Investigation on the relationship between the integrity of food matrix and nutrient extraction yield of broccoli

- Nutrient extraction yield was influenced by the degree of structure disintegration.
- The nutrient distribution was not uniform throughout the whole broccoli.
- For different parts of broccoli, the nutrient extraction conditions were different.
- For nutrient extraction, the physical properties need to be looked closely before.

In this work, experiments to investigate the relationship between the integrity of food matrix and nutrient extraction yield have been conducted. Broccoli was employed as the food material of interest, because of its unique structure and physical properties. Vitamin C was used as the targeted nutrient. The cellular structure disruption conditions were optimized until the maximum nutrient yields were achieved under those conditions. The highest vitamin C yields were achieved when operating time was 5 min for floret, and 10 min for buds and stalks. The highest vitamin C contents were 70.0 g/100 g for florets, 102.6 mg/100 g for buds and 44.2 mg/100 g for stalks respectively. The results indicate that for different parts of a broccoli, presenting different cellular integrity, hardness and porosity, the maximum nutrient extraction yields were different under the same operation conditions. The results of this work have confirmed the determining role of food microstructure in nutrient release during nutrient content measurements or nutrient extraction experiments.