Composition and Postharvest Performance of Broccoli Cultivars

The composition of florets (% dry matter, sugars, chlorophyll and carotenoids, Vitamin C, and glucosinolates), antioxidant activity, head firmness in relation to water loss, and storage life all differed significantly among 12 commercial cultivars (Avenger, Bravado, Emerald Crown, Endurance, Expo, Green Magic, Heritage, Imperial, Ironman, Legacy, Marathon, and Patron) of broccoli grown in two trials (June and October harvests) in Salinas CA during 2010.   At 10°C, storage life (defined as the days to initiate yellowing) ranged from 10 to more than 18 days.  Head firmness ranged from 70 to 99 N.   Conditions to induce water loss (15°C 75%RH for 20h) resulted in a range of 3.6 to 5.3% weight loss which corresponded to head firmness loss from 10-38%.  There was not a direct relationship between % weight loss and firmness loss among the cultivars. Vitamin C concentrations were high in florets of all cultivars and ranged from 110-196 mg/100g FW.  The % dry weight of florets ranged from 11.5-14.0% and that of stem tissue ranged from 6.8-8.6%.   Total sugar content of florets and stem tissues averaged 12.4 (9.2-17.3) and 18.7 (13.3-25.0) mg/g FW, respectively.  Fructose, glucose and sucrose comprised 43, 39 and 18% of total sugars, respectively.  Antioxidant activity ranged from 44 to 90 mg Trolox equivalents/100g FW, with activity of most cultivars near the average of 66.  Total glucosinolate and glucoraphinin concentrations ranged from 7.5 to 10.7, and 1.2 to 5.0 µmole/g DW, respectively.  Glucoraphinin concentrations averaged 32-45% of total glucosinolates.