Sensory Evaluation of Common Ice Plant (Mesembryanthemum crystallinum L.) in Response to Sodium Chloride Concentration in Hydroponic Nutrient Solution.

Common ice plant (Mesembryanthemum crystallinum L.) is a novel edible plant with a succulent and savory flavor. The plants display prominent epidermal bladder cells (EBCs) on the surface of the leaves that store water and sodium chloride (NaCl). The plants have high nutritional value and are adapted to saline soils. Previous research has determined the impact of NaCl on the growth and mineral content of ice plant, but as NaCl has an impact on a food's sensory properties, an interesting question is whether saline growth media can affect the plant's taste and texture, and if this alters consumers' sensory response to ice plant. The objective of this study was to evaluate the sensory aspects of ice plant, as well as consumer liking in response to increasing NaCl concentration in hydroponic nutrient solution. Four-week-old seedlings of ice plant were transplanted into deep water culture (DWC) hydroponic systems and treated with five NaCl concentrations (0 M [control], 0.05 M, 0.10 M, 0.20 M, and 0.40 M NaCl). Eight-week-old plants (after four weeks of NaCl treatment) were harvested, and the middle leaves of each plant were sampled for consumer testing. A total of 115 participants evaluated various flavor, texture, and appearance aspects of ice plant and provided their liking ratings. The consumers were able to discriminate differences in salt intensity from the plants based on NaCl treatment in the hydroponic nutrient solution. Low NaCl concentrations (0.05-0.10 M) did not have obvious adverse effect on consumer liking, which aligns with the result of previous research that 0.05-0.10 M NaCl could largely stimulate the growth of ice plant. NaCl concentrations higher than 0.20 M are not recommended from both a production and consumer perspective. With increased NaCl level in plant samples, the consumers detected more saltiness, sourness, and fishiness, less green flavor, and similar levels of bitterness and sweetness. NaCl treatment had no effects on leaf appearance and texture, and the consumers' overall liking was mainly determined by flavor. Overall, ice plant presents some unique attributes (salty and juicy) compared to other edible salad greens; however, consumer awareness of ice plant is very low, and purchase intent is relatively low as well. Consumers picture ice plant being used mainly in salads and in restaurants.

On the validity of longitudinal comparisons of central location consumer testing results prior to COVID-19 versus home use testing data during the pandemic.

Consumer testing assays a panel's liking of a food or other sensory stimulus. However, liking can be influenced by mood, with people feeling more uncomfortable, or more unhappy reporting lower liking ratings than those in a higher affect. Though consumer testing typically takes place as a central location test (CLT, usually in a set of standardized sensory booths), the COVID-19 pandemic has resulted in a global pivot to home use tests (HUTs), where panelists can taste and smell samples unmasked more safely while in their own homes. Unfortunately, as this situation differs in many ways to a central location test, this puts the validity of longitudinal comparisons of liking scores under question. Further, as people across the globe report feelings of worry, unease, and stress during the pandemic, this may present a second source of variation in affect with previous years. We tested a set of snack bar samples both at home and in a central location, in repeated measures with the same panel, to test the validity of comparisons across locations. We further compared CLT results to those when testing the same samples in a previous year. Finally, we performed a meta-analysis of existing data on this subject. While liking behavior in CLTs did not differ between years, panelists rated some samples higher when in their own homes, in line with results from the meta-analysis of previous reports. Interestingly, panelists in the study also assigned fewer penalties in the HUT, implying a less analytical mindset when in the home. Results suggest that care should be taken when comparing results taken at home during the COVID-19 pandemic to those taken previously in a central location. PRACTICAL APPLICATION: Consumer testing is applied in the food industry to evaluate a panelist's liking for a food product or stimulus. However, liking is also dependent on factors extrinsic to the samples tested. Thus, with the switch to in-home testing due to COVID-19, we compared liking scores from in-home and central locations testing, with higher scores common in HUTs.

An evaluation of alternative biodegradable and reusable drinking straws as alternatives to single-use plastic.

The manufacture of single-use plastic items uses fossil fuels, and releases greenhouse gases. Plastic waste is also harmful to humans and wildlife. Recent attention towards the regulation or elimination of plastic straws has led to the development of many alternatives to single-use plastic straws, some intended to be disposed of immediately after use, and others to be cleaned and reused. Unfortunately, anecdotes are widespread of inferior sensory experiences from such alternatives, with straws either losing stability when wet, imparting negative flavor properties to a beverage, or feeling unpleasant in the mouth. Despite such reports, little formal research exists categorizing these alternatives. Here, we examine popular choices for straw materials in a focus group (n = 9) and in a consumer sensory test (n = 102), as well as testing the durability of straws when soaked in water. Cornstarch straws offered the most similar sensory experience to plastic, whereas options such as paper, wheat, pasta, and rice straws all scored low on mouthfeel and flavor liking, with off-flavors commonly reported in beverages consumed with these straws. A Kano analysis (n = 193) to determine the factors consumers find essential in drinking straws confirmed the most important to be that no flavors were imparted to beverages when used. Finally, a consumer survey (n = 579) confirmed that straw consumers primarily use them out of default availability; most use them only if they are given without asking, and most would readily give up plastic straws, but may be unfamiliar with other options. PRACTICAL APPLICATION: Plastic straws contribute to waste and result in the release of greenhouse gases in their manufacture. Despite this, they provide a superior sensory experience compared to other options. Here, we review aspects of this experience, along with consumers motivations for using straws.

Characterization of the Fermentation and Sensory Profiles of Novel Yeast-Fermented Acid Whey Beverages.

Acid whey is a by-product generated in large quantities during dairy processing, and is characterized by its low pH and high chemical oxygen demand. Due to a lack of reliable disposal pathways, acid whey currently presents a major sustainability challenge to the dairy industry. The study presented in this paper proposes a solution to this issue by transforming yogurt acid whey (YAW) into potentially palatable and marketable beverages through yeast fermentation. In this study, five prototypes were developed and fermented by Kluyveromyces marxianus, Brettanomyces bruxellensis, Brettanomyces claussenii, Saccharomyces cerevisiae (strain: Hornindal kveik), and IOC Be Fruits (IOCBF) S. cerevisiae, respectively. Their fermentation profiles were characterized by changes in density, pH, cell count, and concentrations of ethanol and organic acids. The prototypes were also evaluated on 26 sensory attributes, which were generated through a training session with 14 participants. While S. cerevisiae (IOCBF) underwent the fastest fermentation (8 days) and B. claussenii the slowest (21 days), K. marxianus and S. cerevisiae (Hornindal kveik) showed similar fermentation rates, finishing on day 20. The change in pH of the fermentate was similar for all five strains (from around 4.45 to between 4.25 and 4.31). Cell counts remained stable throughout the fermentation for all five strains (at around 6 log colony-forming units (CFU)/mL) except in the case of S. cerevisiae (Hornindal kveik), which ultimately decreased by 1.63 log CFU/mL. B. bruxellensis was the only strain unable to utilize all of the sugars in the substrate, with residual galactose remaining after fermentation. While both S. cerevisiae (IOCBF)- and B. claussenii-fermented samples were characterized by a fruity apple aroma, the former also had an aroma characteristic of lactic acid, dairy products, bakeries and yeast. A chemical odor characteristic of petroleum, gasoline or solvents, was perceived in samples fermented by B. bruxellensis and K. marxianus. An aroma of poorly aged or rancid cheese or milk also resulted from B. bruxellensis fermentation. In terms of appearance and mouthfeel, the S. cerevisiae (IOCBF)-fermented sample was rated the cloudiest, with the heaviest body. This study provides a toolkit for product development in a potential dairy-based category of fermented alcoholic beverages, which can increase revenue for the dairy industry by upcycling the common waste product YAW.

Impact of sustainability and nutritional messaging on Italian consumers' purchase intent of cereal bars made with brewery spent grains.

This work focuses on the reuse of brewery spent grains (BSGs), the most abundant by-product of the beer industry, today mainly used as animal feed. BSGs are rich in fibers and proteins as well as phenolic compounds, all of which are beneficial for human nutrition. Cereal bars containing 12% BSG were formulated and characterized instrumentally. Moreover, 159 panelists representative of young Italian consumers evaluated the bars in a central location test, along with a commercial cereal bar. Products were first evaluated blind, and then in an informed condition where additional product-specific nutritional and sustainability information was revealed, thus the purchase intent was determined. While the control product outperformed the BSG bar in most of the hedonic and sensory measures, the BSG sample was perceived as "natural/made with natural ingredients" by a significantly higher number of panelists (49%) compared to the control (30%). Additionally, even in the lower performing formulation, a significant positive effect on purchase intent was observed when providing either nutrition (fiber content) or sustainability (use of upcycled ingredients) information. The acceptable price range for the BSG and the commercial bar was very similar, whereas the optimal pricing point for the BSG was lower than the control. For the BSG product, sustainability information had significantly higher impact on purchase intent than nutrition-based information. Results highlight the importance of understanding consumer attitudes toward upcycling and the use of byproducts as ingredients in new food formulations. PRACTICAL APPLICATION: Results show how providing information on product nutrition and sustainability can increase purchase intent in the context of a cereal bar containing upcycled ingredients. The findings of this study can help food and consumer researchers to develop acceptable products that include BSG as an ingredient, potentially replacing other cereals in the recipe. The use of this brewery by-product could add value to the beer supply chain and to the final product as well, being also aligned with the current market trend of sustainability and functional health benefits.

Applying sorting algorithms to sensory ranking tests - A proof of concept study.

In a sensory or consumer setting, panelists are commonly asked to rank a set of stimuli, either by the panelist's liking of the samples, or by the samples' perceived intensity of a particular sensory note. Ranking is seen as a "simple" task for panelists, and thus is usually performed with minimal (or no) specific instructions given to panelists. Despite its common usage, seemingly little is known about the specific cognitive task that panelists are performing when ranking samples. It becomes quickly unruly to suggest a series of paired comparisons between samples, with 45 individual paired comparisons needed to rank 10 samples. Comparing a number of elements with regards to a scaled value is common in computer science, with a number of differing sorting algorithms used to sort arrays of numerical elements. We compared the efficacy of the most basic sorting algorithm, Bubble Sort (based on comparing each element to its neighbor, moving the higher to the right, and repeating), vs a more advanced algorithm, Merge Sort (based on dividing the array into sub arrays, sorting these sub arrays, and then combining), in a sensory ranking task of 6 ascending concentrations of sucrose (n = 73 panelists). Results confirm that as seen in computer science, a Merge Sort procedure performs better than Bubble Sort in sensory ranking tasks, although the perceived difficulty of the approach suggests panelists would benefit from a longer period of training. Lastly, through a series of video recorded one-on-one interviews, and an additional sensory ranking test (n = 78), it seems that most panelists natively follow a similar procedure to Bubble Sorting when asked to rank without instructions, with correspondingly inferior results to those that may be obtained if a Merge Sorting procedure was applied. Results suggests that ranking may be improved if panelists were given a simple set of instructions on the Merge Sorting procedure.

Bridging Sensory Evaluation and Consumer Research for Strategic Leafy Brassica (Brassica oleracea) Improvement.

Plant breeders working with new or underrepresented horticultural crops often have minimal sensory resources available to aid in the breeding and selection of new varieties. Kale (Brassica oleracea var. acephala) is a recently popularized horticultural crop in Western markets, however, plant breeding programs have little knowledge regarding the underlying sensory characteristics motivating this trend. We employed a multilayered, sensory-driven approach to understand the inherent consumer values, sensory attributes, and consumer preferences for kale types currently available on the market and novel genotypes from the Cornell AgriTech vegetable breeding program. Underlying consumer values related to storability, health and wellbeing, and sensory characteristics were identified through Qualitative Multivariate Analysis (QMA). A trained descriptive panel developed a lexicon of 44 sensory attributes common within kale germplasm, 21 of which exhibited significant differences among the 15 tested kale genotypes. Following a consumer test, four clusters of kale consumers were identified with agglomerative hierarchical clustering (AHC) and external preference mapping was used to connect consumer hedonic scores with descriptive data. Consumers demonstrated a preference for familiar kale types (that is, curly types), while new test hybrids scored favorably within flavor and appearance modalities. Preference mapping highlighted the utility of plant breeding in developing products to expand the existing sensory space. This work provides important resources for horticultural crop selection efforts, and it serves as a strategic model for breeding programs working with new or unfamiliar traits. PRACTICAL APPLICATION: Plant breeders are responsible for selecting and improving traits that influence consumer acceptance, including quality traits such as appearance and flavor. Understanding the relative importance of sensory characteristics and the variation of these sensory characteristics can help plant breeders prioritize these traits within their program. We have developed a standardized sensory lexicon for kale and related leafy Brassicas, identified variation for texture and flavor in our breeding program, and gained a better understanding of consumer preferences to guide future breeding efforts.

Dynamic Context Sensory Testing-A Proof of Concept Study Bringing Virtual Reality to the Sensory Booth.

Eating is a multimodal experience. When we eat, we perceive not just the taste and aroma of foods, but also their visual, auditory, and tactile properties, as well as sensory input from our surroundings. Foods are commonly tested within a sensory booth, designed specifically to limit such input. Foods are not commonly experienced in such isolation, but alongside this context, which can alter how a food is perceived. In this study, we show that the sensory properties of food can be altered by changing the environment it is consumed in, using virtual reality (VR) to provide an immersive, dynamic context to the eating experience. The purpose of this project was to develop an affordable and easy-to-implement methodology for adapting VR technology to sensory evaluation, without prohibitive amounts of expensive equipment or specialized programming knowledge. Virtual environments were formed by processing custom-recorded 360 degree videos and overlaying audio, text, sensory scales, and images to simulate a typical sensory evaluation ballot within the VR headset. In a pilot test, participants were asked to taste 3 identical blue cheese samples in 3 virtual contexts-a sensory booth, a park bench, and a cow barn. Respondents rated their liking of the sample, as well as its saltiness, and pungency, attributes either reflective of one context (pungency in the barn), or presumably unrelated (saltiness). Panelists duly rated the sample's flavor as being more pungent when consumed in the barn context. These results provide proof of concept for VR in applied sensory studies, providing an immersive context to a sensory test while remaining in place. PRACTICAL APPLICATION: We consume foods in environments that can "spill over" into our perceptions of the food. Thus, we consider some foods "unsuitable" for certain settings, with others deemed more suitable for this locale. This has been studied for many years as sensory "context," with written descriptions, pictures, or videos of such contexts. We present a method generating virtual reality contexts without any specist programming knowledge, for a few hundred dollars. In an accompanying pilot test, perception of a sample was significantly influenced by the VR context in which it was delivered.