Valorisation of Ageing Shallot through Functional Ingredient Development with Pancreatic Lipase Inhibitory Potential

Abstract Black shallot, produced by ageing Thai red shallots, is a value-added Allium ingredient with potential functional properties related to lipid digestion. In this study, shallots were aged at 70 °C for 21 days, and 15 days was identified as the optimum based on antioxidant activity and pancreatic lipase inhibition. Ageing for 15 days increased total phenolic content, reducing power, and lipase inhibitory activity, while markedly lowering DPPH IC₅₀. The optimized black shallot was formulated into a spread and assessed for physicochemical, microbiological, rheological, sensory, and bioaccessibility properties. The spread had a pH of 3.6–3.7 and total viable counts below 10 CFU g-1, indicating low microbial load. Compared with fresh-shallot spread, the black shallot spread showed higher phenolic content, stronger reducing power, greater pancreatic lipase inhibition, weak-gel and shear-thinning behaviour, and slightly better sensory acceptance despite darker colour. Black shallot contained 16.1 mg g-1 S-allyl-L-cysteine, with 11% bioaccessibility after in vitro digestion. Overall, ageing for 15 days produced black shallot suitable for spread formulation with improved antioxidant-related properties and strong in vitro pancreatic lipase inhibitory activity.