Fresh Mass Loss Research Articles

Postharvest quality of Aster ericoides after treatment with silver thiosulphate and sucrose

ABSTRACT: Aster (Aster ericoides L.) is a flower crop of North American origin, which belongs to the family Asteraceae. This plant presents capitulum-type inflorescences, widely used as cut flowers. In Brazil, it has been grown only recently, but still has a high expansion potential. In floriculture, pulsing and conditioning solutions are often used to extend the vase life of cut flowers. The present study aimed to evaluate the influence of silver thiosulphate (STS) pulsing and sucrose solutions on the postharvest life of A. ericoides stems. The experiment was carried out under a complete randomized design with treatments arranged in a 2x5 factorial scheme. Treatments consisted of flower stems treated with STS pulsing for 30 minutes, combined with four sucrose concentrations (5, 10, 15, and 20%) for six hours, plus a control (without treatment). Each plot contained four replicates of 10 stems, totalizing 400 stems. The following variables were daily: vase life, fresh mass, and relative water content (RWC). For pulsing data, means were compared by the Tukey’s test (p≥5%). Yet for sucrose concentrations, means were submitted to a polynomial regression to verify the behavior of variables as a function of concentrations increases. Likewise, each treatment was evaluated for fresh mass and RWC variations over time by a polynomial regression. Results indicated no effect of STS pulsing (2mM) on the vase-life length of aster stems. In contrast, the sucrose solution at 10% extended the vase life of stems by two days, decreased fresh mass loss, and helped maintain water balance in stems.

Modified atmosphere in minimally processed cauliflower conservation and quality

The objective of this work was to evaluate modified atmosphere effectiveness in minimally processed cauliflower aiming food safety maintenance for consumers, as conservation of product physical and chemical characteristics for better quality. Cauliflowers cv. Cindy were selected, washed, sanitized with sodium hypochlorite (200 mg L-1) and rinsed. After processing, they were immersed, one more time, in sodium hypochlorite solution (50 ppm) and dried by the air. Portions of 200 g were made and placed in different atmospheres: T1 = 0.05 % CO2 + 23 % O2; T2 = vacuum; T3 = tray of expanded polystyrene with polyvinyl chloride film (PVC) and T4 = 6 % CO2 + 4 % O2 + 90 % N2. The packages were stored in cold chamber at 5 ºC ± 1 and 85% ± 5 of relative humidity. Analysis were performed every two days and the evaluated traits were: loss of fresh mass, respiratory activity, soluble solids, titratable acidity, pH, reducing sugars, instrumental color, visual and microbiological analysis. The experimental design was completely randomized, in factorial design. Data were submitted to analysis of variance and means were compared using Tukey test at 5% of probability and regression analysis for storage period. Tray of expanded polystyrene with PVC delayed for two days product climacteric peak in relation to other modified atmosphere. Furthermore, it provided quality attributes maintenance. The best notes of visual appearance and the best intention of purchase were attributed to minimally processed cauliflower wrapped in modified atmosphere with 6% CO2. + 4% O2.

Methyl jasmonate and salicylic acid on postharvest physiology of Bird of Paradise

Bird of Paradise (Strelitzia reginae Banks) has great market potential due to its intrinsic beauty and longer vase life. However, storage and transportation conditions are not always adequate and may lead to negative consequences on postharvest physiology and the quality of these flowers. Thus, this study determined the effect of pulsing treatment containing methyl jasmonate (MeJA) or salicylic acid (SA) in association with sucrose on the postharvest physiology of Bird of Paradise. Two independent experiments were carried out. In the first one, floral stems were treated with 100, 250 and 400 ?mol L-1 of MeJA plus 200 g L-1 of sucrose for 24 h. In the second experiment, the treatments consisted of 2, 4 and 6 mmol L-1 of SA in association with 200 g L-1 sucrose for 24 h. After the pulsing treatment, the floral stems of both experiments were kept in containers with water at room temperature. The analyses were performed on days 0 and 7 and the assessment comprised: water uptake rate, transpiration rate, fresh mass loss, electrolyte leakage, peroxidase activity (POD) and phenolic compounds of the bracts and sepals. MeJA and SA reduced the water uptake rate by the stems. SA reduced transpiration rate, loss of fresh mass and phenolic compounds of sepals on day 0. On day 7, MeJA treatment reduced electrolyte leakage and increased POD activity. Otherwise, SA had no effect on electrolyte leakage and reduced POD activity. These results suggest that MeJA and AS act antagonistically on the electrolyte leakage and POD activity which might promote different effects on the postharvest physiology of Bird of Paradise stems, such as adverse patterns of the transpiration rate.

Bioactive compounds and antioxidant activity of buriti fruits, during the postharvest, harvested at different ripening stages

Abstract The buriti ( Mauritia flexuosa L.f.) is a highly nutritious fruit with a yellowish-orange pulp and a bittersweet taste. Its endocarp is surrounded by a spongy material made of starch and oil, while the fruit skin is hard, consisted of small reddish-brown scales. This work aimed to characterize the bioactive compounds and the antioxidant activity of buriti fruits, during the postharvest time, harvested at different ripening stages. The fruits were harvested in a transitional environment savannah/forest at private properties in the city of Boa Vista, Roraima, Brazil. Fruits were analyzed for five consecutive years (2012–2016), at three different ripening stages: immature (with up to 75% green color between the scales), mature (with up to 50% green color between the scales) and ripened (with up to 25% green color between the scales). The selected fruits were standardized on the basis of their appearance, such as color of the epidermis and phytosanitary conditions, and later sanitized. Different fruit variables were analyzed every 2 days during a 10-day postharvest period including loss of fresh mass, pH, total acidity, soluble solids, total pectins, pectin methyl esterase and polygalacturonase enzyme activity, respiratory behavior (CO 2 and ethylene), and functional activity such as phenolic compounds, carotenoids and antioxidant activity (ORAC and DPPH). High antioxidant activity, in both methods, was observed in buriti fruits at different ripening stages during the postharvest storage period, characterized by high phenolic and carotenoid compounds. Fruits harvested at mature and immature stages showed a longer postharvest shelf life. It was observed a climacteric behavior of the buriti fruits here analyzed, that showed an increase in the respiration rate and ethylene production, indicated by the peak of CO 2 and ethylene production. Similar changes were observed in the fruit pH, total acidity and soluble solids, as well as in the activity of peptic enzymes whereas a decrease was observed in the total pectin contents. The fruits showed reasonable amount of phenolic compounds, carotenoids and antioxidant activity, thus confirming the functional potential of these fruits.

Fruit quality of Brazilian genotypes of feijoa at harvest and after storage

Abstract: The objective of this work was to evaluate the physicochemical attributes and vitamin C contents of fruits of five Brazilian genotypes of feijoa (Acca sellowiana), at harvest and after cold storage. The Alcântara, Mattos, Helena, and Nonante cultivars, as well as accession 2316, were studied. The assessed attributes were: fresh mass loss, titratable acidity, soluble solids contents, soluble solids contents/titratable acidity ratio, pH, skin and flesh color, texture, and vitamin C contents (skin and flesh). After storage, there were reductions of 2.9% in soluble solids contents, of 32.2% in titratable acidity, and of approximately 85% in texture attributes, besides increases of 36.3% in the soluble solids contents/titratable acidity ratio and of 21.7% in the pH of fruits. The vitamin C content in the skin was higher than that in the flesh, and increased in both skin and flesh after storage. 'Alcântara' fruits have the highest contents of vitamin C in the skin and flesh. Fruits of 'Nonante' and 'Mattos' show better preservation of the texture attributes, and fruits of 'Nonante', the lowest levels of flesh browning during storage.

The influence of pulsed light exposure mode on quality and bioactive compounds of fresh-cut mangoes.

This study investigated the effect of pulsed light (PL) on the respiratory rate, quality (firmness, color and soluble solid content), bioactive compounds (ascorbate and carotenoid) and total antioxidant activity of fresh-cut "Tommy Atkins" mangoes. Fresh-cut mangoes were subjected to PL treatments: control (0P), 1 pulse (1P; 0.7Jcm-2), 4 successive pulses (4P; 2.80Jcm-2) and 1 pulse per day for 4days (1P4D; 2.80Jcm-2) before storage for 7days at 6°C. The 1P and the 4P treatments reduced fresh mass loss during storage, while 4P-treated samples also showed a slower decline of yellow color, as shown by parameter b and overall better visual appearance. After 7days of storage, total ascorbate content was 40% higher in the 1P4D treatment than in control, whereas total carotenoid content (0.894mgg-1 FM) and total antioxidant activity (144μmol trolox 100g-1 FM) were the highest in the 4P-treated samples. Results suggest that PL mode of application is more important than the fluence or final dose received by fresh-cut mangoes; moreover, 4P is an effective method to preserve, or even improve quality of fresh-cut mangoes.

Potential use of germicides in vase solutions for gladiolus ‘White Friendship’

Gladiolus (Gladiolus x hortulanus) is one of the most important crops for cut flowers worldwide, however having a short longevity. Usually, stems are harvested at the bud stage and need water and carbohydrates to support inflorescence development and to ensure flower quality. Vase solutions can supply these elements. However, sugars may benefit bacterial proliferation, which eventually can block xylem vessels. Bactericides potentially inhibit microorganism proliferation and new compounds are being tested constantly. This experiment was conducted to evaluate ‘White Friendship’ cut gladiolus performance in vase solutions with sodium dichloroisocyanurate dihydrate (Na-DCC), 8-hydroxyquinoline (8-HQ) or polymeric biguanide (PB). Inflorescences harvested at commercial maturity were placed in distilled water with 4% w/v of sucrose plus the germicides and kept under ambient conditions. Vase life, inflorescence postharvest development, fresh mass, membrane stability index and water relations were evaluated. There were no visual symptoms of toxicity in the treatments. The highest values of vase life, fully-open flowers, fresh mass and water balance were obtained with the Na-DCC treatment. Inflorescences treated with 8-HQ exhibited the highest values of solution uptake and wilting flowers. PB had a limited effect in gladiolus postharvest since the obtained results were similar to the sucrose alone. There was no effect of germicides on membrane stability index and its reduction was due to flower senescence progress only. Vase solution with Na-DCC plus sucrose improved water balance, increased open flowers, reduced wilting of flowers and fresh mass loss. Therefore, vase solutions with sucrose 4% w/v and Na-DCC enhance postharvest quality of cut gladiolus inflorescences.

Qualidade de pitaia (Hylocereus undatus) submetida à adubação orgânica e armazenada sob refrigeração

Resumo Neste trabalho, foi investigado o efeito da adubação orgânica, associada à refrigeração, na qualidade de pitaias vermelhas. As plantas foram adubadas, durante 4 anos, a cada três meses, conforme os seguintes tratamentos: testemunha (sem adubação) (T1); esterco bovino (14 kg/planta) (T2); esterco de galinha (2 kg/planta) (T3) e esterco de galinha (2 kg/planta) + esterco bovino (14 kg/planta) (T4). Os frutos foram armazenados por 21 dias a 13 °C e avaliados, nos dias 0, 7, 14 e 21, quanto à perda de massa fresca, cor, firmeza, acidez total titulável (AT), pH, sólidos solúveis totais (SST), SST/AT, açúcares totais, redutores e não redutores. Os resultados mostraram que, durante o armazenamento refrigerado da pitaia, os tratamentos de adubação orgânica interferiram nos parâmetros de qualidade avaliados, atenuando a perda de qualidade de frutos. Destaca-se que a adubação com esterco de bovino associada ao esterco de galinha foi mais eficaz que as demais adubações orgânicas e resultaram em frutos com menores perdas de qualidade durante o armazenamento.

Influence of maturity stage on fruit longevity of cherry tomatoes stored at ambient and controlled temperature

Fruit maturity stage has direct influence on the post-harvest life and consumer quality. Therefore, the understanding of the maturation process and its quality characteristics for storage are key factors for commercialization. In face of the foregoing, this study aimed to determine shelf life and changes in physical and chemical indexes of cherry tomatoes (Perinha Água Branca (PAB) and Mascot), assessing fruit harvested at four maturity stages and stored at ambient and controlled temperatures. For this, it was used fruit at turning, pink, red and ripe maturity stages, submitted to ambient (25 ± 2 °C) and controlled (12 °C and 90% RH) temperature, and assessed over time the indexes of fresh mass loss, titratable acidity, pH, soluble solids and ascorbic acid. The experimental design was completely randomized design in a factorial scheme of 2×4×7 for ambient temperature and 2×4×8 for controlled temperature. At ambient temperature, a longevity of up to 20 days was observed for PAB and Mascot fruit harvested at turning and pink maturity stages. When harvested at red and ripe stages, the longevity was of 15 days for PAB fruit and of 15 and 11 days, respectively, for Mascot fruit. At controlled temperature, PAB fruit showed longevity of 24 days when harvested at turning and pink stages and of 20 and 7 days, respectively, when harvested at red and ripe stages. A longevity of up to 27 days was observed for Mascot fruit harvested at turning stage and of 24 days for the other stages. The fruit harvested at turning and pink maturity stages, associated with storage under controlled conditions, presented higher longevity and maintenance of physical and chemical indexes of quality.

Model-Assisted Estimation of the Genetic Variability in Physiological Parameters Related to Tomato Fruit Growth under Contrasted Water Conditions.

Drought stress is a major abiotic stress threatening plant and crop productivity. In case of fleshy fruits, understanding mechanisms governing water and carbon accumulations and identifying genes, QTLs and phenotypes, that will enable trade-offs between fruit growth and quality under Water Deficit (WD) condition is a crucial challenge for breeders and growers. In the present work, 117 recombinant inbred lines of a population of Solanum lycopersicum were phenotyped under control and WD conditions. Plant water status, fruit growth and composition were measured and data were used to calibrate a process-based model describing water and carbon fluxes in a growing fruit as a function of plant and environment. Eight genotype-dependent model parameters were estimated using a multiobjective evolutionary algorithm in order to minimize the prediction errors of fruit dry and fresh mass throughout fruit development. WD increased the fruit dry matter content (up to 85%) and decreased its fresh weight (up to 60%), big fruit size genotypes being the most sensitive. The mean normalized root mean squared errors of the predictions ranged between 16–18% in the population. Variability in model genotypic parameters allowed us to explore diverse genetic strategies in response to WD. An interesting group of genotypes could be discriminated in which (i) the low loss of fresh mass under WD was associated with high active uptake of sugars and low value of the maximum cell wall extensibility, and (ii) the high dry matter content in control treatment (C) was associated with a slow decrease of mass flow. Using 501 SNP markers genotyped across the genome, a QTL analysis of model parameters allowed to detect three main QTLs related to xylem and phloem conductivities, on chromosomes 2, 4, and 8. The model was then applied to design ideotypes with high dry matter content in C condition and low fresh mass loss in WD condition. The ideotypes outperformed the RILs especially for large and medium fruit-size genotypes, by combining high pedicel conductance and high active uptake of sugars. Interestingly, five small fruit-size RILs were close to the selected ideotypes, and likely bear interesting traits and alleles for adaptation to WD.

Determination of harvest time and quality of native camu-camu fruits (Myrciaria dubia(Kunth) Mc Vaugh) during storage

Introduction. Camu-camu (Myrciaria dubia (Kunth) Mc Vaugh) is a fruit species of the Myrtaceae family. It presents great economic potential due to its nutritional and antioxidant capacity and high vitamin C contents, reaching 7355 mg ascorbic acid 100 g-1 pulp. The present work aimed to determine the harvest time and quality of camu-camu native fruits during storage. Materials and methods. The experiment was carried out in a completely randomized design with three replications, containing 30 fruits each, in a factorial scheme (3×8), composed of three different maturation stages (immature, semi-mature and mature) and eight days of storage. Fruits were evaluated every day regarding the following variables: loss of fresh mass, pH, soluble solid contents (SS), titratable acidity (TA), ascorbic acid (AA), chlorophyll A and B content, and the maturation index (SS:TA). Results and discussion. Fruits at the semi-mature stage presented the greatest amount of ascorbic acid, conserving the quality attributes (SS, AT and fresh mass) and the ascorbic acid contents for longer. Fruits at the immature stage presented the highest values for chlorophylls A and B, and this stage is also recommended for the extraction of these biocompounds. Conclusion. The recommended harvest time of the camu-camu fruit is the semi-mature stage, when the fruit presents better quality and a longer shelf life, and conserves the desired nutritional values for longer.

Heliconia ‘Golden Torch’ postharvest: stem ends cutting and renewing vase water benefits

The postharvest longevity is one of the main aspects that should be considered in the production of cut flowers and is a pre-requisite for product quality and marketing success. However, cut flowers are highly perishable products that need to be treated and stored to maintain its quality and value. This study aimed to assess Heliconia psittacorum ‘Golden Torch’ inflorescences postharvest longevity, submitted to periodic stem ends cutting and vase water renewal. The experimental design was a completely randomized 3x2 factorial, corresponding to the stem ends cuts (1 cm; without cutting; cutting at 24 hours; cutting at 48 hours) and water renewal (with and without renewal), with four repetitions. The assessed variables were: water uptake by flower stems (WUFS); loss of fresh stem mass (LFSM); dry matter of flower stems (DMFS) and postharvest longevity (PHL). The stem cut significantly influenced WUFS and LFSM. However, the water renewal factors affected all variables, while the interaction between factors (stem cuts x water renewal) only influenced PHL. The cuts at the stem base of Heliconia ‘Golden Torch’ procedures enable the restoration of water potential and this practice, associated with water renewal during storage allows greater tissues hydration, maintaining the postharvest quality.

Utilização de biofilme comestível na conservação pós-colheita de pimentão verde (capsicum annuum L.)

A utilização de biofilmes comestíveis são uma das alternativas tecnológicas eficientes na manutenção da vida útil de frutos e hortaliças. A fina camada de material comestível atua como excelente propriedade de barreira artificial, e associada à refrigeração age mantendo a qualidade pós-colheita dos frutos. Este trabalho teve como objetivo avaliar a aplicação do biofilme a base de alginato de sódio sobre a manutenção da qualidade pós-colheita de pimentões verdes (Capsicum annuum L.). Os frutos foram selecionados, lavados, sanitizados, revestidos com 1% e 3% de alginato. Frutos sem revestimento foram utilizados como controle Após aplicação do revestimento os frutos foram armazenados em expositor vertical a 7°C e 87±1% UR por até 15 dias. A cada três dias Foram realizadas analises de perda de massa fresca, firmeza do fruto, teores de acidez titulável e de ácido ascórbico, pH, parâmetros de cor, e atividade da enzima pectinametilesterase (PME). O uso do revestimento foi eficiente em retardar o metabolismo dos frutos de pimentão. O revestimento também foi capaz de manter por mais tempo a firmeza dos frutos quando comparados com o controle. Frutos revestidos apresentaram maiores valores de SS e AT, menor atividade da enzima pectinametilesterase, menor perda de massa fresca, e melhor aspecto visual durante os 15 dias de armazenamento.

Bioatividade de indutores de resistência no manejo da antracnose da goiabeira (Psidium guajava L.)

RESUMO A cultura da goiaba apresenta perdas em torno de 40 a 60% na pós-colheita relacionadas a problemas fitossanitários, como a antracnose causada pelo fungo Colletotrichum gloeosporioides. Pesquisas com métodos alternativos utilizando indutores de resistência têm sido bastante promissoras na busca de produtos com alto potencial no controle de patógenos em pós-colheita. Assim, o presente trabalho teve como objetivo avaliar os indutores de resistência no controle da antracnose e seus efeitos na qualidade físico-química em frutos de goiabeira ‘Paluma’. Os tratamentos utilizados foram: Agro-mós®, Ecolife®, Fosfitonova K®, Cuprogarb 500®, Rocksil® e testemunha (água destilada esterilizada). Realizou-se o teste in vitro, com discos de colônia de C. gloeosporioides (0,45 cm de diâmetro) com sete dias de cultivo e, postos em meio de cultura BDA acrescidos com os indutores. Foi determinada a porcentagem de inibição do crescimento micelial de C. gloeosporioides. O ensaio in vivo foi realizado com frutos de goiabeira variedade Paluma, desinfestados e tratados com indutores. Em seguida, discos de colônia do C. gloeosporioides foram inoculados e do primeiro ao oitavo dia após a inoculação, foram feitas avaliações do diâmetro das lesões nos frutos. As análises pós-colheita foram realizadas, avaliando a perda de massa fresca, sólidos solúveis totais (SST), acidez titulável (AT), razão SST/AT e potencial hidrogeniônico (pH). Foi utilizado o delineamento inteiramente casualizado, em esquema de parcela subdivididas 6x8 (tratamentos x período de avaliação) e as médias comparadas pelo teste de Tukey a 5% de probabilidade. Os indutores Agro-mos®, Ecolife®, Fosfitonova K®, Cuprogarb 500® e Rocksil® inibiram o crescimento micelial do C. gloeosporioides in vitro, reduziram o diâmetro das lesões e mantiveram a qualidade pós-colheita em frutos de goiabeira ‘Paluma’.

Fresh properties, compressive strength and microstructure of fly ash geopolymer paste blended with iron ore tailing under thermal cycle

This study aims to broaden the application of iron ore tailing (IOT) in geopolymer. Fresh properties, residual strength, mass loss and microstructure evolution of geopolymer prepared by using fly ash as starting material blended with IOT and activated by sodium silicate and sodium hydroxide solutions were investigated after exposure to 3 and 7 heat-cooling thermal cycles at different target heating temperatures of 200°C, 400°C and 800°C when fly ash was partially replaced by IOT at levels ranging from 0% to 30% with an interval of 10%, by weight. The experimental results uncover that IOT addition influences the workability and setting time of geopolymer especially when more than 20% of IOT is added. Under the effects of thermal cycles, the compressive strength decreases significantly especially after 7 thermal cycles. The loss in compressive strength increases as the cycle target temperature increases from 200°C to 800°C. The presence of IOT evidently improves the thermal resistance of geopolymer with the replacement level of IOT less than 30%. The reduced Ca(OH)2 and the associated formation of additional C-S-H evidences the role of IOT in the formation of C-S-H and supports the results of the increasing compressive strength. Replacing of fly ash with 20% IOT leads to a reduction of the porosity and microcrackings which results in much denser microstructure. Surface Vickers-hardness of geopolymer has also been optimized by IOT addition regardless of exposure target temperature.

Longitudinal data assessment of global stability index in kale leaves

Kale plants are usually sold “in natura” in street markets and malls. Kale leaves can have their appearance compromised by dehydration and discoloration due to increased post-harvest time exposure. We aimed to analyze the Global Stability Index (GSI) in kale accessions by means of repeated measurement analysis and curve grouping as a complementary form of superior sample identification with regard to post-harvest preservation. Thirty kale accessions were evaluated using a randomized block design with four blocks and five plants per plot. Two commercial leaves per plant were collected, and kept on workbenches in the shade at a temperature of 18 ± 1 °C. Subsequently, the degrees of discoloration and dehydration, total chlorophyll content, and accumulated fresh mass loss were evaluated over a 15-day period. From these data, the GSI was calculated for each day of evaluation. In addition, using mixed models, thirteen co-variance structures were tested. For graphical analysis, thirteen linear and non-linear models were assessed followed by curve grouping using multivariate analysis. The GSI was efficient for differentiating accessions, which became an important tool in post-harvest studies. GSI values were not equally correlated, therefore the use of mixed models became an important approach. The unstructured matrix was the best fit to model the dependence of error. The Melow I model was the best fit for studying the GSI. The accessions UFVJM-10, UFLA-1, COM-1, UFVJM-32, COM-3, UFVJM-8, UFVJM-36 and UFVJM-24, belonging to 3 and 5 clusters, are recommended for crop cultivation and as parental material in breeding programs.

Post-harvest conservation of camu–camu fruits (Myrciaria dubia (Kunth) Mc Vaugh) using different temperatures and packages

The camu-camu tree (Myrciaria dubia (Kunth) Mc Vaugh) is fruit-bearing tree belonging to the family Myrtaceae. This work was conducted with the purpose of evaluating the type of storage temperature and package which allow better conservation of the quality attributes of camu-camu. The experimental design utilized was the completely randomized with three replications in a factorial arrangement (3x3x8), constituted of three different storage temperatures (laboratory ambiente or 25 ± 2 °C, 15 °C and 20 °C), three types of packages (no package, PET and PVC) and fourteen days’ storage, the fruits being analyzed every two days. The fruits were evaluated as to fresh mass loss, pH, soluble solids contents, titrable acidity, ascorbic acid, carotenoids, anthocyanins, chlorophylls A and B and maturation index (SS/AT). According to the results obtained, the quality attributes and ascorbic acid content were conserved for longer time in the fruits stored on PVC-film covered expanded polystyrene trays at 15 °C. It follows that the best temperature for the storage of camu-camu is 15 °C and the package that best keeps its quality attributes is the PVC-film covered expanded polystyrene tray.

Beneficiamento pós-colheita de lima ácida 'Tahiti' afeta sua qualidade e conservação

RESUMO: O objetivo deste trabalho foi determinar os efeitos das etapas de beneficiamento pós-colheita de lima ácida 'Tahiti' na sua qualidade e conservação. Foram utilizados frutos colhidos por torção, em estádio de maturação fisiológica e beneficiados de acordo com o procedimento para frutos de exportação. Foram estabelecidos cinco pontos de coleta de frutos ao longo do processo de beneficiamento, os quais correspondem aos tratamentos estudados: "Campo"- coleta diretamente na planta; "Recepção"- na área de recepção da unidade de beneficiamento; "Repouso"- após a primeira etapa do beneficiamento; "Beneficiamento completo"- após o beneficiamento completo; e "Centro de comercialização"- na recepção do centro de comercialização. Foram conduzidas análises físicas e químicas durante 20 dias de armazenamento a 22±2ºC e 70±5% de UR. Os frutos que passaram pelo processo de beneficiamento completo e os que foram coletados no centro de comercialização apresentaram maior perda de massa fresca, maior incidência de oleocelose, menor porcentagem de frutos em condição de comercialização ao final do período de armazenamento, escurecimento da polpa e maior degradação de ácido ascórbico. A qualidade e conservação dos frutos de lima ácida 'Tahiti' foram prejudicadas pela movimentação, manipulação e injúrias mecânicas que ocorrem durante as etapas de beneficiamento pós-colheita.

<b>Handling and postharvest shelf life of ora-pro-nobis leaves

The goal of this study was to assess the effects of hydrocooling and plastic bag use on the postharvest quality ora-pro-nobis (Pereskia aculeata Mill.) leaves stored at 5 and 25ºC. The experiments were conducted in a split plot scheme, with treatments in plots and subplots storage time in a randomized block design. The leaf chlorophyll content, mass loss (ML), relative water content (RWC), soluble sugars levels, reducings (RED), non-reducings and starch were determined. In leaves stored at 25ºC, the ML was higher when leaves were hydrocooled. The highest RWC resulted from the use of plastic bag, which prevented the leaves from wilting for a longer period of time. The soluble sugars levels varied according to the increase or decrease in RWC. The contents of RED decreased with the time of storage at 25°C. The cold storage increased the shelf life of ora-pro-nobis by 168 hours. The hydrocooling increased the RWC of leaves, although it did not influence the shelf life. The perforated plastic bag was effective in increasing the shelf life, and when associated with hydrocooling, the plastic bags provide a lower rate of loss of fresh mass.

Ethylene and changes during ripening in 'Horvin' plum (Prunus salicina Lindl.) fruits

The plum is a fruit prized for its nutraceutical properties because of its high content of fiber and sorbitol, which aid in digestion; furthermore, it is characterized as containing antioxidant pigments and an antiseptic action with anthocyanins. These fruits are classified as climacteric and continue the process of respiration and ripening after harvesting; because of this, it is necessary to harvest early so they can withstand transport, which often causes the fruits to not reach the consumption maturity required by consumers. The effect of ethylene on the ripening of plum fruits was evaluated, for which a completely randomized design with 10 treatments was used, which resulted from the combination of two factors plus a control without applications. The first factor was the ethylene dose (100; 1,000 and 2,000 mg L-1) and the second factor was the length of exposure to the ethylene (5, 10 and 15 minutes). The fruits were stored at room temperature for 9 days. In the fruits treated with ethylene, a significant increase in the respiration index and total soluble solids was observed. Additionally, greater total titratable acids and firmness values were obtained with the control treatment than with the ethylene; similarly, the ethylene application increased the fresh mass loss in the plum fruits. Overall, differences between the fruits treated with ethylene and the control were observed, but not between the doses, indicating that the lowest ethylene dose (100 mg L-1) can obtain the desired uniformity in plum fruits.