Brown Rot Disease in Stored Nectarines: Modeling the Combined Effects of Preharvest and Storage Conditions.

Brown rot in stored stone fruits, caused by Monilinia spp., may be due to preharvest and storage factors, but the combined effect of these factors has yet to be investigated. We set up two experiments to monitor the progression of brown rot during the storage of nectarines subjected to various preharvest and storage conditions. We assessed the effects of different agricultural practices (irrigation regimen × fruit load) and harvest dates on brown rot progress during storage in 2018 and the effect of different storage temperatures in 2019. We found that the cumulative incidence of brown rot during storage increased with individual fruit mass, which was influenced by agricultural practices, and for later harvest dates. It also increased with storage temperature. We observed that during storage no secondary infections developed in nectarines not in direct contact with fruits infected with Monilinia laxa. These findings led to the identification of candidate variables describing the brown rot risk on nectarines during storage, such as individual fruit mass, meteorological conditions before fruit harvest, prevalence of brown rot at harvest, and storage temperature. We used these variables to build a mathematical model for estimating the time-to-appearance of brown rot symptoms in stored nectarines. This model fitted the experimental data well, highlighting the need to pay greater attention to the interaction between preharvest and storage conditions. This model could be used to evaluate management strategies for reducing the impact of brown rot in nectarines during storage.

Reflections on the physical, executive developmental and systems applied framework in child neuropsychological rehabilitation.

This paper describes the influence of the Physical, Executive, Developmental and Systems (PEDS) framework on the delivery of community-based child neuropsychological rehabilitation and how it has been enhanced by the proliferation of neuroscientific, neuropsychological and psychosocial research and evidence-base in childhood brain injury and rehabilitation over the past decade. The paper signposts to some of the key models, theories and concepts currently shaping service delivery. Application of the PEDS framework in a clinical case is described.

Temperature and storage time increase provitamin A carotenoid concentrations and bioaccessibility in post-harvest carrots.

The aim was to enhance provitamin A carotenoid (proVA CAR) concentrations and bioaccessibility in carrots by manipulating post-harvest factors. To that end, we assessed the effects of Ultraviolet-C light, pulsed light, storage temperature, and storage duration. We also measured CAR bioaccessibility by using an in vitro model. Pulsed light, but not Ultraviolet-C, treatment increased proVA CAR concentrations in the cortex tissue (p < 0.05). Longer storage times and higher temperatures also increased concentrations (p < 0.05). The maximal increase induced by pulsed light was obtained after treatment with 20 kJ/m2 and 3-days of storage at 20 °C. However, the positive effect induced by pulsed light decreased considerably over the next seven days. ProVA CAR in carrots with the highest concentrations also proved to be more bioaccessible (p < 0.05). Thus, proVA CAR concentrations in stored carrots can be increased significantly through storage times and temperatures. Pulsed light can also significantly increase proVA CAR concentrations, but only temporarily.

Role of biological control agents and physical treatments in maintaining the quality of fresh and minimally-processed fruit and vegetables.

Fruit and vegetables are an important part of human diets and provide multiple health benefits. However, due to the short shelf-life of fresh and minimally-processed fruit and vegetables, significant losses occur throughout the food distribution chain. Shelf-life extension requires preserving both the quality and safety of food products. The quality of fruit and vegetables, either fresh or fresh-cut, depends on many factors and can be determined by analytical or sensory evaluation methods. Among the various technologies used to maintain the quality and increase shelf-life of fresh and minimally-processed fruit and vegetables, biological control is a promising approach. Biological control refers to postharvest control of pathogens using microbial cultures. With respect to application of biological control for increasing the shelf-life of food, the term biopreservation is favored, although the approach is identical. The methods for screening and development of biocontrol agents differ greatly according to their intended application, but the efficacy of all current approaches following scale-up to commercial conditions is recognized as insufficient. The combination of biological and physical methods to maintain quality has the potential to overcome the limitations of current approaches. This review compares biocontrol and biopreservation approaches, alone and in combination with physical methods. The recent increase in the use of meta-omics approaches and other innovative technologies, has led to the emergence of new strategies to increase the shelf-life of fruit and vegetables, which are also discussed herein.

Fine monitoring of major phenolic compounds in lettuce and escarole leaves during storage.

Two varieties of lettuce (Lactuca sativa L. var. crispa and capitata) and one variety of escarole (Cichorium endivia var. latifolium) were chosen due to their different browning sensitivity during storage as minimally processed products. The changes in the compositions and contents of the primary polyphenolic compounds were investigated during the first few hours of storage and then after 1, 2, 3, and 6 days of storage at 6°C and revealed sharp variations. Browning development, activity of phenylalanine ammonia lyase, and concentration of ascorbic acid were also examined during storage. The content of chicoric acid, which was the most abundant phenolic compound, varied substantially during the first 24 hr of storage and between the different varieties. Oak leaf lettuce, which was the most sensitive variety to browning, was characterized by a higher maintained chicoric acid level with a constant decreased chlorogenic acid level during the storage period. PRACTICAL APPLICATIONS: Browning development is responsible for the short shelf life of minimally processed vegetables, such as lettuce (Lactuca sativa). Polyphenolic compounds, as substrates of enzymatic reactions, are involved in the browning susceptibility of leaves. Comparisons of the profiles and contents of these compounds in different leaves showed dramatic variations during storage. This study provides additional information to better control, optimize minimally processed produce and select more suitable leaves for the fresh-cut industry.

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; 0.7 J cm-2), 4 successive pulses (4P; 2.80 J cm-2) and 1 pulse per day for 4 days (1P4D; 2.80 J cm-2) before storage for 7 days 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 7 days of storage, total ascorbate content was 40% higher in the 1P4D treatment than in control, whereas total carotenoid content (0.894 mg g-1 FM) and total antioxidant activity (144 µmol trolox 100 g-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.

Understanding the physiological effects of UV-C light and exploiting its agronomic potential before and after harvest.

There is an abundant literature about the biological and physiological effects of UV-B light and the signaling and metabolic pathways it triggers and influences. Much less is known about UV-C light even though it seems to have a lot of potential for being effective in less time than UV-B light. UV-C light is known since long to exert direct and indirect inhibitory and damaging effects on living cells and is therefore commonly used for disinfection purposes. More recent observations suggest that UV-C light can also be exploited to stimulate the production of health-promoting phytochemicals, to extent shelf life of fruits and vegetables and to stimulate mechanisms of adaptation to biotic and abiotic stresses. Clearly some of these effects may be related to the stimulating effect of UV-C light on the production of reactive oxygen species (ROS) and to the stimulation of antioxidant molecules and mechanisms, although UV-C light could also trigger and regulate signaling pathways independently from its effect on the production of ROS. Our review clearly underlines the high potential of UV-C light in agriculture and therefore advocates for more work to be done to improve its efficiency and also to increase our understanding of the way UV-C light is perceived and influences the physiology of plants.

Qualidade de melões ‘Louis‘ armazenados em quatro temperaturas / Quality of ‘Louis‘ melons stored under four storage temperatures

Este trabalho teve como objetivo estabelecer a melhor temperatura para a conservação de melões ‘Louis‘. Os frutos foram armazenados sob condição de ambiente (22±2°C e 80±5% UR), sob refrigeração (3±1°C e 80±5% UR; 6±1°C e 80±5% UR; e 9±1°C e 80±5% UR) e avaliados quanto à coloração e firmeza da polpa, teores de sólidos solúveis, acidez titulável, atividade das enzimas peroxidase, polifenoloxidase, poligalacturonase e pectinametilesterase e perda de massa fresca. Os melões ‘Louis‘ armazenados a 22°C apresentaram maior redução nos teores de sólidos solúveis e acidez titulável, além de apresentarem maior atividade da enzima poligalacturonase, com conservação por até 18 dias. Os frutos armazenados a 6°C mantiveram a qualidade comercial durante 25 dias de armazenamento, apresentando os maiores teores de sólidos solúveis e menor atividade das enzimas peroxidase e poligalacturonase.

This research aimed to establish the best temperature for the conservation of ‘Louis‘ melons. Fruit were stored under ambient condition (22°C and 80% RH) and under refrigeration (3°C - 80% RH, 6°C - 90% RH e 9°C - 80% RH) and evaluated for color and resistance of pulp, soluble solids, titratable acidity content, peroxidase, polyphenol oxidase, polygalacturonase and pectin methyl esterase activity and weight loss. ‘Louis‘ melons at 22°C showed greater reduction in soluble solids and titratable acidity content, and had higher activity of the enzyme polygalacturonase, culminating in conservation for 18 days. Melons stored at 6°C preserved the shelf-life for 25 days, showed the highest soluble solids and lower activity of peroxidase and polygalacturonase.

Influence of packaging conditions on natural microbial population growth of endive.

The influence of three packaging conditions, i.e., unmodified atmosphere packaging (UAP), passive modified atmosphere packaging (MAP), and active MAP, on the natural microbial population growth of endive was investigated at 20 degrees C. For UAP, endive was placed in macroperforated oriented polypropylene pouches that maintained gas composition close to that of air (21 kPa O2 and 0 kPa CO2) but also limited superficial product dehydration. For MAP, endive was placed in low-density polyethylene pouches that induced a 3 kPa O2 and 5 kPa CO2 equilibrium atmosphere composition. Steady state was reached after 25 h of storage with an oxygen absorbing packet (active MAP) compared with 100 h without the packet (passive MAP) and was maintained for 200 h. After 312 h of storage, both active and passive MAP reduced total aerobic mesophile, yeast, and mold population growth compared with endive in UAP. Active MAP accelerated and improved the inhibition of Pseudomonas spp. and Enterobacteriaceae, respectively, probably because of the rapid O2 depletion during the transition period. A shift in the Enterobacteriaceae subpopulation from Rhanella aquatilis to Enterobacter agglomerans was observed for both passive and active MAP.

Intrathecal ropivacaine in rabbits: pharmacodynamic and neurotoxicologic study.

BACKGROUND: Ropivacaine is available for spinal or intrathecal use in humans, although data on neurotoxicity after spinal injection are not yet available. The authors experimentally determined the relationship between doses of intrathecal ropivacaine and spinal effects and local neurotoxic effects. METHODS: Eighty rabbits equipped with an intrathecal lumbar catheter were studied. Sixty were randomly assigned to receive 0.2 ml of intrathecal solutions as a sole injection of: 0.2%, 0.75%, 1.0%, and 2.0% ropivacaine (doses from 0.4-4.0 mg; groups R0.2 to R2.0), 5.0% lidocaine (10 mg; group L), or 0.9% NaCl as control (group C). Twenty other rabbits received either repeated injections of 0.2 ml of 0.2% ropivacaine every 2 days during 2 weeks (total dose of 2.8 mg; group RINT); or a continuous intrathecal infusion of 0.2% ropivacaine at the rate of 1.8 ml/h over 45 min (2.7 mg; group RCONT). Injection rate was 30 s in all groups except Rcont. Time to onset, duration and extent of motor block, and variations of mean arterial blood pressure were recorded in all groups. Somatosensory evoked potentials were also recorded in group RCONT and RINT. Seven days after the last intrathecal injection spinal cord and nerves were sampled for histopathologic study. RESULTS: In groups R0.2 and RINT, the lowest dose of ropivacaine induced a clinically visible spinal block in only 50% of rabbits, but SEPs recorded in group RINT were decreased by 70% in the lumbar dermatome. Complete motor block was observed with doses greater than 1.5 mg of ropivacaine (group RCONT and R0.75 to R2.0). Onset time was shorter and duration of block increased as doses of ropivacaine increased. Significant hypotension was observed only with 4.0 mg of ropivacaine (concentration of 2.0%). Complete paralysis and hypotension were observed with 5.0% lidocaine. No neurologic clinical lesion was observed in rabbits receiving saline or ropivacaine within the 7 days after the last intrathecal injection, and histopathologic study revealed no sign of neurotoxicity in these groups. In contrast, intrathecal lidocaine induced clinical and histopathologic changes. CONCLUSION: Ropivacaine induced dose-dependent spinal anesthesia, and did not induce any neurotoxicologic lesion in this experimental animal model.