Effects of Post-Harvest Elicitor Treatments with Ultrasound, UV- and Photosynthetic Active Radiation on Polyphenols, Glucosinolates and Antioxidant Activity in a Waste Fraction of White Cabbage ( Brassica oleracea var. capitata )

• Published in: Molecules (Basel, Switzerland) Vol. 27; no. 16; p. 5256
• Main Authors: Seljåsen, Randi, Kusznierewicz, Barbara, Bartoszek, Agnieszka, Mølmann, Jørgen, Vågen, Ingunn M
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.08.2022; MDPI
• Subjects: Abiotic factors; Acids; Anthocyanin; Anthocyanins; Antioxidants; Antioxidants - pharmacology; bioactive compounds; Biosynthesis; Brassica - chemistry; Brassica oleracea; Cellulose acetate; Economic justification; Flavonoids; Flavonols; Flowers & plants; Food; Functional foods; Functional foods & nutraceuticals; Glucosinolates; Glucosinolates - chemistry; Glucosinolates - pharmacology; head cabbage; Hydroxycinnamic acid; Indoles; Leaves; Lettuce; Metabolites; Monosaccharides; Phenols; Photosynthesis; Photosynthetically active radiation; Phytochemicals; Polyphenols; Polyphenols - pharmacology; pre-processing; rest raw material; Sugars; Ultrasonic imaging; Ultrasound; Ultraviolet radiation; Ultraviolet Rays; Vegetables; waste valorization; Water; Water baths; Canada; Norway; rest raw material; bioactive compounds; pre-processing; waste valorization; head cabbage
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27165256

Biosynthesis of phytochemicals in leaves of can be initiated by abiotic factors. The aim of the study was to investigate elicitor treatments to add value to waste of cabbage. A leaf waste fraction from industrial trimming of head cabbage was exposed to UV radiation (250-400 nm, 59 and 99 kJ∙m , respectively), photosynthetic active radiation (PAR, 400-700 nm, 497 kJ∙m ), and ultrasound in water bath (35 kHz, at 15, 30 and 61 kJ∙l water), in order to improve nutraceutical concentration. UV was more effective than PAR to increase the level of flavonols (2 to 3-fold higher) and hydroxycinnamate monosaccharides (1 to 10-fold higher). PAR was three times as effective as UV to increase anthocyanins. Interaction of PAR + UV increased antioxidant activity (30%), the content of five phenolics (1.4 to 10-fold higher), and hydroxycinnamic monosaccharides (compared with PAR or UV alone). Indoles were reduced (40-52%) by UV, but the other glucosinolates (GLS) were unaffected. Ultrasound did not influence any parameters. The results are important for white cabbage by-products by demonstrating that UV + PAR can be successfully used as an effectual tool to increase important phenolics and antioxidant activity of waste fraction leaves without an adverse effect on the main GLS.