47 resultados para Davis, Joyce
Resumo:
This project has investigated the correlation between antimicrobial activity and the non-peroxide activity of particular Leptospermum-derived honeys. Initial investigations tested the efficacy of these honeys against one particular bacteria (Staphylococcus aureus), while later studies assessed the effect of this honey on a range of food pathogens, animal pathogens (e.g. in mastitis) and human pathogens (e.g. golden Staph). Using honeys sourced from around Australia and screened against several reference microorganisms, the anti-microbial potency of one particular Australian honey (from Leptospermum polygalifolium) was shown to be comparable to NZ Manuka honey (from L.scoparium). The results of this screening of active honeys against pathogenic bacteria has supported the registration of honey by Capilano Honey Limited as a “Drug” with the Therapeutic Goods Administration based on its antimicrobial activity.
Resumo:
White nectarines (Prunus persica var. nucipersica) were fumigated with methyl bromide (MB) at a nominal treatment dose of 18 g m-3 at 18°C for 5 h and 30 min as a quarantine disinfestation treatment against Bactrocera tryoni, the Queensland fruit fly. Three large scale trials were conducted against each of the four immature lifestages, eggs and first, second and third instars. There were no survivors from the estimated 43,614 eggs, 41,873 first instars, 41,345 second instars and 33,549 third instars treated, thereby resulting in an efficacy of GROTERDAN99.99% mortality at the 95% confidence level for each lifestage. Of the 12 trials reported herein, the highest concentration of MB, sampled from the chamber headspace analysed by gas chromatography, was 18.7 g m-3. The maximum chamber temperature from 5 min readings was 19.7°C and the maximum fruit core temperature was 19.5°C. The treatment time for all trials was exactly 5.5 h. Thus the recommended treatment dose to disinfest nectarines from B. tryoni is 19.0 g m-3 MB at 20.0°C for 5.5 h. Fruit quality trials were conducted on white nectarines at three combinations of treatment parameters: 15 g m-3 MB at 19°C for 5.25 h; 18 g m-3 MB at 19°C for 5.5 h and 21 g m-3 MB at 19°C for 5.5 h. The fruit were stored at 0, 4 and 8 days at 4°C and 8 days at 4°C followed by 4 d at 22°C. They were then were assessed for skin colour, flesh colour, skin defects, flesh defects, fruit weight loss, flesh firmness, total soluble solids, titratable acidity and rots. There was no significant difference between untreated control and MB treated fruits in any of the parameters measured. Thus the treatments did not have adverse effects on fruit quality.