traits and nutritional components in seeds using machine-learning modelling techniques. © 2020 Society of Chemical Industry.

Insights into Drivers of Liking for Avocado Pulp (Persea americana): Integration of Descriptive Variables and Predictive Modeling

Trends in new food products focus on low-carbohydrate ingredients rich in healthy fats, proteins, and micronutrients; thus, avocado has gained worldwide attention. This study aimed to use predictive modeling to identify the potential sensory drivers of liking for avocado pulp by evaluating acceptability scores and sensory descriptive profiles of two commercial and five non-commercial cultivars. Macronutrient composition, instrumental texture, and color were also characterized. Trained panelists performed a descriptive profile of nineteen sensory attributes. Affective data from frequent avocado adult consumers (n = 116) were collected for predictive modeling of an external preference map (R² = 0.98), which provided insight into sensory descriptors that drove preference for particular avocado pulps. The descriptive map explained 67.6% of the variance in sensory profiles. Most accepted pulps were from Hass and Colin V-33; the latter had sweet and green flavor notes. Descriptive flavor attributes related to liking were global impact, oily, and creamy. Sensory drivers of texture liking included creamy/oily, lipid residue, firmness, and cohesiveness. Instrumental stickiness was disliked and inversely correlated to dry-matter and lipids (r = -0.87 and -0.79, respectively). Color differences (∆E_ab*) also contributed to dislike. Sensory-guided selection of avocado fruits and ingredients can develop products with high acceptability in breeding and industrialization strategies.