|XIO, ZHENLEI - University Of Maryland|
|SAFTNER, ROBERT - Retired ARS Employee|
|Luo, Yaguang - Sunny|
|WANG, QIN - University Of Maryland|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2015
Publication Date: 8/3/2015
Citation: Xio, Z., Lester, G.E., Park, E., Saftner, R.A., Luo, Y., Wang, Q. 2015. Evaluation and correlation of sensory attributes and chemical compositions of emerging fresh produce: Microgreens. Journal of Agricultural and Food Chemistry. 110:140-148.
Interpretive Summary: Microgreens are popular and highly nutritious vegetable seedlings harvested at the ‘seed-leaf’ or cotyledon stage of maturity. Although many microgreens are considered highly flavorful their sensory attributes (flavor and taste profiles) have not been determined nor have their sensory profiles been related to their chemical compositions. We selected six microgreens varieties which differ in color, visual appearance, flavor, and taste, and correlated this sensory profile with their chemical and nutritional composition. All microgreens tested have “good” to “excellent” overall eating quality rated by consumer panelists, and each variety possess unique flavor and taste, e.g. astringency and bitterness (peppercress), heat (Dijon mustard), grassy (opal basil), sweetness (red amaranth and bull’s blood beet). This information will benefit microgreen growers by providing scientific information for consumers and chefs to select the right microgreens for their intended food pairing purposes, and market their products to the targeted customers, thus sustaining growth of the microgreen industry.
Technical Abstract: Microgreens are an emerging healthy food product with vivid colors and diverse flavors. However, information pertaining to their sensory attributes is scarce. In this study, six microgreen varieties were specifically selected from 25 varieties to represent five distinct flavor groups: 1) mustard (Dijon mustard, Brassica juncea L. Czern.); 2) herbal (opal basil, Ocimum basilicum L.); 3) veggie (bull’s blood beet, Beta vulgaris L.); 4) mild flavor (red amaranth, Amaranthus tricolor L.), and 5) peppery/radish (peppercress, Lepidium bonariense L. and China rose radish, Raphanus sativus L.) by a preliminary in-house panel. Sensory attributes of the six selected varieties of microgreens were further investigated and correlated with their chemical composition and nutritional values. A consumer acceptance test was carried out by 80 non-trained consumer panelists representing a range in age, gender and ethnicity. Bull’s blood beet was rated highest in acceptability of appearance, texture, flavor and overall eating quality. In contrast, peppercress was rated lowest in acceptability of flavor and overall eating quality but highest in a peppery/radish flavor. Chemical compositions and nutritional values also differed among the six varieties. China rose radish had the highest titratable acidity and total sugars, while red amaranth had the highest pH value and lowest total sugars. The highest amounts of total ascorbic acid, phylloquinone, carotenoids, tocopherols and total phenolics were found in China rose radish, opal basil, red amaranth, China rose radish and opal basil, respectively. The relationships between sensory-sensory attributes and sensory-chemical compositions were further studied. In general, overall eating quality of an individual microgreen was best correlated with flavor scores. The microgreen’s pH values and total phenolic contents were strongly correlated with flavor-related sensory attributes (such as sourness, astringency, bitterness which, if too intense, negatively affected overall eating quality and would limit the use of the micrgreens to specific food parings such as spicy or strongly flavored ethnic foods. Despite the differences amongst individual microgreens, all of the microgreens evaluated demonstrated “good” to “excellent” consumer acceptance and nutritional quality.