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Browsing by Author "Rainha, Nuno"

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  • Assessment of molluscicidal activity of essential oils from five Azorean plants against Radix peregra (Müller, 1774)
    Publication . Teixeira, Tânia; Rosa, José S.; Rainha, Nuno; Baptista, José A. B.; Rodrigues, Armindo
    The molluscicidal activity of essential oils from two endemic (Juniperus brevifolia; Laurus azorica) and three introduced (Hedychium gardnerianum; Pittosporum undulatum; Psidium cattleianum) Azorean plants against the snail Radix peregra was studied under laboratory conditions. Essential oils from leaves of H. gardnerianum, L. azorica and J. brevifolia presented promising molluscicidal activity on both adults and juveniles stages of R. peregra. The molluscicidal activity of these essential oils was found to be both time and concentration dependent. Lethal concentrations (LC50) varied between 15.4 (L. azorica) and 44.6 ppm (H. gardnerianum) for juveniles and from 45.3 (H. gardnerianum) to 54.6 ppm (J. brevifolia) for R. peregra adults. Ovicidal effect, calculated as percentage of egg hatching, at 100 ppm concentration, was observed in essential oils from P. undulatum flowers (4.2% of hatching) and leaves of H. gardnerianum (4.9%), L. azorica (7.4%) and J. brevifolia (17.7%). The present study is the first attempt to assess the molluscicidal potential of some Azorean plants essential oils against a Lymnaeidae snail. In fact, the H. gardnerianum, L. azorica and J. brevifolia can offer natural alternative tools for the control of R. peregra population, but more research is needed in order to determine the mode of action of these oils and determine the side effects on the ecosystem where this freshwater snail occurs.
    2012-03Journal article Open access Show more
  • Bovine Milk Formula Based on Partial Hydrolysis of Caseins by Bromelain Enzyme : Better Digestibility and Angiotensin-Converting Enzyme-Inhibitory Properties
    Publication . Medeiros, Vera; Rainha, Nuno; Paiva, Lisete S.; Lima, Elisabete; Baptista, José
    A new methodology was developed using bromelain as a proteolytic enzyme for the production of a partially hydrolyzed bovine milk formula, without changing the milk's organoleptic and nutritional properties. This study also revealed that the in vitro angiotensin-converting enzyme inhibition increased in the modified milk as compared with the control sample, showing the highest angiotensin-converting enzyme-inhibitory activity for fractions with molecular weights between 3 and 10 kg mol⁻¹. The Lineweaver-Burk plot revealed that the produced milk formula acted as a non-competitive inhibitor, as determined by high performance liquid chromatography.
    2013-11-21Journal article Open access Show more