Effects of boiling and peeling treatments on the physicochemical properties of Durian (Durio zibethinus) seed flour

Durian (Durio zibethinus) seed flour represents an underutilized byproduct with significant potential for food applications. This study systematically evaluated how boiling and peeling pre-treatments affect the physicochemical properties of durian seed flour using a factorial completely randomized design with four treatments: boiled-peeled (BP), boiled-unpeeled (BUP), unboiled-peeled (UBP), and unboiled-unpeeled (UBUP). Results revealed that boiling significantly increased cohesiveness (Carr Index: 16.67% in BP vs 6.67% in UBUP) and thermal stability (peak temperature: 144.67°C in BP vs 26.87°C in UBUP) through starch gelatinization, while reducing flowability. Skin removal improved lightness (L* = 87.11 in UBP vs 60.02 in BUP) and flow properties. Unpeeled flours exhibited superior functional properties, with UBUP showing the highest water solubility (0.16%) and foam stability (94.44%), attributed to preserved seed coat polysaccharides and amphiphilic compounds. Thermal analysis confirmed boiling-induced structural stabilization, whereas unboiled-unpeeled flour displayed anomalous low transitions, suggesting enzymatic degradation. Color analysis aligned with consumer preferences, as peeled flours (UBP, BP) achieved higher lightness (L* > 83) compared to unpeeled counterparts (L* < 71). The study demonstrates that processing methods dictate flour functionality: peeled flours are optimal for visual quality and flowability, while unpeeled variants excel in foaming and solubility. These findings provide critical insights for tailoring durian seed flour production to specific applications, bridging the gap between agricultural waste valorization and functional ingredient development. Future research should explore protein isolation techniques and industrial-scale processing to fully exploit this sustainable resource.