ELSEVIER Food Chemistry, Vol. 59, No. 3. pp. 333-338, 1997 0 1997 Published by Elsevier Science Ltd All rights reserved. Printed in Great Britain PII: SO308-8146(96)00102-1 0308-8146/97 $17.00+0.00 Effect of salts on some of the functional properties of bovine plasma protein concentrate Aladesanmi A. Oshodi & Ebun-Oluwa Ojokan Department of Chemistry, Federal University of Technology, P.M.B. 704, Akure, Nigeria (Received 24 March 1995; revised version received 11 January 1996; accepted 11 January 1996) The effects of salts, NaCI, Na2S04, KCI and CH3C02Na on some of the func- tional properties of bovine plasma protein concentrate (BPPC) were investigated. Results showed that the least gelation concentration of 6.0% observed in distilled deionized water was improved to between 2% and 4% in the presence of the salts used. The foaming capacity of about 36.0% in water considerably increased to between 52.0% to 158.0% depending on the type and concentration of the salts. The water absorption capacity decreased at low salt concentrations compared with values in distilled water and increased with increase in salt concentration while the emulsion capacity decreased with an increase in salt concentration. The variation of protein solubility with pH was found to depend on salt type and concentration. 0 1997 Published by Elsevier Science Ltd. All rights reserved INTRODUCTION concentrations are approximately 0.24.3 M (Altschul & Wilcks, 1985). Despite the growing shortage of proteins of animal origin suitable for human consumption, vast quantities of blood are wasted annually due to apathy in the food industry (Akers, 1973). With the rise in world popu- lation, particularly in the developing countries, it is logical to find some means of making the maximum use of by-products of the meat industry. By-products such as blood, are known to be a source of nutritional and functional proteins. However, bovine blood has been used only in limited quantities for direct human con- sumption because of its intense colour and characteristic taste (Lee et al., 1987). Methods for the separation of blood into plasma and red cell fractions by centrifuga- tion have been developed commercially (Nazlink & Lawne, 1983). More recently, preparation of colourless globin from bovine haemoglobin was reported (Lee et al., 1990). There is now growing interest in utilizing blood from slaughtered animals owing to its high content of quality plasma proteins and nutritionally available iron (Lee et al., 1987). The present report is on the effect of NaCI, Na2S04, CH3C02Na and KC1 on some of the physicochemical properties of bovine plasma protein concentrate. MATERIALS AND METHODS The bovine plasma protein concentrate (BPPC) was prepared as described by Oshodi and Hall (1993). The salts used were NaCl, Na2S04, KC1 and CH3C02Na, all British Drug Houses products. The required concen- trations of the various salt solutions used were prepared by weighing 0.5, 1, 2, 5, 10, 15 and 20 g of the salts which were dissolved in 99.5, 99, 98, 95, 90, 85 and 80 g of distilled, deionized water, respectively. The variations of protein solubility with pH for BPPC in the various salt concentrations were determined using the method described by Sathe and Salunkhe (198 1) and a supernatant was obtained whose protein content was determined by the Biuret method (Wiechselboven, 1946). The presence of salt may increase the total water The least gelation concentration, water absorption content of the protein system at specific water and foaming properties of the BPPC were determined activity values, although it may reduce the preferential using the methods of Sathe et al. (1982), replacing water binding of water to the protein (Sathe & Salunkhe, with appropriate salt solutions. 1981). These effects are markedly dependent on the The emulsion capacity and stability were determined nature of the anion and cation components (Sathe & by the method described by Sathe and Salunkhe (1981). Salunkhe, 1981; Altschul & Wilcks, 1985). The effect The results are means of at least triplicate determi- of salt is significant because, in many foods, salt nations. 333