IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 03 Issue: 01 | Jan-2014, Available @ http://www.ijret.org 607 STUDY OF PROTEIN CONTENT AND EFFECT OF pH VARIATION ON SOLUBILITY OF SEED PROTEIN OF ELEUSINE CORACANA (VARIETY DFM-1 AND HR-374) Sangeeta Gupta 1 , S.K. Shrivastava 2 , Manjul Shrivastava 3 1, 2 Department of Applied Chemistry, Jabalpur Engineering College, Jabalpur-482011(M.P.) India 3 Department of Chemistry Govt. M.H. College of Home Science &, Science for Women Jabalpur (M.P.) India Abstract Protein utilization in the different food systems principally depend on their functional properties. The solubility behavior of the seed protein is of great importance from the several points of view. It determines their utility for many industrial purposes. Solubility is a critical functional property, since a protein generally has to be in solution in order to exert its other desirable functional characteristics. Nitrogen Solubility Index and Protein Dispersibility Index (PDI) are the two most common methods of evaluating solubility characteristics. Hence in this study seeds of Eleusine coracana (variety DFM-1 and HR-374) minor millet were studied for protein solubility at wide range of pH from 0.5 to 13.5. Keywords: Protein solubility, Protein Dispersibility Index, Nitrogen Solubility Index, Minor millet Seeds, Variety of Eleusine coracana. ---------------------------------------------------------------------***--------------------------------------------------------------------- 1. INTRODUCTION Millets are staple foods that supply a major portion of calories and protein to large segments of populations in the semi-arid tropical regions of Africa and Asia. Finger millet (Eleusine coracana) is the primary food source for millions of people in tropical dry land regions. It also has nutritional qualities superior to that of rice and is on par with wheat. It is also known as Finger millet or Ragi in India [1-2]. Nutritional and functional qualities of protein are largely determined by its amino acid content and nitrogen solubility. Nitrogen solubility is one aspect of hydration which is the most important characteristics in evaluating protein quality since many functional properties of protein depend upon their capacity to go into solution initially. Solubility is affected by many factors such as pH during extraction or solubilization, size of meal particle, temperature and meal solvent ratio, composition of solvent and character of protein [3]. 2. MATERIALS AND METHODS New hybrid, authentic, healthy and matured seeds of minor millets variety Eleusine coracana (variety DFM-1 & HR-374), under investigation were procured from Agriculture Research Station Dindori, regional extention of Jawaharlal Nehru Krishi Vishwavidyalaya, Jabalpur (M.P.). In the present investigation the seeds of Eleusine coracana (variety DFM-1 & HR-374) minor millet were analyzed for their protein content and protein solubilization with pH variation in the powdered form, because size of seed powder has been shown to influence the nitrogenous extraction [4,5]. The seeds were sun dried and powdered to 60 meshes [6]. The effect of pH variation of the extractant on the protein solubilization were studied by varying pH of water, ranging from 0.5 to 13.5, brought by addition of hydrochloric acid or sodium hydroxide solution. One gram of the seed powder was suspended in 20 ml of extractant of desired pH. The contents were shaken in electrical shaker for about 2 hours at room temperature and centrifuged for 20 minutes at 2000 rpm in a centrifuge. The nitrogen solubilized was determined in supernatant so obtained by Semi-Micro Kjeldahl method [7]. 3. RESULTS AND DISCUSSION The seeds of Eleusine coracana (variety DFM-1 & HR-374) were studied for their protein solubility behaviors in considerable wide pH range from 0.5 to 13.5 .The results of protein solubility are given in Table 1. These results are also graphically represented in Figure 1.1 to 1.2. The determination of percent of total proteins (12.25 percent) of Eleusine coracana variety DFM-1 solublized showed the maximum solubility (6.95 percent) at pH 12.0, while it was minimum (1.39 percent) at pH 2.0. At the remaining pH, solubility of the proteins was found to fluctuate between 1.405-4.84 percent.