Genotypic effects on the phytochemical quality of seeds and sprouts from commercial broccoli cultivars

Determining ontogenic diversity in vegetables, in general or Brassicas in particular, regarding the bioactive content, is an interesting task since the most promising Brassicaceae foods could have the highest nutritional and health-promoting properties. Therefore, vitamin C, phenolic compounds, glucosinolate content, and total antioxidant capacity were evaluated in commercial cultivars of broccoli (Brassica oleracea var. italica; cv. Nubia, cv. Marathon and cv. Viola) seeds and during the sprouting period. Vitamin C was not detected in dormant seeds and its content increased with the germination, reaching values ranging from 53 (cv. Nubia) to 64 (cv. Marathon) mg/100 g FW, at the end of the monitored period (14days). The total glucosinolate content in seeds and 3-day-old sprouts was higher in cv. Marathon (1005 and 556 mg/100 g FW, respectively), however cv. Viola sprouts registered the highest glucosinolate content 7 and 14 days after sowing (235 and 208 mg/100 g FW, respectively). Aliphatic glucosinolates were more affected by genetic factors than the indolic glucosinolates, being glucoraphanin the predominant glucosinolate in cv. Nubia and cv. Marathon, whereas glucoiberin was the major glucosinolate in cv. Viola. The flavonoid and total phenolic content was significantly higher in cv. Viola. Also, seeds of this cultivar showed the highest antioxidant capacity (2.7 mg Trolox/g FW).     

Acylated anthocyanins in broccoli sprouts

Broccoli is a nutritious vegetable and a good source of vitamins and minerals. It also contains important antioxidant phytochemicals like β-carotene and α-tocopherol, indoles and isothiocyanates. On the other hand, edible sprouts are novel nutritive plant-derived foods, good source of flavonoids and other polyphenols (Moreno, Pérez-Balibrea, et al., 2006).     

Improving the phytochemical composition of broccoli sprouts by elicitation

In order to increase the concentrations of bioactive compounds in broccoli sprouts, exogenous elicitors: methionine, tryptophan, chitosan, salicylic acid (SA) and methyl jasmonate (MeJA) were sprayed at different concentrations during germination. The effects of the elicitors on vitamin C, phenolic compounds and glucosinolate levels were assessed in 3, 5 and 7-days old seedlings. The application of 200, 300 μM SA and 0.01% chitosan induced increases, by 26%, 18% and 54%, respectively in the content of vitamin C in 5 days old broccoli sprouts. Flavonoid concentration was also increased by 31% and 33% after 10 μM MeJA and 100 μM SA treatments, respectively in 7 days old broccoli sprouts. In contrast, methionine or tryptophan solutions did not positively affect the vitamin C or the phenolic compounds in the sprouts. The individual classes of glucosinolates respond differently to the elicitor treatment. Methionine, a sulphur-containing amino acid, applied at 5 mM, significantly increased, by 32%, the levels of aliphatic glucosinolates. However, indole glucosinolates presented a significant response to the induction with tryptophan, SA or MeJA treatments. Tryptophan at 10 mM concentration augmented by 1.8-fold the indole glucosinolate concentration in 7 days old broccoli sprouts, and the treatments of 100 μM SA and 25 μM MeJA also induced significantly higher amounts of indole glucosinolates (by 33% and 51%, respectively) in 7 days old treated broccoli sprouts. Therefore, the application of elicitors could be a useful tool for improving the bioactive metabolites in broccoli sprouts for fresh consumption or functional ingredients for nutraceuticals foods.     

Effect of 1-methylcyclopropene on shelf life,visual quality,antioxidant enzymes and health-promoting compounds in broccoli florets

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.     

Role of elicitation on the health-promoting properties of kidney bean sprouts

The influence of germination of kidney beans for 4, 6 and 8 days in different elicitors (ascorbic acid, folic acid, glutamic acid, glutamic acid/chitosan and lactic acid/chitosan) on the production of health-promoting ingredients was studied. Sprouts were characterized according to their protein profile, soluble phenolic compounds (SPC) and γ-aminobutyric acid (GABA) content. Additionally, the antioxidant and angiotensin-converting enzyme (ACE) inhibition activities of aqueous extracts from kidney bean elicited sprouts were determined. Elicitation by glutamic acid for 8 days led to the highest SPC and GABA accumulation in kidney bean sprouts and their extracts were selected based on their highest phytochemical content. These extracts also showed remarkable antioxidant and ACE-inhibitory activities. The IC₅₀ for ACE inhibition of glutamic acid-extracts increases 89-fold after the in-vitro gastrointestinal digestion. These results will contribute not only to improving the health-promoting potential of kidney bean sprouts but also to obtaining ingredients which might reduce oxidative stress and hypertension.     

Analysis and metabolite profiling of glucosinolates,anthocyanins and free amino acids in inbred lines of green and red cabbage (Brassica oleracea L.)

We profiled and quantified glucosinolates (GSLs), anthocyanins and free amino acids in thirty-seven inbred lines green and red cabbage. Analysis of these distinct cabbages revealed the presence of 8 GSLs, 13 anthocyanins and 12 free amino acids. GSL contents were varied among the different lines of cabbage. The maximum levels of glucoraphanin (14.91 μmol/g DW) and glucobrassicin (12.37) were found in FX 1-28 and FX 1-32 lines, respectively. Total GSLs in red cabbage lines were 50% higher than those of green cabbage. Anthocyanin contents in red cabbage were ranged from 4.11 to 6.81 mg/g DW in FX 2-3 and FX 1-34 lines, respectively. Among the 13 anthocyanins, both cyanidin 3-(feruloyl) (sinapoyl)diglucoside-5-glucoside and cyanidin 3-(sinapoyl) (sinapoyl)diglucoside-5-glucoside levels were the highest amounts. The amounts of total free amino acids were ranged from 523.5 to 1308 mg/100 g fresh weight (FW) in green cabbage and 484.8 to 1271 in red cabbage, respectively. In red cabbage lines, 9.4% of the total free amino acids accounted essential amino acids such as valine, threonine, isoleucine, leucine and lysine. Thus, the amounts of GSLs, anthocyanins, and amino acids varied widely, and the variations in these compounds between the lines of cabbage were significant.     

Effect of temperature and modified atmosphere packaging on overall quality of fresh-cut bell peppers

The effect of vacuum packaging (VP) and modified atmosphere packaging without vacuum (MAP) on shelf-life of fresh-cut green bell pepper stored at 5°C and 10°C were evaluated. In-package atmosphere, overall quality, percentage of leaked juice, texture, ascorbic acid content, ethanol and acetaldehyde, and microbial growth, were evaluated at different intervals of storage. MAP-fresh-cut peppers presented better visual quality, less leaked juice and higher firmness than those stored under VP. Microbiological and quality analysis revealed a limit of shelf-life of 14 and 21 days, when fresh-cut peppers were stored at 10°C and 5°C, respectively. We conclude that MAP could be used to maintain quality attributes of fresh-cut peppers for up 21 days at 5°C.     

Tyr-Pro-Lys,an angiotensin I-converting enzyme inhibitory peptide derived from broccoli (Brassica oleracea Italica)

To investigate the naturally occurring angiotensin I-converting enzyme (ACE) inhibitor, broccoli (Brassica oleracea Italica) extracts were used for its isolation and identification. After treatment with 50% acetone for membrane breakdown, ethyl acetate, n-butanol, and water were used for the preparation of broccoli extracts. The water-soluble extract from broccoli had 76.9% ACE inhibitory activity, while those of other organic solvent extracts showed lower ACE inhibitory activities. An ACE inhibitory peptide was isolated using column chromatographic methods including: Amberlite XAD-4, Sephadex LH-20, and high performance liquid chromatography. The purified ACE inhibitory peptide was identified to be a tripeptide, Tyr-Pro-Lys, having an IC₅₀ value of 10.5 μg protein/ml.     

Flacourside,a new 4-oxo-2-cyclopentenylmethyl glucoside from the fruit juice of Flacourtia indica

A new glucoside ester, named flacourside, has been isolated together with known methyl 6-O-(E)-p-coumaroyl glucopyranoside and 6-O-(E)-p-coumaroyl glucopyranose from the n-butanol extract of fruit juice of the Flacourtia indica. The structure of flacourside has been determined to be 4-oxo-2-cyclopentenylmethyl 6-O-(E)-p-coumaroyl-β-d-glucopyranoside on the basis of spectroscopic studies.     

Ascorbic acid,nitrate, and nitrite concentration relationship to the 24 hour light/dark cycle for spinach grown in different conditions

Nitrate, nitrite and ascorbic acid (vitamin C) concentrations were determined for spinach (Spinacia oleracea L.) over a 24 h period to determine if light intensity (including dark periods) at time of harvest impacts concentrations in raw vegetables. Nitrate, nitrate and ascorbic acid concentrations varied significantly over the 24 h period and appeared to be related to changes in light intensity. Light intensity at the time an experimental sample is collected may affect the concentration of some constituents that a researcher is studying. Also, nitrate and nitrite concentrations in raw spinach can be reduced by harvesting at the best time of day. The highest nitrate concentrations in spinach occurred in the dark just prior to an increase in light intensity. Ascorbic acid was near its highest level for the 24 h period when the light intensity initially increased, then decreased to its lowest level around 3–6 h later.     

Effect of salinity stress on phenolic compounds and carotenoids in buckwheat (Fagopyrum esculentum M.) sprout

The effect of salinity stress on the nutritional quality of buckwheat sprouts cultivated for 1, 3, 5, and 7d was investigated by analysis of the antioxidant activity and levels of phenolic compounds and carotenoids. Treatment with various concentrations of NaCl (10, 50, 100, and 200mM) resulted in an increase in the amount of phenolic compounds and carotenoids in the sprouts compared with the control (0mM). The phenolic contents of sprouts treated with 10, 50, and 100mM after 7d of cultivation were 57%, 121%, and 153%, respectively, higher than that of the control (0mM NaCl). Moreover, the accumulation of phenolic compounds was primarily caused by an increase in the levels of 4 compounds: isoorientin, orientin, rutin, and vitexin. The carotenoid content of sprouts treated with 50 and 100mM NaCl was twice higher than that of the control. In addition, the antioxidant activity of ethanol extracts of the sprouts was increased by NaCl treatment. Although the growth rate of sprouts decreased with >50mM NaCl, these results suggest that treatment of an appropriate concentration of NaCl improves the nutritional quality of sprouts, including the level of phenolic compounds, carotenoids, and antioxidant activity.     

The use of photochemiluminescence for the measurement of the integral antioxidant capacity of baobab products

The number of methods to measure antioxidants in botanicals, foods, nutraceuticals and other dietary supplements are increased considerably in the last 10 years. However most techniques require long experimental times and high costs to determine antioxidant capacity of hydrophilic or lipophilic compound in a food mixture. By means of a photochemiluminescence method, we assessed the Integral Antioxidant Capacity (IAC) which represents the sum of the antioxidant capacity of hydrophilic and lipophilic antioxidants. In this study the IAC of extracts from Adansonia digitatata (i.e. red fiber, fruit pulp and leaves), was assessed in comparison to those deriving from other natural sources of antioxidants (i.e. orange, kiwi, apple and strawberry). When compared, IAC values for the examined product resulted as follows: Adansonia digitata red fibre ? Adansonia digitata fruit pulp ? Adansonia digitata fresh leaves ? Adansonia digitata seeds ? Adansonia digitata radix cuticle ? orange fresh pulp ? strawberry fresh fruit pulp > Adansonia digitata radix > bilberry fresh pulp ? kiwi fruit pulp. Results clearly indicate the interesting antioxidants properties of Adansonia digitata red fibre, in particular the IAC value of baobab red fibre was 66 time higher than that of orange pulp, with value of 1617.3 μmol/g and 24.3 μmol/g, respectively.     

Antioxidant activity and phenolic compounds of fractions from Portulaca oleracea L.

Portulaca oleracea fractions obtained from the crude extract of the plant by reversed-phase separation were investigated for their antioxidant activities and phenolic compounds content. Five fractions were classified based on optical absorption between the wavelength range of 200–400 nm. Fraction 3 displayed higher absorption than the other fractions. The total amount of quantified phenolics in this fraction was found to be quite high compared to that of crude extract. Chlorogenic, caffeic, p-coumaric, ferulic and rosmarinic acids were the free phenolic acids, and quercetin and kaempferol were the free flavonoids detected in Fraction 3. IC₅₀ value of crude extract was found to be 511.8 μg/ml whereas Fraction 3 exhibited an IC₅₀ value of 154.1 μg/ml. TEAC of Fraction 3 was found to be almost four times higher than that of the crude extract. Fraction 3 was also found to show the highest lipid peroxidation inhibiting capacity, determined by TBARS assay.     

Effect of decontamination on the microbial load,the sensory quality and the nutrient retention of ready-to-eat white cabbage

The effect of different decontamination treatments such as washing with sodium hypochlorite (20 and 200 mg/L), peroxyacetic acid (80 and 250 mg/L), neutral electrolysed oxidising water (4.9 and 31.7 mg/L free chlorine) and contact with 1.55 mg/L chlorine dioxide gas on the microbial and sensory quality, and the nutrient content of fresh-cut white cabbage was studied. Only rinsing with 200 mg/L sodium hypochlorite, peroxyacetic acid or contact with gaseous chlorine dioxide resulted in significantly higher reductions of the total plate count (1.5–2.5 log cfu/g) than the ones achieved by washing with tap water (0.5 log cfu/g). However, those treatments giving the best results from a microbial point of view induced significant changes in the sensory quality. Regarding the effects on nutrient content, the mechanical effects caused by water washing already reduced the vitamin C content by 16–29%. Contrary to washing with neutral electrolysed oxidising water and contact with chlorine dioxide gas, a supplementary decrease of the vitamin C content ranging between 9 and 28% was observed, when peroxyacetic acid or 200 mg/L sodium hypochlorite were used. After the use of peroxyacetic acid or gaseous chlorine dioxide, the phenol content also showed a decreasing trend, although not statistically significant. Apart from the effect of washing with water, the lipophilic nutrients were well retained after a decontamination step except for the α-tocopherol content, when peroxyacetic acid was used (−43 to 56%), and for the all-trans-β-carotene content (−8%) of cabbage in contact with gaseous chlorine dioxide. Because of its potential to reduce the initial microbial load without negative effects on the sensory quality, in combination with its limited effects on nutrient content, a treatment with 80 mg/L peroxyacetic acid is preferable to decontaminate fresh-cut white cabbage.     

Chlorogenic acids and related compounds in medicinal plants and infusions

The consumption of plant infusions for prevention and treatment of health disorders is a worldwide practise. Various pharmacological activities inherent to medicinal plants have been attributed to their phenolic composition, including chlorogenic acids (CGA). Studies have shown potential beneficial properties of CGA to humans such as antioxidant, hepatoprotective, hypoglycaemic. In the present study, the CGA composition of 14 dried medicinal plants was determined by HPLC-UV and LC-DAD–ESI-MS. The plants with the highest CGA contents were Ilex paraguariensis, Bacharis genistelloides, Pimpinella anisum, Achyrochine satureioides, Camellia sinensis, Melissa officinalis and Cymbopogon citratus, with 84.7 mg/100 g–9.7 g/100 g, dry weight. Plant infusions were prepared (at 0.5%) in order to evaluate the actual consumption of CGA through these beverages. Total CGA contents in the infusions were similar to those in the methanolic extracts and indicated that a satisfactory extraction occurs during the preparation of infusions. These CGA-rich plants deserve attention regarding the pharmacological properties attributed to CGA.     

Toxic compounds in essential oils of coriander, caraway and basil active against stored rice pests

Essential oils, distilled from seeds of Coriander sativum and Carum carvii and from leaves of five different varieties of Ocimum basilicum, were fractionated by column chromatography and tested in the laboratory for volatile toxicity against three stored rice pests (Sitophilus oryzae, Rhyzopertha dominica and Cryptolestes pusillus). The active fractions were analyzed by GC-MS. Coriander contained linalool (1617 ppm of the oil) as the main product active against the three pests. Camphor-rich fractions (over 400 ppm) were very toxic to R. dominica and C. pusillus. The caraway profile included carvone and limonene as expected but (E)-anethole, generally regarded as a minor product in the essential oil of this species, was also a major component, being present at 365 ppm. Carvone was the most effective (972 ppm) monoterpenoid against S. oryzae. In addition, (E)-anethole at 880 ppm was toxic to R. dominica while vapors of limonene (1416 ppm) and fenchone-rich (554 ppm) fractions killed adults of C. pusillus only. Three major essential oil profiles were present in the five varieties of O. basilicum analyzed: methyl eugenol/estragole, estragole and estragole/linalool chemotypes. The abundance of components had a strong influence on the outcome of the bioassays. Fractions, where combinations of products occurred with or without other minor compounds, were often more toxic than any one compound alone.     

Glucosinolates profile of Brassica rapa L. subsp. Sylvestris L. Janch. var. esculenta Hort

Glucosinolates in different ecotypes of Brassica rapa L. subsp. sylvestris L. Janch. var. esculenta Hort. widely distributed in Southern Italy and locally known as “friariello” and “cima di rapa”, were characterized and their glucosinolate composition was compared with that of broccoli (Brassica oleracea L. var. italica).     

Effect of Lactococcus garvieae, Lactococcus lactis and Enterococcus faecalis on the behaviour of Staphylococcus aureus in microfiltered milk

The effect of four strains of Lactococcus garvieae, three strains of Lactococcus lactis and one strain of Enterococcus faecalis on Staphylococcus aureus SA15 growth in microfiltered milk was evaluated. Lactococcus and Enterococcus strains were co-cultured with S. aureus in microfiltered milk and in medium buffered at pH 6.8. All Lactococcus and Enterococcus strains were able to inhibit S. aureus growth after 6h of incubation. Inhibition by L. lactis and E. faecalis strains could be partially attributed to the decrease in pH below 6.0 as it has been observed in medium buffered at pH 6.8. L. garvieae strains were the most effective to inhibit S. aureus growth without acidification. Inhibition of S. aureus could not be attributed neither to production of lactate, acetate or nor to antistaphylococcal substance. Amino acids competition was not involved in the inhibition by L. garvieae as addition of valine, isoleucine, threonine, methionine and phenylalanine did not suppress the inhibition of S. aureus.