Dr. R. V. PrasadPatel Utpalkumar B2020-07-062020-07-062018http://krishikosh.egranth.ac.in/handle/1/5810148644India is considered as home of spices and black pepper (Piper nirgum L.) is called king of spices. Spices are used to improve flavour and taste of food products and generally ground before use. In a normal grinding process, heat is generated when energy is used to fracture the particles and spices loose some of their essential oil or flavouring components due to the temperature rise. Therefore, cooling of spices at low temperature with liquid nitrogen before feeding to the grinder and maintaining the low temperature in the grinding zone can significantly help in retention of essential oils. The physical properties; size, bulk density, co-efficient of friction and angle of repose of black pepper were observed to be 5.05 ± 0.63 mm, 550±50 kg/m3, 0.49 ± 0.15, 38 ± 0.26°. The chemical properties; moisture, fat, protein, fiber, ash, carbohydrate and essential oil were observed to be 12.04 ± 0.29, 8.12 ± 0.28, 12.25 ± 0.08, 16.81 ± 0.41, 3.50 ± 0.31, 47.28 ± 1 and 4.88 ± 0.1 per cent respectively. Optimization of cryogenic grinding of black pepper was carried out with respect to grinding time, liquid nitrogen consumption and essential oil yield. The effect of grinding temperature (0 to -100 °C), feed rate (8, 9 and 10 kg/h) and sieve size (0.8, 1 and 1.5 mm) were studied with three factorial complete randomized design. The optimized conditions for cryogenic grinding were -52 °C temperature, 10 kg/h feed rate and 1.5 mm sieve size. The essential oil extracted from black pepper was 3.36 %. Black pepper powder was further evaluated for extraction of essential oil in supercritical fluid extraction. Response surface methodology (RSM) was used for optimization to determine effects of temperature (20, 30, 40, 50 and 60 °C), pressure (100, 150, 200, 250 and 300 bar), dynamic time (30, 60, 90, 120 and 150 min) and static time (30, 45, 60, 75 and 90 min) with respect to extract yield and piperine content. The optimized conditions observed were 47 °C temperature, 245 bar pressure, 130 min dynamic time and 30 min static time. The extract yield and piperine obtained at optimized conditions were 5.61 % and 1259 mg/100g respectively.en-USnullThesis