Leandro Camargo Neves

Dano de frio em limas-ácidas Tahiti, colhidas em diferentes épocas e submetidas a tratamentos térmicos e bioquímicos

The aim of this study was to establish an effective and satisfactory method to control chilling injuries on Tahiti lime. Thus, the fruits that were harvested in Boa Vista, RR, 140 and 150 days after flowering, showed average values of 7.9 and 8.2oBrix and 6.3 and 6.0mL of citric acid/100mL of flesh and 2.8 and 3.0 pH, respectively in two harvests. After the harvest the fruits were taken to the laboratory of Plant Production/UFRR, selected, cleaned and submitted to the following treatments: T1 - control; T2, T3 and T4 - maintained at 35oC for 6, 12 and 24 hours, respectively; T5 - intermittent warming at 20oC for 8 hours, after 5 and 10 days at 1oC; T6 - intermittent warming at 20oC for 8 hours, after 10 and 20 days at 1oC; T7 - ethephon at 1,500 mg.L-1; and T8 - ethephon at 3,000 mg.L-1.The treatments T9 to T16, only differed from T1 to T8, only on the harvest date (10 days after the first one). The experiment was evaluated every 15 days, during 75 days at 1 ± 0.5 oC and 92 ± 5 % of RU, regarding the chilling injury, visual aspect, lack of fresh mass, soluble solids (SS), titratable acidity (TA), SS/TA (ratio - RT), total chlorophyll and ascorbic acid. The delay of the harvest did not provide any significative effect. All treatments, except the control and intermittent warming in 10 and 20 days, were efficient to control the chilling injury. However, the chemical and thermal conditioning speeded up the metabolism of fruits, mainly concerning the lack of fresh mass and visual aspect characteristics. The higher chlorophyll and ascorbic acid content, as well the best visual aspect, no rottenness incidence and the lower lack of fresh mass were detected on fruits submitted to the intermittent warming at 5 and 10 days. The SS, AT and RT were considered compatible to the quality standard and did not vary statistically among the treatments which had shown resistance to the chilling injury.

Caracterização físico-química, bioquímica e funcional da jabuticaba armazenada sob diferentes temperaturas

The present study aimed to measure the postharvest quality, the total phenolic compounds and antioxidant capacity of the jabuticaba fruits under a modified atmosphere at different temperatures of cold storage. After the fruits were harvested in the mature green stage, they were packed in expanded polystyrene (EPS) trays, covered by low densidy polyethylene (LDPE) plastic film and, stored at 0, 3, 6, 9 and 12 ± 1oC and RH of 87 ± 2%, being evaluated every 5 days. Fruit were evaluated for weight loss, respiratory rate, pH, titrable acidity, soluble solids content, ascorbic acid content, texture, total and soluble pectin and polyphenoloxidase activity, phenolics composition and antioxidant capacity. For the fruits stored at 9 and 12oC the respiratory peak was delayed when compared to other fruits stored at low temperatures, and the respiration rate was lower. The soluble solid contents increased with storage time at all temperatures, but at 9 and 12oC the increase was proportionally smaller. The texture and ascorbic acid contents were also higher in fruits stored at 9 and 12oC, and they showed the lowest levels of soluble pectin. The polyphenoloxidase activity decrease during the 30 days of cold storage, independent of the temperature, but the lowest values were found in the fruit stored at 9 and 12oC. With respect to the total phenolic compounds and antioxidant activity, the fruits stored at 12oC showed the best scores after 30 days of cold storage. In this sense, the temperature of 12oC was more effective in maintaining the postharvest quality of the jabuticabas.

QUALIDADE DE FRUTOS PROCESSADOS ARTESANALMENTE DE AÇAÍ (Euterpe oleracea MART.) E BACABA (Oenocarpus bacaba MART.)

The fruits of acaizeiro (Euterpe oleracea Mart.) and of bacabeira (Oenocarpus bacaba Mart), two native tropical palms and socio-economically important for the Amazonian states, are utilized, almost in its entirety, in the production of processed pulp on agricultural family systems. In this sense, the present study aimed to the evaluation of physical, chemical, physic-chemical and functional quality of processed pulps of acai and bacaba. The fruits were harvested in private rural properties in the county of Canta/Roraima (bacaba) and Boa Vista/Roraima (acai). For the preparing of the experiment, the processed pulps were stored in small containers of polyethylene terephthalate (PET) transparent and cover (same material), with capacity of 145ml and, refrigerated at 3 ± 0.2 °C and 45% RH for 5 days. It was analyzed the follow parameters: pH, titratable acidity (TA), soluble solids (SS), ratio (SS/TA), total and reducing sugars, total and soluble pectin, and the content of anthocyanins and total phenolics. At the end, for the acai pulps, taking into account the limits set by Standard Identity and Quality (PIQ), only the TA parameter presented itself outside the normative instruction. However, the lack of standards for the bacaba pulps prevented such a comparison. Regarding the total content of pectin, it is possible concluded that both pulps presented low concentrations of this component, and aren’t suitable for producing jams and jellies without the addition of gelling agents. The total phenolic contents and anthocyanins, in both pulps, although decreasing with the refrigerated storage time, show reasonable concentrations in comparison to other foods with functional appeal.