Optimization of pH to extract sinapates from mustard using green technology

Tuesday, May 2, 2023

4:30 PM – 6:00 PM MDT

Presenting Author(s)

Ruchira Nandasiri, PhD, PAg (he/him/his)

Doctor/Post-Doctoral Fellow
St. Boniface Hospital Albrechtsen Research Centre
Winnipeg, MB, Canada

Co-Author(s)

Thu M. Nguyen, BE (she/her/hers)

Masters Student
university of manitoba
Winnipeg, Manitoba, Canada

Co-Author(s)

OF

Olamide S. Fadairo, MSc

PhD Candidate
RCFTR University of Manitoba
Winnipeg, MB, Canada
N.A Michael Eskin

Distinguished Professor
University of Manitoba
Winnipeg, Manitoba, Canada

Abstract: Mustard is a rich source of phenolic compounds with a potential for applications in the food and pharmaceutical industries. The extractability of these phenolic compounds, particularly sinapine, sinapic acid and canolol, can be substantially enhanced by pre-treatment and extraction techniques. Green household ingredients, such vinegar and sodium bicarbonate, were used to modify the pH of different mustard seeds prior to pre-heating by sautéing followed by pressurized cooking (115^oC at 10.2 psi). Statistical analysis showed an interesting trend in which pH affected the compositional changes of the major sinapates. Both yellow and black mustard yielded competitive amounts of sinapine, sinapic acid, and canolol. The highest yields of sinapic acid and canolol, however, were recorded in crushed black mustard seeds adjusted to neutral pH. These were significantly (p < 0.05) higher compared to the corresponding acid or alkaline pH treated mustard samples. In addition, the pH affected the antioxidant activity of the extracts. With the exception of the metal ion chelation assay, all other antioxidant methods, including ferric reducing antioxidant power (FRAP) assay, DPPH free radical-scavenging assay and ABTS•+ Scavenging Assay, significantly (p < 0.05) increased with the pretreatment time for all three pH levels studied. Interestingly, the total phenolic content significantly increased (p < 0.05) at the lower pH level with the highest total phenolic content (2040.32 ± 360.12 mg/g DW) obtained from yellow mustard seed adjusted to neutral pH.

Keywords: Mustard, sinapates, pH, canolol, antioxidant