Glucosinolates In Sprouts Research Articles

Combination of light quality and melatonin regulates the quality in mustard sprouts

Mustard sprouts is a new form of vegetable product that is gaining attention due to its high content of health-promoting compounds such as glucosinolates. This study investigated the effects of different light qualities (white, red, and blue) alone and in combination with 100 μmol L−1 melatonin on the growth and health-promoting substance content of mustard sprouts. The results showed that white light + melatonin treatment promoted the accumulation of glucosinolates in sprouts (compared with white light increased by 47.89%). The edible fresh weight of sprouts treated with red light + melatonin was the highest, followed by white light + melatonin treatment. In addition, the sprouts treated with blue light + melatonin contained more ascorbic acid, flavonoids, and total phenolics. Therefore, the combined treatment of light quality (especially white light) and melatonin can provide a new strategy to improve the quality of mustard sprouts.

Accumulation of Phenolic Compounds and Glucosinolates in Sprouts of Pale Green and Purple Kohlrabi (Brassica oleracea var. gongylodes) under Light and Dark Conditions

Kohlrabi is considered an important dietary vegetable worldwide. In this study, we investigated the growth and accumulation of phenolic compounds (PCs) and glucosinolates in sprouts of pale green and purple kohlrabi (Brassica oleracea var. gongylodes) in response to light and dark conditions. Pale green kohlrabi presented high fresh weight and root length irrespective of light treatment, whereas under dark conditions, it presented higher fresh weight and shoot length than purple kohlrabi. In contrast, the root length of both kohlrabies increased markedly under light conditions compared to that under dark conditions. Thirteen PCs and eight glucosinolates were detected and quantified in 10-day-old pale green and purple kohlrabies. In both kohlrabies, the individual and total phenolic levels were much higher under the light treatment than under the dark treatment. Under light and dark conditions, the total phenolic content was 6362.13 and 5475.04 µg/g dry weight in the pale green kohlrabi, respectively, whereas in the purple kohlrabi, it was 10,115.76 and 9361.74 µg/g dry weight, respectively. Dark conditions favored higher accumulation of glucosinolates than light conditions. Progoitrin, neoglucobrassicin, glucoerucin, and 4-methoxyglucobrassicin were the predominant glucosinolates in both kohlrabies and were present in much higher amounts in the pale green kohlrabi. In pale green kohlrabi under dark conditions, the total glucosinolates content was 4.75 and 2.62 times higher than that of the purple kohlrabi under light and dark conditions, respectively. Among individual glucosinolates, in the pale green kohlrabi under the dark condition, progoitrin was found to have the highest content, which was 90.28 and 54.51 times higher than that in the purple kohlrabi under light and dark conditions, respectively. These results show that the phenolic and glucosinolates levels varied widely, and these variations between the two types of kohlrabi under both light and dark conditions were significant. Our findings suggest that light and dark conditions enhance the accumulation of PCs and glucosinolates, respectively, during the development of kohlrabi seedlings.

Effect of NaCl treatments on glucosinolate metabolism in broccoli sprouts

To understand the regulation mechanism of NaCl on glucosinolate metabolism in broccoli sprouts, the germination rate, fresh weight, contents of glucosinolates and sulforaphane, as well as myrosinase activity of broccoli sprouts germinated under 0, 20, 40, 60, 80, and 100 mmol/L of NaCl were investigated in our experiment. The results showed that glucoerucin, glucobrassicin, and 4-hydroxy glucobrassicin in 7-d-old broccoli sprouts were significantly enhanced and the activity of myrosinase was inhibited by 100 mmol/L of NaCl. However, the total glucosinolate content in 7-d-old broccoli sprouts was markedly decreased although the fresh weight was significantly increased after treatment with NaCl at relatively low concentrations (20, 40, and 60 mmol/L). NaCl treatment at the concentration of 60 mmol/L for 5 d maintained higher biomass and comparatively higher content of glucosinolates in sprouts of broccoli with decreased myrosinase activity. A relatively high level of NaCl treatment (100 mmol/L) significantly increased the content of sulforaphane in 7-d-old broccoli sprouts compared with the control. These results indicate that broccoli sprouts grown under a suitable concentration of NaCl could be desirable for human nutrition.

Identification and Quantification of Glucosinolates in Sprouts Derived from Seeds of Wild Eruca sativa L. (Salad Rocket) and Diplotaxis tenuifolia L. (Wild Rocket) from Diverse Geographical Locations

The Brassicaceae rocket species Eruca sativa L. (salad rocket) and Diplotaxis tenuifolia L. (wild rocket) are consumed throughout the world in salads, predominantly the leaves but also the flowers and more recently the sprouts (seedlings). Ontogenic profiling of glucosinolates and flavonoids in plants derived from commercial seed of these species has previously been done, but no studies have been conducted to determine how geographical origin affects glucosinolate composition in rocket species. Seeds from wild E. sativa L. and D. tenuifolia L. from diverse regions of the world were obtained from gene banks and grown under controlled conditions. Sprouts were harvested when they would normally be harvested for consumption, and glucosinolates were extracted and profiled in these accessions. All of the sprouts from Italian E. sativa L. had consistently high total glucosinolate content, with only a few exceptions, and also the highest percentage contents of 4-mercaptobutylglucosinolate. In contrast, sprouts produced from Central and Eastern European seeds had a much higher percentage of 4-methylthiobutylglucosinolate. With a single exception, Tunisia, all sprouts produced from North African seeds had very high 4-methylthiobutylglucosinolate contents. The single sample from China had a high total glucosinolate content and glucosinolate profile that was very similar to the accessions from Uzbekistan and Pakistan. All of the D. tenuifolia L. sprouts had consistently high total glucosinolate contents, and a high percentage of this was 4-mercaptobutylglucosinolate. This glucosinolate variation in levels and profiles of the rockets can be used for genetic studies, selected breeding, and human intervention studies.