https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 The effects of drying on physico-chemical properties and antioxidant capacity of the brown alga (Hormosira banksii (turner) decaisne) https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33071 Hormosira banksii is a rich source of polyphenols, which can be utilized in the food or pharmaceutical industries. This study aimed to determine the impact of six drying methods on properties of the alga H. banksii. Our data revealed that drying conditions significantly affected recovery yield, residual moisture, extraction yield, total phenolic content (TPC) as well as antioxidant capacity of H. banksii (P < 0.05). Optimal conditions for oven, vacuum and de‐humidification were 40, 50 and 50C, respectively, and microwave power is 840 W. Under optimal conditions, H. banksii prepared by freeze, de‐humidification and vacuum had significantly higher levels of TPC, total flavonoid content (TFC) and proanthocyanidins as well as possessing stronger antioxidant capacity in comparison with those prepared by sun, microwave and oven drying methods. As freeze drying is costly and time‐consuming, de‐humidification (50C, air in and out of 11.1 and 15.4%) and vacuum (50C, 10 psi) were recommended for drying H. banksii. Practical Applications: Algae possess various antioxidants with potential benefits for health. Drying is considered as a method for preserving materials, transport with low costs and especially first step for extraction, isolation and purification of active compounds. Thus, it is important to investigate the effects of drying conditions on the properties of the dried alga H. banksii. From the findings, the different drying conditions significantly affected the phytochemical profile and antioxidant activity of the dried alga and the optimal drying conditions could be applied for preparation of dried H. banksii for further processing (extraction, fractionation and isolation of bioactive compounds) as well as potential industrial applications (as a reference for drying H. banksii and other algae).]]> Fri 24 Aug 2018 13:45:06 AEST ]]> Optimization of ultrasound-assisted extraction conditions for recovery of phenolic compounds and antioxidant capacity from banana (Musa cavendish) peel https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34477 Musa cavendish) peel using response surface methodology. The results showed that recovery yields of phenolic compounds, flavonoids, proanthocyanidins and antioxidant properties were affected by the extraction parameters; of which the acetone concentration had the greatest effect. Optimal extraction conditions were found to be at ultrasonic temperature of 30°C, ultrasonic time of 5 min, ultrasonic power of 150 W, sample to solvent ratio of 8:100 g/mL and acetone concentration of 60%. Under these optimal conditions, 23.49 mg of phenolic compounds, 39.46 mg of flavonoids and 13.11 mg of proanthocyanidins could be extracted from 1 g of banana (M. cavendish) peel. Practical applications: Banana peel known as waste is generated in a big quantity with limited utilization. Therefore, it is necessary to utilize this by‐product for adding value to food industry. This study was designed to establish a simple, effective extraction method for maximum recovery of phenolic compounds from banana peel. Findings from this study can be used for further isolation and purification of phenolic compounds from banana peel for subsequent application in nutraceutical and pharmaceutical industry.]]> Fri 15 Mar 2019 13:30:50 AEDT ]]>