Antioxidant, α-amylase, and α-glucosidase inhibitory activities of onion (Allium cepa) and shallot (Allium oscalonicum L.) in food ingredients

Abstract

Both onion and shallot are the most common ingredients to use for many recipes. Consuming onion and shallot provide health benefits including antidiabetic effects. However, the benefits of onion and shallot mixture at different ratios have not been studied in terms of total phenolic content, total antioxidant capacity, superoxide dismutase (SOD)-like activity, and antidiabetic effects. Our study revealed that shallot significantly increased total phenolic content in the mixture from 492 ± 32 μg mL−1 (100% v/v onion) to 803 ± 24 μg mL−1 (100% v/v shallot) depending on the ratios of shallot in the mixture. Shallot also significantly enhanced total antioxidant capacity, SOD-like activity, α-amylase inhibition, and α-glucosidase inhibition in the mixture. Shallot juice exhibited the highest percentage inhibition of α-amylase activity (40.51 ± 1.57%) and α-glucosidase activity (89.61 ± 2.85%) in comparison to those of onion juice and the mixture. In addition, significant positive correlation between phenolic compound and different variables was observed (P < 0.05). Phenolic compounds present in onion and shallot are probably responsible for many health benefits including antidiabetic effects.