Browsing by Author "Martins, Nuno"
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- 1-Methylcyclopropene and lemongrass essential oil nanocoatings effect on the preservation of cold stored ‘Rocha’ pearPublication . Gago, Custódia; Guerreiro, Adriana; Cruz, Sandra; Martins, Nuno; Cabrita, Maria João; Miguel, Maria; Faleiro, Maria Leonor; Antunes, Maria DulceThe effects of coating 'Rocha' pear with alginate-based nanoemulsions enriched with lemongrass essential oil (LG) was evaluated and compared to the usual 1-MCP treatment. Fruit were treated with 1-MCP (312 nL L-1) or coated with nanoemulsions: sodium alginate 2 % (w/w) + lemongrass essential oil 1.25 % (w/w) (LG 1.25 %) or lemongrass essential oil 2.5 % (w/w) (LG 2.5 %). Then, fruit were stored at 0 degrees C and 90-95 % relative humidity (RH), for eight months. Fruit samples were collected at harvest and after two, four, six and eight months of cold storage, and then transferred to shelf-life at 22 degrees C. Upon removal and after 7 d shelf-life, fruit symptoms of superficial scald and internal browning, ethylene production, color CIE (L*, hue), firmness, soluble solids content (SSC), titratable acidity (TA), weight loss, electrolytic leakage (EL), antioxidant activity and fatty acids of pear peel, microbial growth and sensory analyses were evaluated. Coatings and 1-MCP reduced fruit color evolution and preserved better firmness than control. Coatings and 1-MCP did not affect SSC and TA. Treatments did not influence the sensory quality. Microbial growth was within the safety limits in all treatments. Treatments with 1-MCP and LG-nanoemulsions were similarly efficient to reduce superficial scald, nevertheless the LG-nanoemulsions showed higher internal disorders after 8 months of storage and LG 2.5 % had higher decay at the same period, similar to control. 1-MCP treated fruit had the lowest softening rate after shelf-life up to 4 months and LG 2.5 % showed higher weight loss. Also, ethylene production was higher in control and LG 1.25 % up to 6 months plus shelf-life, while after 8 months there was no difference among treatments. This study suggests that 1-MCP is the most efficient for preserving quality of 'Rocha' pear for 8 months, while up to 6 months the best effect is obtained with LG 1.25 % nanocoatings.
- 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 . Gago, Custódia; Guerreiro, Adriana; Mariana Souza; Martins, Nuno; Fonseca, Daniela; Cabrita, Maria João; 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.
- 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.