~ 2505 ~  International Journal of Chemical Studies 2020; 8(3): 2505-2509                     P-ISSN: 2349–8528  E-ISSN: 2321–4902 www.chemijournal.com IJCS 2020; 8(3): 2505-2509 © 2020 IJCS Received: 14-03-2020 Accepted: 17-04-2020   Devendra Kumar Assoc. Professor, PFE, CAE, DRPCAU, Pusa, India Mohan Singh Professor & Head Department of PHP&FE, JNKVV, Jabalpur, Madhya Pradesh, India Shobha Rani Sr. Scientist & Head KVK, Jehanabad, Bihar, India Varsha Kumari S.M.S. (H.Sc.), KVK, Vaishali, India Corresponding Author: Devendra Kumar Assoc. Professor, PFE, CAE, DRPCAU, Pusa, India Effect of material parameters and machine parameters on physical property of extrudates prepared from different blends of sattu and kodo Devendra Kumar, Mohan Singh, Shobha Rani and Varsha Kumari DOI: https://doi.org/10.22271/chemi.2020.v8.i3aj.9587 Abstract In the present study extrudates were prepared to identify the optimum machine parameters and prepare good quality ready to eat extruded snacks from a suitable blend of sattu and kodo Extrusion aims at producing a voluminous, expanded, crispy product resembling a baked product. The increase in proportion of sattu and die head temperature increases the water absorption index. The water absorption index achieved a maximum value of 58.5% and a minimum value of 48.7%. The bulk density increases with the increase in moisture content increases in proportion of sattu and the increase in barrel temperature with decrease in die head temperature and increase in screw speed. The bulk density achieved a maximum value of 0.60 g/mm 3 and a minimum value of 0.46 g/mm 3 . Keywords: kodo, extruder, moisture, sattu, millet 1. Introduction Extrusion cooking combines the heating of food raw material with the act of extrusion to create a cooked and shaped food product. Cooking of food ingredients during the extrusion process results in the gelatinization of starch, denaturation of protein, inactivation of many raw food enzymes responsible for food deterioration during storage, the destruction of naturally occurring toxic substances such as trypsin inhibitors in soybeans, and the diminishing of microbial counts in the final product. Humans and other monogastric species cannot easily digest un-gelatinized starch. Extrusion cooking is somewhat unique because gelatinization occurs at much lower moisture levels (12-22%) than necessary in other food processing operations rather processing conditions that increase temperature, shear, and pressure tend to increase the rate of gelatinization. The presence of other food compounds, particularly lipids, sucrose, dietary fibre and salts, also affects gelatinization (Harper 1981) [1] . Extrusion cooking is a high-temperature short-time (HTST) process capable of generating high temperatures up to 200 o C or so; high pressures up to 2000 psi, and relatively high shear rates of 10 to 200 s -1 in extrudes the retention time is sufficient so that each cereal particle achieves temperature and moisture equilibrium. The extruder barrel itself consists of jackets that contain the rotating screws. In the feeding zone, low-bulk-density raw materials are introduced into the extruder barrel. The overall feed rate is limited by the ability of the screws in this section to transport the dry feed. In the compression zone, kneading continues, and the screws of the extruder start to achieve a higher degree to fill as their screw pitch decreases. The raw material loses its granular texture, and its density begins to increase, as does the pressure inside the barrel. 2. Methods and Materials Sattu and kodo were procured from local market. After initial removal of foreign materials, all the mixture of sattu powder and kodo flour) were blended in predetermined proportions and mixed thoroughly in mixer and then they were fed to the Brabender single screw extruder at specific moisture content for making the extruded product at different predetermined set of operations. Bulk Density Bulk density is the mass per unit bulk volume where the volume is calculated including the