Structure-function relationships of plant-derived antioxidants in ghee: oxidative stability, thermal behaviour, and...

Lipid oxidation is a major factor limiting the shelf life and quality of ghee, necessitating the exploration of clean-label antioxidant approaches. This study evaluated the effectiveness of natural antioxidants derived from Harde (Terminalia chebula) and Arjuna (Terminalia arjuna) in enhancing the oxidative stability and functional performance of ghee. Antioxidant-incorporated ghee samples were assessed for radical scavenging activity using DPPH and ABTS assays, oxidative stability by Rancimat induction period, and behaviour under short-term thermal exposure. Physicochemical characteristics, fatty acid composition (GC-MS), triacylglycerol (TAG) profile, and β-sitosterol content were also determined to evaluate whether botanical incorporation affected milk fat authenticity. Compared with the control, antioxidant-incorporated ghee exhibited significantly greater radical scavenging activity and a 3.8-4.2-fold increase in induction period, indicating enhanced resistance to oxidative deterioration. Although antioxidant activity decreased following simulated intestinal digestion and thermal treatment, treated samples retained significantly higher activity than the control, suggesting that a proportion of antioxidant constituents remained functionally stable under the experimental conditions employed. Lower peroxide values were observed in antioxidant-incorporated samples after thermal exposure, indicating reduced formation of primary oxidation products during the initial stages of heating. No alterations were detected in physicochemical properties, fatty acid composition, TAG distribution, or β-sitosterol levels relative to the control, supporting the compositional characteristics of ghee following antioxidant incorporation. Among the treatments, Harde demonstrated superior antioxidant activity compared with Arjuna, which may be attributed, at least in part, to its higher phenolic content. These findings demonstrate that Harde and Arjuna can serve as effective plant-derived antioxidants for improving the oxidative stability of ghee while maintaining its compositional characteristics.