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Purslane (Portulaca oleracea L.) is the eighth most common plant distributed throughout the world being a heat- and drought-tolerant plant. In this study, we evaluated the effect of salinity on total amounts of fatty acids (FAs) and ω3/ω6 ratio in leaves of purslane. Plants exposed to four levels of chloride salinity in the root zone (60, 90, 120 and 240 mM NaCl) for 40 days showed no signs of toxicity or death. The main FAs detected were C16:0>C18:3>C18:2. The ratio of ω6 to ω3 was not changed with salt stress. Hierarchic cluster analysis brought together 60 and 90 mM NaCl in control plants, based on their FA content. The results of this study confirm the purslane as a plant rich in FAs whose consumption may contribute to dietary intake of ω3 polyunsaturated fatty acid, with obvious benefits to human health.

Sweet potato peels (SPP) are a major waste generated during root processing and currently have little commercial value. Phenolics with free radical scavenging activity from SPP may represent a possible added-value product for the food industry. The aqueous extraction of phenolics from SPP was studied using a Central Composite Design with solvent to solid ratio (30-60 mL g), time (30-90 min) and temperature (25-75 °C) as independent variables. The comparison of response surface methodology (RSM) and artificial neural network (ANN) analysis on extraction modelling and optimising was performed. Temperature and solvent to solid ratio, alone and in interaction, presented a positive effect in TPC, ABTS and DPPH assays. Time was only significant for ABTS assay with a negative influence both as main effect and in interaction with other independent variables. RSM and ANN models predicted the same optimal extraction conditions as 60 mL g for solvent to solid ratio, 30 min for time and 75 °C for temperature. The obtained responses in the optimized conditions were as follow: 11.87 ± 0.69 mg GAE g DM for TPC, 12.91 ± 0.42 mg TE g DM for ABTS assay and 46.35 ± 3.08 mg TE g DM for DPPH assay. SPP presented similar optimum extraction conditions and phenolic content than peels of potato, tea fruit and bambangan. Predictive models and the optimized extraction conditions offers an opportunity for food processors to generate products with high potential health benefits.

Aqueous extractions from two species of Erica consumed as infusions in several countries to heal ailments were investigated for their phenolic and flavonoid contents, along with antioxidant capacity and radical scavenging capacity using total antioxidant activity, ferric-reducing antioxidant power, reducing power, 1,1diphenyl-2-picrylhydrazyl and 2-2'-azino-bis(3 ethylbenzothiazoline-6-sulfonic acid) radicals, respectively. Antioxidant properties and total phenolic content differed significantly among these plants. Aqueous extracts of leaves possessed, on average, the highest antioxidant capacity and phenolic content (34.09 Ϯ 10.81 mg ascorbic acid equivalent/g dry weight and 30.59 Ϯ 10.19 mg gallic acid equivalent/ g dry weight, respectively) of all three plant parts. A significant correlation (r 2 = 0.952) between antioxidant capacity and total phenolic content was found, indicating that phenolic compounds are the major contributors to the antioxidant properties of these plants. Upon application of hierarchical cluster analysis to the results obtained, leaves with flowers were grouped in one cluster, whereas branches remained in another cluster, showing little interference from the collection site or species factors. PRACTICAL APPLICATIONSResults obtained support that there may exist benefits for health from ingesting this plant infusions and that these plants have a great potential to serve as a cheap antioxidant source. bs_bs_banner Journal of Food Quality