Mustard oil is one of India's most consumed edible oils, valued for its characteristic pungency and flavour. Whether processing kachi ghani grades or fully refined mustard and rapeseed oil, the bleaching step determines final colour, clarity and stability. This guide covers how activated bleaching earth fits into mustard oil refining.
The Colour Challenge in Mustard Oil
Crude mustard and rapeseed oil contains chlorophyll, carotenoids and oxidation products that give it a deep yellow-to-brown colour. For refined grades, refiners must reduce this colour to meet Lovibond specifications. Activated bleaching earth adsorbs both chlorophyll (green) and carotenoid (yellow-red) pigments, along with phospholipid residues left after degumming.
Typical Dosage and Conditions
Mustard and rapeseed oil generally require 0.8–2.0% bleaching earth depending on crude colour and the target specification. Bleaching is carried out at 90–110°C under vacuum for 20–30 minutes. Bleach Master's high bleachability allows refiners to meet colour targets at the lower end of the dosage band, reducing both cost and spent-earth volumes.
Phospholipid and Soap Removal
Non-hydratable phospholipids that survive water degumming, and trace soaps from alkali neutralisation, are effectively adsorbed by the acid sites on activated bleaching earth. Removing these improves deodoriser performance and final oil stability.
Preserving the Product Profile
For grades where some natural character is retained, careful dosage control prevents over-stripping. Working with a consistent, predictable bleaching earth makes it easier to dial in the exact level of colour and impurity removal required for each market.
Reliable Supply for Mustard Oil Refiners
Umiya Minerals supplies Bleach Master to mustard and rapeseed oil refiners across northern and western India, with logistics from Bhuj-Kachchh and consistent batch quality that simplifies process control.
Frequently Asked Questions
How much bleaching earth does mustard oil refining need?
Typically 0.8–2.0% by weight of oil, depending on the crude colour and the target Lovibond specification. Higher-quality, higher-surface-area earth lets refiners work toward the lower end.
Does bleaching earth remove the pungency of mustard oil?
Bleaching earth mainly removes colour pigments, phospholipids and oxidation products. The pungency compounds (allyl isothiocyanate) are largely addressed during deodorisation; bleaching has limited direct effect on pungency.
Can activated bleaching earth refine both mustard and rapeseed oil?
Yes. Mustard and rapeseed oil have similar pigment and phospholipid profiles, so the same activated bleaching earth and broadly similar dosage and contact conditions apply to both.
What colour reduction can I expect?
With correct dosage and a high-bleachability earth, refiners can achieve substantial reductions in Lovibond red and yellow units, sufficient to meet refined mustard/rapeseed oil specifications when combined with proper degumming and deodorisation.
Need Activated Bleaching Earth for Your Refinery?
Contact Umiya Minerals for product samples, technical data sheets, and bulk pricing. We supply pan-India from Bhuj, Gujarat.