Kinetics studies of some physico-chemical substances during roasting and preparation of beverage made by Cassia occidentalis seeds

Kinetic Studies and Moisture Diffusivity During Cocoa Bean Roasting

Cocoa bean roasting allows for reactions to occur between the characteristic aroma and taste precursors that are involved in the sensory perception of chocolate and cocoa by-products. This work evaluates the moisture kinetics of cocoa beans during the roasting process by applying empirical and semi-empirical exponential models. Four roasting temperatures (100, 140, 180, and 220 °C) were used in a cylindrically designed toaster. Three reaction kinetics were tested (pseudo zero order, pseudo first order, and second order), along with 10 exponential models (Newton, Page, Henderson and Pabis, Logarithmic, Two-Term, Midilli, Verma, Diffusion Approximation, Silva, and Peleg). The Fick equation was applied to estimate the diffusion coefficients. The dependence on the activation energy for the moisture diffusion process was described by the Arrhenius equation. The kinetic parameters and exponential models were estimated by non-linear regression. The models with better reproducibility were the pseudo first order, the Page, and the Verma models (R2 ≥ 0.98). The diffusion coefficients that were calculated were in the order of 1.26 to 5.70 × 109 m s−2 and the energy activation for moisture diffusion obtained was 19.52 kJ mol−1.

Aqueous extraction kinetics of soluble solids, phenolics and flavonoids from sage (Salvia fruticosa Miller) leaves

In the present study, aqueous extraction kinetics of total soluble solids (TSS), total phenolic content (TPC) and total flavonoid content (TFC) from Salvia fruticosa leaves were investigated throughout 150 min. of extraction period against temperature (60-80 °C), particle size (2-8 mm) and loading percentage (1-4 %). The extract yielded 25 g/100 g TSS which contained 30 g/100 g TPC and 25 g/100 g TFC. The extraction data in time course fit with reversible first order kinetic model. All tested variables showed significant effect on the estimated kinetic parameters except equilibrium concentration. Increasing the extraction temperature resulted high extraction rate constants and equilibrium concentrations of the tested variables notably above 70 °C. By using the Arrhenius relationship, activation energy of the TSS, TPC and TFC were determined as 46.11 ± 5.61, 36.80 ± 3.12 and 33.52 ± 2.23 kj/mol, respectively. By decreasing the particle size, the extraction rate constants and diffusion coefficients exponentially increased whereas equilibrium concentrations did not change significantly. The equilibrium concentrations of the tested parameters showed linear behavior with increasing the loading percentage of the sage, however; the change in extraction rates did not show linear behavior due to submerging effect of 4 % loading.

Toxicological reproductive study of Cassia occidentalis L. in female Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cassia occidentalis L. (Leguminosae) has long been used as natural medicine in rainforests and other tropical regions for the treatment of inflammation, fever, liver disorders, constipation, worms, fungal infections, ulcers, respiratory infections, snakebite and as a potent abortifacient.

AIM OF THE STUDY

This study has investigated the effects of oral sub-acute administration of Cassia occidentalis during pregnancy in female Wistar rats.

MATERIALS AND METHODS

Three groups of pregnant rats were treated orally from the 1st to the 6th day (pre-implantation period) and from the 7th to the 14th day (organogenic period) of pregnancy, with doses of 250 and 500 mg/kg. On the 20th day of pregnancy, the animals were euthanized and reproductive parameters evaluated.

RESULTS

The results revealed no statistically significant differences between the control and treated groups in terms of offspring/dam relationship; fetuses, placentae and ovaries weights; number of implantation and resorption sites; number of corpora lutea in the ovaries and pre- and post-implantation loss rates. However, the presence of dead fetuses was registered in both doses of 250 and 500 mg/kg of Cassia occidentalis.

CONCLUSIONS

Further studies should therefore be conducted to obtain more detailed characteristics of the toxic effects of this species, the use of which is not recommended during pregnancy.