Submitted to: Applied Engineering in Agriculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/4/2014
Publication Date: 6/1/2014
Publication URL: http://handle.nal.usda.gov/10113/59551
Citation: Garcia, R.A., Stein, S.D., Piazza, G.J. 2014. Poultry blood preservation and the impact of preservation on flocculant activity. Applied Engineering in Agriculture. 30(3):445-453. DOI: 10.13031/aea.30.10436. Interpretive Summary: Poultry processors do not have any use for chicken blood, and they have to pay for its disposal. Our laboratory has previously reported that chicken blood can be used to make a valuable product known as a ‘flocculant’. Flocculants are used in applications such as water treatment to help remove small particles from the water. There are some practical problems, however, related to using chicken blood for this purpose. The blood must be collected, stored and transported very inexpensively, but such inexpensive handling may allow the blood to degrade severely. The blood will coagulate, the blood cells will break open, and microorganisms growing in the blood will produce toxic gas. ARS researchers investigated simple chemical preservative techniques that could stall the degradation processes, while retaining the useful properties of blood. The results presented support the commercialization of blood based flocculant technology.
Technical Abstract: Chicken blood is an attractive but problematic raw material for the production of biobased flocculants. Blood begins to degrade as soon as it is collected – it rapidly coagulates, and at longer time scales, the red blood cells lyse and microbial growth results in hydrogen sulfide production. This study investigated the extent to which these types of degradation can be limited by inexpensive chemical treatments, under non-sterile, non-refrigerated conditions. It is shown that while the anticoagulants potassium citrate and potassium oxalate are effective under refrigerated conditions, at ambient temperatures they can only prevent coagulation for about one day. The effectiveness of potassium EDTA, on the other hand, is not as temperature dependent. Similarly, blood treated with oxalate or citrate produces dangerous amounts of hydrogen sulfide, but blood treated with EDTA produces significantly less of the toxic gas. Anticoagulated blood does undergo some red blood cell lysis under the conditions investigated, and a method for limiting this lysis is proposed. Finally, it is shown that chicken blood preserved with EDTA can be held in non-refrigerated, non-sterile conditions for at least four days without sacrificing the effectiveness of the flocculant made from the blood.