Changes in strawberry phenolics, anthocyanins, and antioxidant capacity in response to high oxygen treatments

Changes in fruit quality, decay, phenolic and anthocyanin content, and antioxidant capacity of strawberries (Fragaria × ananassa Duch. cv. Allstar) stored under air and high oxygen atmospheres at 5 °C were investigated. Freshly harvested strawberries were placed in jars and ventilated continuously with air or with 40, 60, 80, or 100 kPa O₂ at 5 °C for up to 14 days. Samples were taken initially, and after 3, 7, 10 and 14 days of storage. While fruit quality parameters such as titratable acidity, total soluble solids and surface color were only slightly affected by differing levels of O₂, the higher oxygen concentration treatments significantly reduced decay. Oxygen concentrations higher than 60 kPa also promoted increases in ORAC values, total phenolics and total anthocyanins as well as individual phenolic compounds analysed by HPLC during the initial 7 days of storage. However, this effect diminished with prolonged storage. No significant differences in ORAC values, total phenolics, total anthocyanins, or the individual phenolic compounds were observed among the high O₂ and air-stored fruits after 14 days of storage. These results indicate that high oxygen treatments exert the most effects on fruit quality and antioxidant capacity of strawberry fruit in the first 7 days of storage.     

Study of the chemical composition of edible red macroalgae Grateloupia turuturu from Brittany (France)

The chemical composition and its seasonal variation of the red seaweed Grateloupia turuturu, an invasive macroalgae from Brittany, France, were investigated. Size, ash, protein, lipid, dietary fibre (soluble, insoluble and total), protein pigment (R-phycoerythrin, R-phycocyanin), and fatty acid content were measured in G. turuturu samples collected over 1 year (2006). The average size of this seaweed was 32.0 cm long and approximately 5.0 cm wide, while the size of the thallus was maximal in June (in length and width). On the dry weight basis, this alga was constituted of more than 18% ash, about 23% protein, 2.6% lipids, and approximately 60% dietary fibre. The most abundant fatty acids were palmitic acid and eicosapentaenoic acid (52% and 12% of the fatty acid fraction, respectively). The study of seasonal variations showed that the best period to collect the seaweed for food use is between February and June.