Final Examination for the Degree of MSc Food Science - YIBO XIN
Date and Time
Dr. Massimo Marcone, Chair
Dr. Loong-Tak Lim, Advisor
Dr. Youbin Zheng, Advisory Committee Member
Dr. Donald Mercer, Department Member
TITLE: EFFECTS OF PHOTOPERIODS, ELECTRICAL CONDUCTIVITY, AND BLACK LIQUOR SUPPLEMENT ON SINIGRIN CONCENTRATION AND MYROSINASE ACTIVITY IN
ABSTRACT: Edible microgreens from the Brassicaceae are gaining popularity due to their unique eating quality, and potential health-promoting benefits (e.g., anticancer and antibacterial properties) from their natural metabolites, such as glucosinolates. This thesis studied the effects of photoperiods and electrical conductivity of nutrient solution on sinigrin (one of the major glucosinolates) content and myrosinase activity in three microgreens (kale, mustard, and broccoli) that were grown in in-door controlled environment. Results showed the sinigrin content and myrosinase activity decreased as the photoperiod increased from 6 to 24 h. However, the electrical conductivity of the nutrient solution, within the tested levels ranging from 1.0 to 2.0 mS/cm, had no significant (P>0.05) effect on both sinigrin concentration and myrosinase activity of the microgreens. Supplementing the nutrient solution with black liquor, which is an abundant byproduct from the pulping process of the paper manufacturing industry, from 5 to 20% w/w, significantly increased the yield of the microgreens. However, the sinigrin concentrations were decreased while myrosinase activity marginally increased with increasing ratio of black liquor from 5 to 20% w/w.