Water stability of prawn feed pellets prepared using different binding materials with special reference to tapioca

Abstract

The water stability of prawn feed pellets, made using agar agar (AA), polyvinyl alcohol (PVA), sodium alginate (SA), gelatin, starch and tapioca as binders, was studied by determining the loss in weight in water. AA, PVA and SA were used at 2% level and gelatin and starch were used at 10% and 40% level respectively. Whereas tapioca was tested at six levels of 9.0, 16.6, 23.0, 28.5, 33.3 and 37.5%. AA, PVA and SA have same binding capacity (the loss in weight of pellets was around 24% at the end of 8 hours), while gelatin resulted in higher loss in weight (28 %) of pellets. Starch was found to be a poor binder (weight loss of pellets 48 %). The binding capacity of tapioca at 9 % level was comparable to that of AA, PVA and SA at 2 % level. The loss in wei^t of i>ellets decreased from 24% to 15 % as the amount of tapioca in the feed increased from 9 to 37.5 % at the end of 8 hours. Aeration of the water resulted in higher loss in weight of pellets in the first four hours compared to the loss in weight without aeration. However, at the end of 8 hours there is no significant difierence in the weight loss between the two treatments. The advantages of using tapioca as binder in prawn feeds are discussed.