Growth temperature affects sensory quality and contents of glucosinolates, vitamin C and sugars in swede roots (Brassica napus L. ssp. rapifera Metzg.)

• Swede roots were grown in phytotron at temperatures between 9 and 21 °C.
• High temperature enhanced vitamin C, progoitrin content and bitter taste.
• Low temperature enhanced sugar content and sweet taste, crispiness and juiciness.
• Results indicated a good eating quality of swedes from low growth temperatures.

Swede is a root vegetable grown under a range of growth conditions that may influence the product quality. The objective of this controlled climate study was to find the effect of growth temperature on sensory quality and the contents of glucosinolates, vitamin C and soluble sugars. High temperature (21 °C) enhanced the intensities of sensory attributes like pungent odour, bitterness, astringency and fibrousness, while low temperature (9 °C) was associated with acidic odour, sweet taste, crispiness and juiciness. Ten glucosinolates were quantified, with progoitrin as the dominant component followed by glucoberteroin, both with highest content at 21 °C. Vitamin C also had its highest content at 21 °C, while the total sugar content was lowest at this temperature. In conclusion, the study demonstrated clear effects of growth temperature on sensory quality and some chemical properties of swede and indicated a good eating quality of swedes grown at low temperatures.