Heated winged-bean meal (<i>Psophocarpus tetrganolobus</i>) as a plant-based aquafeed ingredients: Evaluation on digestibility level in Java barb (<i>Barbonymus gonionatus</i>)

Abstract High commercial feed cost due to high utilization of imported dehulled soybean meal as the plant-based aquafeed ingredient causes Java barb production continues to decrease. This condition requires an alternative plant-based aquafeed ingredient, like winged beans. However, winged beans contain protease-inhibitor that can diminish digestibility level of the fish. Heating became a solution to reduce the protease-inhibitor in winged beans. This study evaluated winged bean meal after different heating methods on digestibility level in Java barb. A completely randomized design experimental method with four treatments and three replications was applied in this study. Treatments were composed of winged beans that were unheated (KE), oven-heated at 110°C for 30 minutes (KO) and autoclave-heated at 121°C for 30 minutes (KA), and no winged beans application (commercial feed/control, K). Parameters were total (TD), winged bean meal (ingredient, ID), and protein digestibility (PD) levels. An analysis of variance (ANOVA), continued by the Duncan’s multiple range test (DMRT) with 95% confidence level were employed to determine the best treatment, based on the statistical approach. All parameters indicate a significant difference among treatments. In TD level, all heated winged bean meal treatments (KO, 93.1±0.48% and KA, 92.8±0.43%) present a similar condition with K treatment (93.1±0.42%). In contrast, the highest ID level was obtained from the unheated winged-bean meal treatment (KE, 93.88±0.70%). However, the PD level in KO treatment (90.66±2.54%) was similar to K treatment (91.67±0.90%), and higher than KA (84.07±0.84%) and KE (73.50±2.30%) treatments. Based on the TD and PD levels, this study concludes a positive effect of oven-heated winged beans as an alternative plant-based ingredient in aquafeed, due to showing a similar condition to the digestibility level of commercial feed in Java barb. A future study is necessary to determine a proper dose of oven-heated winged bean meal in aquafeed formulation for Java barb.