https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:21331 Momordica charantia L.) is a medicinal fruit reported to have antidiabetic properties. To grow this tropical fruit year-round in temperate climates, greenhouse production is necessary, sometimes without insect pollinators. Suitable high-yielding varieties with good bioactivity need to be identified. This experiment evaluated the yield of six varieties of bitter melon under greenhouse conditions and their bioactivity in terms of total phenolic and saponin compounds and total antioxidant activity determined using four assays. Results: The larger varieties (Big Top Medium, Hanuman, Jade and White) were more productive than the small varieties (Indra and Niddhi) in terms of total fruit weight and yield per flower pollinated. The bioactivity (total phenolic and saponin compounds and antioxidant activity) of the two small varieties and Big Top Medium was significantly higher than that of the other three large varieties. Two antioxidant assays, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP), were shown to provide the strongest correlations with phenolic and saponin compounds of bitter melon. Conclusion: Preliminary research has identified Big Top Medium as the most suitable variety for greenhouse production. The rich source of phenolic and saponin compounds and their associated antioxidant activity highlight bitter melon as a valuable food.]]> Wed 11 Apr 2018 17:18:45 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28342 (Momordica charantia L.) is a medicinal fruit often used for the treatment of diabetes, due to its content of saponins, phenolics and flavonoids and its antioxidant capacity. The aims were to use response surface methodology (RSM) to optimise the inlet (125.6, 130, 140, 150, 154.1°C) and outlet (72.9, 75, 80, 85, 87.1°C) temperatures for the spray-drying encapsulation of a bitter melon aqueous extract using a combination of maltodextrin and gum Arabic as encapsulating agent and to determine the stability of the optimised encapsulated powder under various storage conditions. The RSM models were adequate to describe and predict the responses for the process yield, the retentions of saponins, phenolics, flavonoids and antioxidant activity, the moisture content and the water solubility index with an overall R²≥0.91. The optimal inlet and outlet temperatures were determined to be 140°C and 80°C, respectively. The optimised spray-dried powder had high values for process yield (71.4±1.4%), retention of bioactive compounds and antioxidant activity (=87.9±2.6%), water solubility index (89.9±0.51%) and had a low moisture content (2.2±0.1%), which was below the Mo=5.71 predicted by the BET model. However, in terms of the morphology of the powder particles under scanning electron microscopy and loss of the bioactive compounds and antioxidant activity, the safest range for preserving the powder at 25°C was determined to range from 22.5% to 33.8%. The encapsulated powder was also slightly more stable at -20 and 10°C than at 30°C, over 150days. Therefore, it can be concluded that spray-drying with the inlet temperature at 140°C and the outlet temperature at 80°C resulted in a very stable encapsulated powder of the bitter melon aqueous extract.]]> Wed 05 Jul 2017 14:38:49 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20934 Sat 24 Mar 2018 08:06:05 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:21219 Camellia sinensis) catechins are strong antioxidants linked with potential health benefits. Based on previous studies, it was hypothesised that the typical household conditions for brewing green tea in a teabag – 200 mL freshly boiled water for 2–3 min, as per the manufacturers’ instructions – were not sufficient to extract all the catechins and that a household microwave oven could be used to improve the extraction. The catechins and the two other main green tea components, caffeine and theanine, were monitored by HPLC. The typical household conditions only extracted 62% (61 mg/g tea), 76% (24 mg/g) and 80% (10 mg/g) of the catechins, caffeine and theanine, respectively, from the five varieties of teabags analysed. However, using microwave assisted extraction (MAE) by first brewing a teabag in 200 mL freshly boiled water for 0.5 min before irradiation for 1 min in a microwave oven (hot MAE), improved the extraction of the catechins and caffeine to 80% (80 mg/g) and 92% (29 mg/g), respectively, although the extraction of theanine was not affected. Therefore, the hot MAE technique could help maximise the extraction of the catechins for those who consume green tea for the potential health benefits of the catechins.]]> Sat 24 Mar 2018 07:55:29 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29023 Momordica charantia L.) has traditionally been used as a medicinal food in many developing countries. It is a tropical fruit claimed to have therapeutic effects due to its content of bioactive compounds. The present review is an attempt to highlight the bitter melon varieties, bioactive composition that is linked to its therapeutic effects, especially antidiabetic effect, in vitro and in vivo models, and understanding of the mechanisms of actions of bitter melon that are associated with epidemiological evidences. This paper also outlines a proposed processing scheme aiming to fully utilize bitter melon and add further value to this fruit.]]> Sat 24 Mar 2018 07:31:06 AEDT ]]>