Dual Role of Raspberry Ketone as Antioxidant and Flavoring Agent in Citrus Flavors

Objectives: To improve the shelf life and protect the citrus oils degradation. Citrus oils have been used since long in flavor and fragrance industry and degrade periodically when exposed to oxygen, high temperatures and low pH. Strategic studies employing an alternative antioxidant may find a solution. Method: Antioxidant study was performed by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH), pH assessment, and sensory analysis, to test the response of raspberry ketone on citrus oils -orange and lemon oil to improve the shelf life. Findings: Raspberry ketone exhibits 70% antioxidant activity in citrus oils (lemon and orange oil) when compared to the antioxidants BHA (76.5%) and tocopherol (76.7%). Antioxidants stabilize the pH of citrus oils. The pH drop of citrus oils is approximately from 4.58 to 3.77, and in the presence of antioxidants, it ranges from 4.52 to 4.07. The sensory scale reports that the likeability of citrus oils with raspberry ketone is good when evaluated in black tea and hardboiled candy, without any off-taste, compared to BHA and tocopherol at a 0.15% dosage. Thus, the addition of raspberry ketone as a flavor and fragrance agent (≤ 0.15%) can also serve as an antioxidant to combat the self-degradation process of citrus oils. Novelty: This study reveals a solution to protect citrus oil degradation by using Raspberry ketone, a flavoring agent as well as antioxidant to avoid the usage of BHA and tocopherol. Keywords: Citrus oils, BHA, Tocopherol, Raspberry ketone, Sensory, DPPH agent