Optimization of Ultrasound-Assisted Extraction of Bioactive Compounds from Pelvetia canaliculata to Sunflower Oil.

In this study, Pelvetia canaliculata L. macroalga, collected from the Atlantic Portuguese coast, was used as a source of bioactive compounds, mostly antioxidants, to incorporate them in sunflower oil with the aim of increasing its biological value and oxidative stability. The lyophilized alga was added to the oil, and ultrasound-assisted extraction (UAE) was performed. Algae concentration and UAE time varied following a central composite rotatable design (CCRD) to optimize extraction conditions. The following parameters were analyzed in the oils: oxidation products, acidity, color, chlorophyll pigments, carotenoids, flavonoids, total phenolic content, antioxidant activity by DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays, and sensory analysis. Extraction conditions did not affect the acidity and the amount of oxidation products in the oil. Chlorophylls and carotenoid contents increased with algae concentration, while flavonoid extraction did not depend on algae content or UAE time. Total phenolics in the oil were highly related only to FRAP antioxidant activity. Storage experiments of supplemented oil (12.5% algae; 20 min UAE) were carried out under accelerated oxidation conditions at 60 °C/12 days. Antioxidant activity (FRAP) of supplemented oil was 6-fold higher than the value of non-supplemented oil. Final samples retained 40% of their initial antioxidant activity. The presence of algae extracts contributed to the increased oxidative stability of sunflower oil.

Exploring physicochemical and cytogenomic diversity of African cowpea and common bean.

In sub-Saharan Africa, grain legumes (pulses) are essential food sources and play an important role in sustainable agriculture. Among the major pulse crops, the native cowpea (Vigna unguiculata) and introduced common bean (Phaseolus vulgaris) stand out. This paper has two main goals. First, we provide a comprehensive view of the available genetic resources of these genera in Africa, including data on germplasm collections and mapping biodiversity-rich areas. Second, we investigate patterns of physicochemical and cytogenomic variation across Africa to explore the geographical structuring of variation between native and introduced beans. Our results revealed that 73 Vigna and 5 Phaseolus species occur in tropical regions of Africa, with 8 countries accounting for more than 20 native species. Conversely, germplasm collections are poorly represented when compared to the worldwide collections. Regarding the nuclear DNA content, on average, V. unguiculata presents significantly higher values than P. vulgaris. Also, V. unguiculata is enriched in B, Mg, S, and Zn, while P. vulgaris has more Fe, Ca, and Cu. Overall, our study suggests that the physicochemical and cytogenomic diversity of native Vigna species is higher than previously thought, representing valuable food resources to reduce food insecurity and hunger, particularly of people living in African developing countries.

Thermal and light stability of anthocyanins from strawberry by-products non-encapsulated and encapsulated with inulin.

BACKGROUND: Strawberry by-products were explored as sources of anthocyanins for the extraction of natural colorants in the development of new value-added products for the food industry. For this purpose, the stability of strawberry anthocyanin extracts was evaluated for color and total anthocyanin content. The anthocyanins were encapsulated with inulin to protect them from processing at high temperatures and exposure to light. Microcapsules were obtained by two drying processes (spray and freeze drying) in order to study their use as coloring ingredients for their use in the food industry. METHODS: Thermal (using the response surface methodology - RSM) and light stability tests were performed, simulating long-term processing and food storage. Antioxidant activity, total anthocyanin content and color analysis were quantified using several methods, and the microcapsules were characterized using scanning electron microscopy. Anthocyanins and their derivatives were identified by high resolution mass spectrometry. RESULTS: The strawberry extracts showed high antioxidant capacity and total anthocyanin content. The RSM of the thermal stability test showed that temperature is the variable with the most significant effect on color stability and total anthocyanin content. The anthocyanins showed more stability at 50°C/60 min, 57°C/102 min, 93°C/18 min and with up to 8 days of light. Microencapsulation of the strawberry extracts with inulin obtained by spray and freeze drying improved the stability of anthocyanins. The spray drying process can offer better applications for the food industry due to the more regular shape of the microcapsules, which supports the potential use of strawberry by-products as coloring ingredients for application in the food industry. CONCLUSIONS: This study can serve as a technical reference for the development of anthocyanin microcapsules with inulin from strawberry by-products obtained by spray drying, resulting in stable natural colorants to be used as ingredients in the food industry.

Edible Leafy Vegetables from West Africa (Guinea-Bissau): Consumption, Trade and Food Potential.

Wild Edible Plants are common in the diet of rural communities of sub-Saharan Africa. In Guinea-Bissau, West Africa, wild plant resources are widely used in human diet, but very few studies have addressed them. The aim of this study is to reveal: (1) the wild and semi-cultivated leafy vegetables consumed in Guinea-Bissau; and (2) the nutritional composition of those plants traded at the largest country market in Bissau. Our results revealed that 24 native or naturalized species with edible leaves are currently consumed by Guinea-Bissau population. Five of them were found at the market: dried leaves of Adansonia digitata, Bombax costatum and Sesamum radiatum, and fresh leaves and shoots of Amaranthus hybridus and Hibiscus sabdariffa. The analysis of the nutritional properties revealed that leaves contain a significant amount of protein (10.1-21.0 g/100 g, dry basis), high values of macronutrients and micronutrients, as well as of phenolic compounds (13.1-40.3 mg GAE/g) and a considerable antioxidant capacity (DPPH 111.5-681.9 mg Eq Trolox). Although price and availability vary among the leafy vegetables analyzed, these traditional foods appear to be a good dietary component that can contribute to food security in Guinea-Bissau and in other West African countries, as these species are widely distributed in this region.