• Comparison of phenolic and flavonoid content and antioxidant activity in vitro among potato varieties.

      Valcarel, Jesus; Reilly, Kim; Gaffney, Michael; Brunton, Nigel; O'Brien, Nora M.; Teagasc Walsh Fellowship Programme (Teagasc, 2011)
      Diets rich in fruits and vegetables have been associated with a lower incidence of cancer and heart disease, which may be related to the antioxidant activity of bioactive compounds present in these foods. Phenolic compounds are potent antioxidants in vitro, of which flavonoids are of particular interest for their potential positive impact on health. Potatoes are one of the most consumed vegetables in the world and therefore an important source of phenolics. In Ireland they are the third most important crop with a farm gate value of approximately 45 million euros annually. The aim of this work was to evaluate the antioxidant activity of methanolic solutions extracted from the skin and flesh of potato tubers against the stable radical DPPH and analyze its relationship to the content of total phenolics and total flavonoids.
    • Effect of organic and conventional cultivation techniques on yield, phenolic content, and sensory parameters in two carrot varieties

      Reilly, Kim; Gaffney, Michael; Brunton, Nigel; Department of Agriculture, Food and the Marine, Ireland; 06/NITARFC6 (Teagasc, 2011)
      Carrots are one of the most important field grown vegetables in Ireland with a farm gate value of 16 million euros in 2007. They contain health promoting bioactive compounds including carotenoids, phenolics and polyacetylenes. Organically grown vegetables are often perceived as healthier and to have better flavour. The objective of this study was to determine levels of phenolics and flavonoids in organic and conventionally grown carrots, and to determine if they can be distinguished by taste.
    • Effect of organic, conventional and mixed cultivation practices on soil microbial community structure and nematode abundance in a cultivated onion crop

      Reilly, Kim; Cullen, Eileen; Lola-Luz, Theodora; Stone, Dote; Valverde, Juan; Gaffney, Michael; Brunton, Nigel; Grant, Jim; Griffiths, Bryan; Department of Agriculture, Food and the Marine, Ireland; et al. (Wiley, 07/06/2013)
      BACKGROUND: Responses of the soil microbial and nematode community to organic and conventional agricultural practices were studied using the Teagasc Kinsealy Systems Comparison trial as the experimental system. The trial is a long term field experiment which divides conventional and organic agriculture into component pest-control and soil treatment practices. We hypothesised that management practices would affect soil ecology and used community level physiological profiles (CLPP), microbial and nematode counts, and denaturing gradient gel electrophoresis (DGGE) to characterise soil microbial communities in plots used for onion (Allium cepa L.) cultivation. RESULTS: Microbial activity and culturable bacterial counts were significantly higher under fully organic management. Culturable fungi, actinomycete and nematode counts showed a consistent trend towards higher numbers under fully organic management but these data were not statistically significant. No differences were found in the fungal/bacterial ratio. DGGE banding patterns and sequencing of excised bands showed clear differences between treatments. Putative onion fungal pathogens were predominantly sequenced under conventional soil treatment practices whilst putative soil suppressive bacterial species were predominantly sequenced from the organic pest-control treatment plots. CONCLUSION: Organic management increased microbial activity and diversity. Sequence data was indicative of differences in functional groups and warrants further investigation.
    • Potential of cultivar and crop management to affect phytochemical content in winter-grown sprouting broccoli (Brassica oleracea L. var. italica)

      Reilly, Kim; Valverde, Juan; Finn, Leo; Rai, Dilip K.; Brunton, Nigel; Sorenson, Jens C; Sorenson, Hilmer; Gaffney, Michael; Department of Agriculture, Food and the Marine, Ireland; 06/NITAFRC6 (Wiley, 08/07/2013)
      BACKGROUND: Variety and crop management strategies affect the content of bioactive compounds (phenolics, flavonoids and glucosinolates) in green broccoli (calabrese) types, which are cultivated during summer and autumn in temperate European climates. Sprouting broccoli types are morphologically distinct and are grown over the winter season and harvested until early spring. Thus they show considerable potential for development as an import substitution crop for growers and consumers during the ‘hungry gap’ of early spring. The present study investigated the effect of variety and management practices on phytochemical content in a range of sprouting broccoli varieties. RESULTS: Yields were significantly higher in white sprouting broccoli varieties. Levels of phenolics and flavonoids were in the range 81.6-270.4 and 16.9–104.8 mg 100g -1 FW respectively depending on year and cultivar, and were highest in varieties TZ 5052, TZ 5055, Red Admiral and Improved White Sprouting. In-row spacing did not affect flavonoid content. Phenolic and flavonoid content generally increased with increasing floret maturity and levels were high in edible portions of the crop. Crop wastes (leaf and flower) contained 145.9-239.3 and 21.5–116.6 mg 100g -1 FW total phenolics and flavonoids respectively depending on cultivar, tissue and year. Climatic factors had a significant effect on phenolic and flavonoid content. Levels of total and some individual glucosinolates were higher in sprouting broccoli than in the green broccoli variety Ironman. CONCLUSION: Levels of total phenolics, flavonoids and glucosinolates are higher in sprouting than green broccoli types. Sprouting broccoli represents an excellent source of dietary bioactive compounds.
    • Variation in bioactive content in broccoli (Brassica oleracea var. italica) grown under conventional and organic production systems

      Valverde, Juan; Reilly, Kim; Villacreces, Salvador; Gaffney, Michael; Grant, Jim; Brunton, Nigel; Department of Agriculture, Food and the Marine, Ireland; 06/NITAFRC6 (Wiley on behalf of Society of Chemical Industry, 30/07/2014)
      BACKGROUND Broccoli and other cruciferous vegetables contain a number of bioactive compounds, in particular glucosinolates and polyphenols, which are proposed to confer health benefits to the consumer. Demand for organic crops is at least partly based on a perception that organic crops may contain higher levels of bioactive compounds; however, insufficient research has been carried out to either support or refute such claims. RESULTS In this study we examined the effect of conventional, organic, and mixed cultivation practices on the content of total phenolics, total flavonoids, and total and individual glucosinolates in two varieties of broccoli grown over 2 years in a split-plot factorial systems comparison trial. Levels of total phenolics and total flavonoids showed a significant year-on-year variation but were not significantly different between organic and conventional production systems. In contrast, levels of the indolyl glucosinolates glucobrassicin and neoglucobrassicin were significantly higher (P < 0.05) under fully organic compared to fully conventional management. CONCLUSION Organic cultivation practices resulted in significantly higher levels of glucobrassicin and neoglucobrassicin in broccoli florets; however, other investigated compounds were unaffected by production practices.