Influence of post harvest processing conditions on yield and quality of ground turmeric (Curcuma longa L.)

Studies were carried out to evaluate the influence of post harvest processing conditions on yield and quality of ground turmeric. Rhizomes were peeled, cooked (autoclave or immersion) in water or alkaline media, sliced, dehydrated, ground, sieved, packaged in polyethylene bags and stored for 60 days at room temperature. Yields ranged from 9.84 to 14.51 g of powder/100 g of rhizome with moisture varying from 8.84 to 9.86 g/100 g. Peel removal caused 30% mass loss but the powder obtained had higher intensity of yellow and red. Cooking caused a reduction in dehydration time and provided a powder with lower moisture content, higher levels of curcuminoid pigments and higher Hunter CIE L*, a* and b* values. Cooking by immersion provided higher quality powder compared to autoclave. Use of alkaline media resulted in a product with lower curcuminoid content, and higher intensity of yellow. There was no change in pigment and colour characteristics during storage