LEXICON TO DESCRIBE FLAVOR OF FRESH LEAFY VEGETABLES

Sensory descriptors for three edible Chilean seaweeds and their relations to umami components and instrumental texture

Although seaweeds exhibit many benefits as a food source, few studies have characterized their sensory attributes. An expert nine-member panel developed a vocabulary with 25 descriptors to describe the appearance, aroma, flavor, texture, and aftertaste of raw and cooked seaweeds consumed in Chile: Durvillaea antarctica, Pyropia spp., and Ulva lactuca. Subsequently, the vocabulary was used in a ranking descriptive analysis (RDA) to evaluate the sensory properties and relate them with physicochemical and physical data. Sensory attributes of the three seaweeds were very different from each other but similar between treatments (raw and cooked). Pyropia spp., both cooked and hydrated, had the highest glutamate content (310 and 324 mg (100 g) ^-1 d.w., respectively), and was perceived by the sensory panel as having the most umami taste. Cooked D. antarctica was perceived as sweeter, had more caramel notes than the hydrated seaweed and was sensed as cartilaginous and hard in accordance with its mechanical properties. Generalized Procrustes analysis revealed that D. antarctica exhibited most of the desirable descriptors, such as caramel, umami and marine aromas while U. lactuca was described as bitter and moldy. This primary vocabulary can assist food scientists and chefs in the development of seaweed products and dishes for the consumer market.

Identification of sensory properties driving consumers' liking of commercially available kale and arugula

BACKGROUND

Kale and arugula are leafy green vegetables whose sensory properties have not been extensively explored. The objective was to assess the sensory properties and consumer acceptability of commercially available kale and arugula while also discovering drivers of consumer liking and barriers to consumer acceptance. Descriptive analysis and consumer testing were completed. The trained panellists (n = 11) were trained for 15 h to evaluate 11 sensory properties relating to the aroma, taste and texture of the kale and arugula. The consumer testing (n = 108) evaluated the leafy greens for overall liking and their liking of taste, aroma, texture and appearance.

RESULTS

Results were analyzed using ANOVA, Tukey's HSD and external preference mapping. Approximately half of the attributes for the kale samples were found to be significantly different. Similarly, significant differences in sensory properties were found in most of the arugula samples. Consumers liked the kale and arugula varieties that were sweet and nutty. Also, they preferred arugula that was described as spicy.

CONCLUSION

The majority of consumers preferred sweet and nutty leafy greens. Organic growing methods did not affect consumer liking; however, organic labels do positively affect hedonic ratings of a consumer's overall liking of the product. This study also identified that 'Baby' leafy greens are well liked by consumers, and this area of produce should be expanded. © 2021 Society of Chemical Industry.

How do trained panelists characterize baby leafy greens? A comparison of descriptive analysis and Napping

Baby leafy greens are one of the fastest growing segments of the salad green market. Baby leafy greens are generally more mild tasting than their fully-mature counterparts. Nevertheless, a diversity of plant species can be grown as baby greens, which exhibit a wide range of sensory attributes. Sensory profiles of baby leaf varieties have not been well described in the literature. This study aimed to describe the differences between several baby leafy green varieties from the plant family Brassicaceae and those which were non-Brassicaceae, and to compare two descriptive methods, traditional descriptive analysis (DA) and Napping, a rapid profiling technique. Both methods used the same trained panelists. In the first study, the panel (n = 11) developed a lexicon for and evaluated four samples grown in a controlled aeroponic environment. In the second study, 12 commercially available samples were evaluated with DA (n = 8) and Napping (n = 11). Panelists identified differences in the pungency, bitterness, and ''green'' attributes across all samples. Principal component analysis (PCA) was used to model associations between the samples and the sensory attributes. The PCA extracted three factors. PC1 ranged from pungent qualities to sweet/grassy, PC2 included green color, and PC3 included saltiness and sourness. The Napping showed similar sample separation (RV = 0.67), but included relevant textural terms (''chewy''; ''rubbery'') not used in the DA. The current lexicon can be applied to a large range of baby leafy greens. Napping showed good correspondence with DA and can be deployed with agricultural products where time and other resources may be limited. PRACTICAL APPLICATION: Sensory evaluation methods have traditionally been applied in the food industry with processed products.While traditional methods such as descriptive analysis have been used to profile products, rapid and inexpensive profiling methods should be screened for their value in describing agricultural products. The results of this study can be applied to breeding and grow-out programs to aid in optimization of the processing,storage, and quality control for the rapidly expanding baby leafy green market.

Effect of Light Characteristics on the Sensory Properties of Red Lettuce (Lactuca sativa)

Leafy green production in high tunnels (HTs) results in increased yields, improved visual quality, and extended production with polyethylene (poly) film and/or shade cloth coverings. However, altering visible and ultra-violet light with HT coverings may reduce phytochemicals, thus influencing plant pigmentation and taste. The objective of this study was to examine various HT coverings on the sensory perceptions, soil temperature, color, and anthocyanin accumulation of red leaf lettuce. The coverings included standard poly, standard poly with removal two weeks prior to harvest (movable), diffuse poly, clear poly, UV-A/B blocking poly (block), standard poly with 55% shade cloth, and the open field. A highly trained descriptive panel evaluated the samples using a scale from 0 (none) to 15 (extremely high) and determined a list of 20 sensory attributes. The color intensity attribute had the most differentiation between coverings, and the open field was higher (i.e., darker) than the others at 7.5 (p < 0.0001), followed by clear and movable coverings at 6.8, and the shade covering scored a 2. Strong relationships existed between both colorimetric (hue°) and anthocyanin analysis to panelist-based scores (R² = 0.847 and 0.640, respectively). The initial crispness was similar for movable, standard, diffuse, and block coverings at 5.3 on average, which was higher than the open field at 4 (p < 0.01). The open field lettuce grew under cooler soil temperatures, which may have slowed down maturation and resulted in softer tissue. Based on this study, HT growers can implement specific coverings to cater to markets that value visual quality.

Descriptive aroma profiles of fresh sweet basil cultivars (Ocimum spp.): Relationship to volatile chemical composition

Few studies have linked sensory descriptions of the aroma profiles of fresh, sweet basil varieties with their volatile chemistry. Using a recently developed lexicon for fresh basil, a descriptive panel characterized the aroma profiles of seven basil varieties. Chemical analysis of fresh basil leaves was performed using GC-MS headspace analysis. Analysis of variance probed for differences in the sensory attributes among varieties and principal component analysis (PCA) related the sensory profiles to volatile chemical composition. Three commercial specialty basils, "Queenette Thai" (QT), "Sweet-Dani" (SD) lemon basil, and MC-9 (cinnamon basil) had strong anise, lemon, and cinnamon-like aromas, respectively. These basils were distinguished from breeding lines of traditional Italian sweet basils where SB-22, CB-1, and CB-39 exhibited strong anise-like aroma and SB-17 had strong "general spice" aromas, characteristic of a warm spice blend. The PCA accounted for 58.7% of the variation in the data and characterized the samples in two dimensions: general spice-citrus and cinnamon-like-anise. There was a strong correspondence between the sensory attributes and volatile chemical composition. SD associated with lemon aroma and citral content; QT, CB-1, and CB-39 associated with anise aroma and methyl chavicol; and MC-9 associated with the cinnamon-like aroma, methyl cinnamate. SB-17 and SB-22 associated with general spice aroma and were in close proximity to the spice-like volatiles, 1,8 cineole, and eugenol, associated with clove aroma. We constructed precise sensory/chemical profiles for fresh basil aroma that can be used to guide breeding programs for variety improvement to meet consumer expectations or market demand. PRACTICAL APPLICATION: Sweet basil aroma is due to a complex array of several aromatic volatile compounds. The presence, concentration, and the particular ratios in which these aroma compounds accumulate significantly impact the sensory attributes. Understanding aroma profiles for fresh basil have practical applications in product development, procurement, food preparation, ethnic cuisine, and processing. Plant genetics and breeding of aroma profiles can be used and incorporated in plant improvement programs.

Dissection of the domestication-shaped genetic architecture of lettuce primary metabolism

Lettuce (Lactuca sativa L.) is an important vegetable crop species worldwide. The primary metabolism of this species is essential for its growth, development and reproduction as well as providing a considerable direct source of energy and nutrition for humans. Here, through investigating 77 primary metabolites in 189 accessions including all major horticultural types and wild lettuce L. serriola we showed that the metabolites in L. serriola were different from those in cultivated lettuce. The findings were consistent with the demographic model of lettuce and supported a single domestication event for this species. Selection signals among these metabolic traits were detected. Specifically, galactinol, malate, quinate and threonate were significantly affected by the domestication process and cultivar differentiation of lettuce. Galactinol and raffinose might have been selected during stem lettuce cultivation as an adaption to the local environments in China. Furthermore, we identified 154 loci significantly associated with the level of 51 primary metabolites. Three genes (LG8749721, LG8763094 and LG5482522) responsible for the levels of galactinol, raffinose, quinate and chlorogenic acid were further dissected, which may have been the target of domestication and/or affected by local adaptation. Additionally, our findings strongly suggest that human selection resulted in reduced quinate and chlorogenic acid levels in cultivated lettuce. Our study thus provides beneficial genetic resources for lettuce quality improvement and sheds light on the domestication and evolution of this important leafy green.

How a Spanish Group of Millennial Generation Perceives the Commercial Novel Smoothies?

The World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO) constantly emphasize the importance of increasing fruit and vegetable consumption; these natural products help in the prevention of major diseases. Smoothies are a simple and convenient way of doing so; thus, their demand is constantly growing and their market is becoming important for the food industry. Therefore, the objective of this research was to determine Millennial consumer opinion towards novel fruit- and vegetable-smoothies available on the retail market. Napping^®, descriptive sensory analysis, and consumer studies were conducted. Napping^® results group samples into four clusters of smoothies; the main grouping factor was the type of fruit and the percentage of vegetables. Penalty analysis showed that smoothies need improvement mainly dealing with sweetness, bitterness, and vegetable flavors. Millennial consumers formed a homogeneous sensory group in which the overall liking was negatively correlated with the level of sweetness, and earthy, carrot, beetroot, and pear flavors. The key liking drivers were sourness and notes of mango, banana, and peach flavors. This research is a new insight into the perception of smoothies, provides comprehensive knowledge for the food industry, and can guide the design of new healthy smoothies.

Development of a Sensory Flavor Lexicon for Mushrooms and Subsequent Characterization of Fresh and Dried Mushrooms

Mushrooms are a nutritious versatile ingredient in many food products. They are low in calories and have various potential medicinal properties as well. Surprisingly, little research on their descriptive sensory properties has been conducted. The objectives of this study were to a) establish a descriptive sensory flavor lexicon for the evaluation of fresh, dried, and powdered mushrooms and 2) use that lexicon to compare a selection of different mushrooms of various species and in fresh dried and powdered forms. A lexicon for describing mushroom was developed using a consensus profile method. A highly trained, descriptive sensory panel identified, defined, and referenced 27 flavor attributes for commercially available mushroom samples prepared as “meat” and broth. Attributes could be grouped in categories such as musty (dusty/papery, earthy/humus, earthy/damp, earthy/potato, fermented, leather (new), leather (old), mold/cheesy, moldy/damp, mushroomy), and other attributes such as fishy, shell fish, woody, nutty, brown, green, cardboard, burnt/ashy, potato, umami, protein (vegetable), yeasty, bitter, salty, sweet aromatics, sour, and astringent. Samples were then tested in three replications and mean values were compared statistically. In addition, principal component analysis was used to understand the characteristics of mushrooms evaluated. Dried mushrooms showed bitter, burnt, musty/dusty, astringent, old leather, and fresh mushroom characteristics and fresh mushroom showed umami, sweet, earthy/potato, earthy/damp, yeasty, and fermented. Mushrooms were grouped and differentiated in similar ways regardless of whether they were tested as broth or “meat”. Mushroom growers, product developers, chefs and other culinary professionals, sensory scientists, researchers, the food industry, and ultimately consumers will benefit from this lexicon describing a wide variety of mushroom flavor properties.

Discrimination of white teas produced from fresh leaves with different maturity by near-infrared spectroscopy

White tea is a special tea product with increasing market demand. The assessment of white tea quality is mainly based on panel sensory by sensory evaluation experts, which is time costly and is limited by many uncertainties. This study established a rapid and accurate method for classification of white teas produced from buds and young leaves and that produced from mature leaves and shoots using near-infrared spectroscopy (NIR). Back propagation neural network modelling and support vector machine (SVM) modelling were compared with six pre-processing methods. The best performance was provided by SVM with particle swarm optimization combined with Savitzky-Golay filter pre-processing method, achieving the accuracy of 98.92% in test samples. The NIR-related chemical compounds of two categories of white teas produced from fresh leaves with different maturity were analyzed, including catechins, alkaloids, amino acids and flavonol glycosides. Compared with chemical component concentration, NIR absorbance had a distinct advantage in quick classification of white teas based on the principal components analysis. In addition, the sensory characteristics of two categories white teas produced from fresh leaves with different maturity were also assessed by panelist. The result showed that characteristics of "umami-like" and "smooth" were more likely present in white teas produced from buds and young leaves, while "woody" and "coarse" characteristics were usually present in white teas produced from mature leaves and shoots. Thus, NIR technique is a rapid and reliable method for discrimination of white teas produced from fresh leaves with different maturity, and is a potential method to discriminate sensory characteristics of white teas.

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.

Descriptive Analysis and Consumer Acceptability of Locally and Commercially Grown Spinach

The consumer demand for locally grown fresh produce is continuously increasing in the United States. The high tunnel systems have been successfully utilized by small acreage growers for local production. Consumers are typically assessing appearance, freshness, flavor and aroma when purchasing produce. A common perception is that locally grown produce tastes better than nonlocal. However, there is not much evidence for supporting this claim. The objective of this study was to identify consumer acceptability and the sensory characteristics/differences of locally grown spinach in open field or in high tunnel and nonlocal commercially grown spinach. Spinach, Spinacia oleracea cv. "Corvair" was grown in open field and in high tunnel at Kansas State Univ. Olathe Horticulture Research and Extension Center (OHREC) in spring 2017 and the commercially grown spinach was purchased at a local retail store. A consumer study (n = 205) was conducted at Kansas State Univ., Olathe campus, and a descriptive sensory analysis was conducted by a highly trained descriptive analysis panel in the Center for Sensory Analysis and Consumer Behavior at Kansas State Univ., Manhattan campus, in spring 2017. The consumer test showed that high tunnel spinach scored significantly higher in overall liking (P < 0.0001), flavor liking (P < 0.0001), and texture liking (P < 0.05) when compared to open field and store purchased spinach. Descriptive analysis showed that locally grown spinach had higher intensity of attributes that indicate premium quality, such as green color and green/spinach flavors. Our results indicate that locally grown spinach was preferred from the consumers for its high organoleptic quality. PRACTICAL APPLICATION: Locally grown spinach demonstrated high intensity in a set of sensory attributes that suggest a product with premium organoleptic quality. Correspondingly to these results, consumers liked spinach produced locally in high tunnels the most. The results of this study can be used for developing marketing strategies that are aiming specifically to the consumer niche that is seeking fresh produce of high organoleptic quality.

Relating sensory profiles of canned amaranth (Amaranthus cruentus), cleome (Cleome gynandra), cowpea (Vigna unguiculata) and Swiss chard (Beta vulgaris) leaves to consumer acceptance

BACKGROUND

The younger generation of South Africans generally do not consume traditional meals prepared using African green leafy vegetables, primarily because they are regarded as bitter, "poverty" foods. Canning of these vegetables could create value-added products that can be sold in the commercial market. Descriptive sensory evaluation and consumer acceptance testing with young females were used to assess the potential of such products.

RESULTS

The sensory attributes of amaranth, cleome and cowpea leaves canned in brine and in a cream sauce were described using 21 attributes grouped by aroma, taste, texture/mouthfeel and aftertaste. Amaranth and Swiss chard products were described as sweet with a popcorn-like aroma. Cleome products were described as bitter, sour, pungent, chemical-tasting, astringent, sandy with a metallic mouthfeel and strong aftertaste. Cowpea products were described as having woody and tobacco aromas as well as a chewy and cohesive texture. Among the products canned with a cream sauce, young female consumers preferred amaranth and Swiss chard; cowpea was less liked, while cleome was least liked.

CONCLUSIONS

Canned amaranth leaves have potential as a commercial product that may be well liked by young consumers. The cowpea leaves product has consumer potential, but the formulation needs revision, while canned cleome leaves need further research work. © 2017 Society of Chemical Industry.

Associations of volatile compounds with sensory aroma and flavor: the complex nature of flavor

Attempts to relate sensory analysis data to specific chemicals such as volatile compounds have been frequent. Often these associations are difficult to interpret or are weak in nature. Although some difficulties may relate to the methods used, the difficulties also result from the complex nature of flavor. For example, there are multiple volatiles responsible for a flavor sensation, combinations of volatiles yield different flavors than those expected from individual compounds, and the differences in perception of volatiles in different matrices. This review identifies some of the reasons sensory analysis and instrumental measurements result in poor associations and suggests issues that need to be addressed in future research for better understanding of the relationships of flavor/aroma phenomena and chemical composition.

Sensory properties and consumer acceptance of sweet tamarind varieties grown in Thailand

BACKGROUND

Sweet tamarind is a major edible fruit and flavoring ingredient particularly in south-east and southern Asia. Little research has focused on the fruit and almost nothing is known of its particular sensory properties. The aims of this research were to develop a lexicon for describing sweet tamarind, to compare varieties grown in Thailand, determine if orchard impacts sensory properties, and determine consumer acceptance of the varieties.

RESULTS

A descriptive sensory lexicon of 25 terms was developed and six varieties were grouped into three clusters based on their sensory properties. The clusters appear to represent varieties that differ in their dark fruity notes and firm, fibrous texture. Generally, the orchard in which the plants were grown had little effect on sensory properties. In general, Sithong was liked by consumers along with Kunthee and Pragaithong. Intapalum was liked less but one small segment of consumers disliked Sithong and liked the Intapalum variety more.

CONCLUSIONS

This research provides a foundation for further sensory and consumer research on sweet tamarind varieties by providing the initial data on the sensory properties of sweet tamarind, a lexicon that can be used for future research, and information on the consumer acceptance of tamarind varieties.