FOOD SCIENCE AND HUMAN NUTRITION
COLLEGE OF HEALTH AND HUMAN SCIENCES
SPROUTS VS. MICROGREENSHOW DO THE RISKS COMPARE?
MARISA BUNNING, PHD
ASSOCIATE PROFESSOR AND EXTENSION SPECIALIST
FOOD SCIENCE AND HUMAN NUTRITION
GOOGLE TRENDS Interest by state
Interest over time
Feb 2019
https://trends.google.com/trends/explore?date=all&geo=US&q=microgreens
CO = #6
FOOD SCIENCE AND HUMAN NUTRITION
The Foundry Dining Facility, CSU Sensory Lab, CSU
FOOD SCIENCE AND HUMAN NUTRITION
LEAFY GREENS & HEALTH: NUTRITION
EAT MORE GREENSLow in CaloriesVitamins A, B6, C, KContain Phytochemicals, Fiber
In general, microgreens contain greater amounts of nutrients and health-promoting micronutrients than their mature counterparts
Choe et al. 2018
FOOD SCIENCE AND HUMAN NUTRITION
LEAFY GREENS & HEALTH:FOOD SAFETY
Commodity Related Outbreaks1998-2008/10
Produce: 45.9%Leafy greens: 22.3%Fruits-nuts: 11.7%Roots: 3.6%Vine-stalk: 12.0%Sprouts: 0.3%
Painter et al. 2013
FOOD SCIENCE AND HUMAN NUTRITION
The high estimate for illnesses attributable to leafy vegetables was many times higher than the low estimate which indicates that leafy vegetables were frequently found in complex foods.
Photo: PBS Food
Painter et al. 2013
LEAFY GREENS & HEALTH:FOOD SAFETY
FOOD SCIENCE AND HUMAN NUTRITION
Sprouts Microgreens Baby Greens Mature (Mesclun) Leafy Greens
1-8 days 7-21 days 21-28 days 28-60 days1-3” long ~2” tall 3-4”
Outbreaks, 1998-2017 (NORS)
57 0 10 350+
FOOD SCIENCE AND HUMAN NUTRITION
PRODUCTION & CONSUMPTION CHARACTERISTICS
Grown in warm, moist environment
Large Surface
Area
High Moisture Content
GenerallyHand
Harvested
Seeds/roots Remain Attached
Cut Surface
from Harvesting
Generally Consumed
Raw
Sprouts
Microgreens
Leafy Greens
Shaded area = food safety challenge
FOOD SCIENCE AND HUMAN NUTRITION
SPROUTS & MICROGREENS ARE DISTINGUISHED BY STAGE OF LEAVES
Sprouts • Harvested when the cotyledons (or seed leaves)
are still un- or under-developed and true leaves have not begun to emerge
• Consumed as entire plant (root, seed, and shoot)
Microgreens• Reach a later stage of growth before harvest, typically
associated with the emergence of ‘true’ leaves• Stem, cotyledons (seed leaves) and first true leaves
are consumed www.agintheclass.org
FOOD SCIENCE AND HUMAN NUTRITION
MONOCOTS VS. DICOTS
Image: http://biologyclermont.info/wwwroot/courses
WheatBarleyPopcorn
Alfalfa ParsleyAmaranth PeasArugula RadishBasil SpinachBean SunflowerBroccoliCarrotsCloverKaleLentilsLettuce: too delicateMustardMung beanMustards
FOOD SCIENCE AND HUMAN NUTRITION
SPROUTS
FOOD SCIENCE AND HUMAN NUTRITION
Photo Credit: UF/IFAS
MICROGREENS
FOOD SCIENCE AND HUMAN NUTRITION
PRODUCTION• Sprouts – water
• Microgreens
Soil – recommendation to sterilize, 180 degrees for 30 minutes
Soil-less mediaCoconut coir: middle fibrous coat Burlap + fertilizerHemp matsFelt-like textilesVermiculite – mineralPerlite, volcanic glassRockwool
Similarities: warm, moist, environment, nutrient-rich media
The limited amount of data available suggests that microgreens may very well be of lower risk than sprouts…but the background level of bacteria is higher than that of conventional vegetables.
Riggio et al. 2019
FOOD SCIENCE AND HUMAN NUTRITION
MONOCOTS: WHEATGRASS
Harvest 2017, Pines International
FOOD SCIENCE AND HUMAN NUTRITION
HARVESTING
HARVEST TOOLS: KNIVES, SCISSORS, SHEARSWASHING METHODS & EQUIPMENT: SALAD SPINNERSDRYING BEFORE PACKAGING
TRAYS MAY BE DELIVERED DIRECTLY TO RETAIL OR CONSUMER TO HARVEST
FOOD SCIENCE AND HUMAN NUTRITION
HARVESTING EQUIPMENT
Immature greens
Microgreens
FOOD SCIENCE AND HUMAN NUTRITION
KNIFE CUTTING
https://www.youtube.com/watch?v=5WTEVn9pnfo
FOOD SCIENCE AND HUMAN NUTRITION
PHOTOS
FOOD SCIENCE AND HUMAN NUTRITION
Rhizosphere: region near plant roots influenced by their growth, respiration and nutrient exchange
HOST PATHOGEN DYNAMICS
Contaminated seeds appear to be the source of most sprout-associated foodborne illnesses… Reed et al. 2018
FOOD SCIENCE AND HUMAN NUTRITION
RESEARCH
Alfalfa
Broccoli
Radish
Fransisca and Feng, 2012
FOOD SCIENCE AND HUMAN NUTRITION
RESEARCH FINDINGS
Plant-Microbe and Abiotic Factors Influencing Salmonella Survival and Growth on Alfalfa Sprouts and Swiss Chard Microgreens
Reed et al. 2018, CFSAN, Applied and Environmental Microbiology
An increase in the frequency of irrigation water exchange will not reduce the levels of Salmonella, and a decreased irrigation frequency will increase the Salmonella population.
FOOD SCIENCE AND HUMAN NUTRITION
REGULATION – FOOD SAFETY MODERNIZATION ACT
Subpart M• Applies to the production of all types of sprouts, including alfalfa, clover and mung
bean sprouts, except soil grown sprouts harvested without roots
• FDA distinguishes between sprouts and microgreens by the stage of the leaves:
– Sprouts = cotyledons are still un- or under-developed; true leaves have not emerged
– Microgreens = harvested after emergence of ‘true leaves’
• For microgreens that are grown using conditions similar to those of sprouts (i.e. warm, moist, and nutrient-rich media), FDA encourages growers consider voluntarily implementing the standards in subpart M, in addition to complying with required provisions of part 112.
FDA; Produce Safety Alliance
FOOD SCIENCE AND HUMAN NUTRITION
RESOURCES
Sprout Safety Alliance, Illinois Institute of Technology, https://www.ifsh.iit.edu/ssa
ReferencesChoe, U., Yu, L., Wang, T. The Science behind Microgreens as an Exciting New Food for the 21st Century. 2018. Journal of Agricultural
and Food Chemistry. 66:11519-11530.Fransisca, L. and Feng, H. Effects of Surface Roughness on Inactivation of E. coli O147:H7 87-23 by New Organic Acid-Surfactant
Combinations on Alfalfa, Broccoli, and Radish Seeds. J. of Food Protection. 75(2): 261-269.Kim, W., Ryu, S, Kim, S., Kim, H., Lee, S. 2018. Population changes and growth modeling of Salmonella enterica during alfalfa seed
germination and early sprout development. Food Sci. Biotechnol. 27(6): 1865-1869.National Outbreak Reporting System (NORS). 2019. Centers for Disease Control and Prevention. Available from:
https://www.cdc.gov/nors/data/dashboard/index.htmlPainter, J. et al. 2013. Attribution of Foodborne Illnesses, Hospitalizations, and Deaths to Food Commodities by using Outbreak
Data, United States, 1998-2008. Emerg Infect Dis.19(3): 407-415.Riggio, G., Wang, Q., Kniel, K., & Gibson, K. (2018). Microgreens—A review of food safety considerations along the farm to fork
continuum. International Journal of Food Microbiology, 290: 76-85.Treadwell, D., Hochmuth, R., Landrum, L., & Laughlin, W. (2010). Microgreens: A new specialty crop. University of Florida IFAS
Extension HS1164.Wright, K., Holden, N. 2018. Quantification and colonization dynamics of Escherichia coli O157:H7 inoculation of microgreens
species and plant growth substrates. International Journal of Food Microbiology. 273: 1-10.
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