Glucosinolates, anthocyanins, total phenols, and vitamin C, as well as antioxidant capacity, were investigated in Chinese kale sprouts treated with both glucose and gibberellic acid (GA3). The combination of 3% (0.03 g/ml) glucose and 5 μol/L GA3 treatment was effective in increasing glucosinolate content while glucose or GA3 treatment alone did not influence significantly almost all individual glucosinolates or total glucosinolates. The total phenolic content and antioxidant activity of Chinese kale sprouts were enhanced by combined treatment with glucose and GA3, which could be useful in improving the main health-promoting compounds and antioxidant activity in Chinese kale sprouts.探究外源施加葡萄糖和赤霉酸对芥蓝芽菜中芥子油苷的积累,花青素、多酚和维生素C 等抗氧化物的含量,以及总抗氧化活性的影响。首次发现葡萄糖和赤霉酸可以协同促进芥蓝芽菜中几乎所有种类芥子油苷以及总芥子油苷的积累,并且可以大幅度提升总多酚的含量以及抗氧化能力。以芥蓝芽菜为材料,使用3%(0.03 g/ml)葡萄糖和5 μmo/L 赤霉酸进行外源处理,以水处理作为对照组。用高效液相色谱法分析芥子油苷和维生素C的含量;采用分光光度法检测花青素的含量;用Folin-Ciocalteu 试剂法测定总多酚的含量;利用亚铁还原能力实验(FRAP)法进行总抗氧化能力的评估。葡萄糖和赤霉酸共同处理可以有效提升芥蓝芽菜中有益健康的植物化学物质含量以及抗氧化能力。

•Gluconapin was the most predominant glucosinolate in all Chinese kale varieties.•Quinone reductase activity was remarkably positively correlated with glucoraphanin content.•Glucoraphanin content was increased in antisense AOP2 transgenic plants.•Quinone reductase activity was increased in antisense AOP2 transgenic plants.The variation of glucosinolates and quinone reductase (QR) activity in fourteen varieties of Chinese kale (Brassica oleracea var. alboglabra Bailey) was investigated in the present study. Results showed that gluconapin (GNA), instead of glucoraphanin (GRA), was the most predominant glucosinolate in all varieties, and QR activity was remarkably positively correlated with the glucoraphanin level. AOP2, a tandem 2-oxoglutarate-dependent dioxygenase, catalyzes the conversion of glucoraphanin to gluconapin in glucosinolate biosynthesis. Here, antisense AOP2 was transformed into Gailan-04, the variety with the highest gluconapin content and ratio of GNA/GRA. The glucoraphanin content and corresponding QR activity were notably increased in transgenic plants, while no significant difference at the level of other main nutritional compounds (total phenolics, vitamin C, carotenoids and chlorophyll) was observed between the transgenic lines and the wide-type plants. Taken together, metabolic engineering is a good practice for improvement of glucoraphanin in Chinese kale.

•CO2 enrichment enhances the accumulation of lycopene, β-carotene and ascorbic acid.•CO2 enrichment improves flavour with an increase in soluble sugar, titratable acid, sugar/acid, and soluble solids.•CO2 enrichment gives better colour and increased consumer preference.•CO2 enrichment improves the organoleptic characteristics of tomato fruits.The objective of the present study was to evaluate the effect of carbon dioxide (CO2) enrichment on the main health-promoting compounds and organoleptic characteristics of tomato (Solanum lycopersicum) fruits grown in greenhouse. The contents of health-promoting compounds, including lycopene, β-carotene, and ascorbic acid, as well as the flavour, indicated by sugars, titrable acidity, and sugar/acid ratio, were markedly increased in CO2 enrichment fruits. Furthermore, CO2 enrichment significantly enhanced other organoleptic characteristics, including colour, firmness, aroma, and sensory attributes in tomato fruits. The results indicated that CO2 enrichment has potential in promoting the nutritional value and organoleptic characteristics of tomatoes.

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.

The effect of 1-methylcyclopropene (1-MCP) on postharvest characters, antioxidants and glucosinolate contents in bolting stems of Chinese kale (Brassica alboglabra Bailey) was investigated. Chinese kale was treated with air (control) and 10 μl l−1 of 1-MCP for 24 h, followed by storage for up to seven days at 20 °C. 1-MCP treatment obviously extended the shelf life, delayed weight loss and decreased the rate of softening, chlorophyll degradation and changes in hue angle. In addition, ethylene production was suppressed and the respiration rate declined. Moreover, 1-MCP treatment postponed the decrease of ascorbic acid, carotenoids and glucosinolates. 1-MCP treatment of bolting stems also delayed the accumulation of total phenolics, and maintained a high level of antioxidant capacity. These results demonstrate that 1-MCP treatment is a good practice for extending shelf life, maintaining the appearance and nutrient value, and reducing the loss of health-promoting compounds, particularly antioxidants and glucosinolates in the Chinese kale.Highlights► 1-MCP treatment extends the shelf life in Chinese kale bolting stems. ► 1-MCP delays weight and firmness loss, chlorophyll degradation and colour change. ► 1-MCP suppresses ethylene production and declines respiration rate. ► 1-MCP maintains high contents of ascorbic acid, carotenoids and glucosinolates. ► 1-MCP delays total phenolics accumulation and maintains high antioxidant capacity.

The germination rate, fresh weight, as well as the contents of anthocyanins and glucosinolates in broccoli sprouts treated with different kinds of sugars, including sucrose, glucose, fructose, mannitol, and fructose/glucose (1:1), were investigated. The results showed that all the sugars induced the accumulation of anthocyanins and glucosinolates with sucrose being the most effective one. In accordance with the accumulation of anthocyanins and glucosinolates, the antioxidant level increased while treated with sucrose. The effect of sucrose on expression of genes related to anthocyanin and glucosinolate biosynthesis were also investigated. The genes involved in the biosynthesis and transcriptional regulation of anthocyanin as well as glucosinolate biosynthetic gene Bo-Elong were all up-regulated by sucrose within 12 h after the sucrose treatment. The application of sucrose improved the nutrition value of broccoli sprouts by enhancing the biosynthesis of anthocyanin and glucosinolate at the level of transcription.Highlights► Anthocyanin accumulated in broccoli sprouts. ► Sucrose enhanced the content of anthocyanin and glucosinolate in broccoli sprouts. ► Sucrose raised the transcriptional level of anthocyanin biosynthetic genes. ► Sucrose raised the transcriptional level of Bo-Elong.

Glucosinolates in Chinese kale (Brassica alboglabra Bailey) were analysed by liquid chromatography–mass spectrometry (LC–MS), and the variation of glucosinolates in three edible parts (sprout, rosette leaf and bolting stem) of 27 Chinese kale varieties was investigated. Thirteen glucosinolates, including eight aliphatic glucosinolates, four indole glucosinolates and one aromatic glucosinolate, were identified in Chinese kale. The contents of total glucosinolate varied extensively among the different edible parts, and the total glucosinolate contents in the sprouts were obviously higher than those in rosette leaves and bolting stems. Obvious differences in the total and individual glucosinolate contents were also observed in each edible part among the different varieties. Gluconapin was the most abundant glucosinolate among all the edible parts of the 27 varieties except for the sprout of JL-26. The JL-26, JL-25 and JL-16 varieties are good candidates for future breeding programs since they contain high levels of methylsulphinylalkyl glucosinolates (glucoiberin and glucoraphanin) in certain edible parts.

The germination, growth, total phenolics, glucosinolate, myrosinase and antioxidant activity of radish sprouts germinated under 0 (control), 10, 50 and 100 mM of NaCl were investigated. The glucoraphasatin (4-methylthio-3-butenyl-glucosinolate), total glucosinolate and total phenolic contents of 5- and 7-day-old sprouts treated with 10 and 50 mM of NaCl were significantly decreased. However, the antioxidant activity of sprouts treated with 10 and 50 mM of NaCl was not affected. The glucoraphasatin and total glucosinolate contents of 5- and 7-day-old sprouts, total phenolic contents of 3- and 5-day-old sprouts were significantly increased and myrosinase activities of 3- and 5-day-old sprouts were inhibited, although the germination was dramatically inhibited by 100 mM of NaCl treatment. These results indicated that salt stress (100 mM of NaCl treatment) could improve the nutritional value of radish sprouts, and germination of sprouts under adequate salt stress could be one useful way to enhance health-promoting compounds of plant food.

The effect of 1-methylcyclopropene (1-MCP) on quality, antioxidant enzymes and glucosinolate contents in broccoli (Brassica oleracea var. italica) florets was investigated in the present study. Broccoli florets were treated with air (control) and 2.5 μl/l 1-MCP for 6 h at 20 °C, and were then stored at 20 °C for 5 days. 1-MCP treatment markedly extended shelf life, reduced postharvest deterioration, retarded chlorophyll degradation and inhibited the increase of malondialdehyde amount and activities of polyphenol oxidase and lipoxygenase in florets. The activities of superoxide dismutase, peroxidase and catalase in florets treated with 1-MCP were higher than those in control florets. 1-MCP treatment reduced the rate of decrease of total carotenoids, ascorbic acid and glucosinolates in florets when compared to those in the control. These results indicated that 1-MCP treatment could be a good candidate for extending shelf life, maintaining visual quality and reducing loss of health-promoting compounds, particularly glucosinolates in broccoli.

Broccoli (Brassica oleracea var. italica) florets were packaged in polyethylene bags with no holes (M0), two microholes (M1), and four macroholes (M2), and then stored at 4 or 20 °C. The effects of modified atmosphere packaging (MAP) treatments on visual quality and glucosinolate contents were determined by comparing with non-wrapped florets. The results showed that MAP treatments, especially with M0 and M1, extended the shelf life and reduced the postharvest deterioration of broccoli florets stored at 4 and 20 °C. All three MAP treatments reduced the decreasing concentration rates of individual, total aliphatic and indole glucosinolates in broccoli florets when compared to those in the control, with M0 being the most significant, followed by M1 and M2 during 23 days of storage at 4 °C or 5 days of storage at 20 °C. Broccoli florets with M0 treatment maintained the visual quality and glucosinolate contents for 13 days at 4 °C and 3 days at 20 °C.

The effects of five domestic cooking methods, including steaming, microwaving, boiling, stir-frying, and stir-frying followed by boiling (stir-frying/boiling), on the nutrients and health-promoting compounds of broccoli were investigated. The results show that all cooking treatments, except steaming, caused significant losses of chlorophyll and vitamin C and significant decreases of total soluble proteins and soluble sugars. Total aliphatic and indole glucosinolates were significantly modified by all cooking treatments but not by steaming. In general, the steaming led to the lowest loss of total glucosinolates, while stir-frying and stir-frying/boiling presented the highest loss. Stir-frying and stir-frying/boiling, the two most popular methods for most homemade dishes in China, cause great losses of chlorophyll, soluble protein, soluble sugar, vitamin C, and glucosinolates, but the steaming method appears the best in retention of the nutrients in cooking broccoli.

The level of mycotoxin fumonisins in corn-based food and feed collected from Linxian County, a high-risk area for esophageal cancer in China, has been analyzed using high-performance liquid chromatographic coupled with evaporative laser scattering detector (HPLC-ELSD). A total of 104 corn kernel samples were obtained from local households, granaries, wholesale markets (central markets), and retail markets (stores and supermarkets). Fumonisin B1 (FB1) was detected in the samples from households, granaries, central markets, and stores, with a positive rate of 61.5%, 50%, 33.3%, and 17%, respectively. No fumonisin was detected in samples from the supermarket. The highest FB1 levels (0.30–3.20 μg/g; mean, 1.42 μg/g) were found in samples from the granary, followed by household (0.25–1.80 μg/g; mean, 0.73 μg/g), central market (0.25–1.10 μg/g; mean, 0.51 μg/g), and store (0.22–0.34 μg/g; mean, 0.28 μg/g). Among the 80 corn kernel samples collected from local households, 18 of 24 (75.0%) moldy samples contained high levels of FB1 (0.28–3.30 μg/g; mean, 1.58 μg/g), and 20 of 56 (35.7%) apparently healthy samples contained low levels of FB1 (0.21–0.82 μg/g; mean, 0.46 μg/g). As the central market plays an important role in trade of corn-based food and feed in China, a total of 115 corn-based food and feed samples were collected from the local central market. The highest FB1 levels (0.30–3.13 μg/g; mean, 1.50 μg/g) were found in feed, followed by unprocessed food (0.31–0.63 μg/g; mean, 0.47 μg/g) and processed food (0.21–0.28 μg/g; mean, 0.25 μg/g). The positive incidence of FB1 in feed, unprocessed, and processed food were 53.6%, 33.3% and 17.9%, respectively. In conclusion, the results showed that corn-based food and feed from Linxian County contained low level of FB1 (<2 μg/g) in general, but efforts should be made to control the fumonisin contamination in corn kernels stored in granaries and households.

Fumonisins are mycotoxins produced by the fungus Fusarium verticillioides, which is a widespread pathogen of corn. The mycotoxins are known to cause fatal diseases in some domestic animals and have been linked to human esophageal cancer in China and South Africa. Here, we describe a simple method for direct and quantitative analysis of the toxins in food products. The method is based on high-performance liquid chromatography coupled with an evaporative laser scattering detector (HPLC–ELSD) without any prior derivatization of the samples. Using this method, we have analyzed corn-based food samples from central markets in eastern China. The results showed that FB1 was the main contaminant in the samples. The overall level of fumonisin contamination was relatively low, with a range of 0.25–1.80 μg/g (mean 0.74 μg/g) in 66.7% (16 of 24) of corn samples from Middle-eastern Area, 0.21–0.29 μg/g (mean 0.24 μg/g) in 28.6% (6 of 21) of corn samples from Northeastern Area, and 0.30–3.13 μg/g (mean 0.47 μg/g) in 30.0% (6 of 20) of corn samples from Southeastern Area.

Carotenoids serve diverse functions in vastly different organisms that both produce and consume them. Enhanced carotenoid accumulation is of great importance in the visual and functional properties of fruits and vegetables. Significant progress has been achieved in recent years in our understanding of carotenoid biosynthesis in tomato (Solanum lycopersicum) using biochemical and genetics approaches. The carotenoid metabolic network is temporally and spatially controlled, and plants have evolved strategic tactics to regulate carotenoid metabolism in response to various developmental and environmental factors. In this review, we summarize the current status of studies on transcription factors and phytohormones that regulate carotenoid biosynthesis, catabolism, and storage capacity in plastids, as well as the responses of carotenoid metabolism to environmental cues in tomato fruits. Transcription factors function either in cooperation with or independently of phytohormone signaling to regulate carotenoid metabolism, providing novel approaches for metabolic engineering of carotenoid composition and content in tomato.

The purpose of this study was to investigate the effect of glucose on glucosinolates, antioxidants and metabolic enzymes in Brassica sprouts. After glucose treatment, total glucosinolates, phenolics and anthocyanin contents and antioxidant activity were significantly enhanced in Chinese kale and pak choi sprouts, while only the anthocyanin and ascorbic acid contents were increased in radish sprouts. These results indicate that glucose treatment has selectively improved the nutritional compounds in different Brassica sprouts.Highlights► Glucose enhances glucosinolates contents in Chinese kale and pak choi sprouts. ► Glucose increases phenolics contents in Chinese kale and pak choi sprouts. ► Glucose reinforces anthocyanin contents in Chinese kale and pak choi sprouts. ► Glucose increases antioxidant activity in Chinese kale and pak choi sprouts. ► Glucose enhances the anthocyanin and ascorbic acid contents in radish sprouts.

The effect of brassinosteroid (BR) on relative water content (RWC), stomatal conductance (gs), net photosynthetic rate (PN), intercellular CO2 concentration (Ci), lipid peroxidation level, activities of antioxidant enzymes and abscisic acid concentration (ABA) in tomato (Lycopersicon esculentum) seedlings under water stress was investigated. Two tomato genotypes, Mill. cv. Ailsa Craig (AC) and its ABA-deficient mutant notabilis (not), were used. Water stress was achieved by withholding water and both the AC and not plants were treated with 1 μM 24-epibrassinolide (EBR) or distilled water as a control. The RWC, gs, Ci and PN were significantly decreased under water stress. However, EBR treatment significantly alleviated water stress and increased the RWC and PN. EBR application also markedly increased the activities of antioxidant enzymes (catalase, ascorbate peroxidase and superoxide dismutase) while it decreased gs, Ci and the contents of H2O2 and malondialdehyde (MDA). Interestingly, ABA concentration in AC and not plants was markedly elevated after EBR treatment although the increasing rate and amplitude of ABA in not plants treated by EBR was significantly lower than those in AC plants. Our study suggested that amelioration of the drought stress of tomato seedlings may be caused by EBR-induced elevation of endogenous ABA concentration and/or the activities of antioxidant enzymes.Research highlights▶ 24-Epibrassinolide alleviates drought stress. ▶ 24-Epibrassinolide application increases abscisic acid concentration. ▶ 24-Epibrassinolide treatment increases activities of antioxidant enzymes.

•Pre-harvest red light irradiation postponed the degradation of glucosinolates.•Pre-harvest red light irradiation significantly increased the vitamin C content.•Pre-harvest red light irradiation enhanced the accumulation of total phenolics.•Antioxidant activity was elevated by pre-harvest red light treatment.The effects of pre-harvest red light irradiation on main healthy phytochemicals as well as antioxidant activity of Chinese kale sprouts during postharvest storage were investigated. 6-day-old sprouts were treated by red light for 24 h before harvest and sampled for further analysis of nutritional quality on the first, second and third day after harvest. The results indicated that red light exposure notably postponed the degradation of aliphatic, indole, and total glucosinolates during postharvest storage. The vitamin C level was remarkably higher in red light treated sprouts on the first and second day after harvest when compared with the control. In addition, red light treatment also enhanced the accumulation of total phenolics and maintained higher level of antioxidant activity than the control. All above results suggested that pre-harvest red light treatment might provide a new strategy to maintain the nutritive value of Chinese kale sprouts during postharvest storage.