Microgreens are welcome by US consumers!

Recently, the interest for microgreens is increasing in the United States. They are tiny versions of regular plants produced from the seeds of vegetables, herbs or grains, having two fully developed cotyledons with the first pair of true leaves emerging or partially expanded. Microgreens are usually harvested in 7–14 days after germination. Although small in size, microgreens can provide intense flavors, vivid colors, and crisp textures and can be served as an edible garnish or as a new salad ingredient. It was found that microgreens are generally packed with more phytonutrients (such as ascorbic acid, a-tocopherol, and b-carotene) than their mature plants, and are excellent sources of vitamins and carotenoids.

US scientists evaluated six species of microgreens, including Dijon mustard (Brassica juncea L. Czern.), opal basil (Ocimum basilicum L.), bull's blood beet (Beta vulgaris L.), red amaranth (Amaranthus tricolor L.), peppercress (Lepidium bonariense L.) and China rose radish (Raphanus sativus L.) for their sensory attributes and chemical compositions.

The main objectives of the study were to (1) assess sensory quality and consumer acceptance of selected microgreens; (2) correlate chemical compositions with sensory attributes of selected microgreens; and (3) evaluate the nutritional values of selected microgreens.

Full study is available online, since August 2015 at:
http://www.sciencedirect.com/science/article/pii/S0925521415300697

Results showed that the six microgreens varied in sensory quality characteristics and the consumer panel ranked bull's blood beet with the highest preference and the peppercress with the lowest acceptance.

Chemical compositions also differed significantly among the six species. China rose radish had the highest titratable acidity and total sugars (10.3 g/kg FW), while red amaranth had the highest pH value (6.43) and lowest total sugars (1.7 g/kg FW). Regarding the phytonutrient concentrations, the highest concentrations of total ascorbic acid (680 mg/kg FW), phylloquinone, carotenoids, tocopherols, and total phenolics (7 g/kg) 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. It was found that overall eating quality of microgreens was best correlated with flavor score and microgreen's pH value and total phenolic content were strongly correlated with flavor attributes, e.g., sourness, astringency, and bitterness.

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Scientists conclude among all the sensory quality attributes tested, the flavor quality attribute best predicted overall eating quality of microgreens, but noticeable visual and textural quality attributes also positively affected consumer acceptance. The pH and TPC (total phenolic content) values could be used by microgreen growers and food service uses (i.e., industry) as indicators of sensory information and predictors of consumer acceptability, providing industry the possibility of predicting the consumer acceptability and likeability for microgreens especially in ethnically unique food markets. In general, the six microgreens evaluated in this study have good consumer acceptability and nutritional value.

Source: Zhenlei Xiao, Gene E. Lester, Eunhee Park, Robert A. Saftner, Yaguang Luo, Qin Wang, 'Evaluation and correlation of sensory attributes and chemical compositions of emerging fresh produce: Microgreens', December 2015, Postharvest Biology and Technology, Vol. 110, pages 140–148
mailto:gene.lester@ars.usda.gov?subject=Microgreens article on FreshPlaza
Contacts:
Gene E. Lester
Food Quality Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA
10300 Baltimore Avenue, Beltsville, MD 20705
United States
Email: gene.lester@ars.usda.gov