Optimum Conditions for Microwave Assisted Extraction for Recovery of Phenolic Compounds and Antioxidant Capacity from Macadamia (Macadamia tetraphylla) Skin Waste Using Water

Abstract

Abstract:This study aimed to develop optimal microwave assisted extraction conditions for recovery of phenolic compounds and antioxidant properties from the macadamia skin, an abundant waste source from the macadamia industry. Water, a safe, accessible, and inexpensive solvent, was used as the extraction solvent and Response Surface Methodology (RSM) was applied to design and analyse the conditions for microwave-assisted extraction (MAE). The results showed that RSM models were reliable for the prediction of extraction of phenolic compounds and antioxidant properties. Within the tested ranges, MAE radiation time and power, as well as the sample-to-solvent ratio, affected the extraction efficiency of phenolic compounds, flavonoids, proanthocyanidins, and antioxidant properties of the macadamia skin; however, the impact of these variables was varied. The optimal MAE conditions for maximum recovery of TPC, flavonoids, proanthocyanidins and antioxidant properties from the macadamia skin were MAE time of 4.5 min, power of 30% (360 W) and sample-to-water ratio of 5 g/100 mL. Under these conditions, an extract could be prepared with TPC of 45 mg/g, flavonoids of 29 mg RUE/g of dried macadamia skin.

Impact of Different Extraction Solvents on Bioactive Compounds and Antioxidant Capacity from the Root of Salacia chinensis L.

“…Total Flavonoids Content (TFC). TFC of Salacia chinensis root was determined as previously described by Dailey and Vuong [12]. 2 mL of deionized water was mixed with 0.15 mL of 5% (w/v) NaNO 2 and 0.5 mL of diluted sample.…”

“…Total Proanthocyanidins Content (TPrC). TPrC of Salacia chinensis root was measured as previously described by Dailey and Vuong [12]. 0.5 mL of diluted sample was mixed with 3 mL of 4% vanillin and followed by adding 1.5 mL HCl 37%.…”

Separation Emulsion via Non-Ionic Surfactant: An Optimization

“…The experimental result showed that all surfactants had a significant impact at high temperature and dosage of surfactant. Thus, RSM was utilised for designing the experimental, analysing the parameters dependent on analysis of variance, and developing the quadratic polynomial formal based model to study the influence of parameters on response and optimisation of the condition of process [23,24]. Moreover, the non-ionic surfactant is less used in demulsification of water in oil emulsion in comparison with other types of surfactant [2], while the properties of non-ionic surfactant are very promising.…”

Physical, Barrier, and Antioxidant Properties of Pea Starch-Guar Gum Biocomposite Edible Films by Incorporation of Natural Plant Extracts

“…The macadamia is recognized as an evergreen, native Australian tree with two more common species, the Macadamia integrifolia (smooth shelled) and the Macadamia tetraphylla (rough shelled) (Munro and Garg 2008). The skin/husk of the macadamia has been suggested to have plenty of phenolic compounds (Alasalvar and Shahidi 2009;Dailey and Vuong 2016).…”