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Broccoli phytochemical content

5.3 Results

5.3.1 Comparison of phytochemicals means over the environments

Glucosinolates

Across all trials, glucoraphanin levels were comparable between locations

and seasons but were more variable at the individual location and season trial

analysis level (Table 5.2). Glucoraphanin, glucobrassicin and neoglucobrassicin

levels were comparable between organic and conventional treatments.

Comparisons of organic versus conventional by location and season for the

glucosinolate phytochemicals are presented in Supplemental Figure 5.1A, B,

and C. Comparable levels of glucosinolates were observed in the organic -

conventional comparisons within locations and seasons.

Tocopherols

Across trials compared regionally, Oregon had higher levels of all three

tocopherols compared to Maine (Table 5.2, Supplemental Figure 5.2A, B and C).

The tocopherols δ- and γ- were higher in Fall compared to Spring (Supplemental

Figure 5.2A and B), but not so for α-tocopherol (Supplemental Figure 5.2C).

Organic and conventional levels for all tocopherol concentrations were in the

same range and not signiicantly diferent. When the three tocopherols were

analysed by organic versus conventional within location and season, there were

no clear signiicant diferences in management system across the season and

location combinations (Table 5.2, Supplemental Figure 5.2 A, B and C).

Carotenoids

Overall, Oregon had higher levels of lutein and β-carotene compared to

Maine (Table 5.2, Supplemental Figures 3A and 3C) and comparative levels of

zeaxanthin (Table 5.2, Supplemental Figure 5.3B). Spring produced higher levels

of all carotenoids compared to Fall levels in contrast to the glucosinolates and

the δ- and γ- tocopherol concentrations. There were no signiicant diferences

between organic and conventional for any carotenoid measured. When

carotenoids were analysed by management system within location and season,

β-carotene showed significantly lower levels in Maine in the Fall compared to

other location and season combinations (Supplemental Figure 5.3A, B and C).

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