Antioxidant properties and sensory evaluation of microgreens from commercial and local farms

Microgreens are young and tender vegetables or herbs that provide attractive color,flavor,and nutrition.The purpose of this study was to evaluate the nutritional and sensory qualities of broccoli microgreens grown by different methods(hydroponically vs.soil grown)and from different sources(commercial vs.local farm).No significant difference in total phenolic concentration and antioxidant capacity was found in all broccoli microgreens,but a significantly higher chlorophyll concentration was found in farm microgreens than the commercial ones.Moreover,the soil-grown farm microgreens possessed a significantly higher vitamin C concentration than hydroponically-grown farm sample and commercial sample.Participants in the sensory study favored farm samples regardless of growing method,and their overall liking was significantly correlated with taste of the microgreens.In addition,six other microgreens from the local farm were analyzed for their nutritional quality.These conclusions suggested a potential for consumers to still benefit nutritionally by purchasing commercial microgreens at a lower cost;however,it may be worthwhile for consumers to purchase microgreens from local farms for a better sensory experience.

Effect of combined light-emitting diodeson the accumulation of glucosinolates in Brassica microgreens

As of recent,microgreen vegetable production in controlled environments are being investigated for their bioactive properties.Phytochemicals like glucosinolates(GLS)are highly sensitive to varying spectral qualities of light,especially in leafy greens of Brassica where the responses are highly species-dependent.The accumulation of bioactive GLS were studied under 8 different treatments of combined amber(590 nm),blue(455 nm),and red(655 nm)light-emitting diodes(rbaLED).A semi-targeted metabolomics approach was carried out to profile common intact-GLS in microgreen extracts of Brassica by means of LC-HRMS/MS.Thirteen GLS were identified,among them were 8 aliphatic,4 indolic and 1 aromatic GLS.Mass spectrometry data showed sinigrin had the highest average concentration and was highest in B.juncea,progoitrin was highest in B.rapa and glucobrassicin in R.sativus.The individual and total GLS in the microgreens of the present study were largely different under rbaLED;B.rapa microgreens contained the highest profile of total GLS,followed by R.sativus and B.juncea.Sinigrin was increased and gluconasturtiin was decreased under rbaLED lighting in most microgreens,glucoalyssin uniquely increased in R.sativus and decreased in B.rapa and glucobrassicin uniquely decreased in both B.rapa and B.juncea.The present study showed that rbaLED contributed to the altered profiles of GLS resulting in their significant modulation.Optimizing the light spectrum for improved GLS biosynthesis could lead to production of microgreens with targeted health-promoting properties.

Nutritional quality and health benefits of microgreens,a crop of modern agriculture

Microgreens are young,tender greens that are used to enhance the color,texture,or flavor of salads and main dishes.They can be grown in small scales and indoors,making them widely adopted by controlled environment agriculture,an indoor farming practice is particularly important for feeding increasing urban populations.Besides,microgreens are attracting more consumers’attention due to their high nutritional value and unique sensory characteristics.This review focuses on the nutrition quality,sensory evaluation,pre-and post-harvest interventions,and health benefits of microgreens.Microgreens are rich in vitamins(e.g.,VC),minerals(e.g.,copper and zinc),and phytochemicals,including carotenoids and phenolic compounds,which act as antioxidants in human body.Pre-harvest interventions,such as illumination,salinity stress,nutrient fortification,and natural substrates,infl uence the photosynthetic and metabolic activities of microgreens and were shown to improve their nutritional quality,while the effects varied among species.After harvesting,packaging method and storage temperature can infl uence the nutrient retention in microgreens.Both in vitro and in vivo studies have shown that microgreens have anti-infl ammatory,anti-cancer,anti-bacterial,and anti-hyperglycemia properties,making it a new functional food beneficial to human health.The sensory attributes and overall acceptability and liking of microgreens are primarily infl uenced by their phytochemical content.Microgreens are only getting popular during the last decades and research on microgreens is still at its early stage.More studies are warranted to optimize the pre-and post-harvest practices for nutrient enhancement and retention and to explore the potential health benefits of different microgreens for the prevention and treatment of chronic diseases.

Advancement in Indoor Vertical Farming for Microgreen Production

With the growing global urban population and the emergence of megacities, there is a huge demand for arable land to meet the food demand and reduce malnutrition. Conventional agricultural practices lead to deforestation of the land for crop production and agricultural intensification to produce higher yield per unit area. These activities have been established to have negative impact on the environment thereby causing soil and water pollution. It is important to consider the use of vertical farming technology, which utilizes both horizontal and vertical space, and efficiently uses nutrients, water, and time (off season production with artificial lighting) more effectively to produce higher yield per unit volume of space than the conventional outdoor farming. Microgreens are taken into consideration to be grown under innovative vertical farming technology since they are rich in phytonutrients and they can be harvested in a short period of time. This paper reviews the current growing conditions of microgreens in vertical farming such as crop selection, media, light, nutrient solution, and containers while identifying knowledge gaps. Further, study in this area may lead to improved growing conditions to help solve the global issues and challenges surrounding food security, safety, and resource optimization.

Production and Financial Analyses of the Rotating Living Wall, an Urban Agricultural System

Experiments were performed from June 2014 to May 2015 at Penn State University’s greenhouse facilities in order to understand the production capacities and financial viability of an innovative growing system referred to as the Rotating Living Wall produced by GreenTowers, a student innovation/entrepreneurship team. The system is a six-foot vertical conveyor that rotates troughs of microgreen plants to achieve even distribution of sunlight as well as relatively low maintenance within a minimal square foot area. Experiments were performed to understand differences in seasonal yields, differences in yields based on variety of microgreen, yield comparison to a traditionally grown microgreen control group;both on a yields per/trough method as well as a yields per/ft.2 method, rotational timing, moving versus stationary growth, differences in growth based on media depth, and differences in production yields from supplemental lighting. Performance criteria were based on measuring fresh weight, dry weight, height, and SPAD-meter readings (soil plant analysis development). Differences in yields throughout seasons were significant as well as differences between the Rotating Living Wall systems compared to a control group of traditional static greenhouse benches. The use of LED supplemental lighting provided significant differences in yields throughout winter season growing. Rotational timing, media depth, and physical movement of plants showed minimal or no significant influence on yields. By establishing the potential revenues and costs that were part of growing with the Rotating Living Wall system, financial viability was analyzed showing that these systems could be profitable when utilized in State College, PA, within certain operating parameters. The research completed throughout these studies has not only provided a baseline of operation for the systems but has also shown potential for the development of urban agricultural systems capable of aiding in the elimination of “food deserts” or urban neighborhoods and rural towns with limited food access.