A comparative study of drying methods on physical characteristics, nutritional properties and antioxidant capacity of broccoli

Abstract

Broccoli is considered one of the attractive raw materials for dehydrated vegetables owing to its high nutritional value. However, information about how drying methods affect the physicochemical and nutritional properties of broccoli is limited. In this study, broccoli pieces were subjected to freeze drying (FD), hot air drying (HAD), microwave vacuum drying (MVD), vacuum drying (VD), MVD combined with HAD (MVD + HAD), and MVD combined with VD (MVD + VD). Quality attributes of dehydrated broccolis were contrasted in terms of color, texture, volume shrinkage, nutritional components, antioxidant activity, and rehydration capacity. Results demonstrated that FD better preserved the nutrients while HAD displayed the worst effect. The combination of MVD + HAD and MVD + VD resulted in higher retention of nutritional compositions, better antioxidant activity, and lower energy consumption than that of HAD. Furthermore, combined drying processing exhibited similar rehydration capacity but lower hardness compared to that of HAD.

Keywords:

• Broccoli
• antioxidant activity
• nutritional composition
• microwave vacuum drying
• combined drying

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We thank the financial support by National Key R&D Program of China (2017YFD0400900), Youth fund of Jiangsu Province’s natural science foundation (BK20180307), Jiangsu Agricultural Science and Technology Innovation Fund (CX (17) 2017) and the Key and General Programs of Modern Agriculture in Jiangsu Province (BE2018382).