English

Abstract

Spices have been in part of our food since centuries, and now become integral part of our life. Cinnamon and Cassia are the bark of evergreen trees and is one of the important spices; however there are multiple species of the trees. In the past, Cinnamon and Cassia have been separated into two distinct species: Cinnamomum verum Presl as Cinnamon and the Cinnamomum cassia Presl, Cinnamomum loureirii Nees, Cinnamomum burmannii Blume species representing Cassia. All four are listed in the Code of Federal Regulations as GRAS. These species are the products that are most common in commercial; trade. Cinnamomum loureirii Nees is one of the major economic species of Cinnamomum belongs to family of Lauraceae and commonly known as Vietnamese or Saigon Cassia and is known for its sweeter flavour and higher volatile oil. Typically its volatile oil varies by quality from 1.5 to 3.0 %, during grinding its amount reduces due to the rise in temperature. For the above reasons Cinnamomum loureirii Nees (Cassia bark) has been selected for cryogenic grinding. Some physical and thermal properties of the Cassia bark were evaluated as a function of moisture content; while mechanical properties were evaluated at moisture content of 11.11 % d.b. and analysis of flavouring components of Cassia bark were also done. And then optimization and validation of product, process and machine parameters, viz., grinding temperature, feed rate, speed of rotor and moisture content of Cassia bark for laboratory scale hammer mill on the basis of responses measured viz., particle size analysis, colour difference, volatile oil content and specific energy consumption for cryogenic grinding of Cassia bark was done using Design-Expert 7.0.0 software. Different experiments were designed using central composite rotatable design (CCRD). Most of the physical and thermal properties of Cassia show linear relationship with moisture content except specific heat, bulk thermal conductivity and bulk thermal diffusivity which follows a second order polynomial relationship. The oil content of Cassia bark was found to be 2.6 ml (100 g) -1 and the chromatogram obtained from Cassia bark essential oil shown a total of 42 flavouring components out of which cinnamaldehyde, (E)- shown the highest peak. The optimum value of product, process and machine parameters viz., feed rate, grinding temperature, rotor speed and moisture content for cryogenic grinding of Cassia bark were predicted as of 2 kg h -1 , -90.31 o C, 1572 rpm and 8.42 % d.b. respectively with desirability level of 0.958. and the predicted values of responses viz., specific energy, particle size, colour difference and volatile oil content of 36.227 kJ kg - 1 , 60.423 µm, 1.721and 3.0 (100 g) -1 respectively at the predicted optimized parameters. The experimental values for specific energy consumption, particle size, colour difference and volatile oil content obtained were 35.850 kJ kg -1 , 62.281 µm, 1.792 and 3.0 ml (100 g) -1 respectively, which validates the predicted optimized