Athula Ekanayake

Effect of White Mustard Essential Oil on Inoculated Salmonella sp. in a Sauce with Particulates

White mustard essential oil (WMEO), from white mustard seed (Sinapis alba L.), is obtained by solvent extraction of defatted and wetted ground mustard; endogenous myrosinase catalyzes the hydrolysis of the glucosinolate sinalbin to yield 4-hydroxybenzyl isothiocyanate (4-HBITC), the antimicrobial component of WMEO. Sauce with particulates was made by mixing sauce, which served as the carrier for WMEO, with frozen vegetable and chicken particulates inoculated with Salmonella sp. WMEO (at 250 to 750 ppm of 4-HBITC) was able to reduce inoculated Salmonella counts by 0.8 to 2.7 log (CFU/g) in a frozen sauce with particulates in a dose-dependent manner, starting from the point of formulating the sauce through the microwave cooking step. High-pressure liquid chromatography-based analytical data confirmed that 4-HBITC was present in all of the samples in the expected concentrations and was completely hydrolyzed after the recommended cooking time in microwave ovens. In another experiment simulating unintentional abuse conditions, where the WMEO containing sauce with particulates was kept at room temperature for 5 h, WMEO (at 250 to 750 ppm of 4-HBITC) was able to reduce inoculated Salmonella counts from the point of first contact and up to 5 h by 0.7 to 2.4 log (CFU/g). Despite the known hydrolytic instability of the active component 4-HBITC, particularly at close to neutral pH values, WMEO was effective in controlling deliberately inoculated Salmonella sp. in a frozen sauce with particulates.

Yellow or White Mustard ( Sinapis alba L.) Oils

Abstract White mustard essential oil (WMEO), an essential oil of low volatility, was solvent extracted after generating it from partially defatted and moistened white or yellow mustard seed. Chemical analysis of the essential oil revealed the presence of para-hydroxybenzyl isothiocyanate (p-HBITC), the active antimicrobial component, and some other known mustard flavor compounds. The fixed oil of mustard did not show any qualitative difference from the mustard oil component in WMEO. The defatted and deheated mustard press cake had an amino acid profile indicative of a good quality food protein. p-HBITC is unstable in aqueous media hydrolyzing in a pH-dependent manner. Despite this, WMEO showed antimicrobial properties in both broth studies and in actual foods at both acidic and neutral pH values. WMEO is new and not available commercially at this time; however, it is a sustainable and underutilized by-product of considerable value for the mustard industry.