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- The effect of alginate-based edible coatings enriched with essential oils constituents on Arbutus unedo L. fresh fruit storagePublication . Guerreiro, Adriana; Gago, Custódia; Faleiro, Leonor; Miguel, Maria Graça; Antunes, Maria DulceThe effect of coating Arbutus unedo fresh fruit with alginate-based edible coatings enriched with the essential oils compounds (EOC) eugenol (Eug) and citral (Cit) was studied. The minimum inhibitory concentrations (MIC) against the main postharvest pathogens were determined for Eug and Cit giving values of 0.10 and 0.15 (w/v), respectively. Twelve formulations of edible coatings were used: sodium alginate (AL) was tested at 1 and 2% (w/v) with incorporation of Eug and Cit at MIC and double MIC or their combination at MIC. Arbutus berries were dipped in those solutions for 2 min, and then stored at 0.5 degrees C. Control consisted of uncoated fruit. On days 0, 14 and 28, samples were taken to perform physicochemical and biochemical analysis [color CIE (L*, h degrees), firmness, soluble solids content (SSC), weight Loss, trolox equivalent antioxidant capacity (TEAC), microbial growth and taste panels]. Results showed that edible coatings of 1% AL were the best to maintain most quality attributes of the commodity through storage at 0.5 degrees C. The incorporation of Cit and Eug into the alginate edible coatings improved the coatings in most cases, AL 1% + Eug 0.20% and AL 1% + Cit 0.15% + Eug 0.10% being those that better preserved sensory and nutritional attributes and reduced microbial spoilage. Thus, these coatings may be useful for improving postharvest quality and storage life of fresh arbutus fruit. (C) 2014 Elsevier B.V. All rights reserved.
- The effect of temperature and film covers on the storage ability of Arbutus unedo L. fresh fruitPublication . Guerreiro, Adriana; Gago, Custódia; Miguel, Maria Graça; Antunes, Maria DulceThe strawberry tree (Arbutus unedo L) fruits are used in small quantities for fresh consumption despite their excellent flavor. The aim of this work was to evaluate the storage ability of strawberry tree fruits for fresh consumption. Harvested fruits were stored in polystyrene foam trays covered with two film types: linear low density polyethylene of 10 mu m thickness (PPL) or polyethylene film perforated with holes of 10 mm diameter spaced 50 mm (PP). Through 15 days storage at 0,3 and 6 degrees C, fruits were analyzed for quality parameters. The strawberry tree fruits presented relevant qualitative properties and were appreciated by panelists. Color parameters (L*, h degrees, C*) had higher decrease at 3 and 6 degrees C than at 0 degrees C. The degrees Brix almost did not change and firmness decreased mainly in the first 4 days storage. Ethanol and weight loss increased with temperature mostly from 3 to 6 degrees C. Strawberry tree fruits are a good source of ascorbic acid, glucose, fructose, anthocyanins and antioxidant activity. Those properties are maintained through 15 days storage at 0 degrees C followed by 3 degrees C. Film covers showed no significant differences between them. The temperature of 0 degrees C was the best for preservation of fruit quality through 15 days shelf-life. (C) 2013 Elsevier B.V. All rights reserved.
- Arbutus unedo L.: Chemical and Biological PropertiesPublication . Miguel, Maria Graça; Faleiro, Leonor; Guerreiro, Adriana; Antunes, Maria DulceArbutus unedo L. (strawberry tree) has a circum-Mediterranean distribution, being found in western, central and southern Europe, north-eastern Africa (excluding Egypt and Libya) and the Canary Islands and western Asia. Fruits of the strawberry tree are generally used for preparing alcoholic drinks (wines, liqueurs and brandies), jams, jellies and marmalades, and less frequently eaten as fresh fruit, despite their pleasing appearance. An overview of the chemical composition of different parts of the plant, strawberry tree honey and strawberry tree brandy will be presented. The biological properties of the different parts of A. unedo and strawberry tree honey will be also overviewed.
- Effectiveness of Sodium Alginate and Carnauba Wax Nanoemulsions with lemongrass essential oil on the quality of ‘Hass’ avocado fruit from early, middle, and late harvest season during prolonged cold storagePublication . Souza, Mariana; Martins, Nuno; Fonseca, Daniela; Cabrita, Maria João; Gago, Custódia; Guerreiro, Adriana; Miguel, Maria da Graça; Antunes, Maria DulceAvocado ( Persea Americana Mill.) has gained popularity as a widely produced and consumed fruit worldwide, raising concerns about its storage and transportation. The avocado, being a climacteric fruit sensitive to chilling injury, faces challenges that affect its shelf life and commercial viability. This research delves into the effectiveness of edible sodium alginate 2 % (weight/weight, w/w) (SA) and carnauba wax 1 % (w/w) (CW) coatings, both independently and in combination with lemongrass essential oil, sodium alginate 2 % (w/w) + lemongrass essential oil 1.25 % (SALG) and carnauba wax 1 % + lemongrass essential oil 1.25 % (w/w) CWLG) as postharvest treatments. Uncoated avocados were used as control (CT). The nanocoating-treatments aim to preserve the quality of 'Hass' avocados harvested during the early, middle, and late season. After treating the fruits, some from each treatment group were kept at 21 +/- 1 degrees C for 7 days (shelf life). The rest were stored at 5 degrees C and 90 % RH for 15, 30, and 45 days before being submitted also to shelf life. In each sampling date, quality parameters measured included: firmness, color (L*, ), weight loss, gray pulp symptoms, ethylene production and pulp electrolyte leakage. Also, fatty acids (FA), hydrogen peroxide (HO), malondialdehyde (MDA), alpha-farnesene (Farn) and conjugated trienols (Ctrols) were quantified in avocado pulp. Fruit quality analysis showed that all coatings improve quality and reduction of gray pulp development, especially CW and the incorporation of lemongrass in both matrices. Therefore, these edible coatings can be an alternative to improve preservation of avocado fruit quality through cold storage and subsequent shelf-life, which potentially reduce fruit waste.