Potential utilization of pigeon pea (

The demand for plant-based foods is increasing alongside growing public health awareness, while soybean availability in Indonesia remains limited due to reliance on imports. This study evaluated the potential of pigeon peas as a partial substitute for soybeans in tempe production. Tempe was produced using three soybean-to-pigeon pea ratios: 60:40 (F1), 50:50 (F2), and 40:60 (F3) in a completely randomized design. Physical characteristics, proximate composition, protein quality, and sensory attributes were analyzed. All formulations produced well-fermented tempe with uniform mycelial growth, a white surface color, and a compact texture, although higher pigeon pea substitution led to a darker interior color. Protein content ranged from 18.0 to 18.6%, meeting the national standard for tempe (≥15%), while fat content in F2 and F3 was below the standard (<7%). In-vitro protein digestibility was high (87.7–88.5%), and amino acid profiles were relatively complete; however, methionine was limiting, resulting in a low estimated PDCAAS (0.17–0.22). Sensory evaluation showed decreased panelist acceptance at higher substitution levels, while brightness, fresh aroma, and texture were significantly correlated with overall acceptance (p<0.01). In conclusion, pigeon pea–substituted tempe has potential as an alternative plant-based protein source, though the addition of complementary cereal is needed for the complementary protein effect.