CHEMICAL AND SENSORY QUALITY OF BROCCOLI (BRASSICA OLERACEA L. VAR ITALICA)

Five cultivars of broccoli (Brassica oleracea L. var. italica) were analyzed for individual glucosinolates, S-methylcysteine sulfoxide (SMCSO), aroma volatiles and sensory quality. Total glucosinolate content ranged from 47 to 93 μmol μmol·g dry weight¹, and SMCSO ranged from 22 to 57 μmol μmol·g dry weight¹. A total of 11 glucosinolates were identified in the broccoli cultivars. The major glucosinolates were: progoitrin, glucoiberin, glucoraphanin, glucobrassicin and neo-glucobrassicin and they accounted for more than 95% of the total content. Glucoiberin was only found in appreciable amounts in purple-headed broccoli. Pentanol, pentanal, hexanal, heptanal and nonanal were the most abundant higher boiling volatiles isolated from cooked broccoli using dynamic headspace trapping on Porapak and solvent desorption with diethyl ether. Sensory analysis by a trained panel showed that scores for cooked vegetable odor (‘hay’ and ‘green peapod’) were significantly different between cultivars. In contrast, scores related to Brassica odor (‘cauliflower’ and ‘mustard’) were not significantly different. The content of individual glucosinolates, SMCSO and higher boiling volatiles in the cultivars is discussed in relation to the sensory quality of the cooked product.     

Potential bioactive compounds in health promotion from broccoli cultivars grown in Spain

Glucosinolates, phenolic compounds and vitamin C were evaluated in two commercial and 12 experimental cultivars of broccoli (Brassica oleracea L var italica) grown under uniform cultural conditions. The predominant glucosinolates in all broccoli cultivars were 4‐methylsulphinylbutyl glucosinolate (glucoraphanin) and 3‐indolylmethyl glucosinolate (glucobrassicin). Other glucosinolates such as 4‐OH‐glucobrassicin and N‐methoxyglucobrassicin were detected in lower amounts. The total glucosinolate concentration ranged from 3.0 µmol g^?1 dw (dry weight) in Pentathlon (experimental cultivar) to 28.3 µmol g^?1 dw in I‐9905 (experimental cultivar). Flavonoids, caffeic acid derivatives and sinapic acid derivatives were quantified in methanol extracts. The largest content of flavonoids was found in the commercial cultivars Marathon and Lord, around 60 mg kg^?1 fw (fresh weight). The vitamin C content of broccoli ranged from 43.1 mg per 100 g fw in Lord (commercial cultivar) to 146.3 mg per 100 g fw in SG‐4515 (experimental cultivar). © 2002 Society of Chemical Industry     

Rocket salad (Diplotaxis and Eruca spp.) sensory analysis and relation with glucosinolate and phenolic content

BACKGROUND: Salad crops of the Brassicaceae family, such as Diplotaxis tenuifolia and Eruca vesicaria, commonly referred to as ‘rocket salads’, have attracted considerable interest as culinary vegetables because of their strong flavour and their content of putative health‐promoting compounds. Among such compounds, glucosinolates and phenolics are well‐known phytochemicals with an important role also in determining the characteristic flavour of these species. In this study, to identify potentially high‐value rocket salads, 37 cultivated types were examined for sensory characters and their relations with glucosinolate and phenolic contents, which ranged from 0.76 to 3.03 g kg^?1 dry weight (DW) and from 4.68 to 31.39 g kg^?1 DW, respectively. RESULTS: The perception of bitter taste was significantly affected by specific glucosinolates, namely progoitrin/epiprogoitrin and dimeric glucosativin. Aroma intensity was negatively related to glucoalyssin content, whereas pungency was significantly related to total glucosinolate content. Kaempferol‐3‐(2‐sinapoyl‐glucoside)‐4′‐glucoside was positively and significantly related to all flavour trait perceptions. Aroma intensity, pungency, crunchiness and juiciness were positively related to typical rocket salad flavour perception through a prominent direct effect. CONCLUSION: Aroma intensity, pungency, crunchiness and juiciness were strong determinants of overall rocket salad flavour perception. Visual traits also characterised sensory components. Bitterness, usually considered a negative flavour trait, was moderately perceived in the examined material, without negatively affecting typical flavour perception. In the range of the examined material, glucosinolate content did not contrast with typical flavour, demonstrating that good taste and putative health‐promoting properties may coexist. Copyright © 2011 Society of Chemical Industry     

Eating quality of raw carrots––correlations between flavour compounds,sensory profiling analysis and consumer liking test

Sensory profiling, analysis of aroma, sugar and dry matter, as well as consumer liking test were used to characterise the quality of six carrot cultivars, grown at two locations in Denmark. The carrot samples were examined at harvest, and after three months of cold storage. Carrot cultivar had an effect on most sensory and flavour compound variables, due particularly to the influence of one cultivar; and also location influenced carrot quality. Storage of carrots was characterised by an increase of a range of aroma components, but the changes in flavour compounds were not correspondingly observed by the sensory analysis. By Partial Least Squares Regression (PLSR) two thirds of the flavour compound variables was found to correlate significantly with one or more of the nine sensory attributes; and all of the sensory attributes were significantly correlated with one or more of the consumer liking test variables bitterness, sweetness and liking.     

Total and individual glucosinolate contents in inflorescences of eight broccoli cultivars grown under various climatic and fertilisation conditions

Total aliphatic, indolic and aromatic glucosinolates were evaluated in the edible portions of fresh harvested inflorescences of five commercial and three experimental broccoli (Brassica oleracea L var italica) cultivars grown under various climatic and agronomic conditions, ie early (winter) or late (spring) season with poor (15 kg ha^?1) or rich (150 kg ha^?1) sulphur fertilisation, in an attempt to identify differences due to genetic and agronomic factors. The predominant glucosinolates in all broccoli cultivars were 4‐methylsulphinylbutyl‐glucosinolate (glucoraphanin), 3‐indolylmethyl‐glucosinolate (glucobrassicin) and 1‐methoxy‐3‐indolylmethyl‐glucosinolate (neoglucobrassicin). The results showed no significance differences in total glucosinolates between rich and poor fertilisation, whereas total glucosinolates were detected more significantly in the late than in the early season. All broccoli cultivars showed a higher content of indolic glucosinolates than aliphatic glucosinolates. Clear advantages were detected in the analysed commercial cultivars, as the experimental cultivars yielded lower concentrations of these compounds. © 2003 Society of Chemical Industry     

Factors affecting dry-cured ham consumer acceptability

The objectives of the present study were (1) to compare the relative importance of price, processing time, texture and intramuscular fat in purchase intention of dry-cured ham through conjoint analysis, (2) to evaluate the effect of dry-cured ham appearance on consumer expectations, and (3) to describe the consumer sensory preferences of dry-cured ham using external preference mapping. Texture and processing time influenced the consumer preferences in conjoint analysis. Red colour intensity, colour uniformity, external fat and white film presence/absence influenced consumer expectations. The consumer disliked hams with bitter and metallic flavour and with excessive saltiness and piquantness. Differences between expected and experienced acceptability were found, which indicates that the visual preference of consumers does not allow them to select a dry-cured ham that satisfies their sensory preferences of flavour and texture.     

Variation of glucosinolates in three edible parts of Chinese kale (Brassica alboglabra Bailey) varieties

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 glucosinolate content of Brassica vegetables. A chemotaxonomic approach to cultivar identification

Quantitative differences in the relative glucosinolate content of Brussels sprouts have been used to assist differentiation between cultivars. The glucosinolate pattern of each individual cultivar, determined directly using gas chromatography, has been found to vary only slightly with growing site. Differing patterns of glucosinolates have been noted amongst the corresponding seeds, thus complementing the data obtained from the mature vegetable.     

Prediction of Sensory Profile of Mango Using Textural Attributes During Ripening

Mango is an important commercial fruit and is marketed based on their colour, firmness and taste. These sensory parameters vary with individual mango and person involved in testing. There is little or no information available on the instrumental estimation of these sensory attributes. The present study, therefore, was conducted to correlate sensory and instrumental textural attributes to explore the possibility of predicting them for seven major cultivars of mango influenced by harvesting dates and ripening period (10 days). In general, the textural property of peel, pulp and fruit decreased while sensory attributes increased during fruit ripening. Sensory qualities like taste, flavour and overall acceptability were significantly affected by harvesting date, cultivar and ripening period. Harvesting time and cultivars, however, did not influence the fruit appearance. Among textural attributes, peel firmness was closely associated with all the sensory parameters indicating that textural parameters could be useful to predict sensory profile of mango cultivars during their ripening. Cultivar-specific variations were observed while evaluating various equations (linear/polynomial/exponential/logarithmic/power) for correlating their textural and sensory attributes. Polynomial equation was found to be the best fit (highest coefficient of determination, R ²) for prediction of sensory quality using textural properties of majority of mango cultivars. All cultivars under study except Alphonso collected from Maharashtra showed R ² value above 0.911 which indicated potentiality of the fitted equations for the prediction of sensory attributes using textural characteristics of mango.     

ALTERATION OF GLUCOSINOLATE CONTENT, PATTERN, AND MUTAGENICITY OF CABBAGE (BRASSICA OLERACEA) GROWN ON MUNICIPAL SEWAGE SLUDGE—AMENDED SOIL

Cabbage (Brassica oleracea var. capitata) was grown on soil (control) or municipal sewage sludge-treated plots. The cabbage was freeze-dried and analyzed for glucosinolate content and pattern. Results showed that cabbage grown on sludge-amended soil contained only half the glucosinolate content of cabbage grown on the control plot. The pattern of individual glucosinolates present was also altered. The sludge-grown cabbage glucosinolate extract was shown to be mutagenic in the non-activated test system of S. typhimurium TA 100. Extracts of both sludge-grown and control cabbage were shown to enhance the mutagenicity on a dose-response basis of aflatoxin B₁, benzo(a)pyrene, and captan.     

The use of glucosinolates for cultivar identification in swede,Brassica napus L var napobmssica (L) peterm

A quantitative study of the glucosinolates in the seed, cortex and medulla (peeled root) from nine cultivars (cvs) of swede, Brassica napus L var napobrassica (L) Peterm using high performance liquid chromatography was undertaken to see whether such characteristics could be used as a biochemical index of cultivar identity. All nine cultivars could be distinguished following an analysis of medulla glucosinolates, but the analysis of seed and cortex glucosinolates yielded no such useful information.     

Genotypic variation of glucosinolates in broccoli (Brassica oleracea var. italica) florets from China

Five main cultivars from China and 143 parent materials grown in a greenhouse were used to investigate the glucosinolates in broccoli florets. Eight aliphatic glucosinolates, four indole glucosinolates, and one aromatic glucosinolate were identified and quantified using high-performance liquid chromatography (HPLC). The results showed that glucoraphanin, glucobrassicin, 4-methoxyglucobrassicin and neoglucobrassicin were present in all samples. However, the predominant type of glucosinolate was different among pure lines. The anti-cancer glucoraphanin concentration ranged from 0.06 to 24.17 μmol/g in pure lines and from 1.57 to 5.95 μmol/g in commercial cultivars. The progoitrin concentration in commercial cultivars varied from 1.77 to 6.07 μmol/g with a mean value of 3.20 μmol/g. Significant variations were observed in the concentration of individual glucosinolates and in each class of glucosinolates among broccoli populations. Dozens of specific lines with altered glucosinolate profiles, as well as ten good candidates for breeding high-chemoprotective glucosinolate cultivars, were obtained according to the putative glucosinolate pathway in broccoli.     

Glucosinolates, l-ascorbic acid,total phenols,anthocyanins, antioxidant capacities and colour in cauliflower (Brassica oleracea L. ssp. botrytis); effects of long-term freezer storage

Blanching and one year freezer storage were performed on one purple, two white and two green varieties of cauliflower (Brassica oleracea L. ssp. botrytis) to assess the effects on several health-related phytochemicals. Blanching, prior to freezing, reduced total aliphatic and indole glucosinolates (GLS) by 31% and 37%, respectively. l-ascorbic acid (L-AA), total phenols (TP), anthocyanins, FRAP and ORAC were on average reduced by 19, 15, 38, 16 and 28%, respectively. The colour measured as CIELAB parameters was partly affected by blanching: lightness was significantly reduced in the white cultivars and in a romanesco type cultivar. Chromaticity was reduced in the coloured cultivars with a twice-as-large reduction in the purple cultivars. Hue increased for all samples, except for the purple cultivar where a decrease was found. Long-term freezer storage did not affect total aliphatic and indole GLS in cauliflower in a major way. Freezer storage did result in an average L-AA decrease of 24% for all but the purple cultivar. Some reductions in the TP levels were also found but not to the extent found for L-AA. When an effect was found in the FRAP and ORAC values, the reductions occurred towards the end of the storage period and were 15% and 37%, on average, respectively. Long-term freezer storage did not affect the anthocyanin content and only minor effects were found for the colour parameters.     

Consumer acceptability of dark, firm and dry (DFD) and normal pH beef steaks

The sensory attributes of dark, firm and dry (DFD) and normal pH beef, both raw and fried, were evaluated and compared by a consumer panel (n=64). Consumer sensory evaluations indicated that the general appearance (P<0.05), colour (P<0.001) and acceptability (P<0.01) of raw normal pH steaks were preferred to those of raw DFD steaks. Twice as many panellists preferred the raw normal pH than raw DFD steaks because of the more attractive red colour, compared to the almost black colour of raw DFD steaks. No significant differences were found between the hedonic ratings of the sensory attributes of fried normal pH and fried DFD steaks. It was expected but not confirmed that consumers would find the tenderness of the DFD steaks more acceptable compared to the normal pH steaks. However, when forced to choose, female consumers significantly preferred fried normal pH steaks to fried DFD steaks, presumably because of a better flavour and more acceptable colour.     

AROMATIC COMPOUNDS IN THREE VARIETIES OF TURNIP GREENS HARVESTED AT THREE MATURITY LEVELS*

Turnip greens (Brassica rapa) are commonly consumed in the southern U.S.A. Typically, they have a bitter taste, which increases with maturity, probably because of increased levels of glucosinolates. While glucosinolate degradation products have been isolated from various members of the Brassica family, the effect of variety and maturity on these products has not been determined. This study focused on the glucosinolate degradation products of three varieties of turnip greens: Purple Top, Seven Top and Tokyo Cross, harvested 45, 60 and 75 days after planting. Four volatile components (benzene acetonitrile, benzene propane nitrile, 1H‐indole‐3‐acetonitrile and benzene ethyl isothiocyanate) were isolated, identified and quantified. All increased significantly (P < 0.05) as the greens matured; however, onlybenzene propane nitrile and 1H‐indole‐3‐acetonitrile were significantly affected (P < 0.05) by variety.