Effects of dietary n-3 polyunsaturated fatty acids and ... - FINS

1 st WorkshopXIII International Feed Technology SymposiumTable 2. Results of 8 laboratories on determination of PDI in FFSB samples processedby dry extrusion at different temperatures190Lab NoPDI110ºC 127ºC 136 ºC 140ºC 145ºC 151ºC 164 ºC1 38.21 25.77 11.62 9.67 8.42 7.25 6.2136.66 22.1 9.22 10.55 8.89 7.82 6.752 37.26 21.32 10.34 9.07 8.74 7.77 6.7436.15 21.46 10.01 9.27 8.81 7.3 6.093 47.63 26.39 9.64 8.91 8.79 7.27 4.0947.18 28.2 10.01 8.36 9.39 6.8 4.234 44.72 31.1 14.69 10.87 9.1 3.96 1.6248.42 30.1 10.64 8.51 8.86 4.57 2.435 45.5 19.83 11.88 9.55 10.08 8.45 8.6647.62 18.17 12.54 9.5 9.9 8.26 8.386 46.24 27.79 10.17 9.12 9.02 8.89 7.7845.61 28.58 10.18 8.92 8.7 8.23 8.17 41.8 25.4 10.1 8.7 8.6 7.9 7.241.9 25.25 10.7 8.8 8.1 8.2 7.18 35.86 11.84 6.15 6.9 5.01 4.73 4.6636.8 12.25 6.81 6.1 5.42 5.48 5.39Average 42.35 23.47 10.30 8.92 8.50 7.06 5.96FFBS samples processed at temperatures between 136 0 C and 145 0 C, representedadequately-processed FFSB (Table 1). The PDI values for these samples obtained in theinter-laboratory study, and shown in Table 2, were 10.30 and 8.50 respectively, whichwere, therefore, the boarder PDI values of the range for adequately processed soybean.It should be stressed that the average PDI values for the range describing adequatelyprocessed FFSB of 8.50 - 10.30 (Table 2) are fairly different from those globallyaccepted (15 - 28). At this stage, there is no firm explanation for the difference betweenglobally accepted values and those established in this study.The repeatibility limit (r) was 2.11, whereas the reproducibility limit (R) was 7.73. Thesevalues are acceptable, but since it has been established in this study that the PDI rangefor adequately processed FFSB was between 8.50 and 10.30, the reproducibility value of7.73 creates a concern with regard to use of the PDI method in practice.CONCLUSIONThe indications that the protein dispersibility index (PDI) might be the best indicator ofthe degree of FFSB processing, could not proven in this study.