Effect of holding period prior to storage on the chemical attributes of Starking Delicious apples during refrigerated storage

In this research, the effects of three different holding periods (6, 12 and 24 hours) prior to storage on the quality attributes of Starking Delicious apples were investigated during storage of 8 months at 0.5 ± 1.0 ºC. Changes in weight loss, flesh firmness, pH values, soluble dry matter amount, titratable acidity values, ascorbic acid contents, and total and reducing sugar content were determined. According to the results, the holding period showed statistically significant changes in the quality attributes of the apples (p < 0.05).

Chemical, biochemical, and microbiological aspects of chitosan quaternary salt as active coating on sliced apples

The biocompatibility of chitosan and chitosan quaternary salt coatings was evaluated for use as edible coatings for sliced apple. Measurement of water loss, color change, and fungal growth appearance were monitored as a function of time. A significant brownish effect was observed on chitosan coated slices, varying greatly from L* = 76.5 and Hue angle = 95.9° (t = 0) to L* = 45.3 and Hue angle = 69.8° (t = 3 days), whilst for TMC coated samples the variation was considerable lower (L* = 74.1; Hue angle = 95.0°) to (L* = 67.0; Hue angle = 83.8°) within the same period. The hydrosoluble derivative N,N,N-trimethylchitosan demonstrated good antifungal activity against P. expansum although highly dependent on the polymer properties such as degree of quaternization. The most efficient formulation was that prepared from derivative having a degree of quaternization of 45%, high solubility, and high viscosity. This formulation restrained fungus spreading up to 30%, while for the control it reached almost 80% of the total assessed surfaces during 7 days of storage.

An artificial neural network model for prediction of quality characteristics of apples during convective dehydration

In this study, the effects of hot-air drying conditions on color, water holding capacity, and total phenolic content of dried apple were investigated using artificial neural network as an intelligent modeling system. After that, a genetic algorithm was used to optimize the drying conditions. Apples were dried at different temperatures (40, 60, and 80 °C) and at three air flow-rates (0.5, 1, and 1.5 m/s). Applying the leave-one-out cross validation methodology, simulated and experimental data were in good agreement presenting an error < 2.4 %. Quality index optimal values were found at 62.9 °C and 1.0 m/s using genetic algorithm.

In vitro and in vivo antifungal activity of natural inhibitors against Penicillium expansum

Penicillium expansum is the causative agent of apple blue mold. The inhibitory effects of the capsaicin derived from Capsicum spp. fruits and yeast Hansenula wingei against P. expansum were evaluated in an in vitro and in in vivo assay using Fuji apples. The minimum inhibitory concentration of capsaicin determined using the broth micro-dilution method was 122.16 µg mL-1. Capsaicin did not reduce blue mold incidence in apples. However, it was able to delay fungal growth in the first 14 days of the in vivo assay. The in vivo effect of the yeast Hansenula wingei AM2(-2), alone and combined with thiabendazole at low dosage (40 µg mL-1), on the incidence of apple diseases caused by P. expansum was also described. H. wingei AM2(-2) combined with a low fungicide dosage (10% of the dosage recommended by the manufacturer) showed the best efficacy (100%) up to 7 days of storage at 21 ºC, later showing a non-statistically different decrease (p > 0.05) after 14 (80.45%) and 21 days (72.13%), respectively. These results contribute providing new options for using antifungal agents against Penicillium expansum.

Correlation, by multivariate statistical analysis, between the scavenging capacity against reactive oxygen species and the bioactive compounds from frozen fruit pulps

The contents of total phenolic compounds (TPC), total flavonoids (TF), and ascorbic acid (AA) of 18 frozen fruit pulps and their scavenging capacities against peroxyl radical (ROO•), hydrogen peroxide (H2O2), and hydroxyl radical (•OH) were determined. Principal Component Analysis (PCA) showed that TPC (total phenolic compounds) and AA (ascorbic acid) presented positive correlation with the scavenging capacity against ROO•, and TF (total flavonoids) showed positive correlation with the scavenging capacity against •OH and ROO• However, the scavenging capacity against H2O2 presented low correlation with TF (total flavonoids), TPC (total phenolic compounds), and AA (ascorbic acid). The Hierarchical Cluster Analysis (HCA) allowed the classification of the fruit pulps into three groups: one group was formed by the açai pulp with high TF, total flavonoids, content (134.02 mg CE/100 g pulp) and the highest scavenging capacity against ROO•, •OH and H2O2; the second group was formed by the acerola pulp with high TPC, total phenolic compounds, (658.40 mg GAE/100 g pulp) and AA , ascorbic acid, (506.27 mg/100 g pulp) contents; and the third group was formed by pineapple, cacao, caja, cashew-apple, coconut, cupuaçu, guava, orange, lemon, mango, passion fruit, watermelon, pitanga, tamarind, tangerine, and umbu pulps, which could not be separated considering only the contents of bioactive compounds and the scavenging properties.

Modified atmosphere efficiency in the quality maintenance of Eva apples

Modified atmosphere is a method of food preservation that provides increased lifetime, decreases deterioration losses, and facilitates marketing. The objective of this study was to evaluate the efficiency of different plastic films in modifying the atmosphere around Eva apples to assure quality maintenance during postharvest storage. The fruits were cleaned and separated into three treatment groups: polypropylene, low density polyethylene, and high density polyethylene packing with a total of 5 fruits per package for each evaluation period. A group of control apples was not submitted to atmospheric modification. After the treatment, all fruits were stored at 0.5±0.5°C (cold storage) for up to 225 days. The analyses were performed at 45, 135, and 225 days after cold storage. Respiration, ethylene production, firmness, mass loss, total pectin, soluble pectin, soluble solids, total acidity, and epidermis background color of each treatment group were evaluated. The high density polyethylene film treatment did not show a decrease in ethylene production during storage and allowed the fruits to maintain a greater firmness and smaller percentage of mass loss during the study period. Moreover, the storage of the Eva apple cultivar under modified atmosphere allowed the preservation of quality for up to seven months.

Glycemic index and glycemic load of tropical fruits and the potential risk for chronic diseases

The objective was to determine the glycemic index and glycemic load of tropical fruits and the potential risk for chronic diseases. Nine fruits were investigated: coconut water (for the purpose of this study, coconut water was classified as a “fruit”), guava, tamarind, passion fruit, custard apple, hog plum, cashew, sapodilla, and soursop. The GI and GL were determined according to the Food and Agriculture Organization protocol. The GL was calculated taking into consideration intake recommendation guidelines; 77.8% of the fruits had low GI although significant oscillations were observed in some graphs, which may indicate potential risks of disease. Coconut water and custard apple had a moderate GI, and all fruits had low GL. The fruits evaluated are healthy and can be consumed following the daily recommended amount. However, caution is recommended with fruits causing early glycemic peak and the fruits with moderated GI (coconut water and custard apple).

Downstream processing of pectinase produced by Aspergillus niger in solid state cultivation and its application to fruit juices clarification

In this work, a protocol for the formulation of an enzyme concentrated product to be applied in fruit juice treatment is described. Downstream processing conditions for the recovery and concentration of pectinases produced by the new strain Aspergillus niger LB-02-SF in solid state cultivation were assessed. The solid-liquid ratio in the extraction step of pectinases recovery from the cultivated media was evaluated and the highest activity was obtained with a solid-liquid ratio of 1:10. The crude extract was concentrated by ultrafiltration and the total pectinase (TP) activity was 73.6-fold concentrated in relation to the crude extract, and a final TP titer of 663 U mL–1 was obtained with 73.7% of recovery yield. KCl and different glycerol concentrations were added to the concentrated extract and the stability of pectinases during the storage at 5°C for 59 weeks was tested. The formulation with 50% w/w glycerol was applied to the treatment of apple and grape juices and the results of these tests were statistically comparable to those obtained with two high-quality commercial preparations.

Biometriikka ja älypuhelimien sormenjälkitunnistus

Ihmisten mitattaviin biometrisiin piirteisiin kuuluvat muun muassa sormenjälki-, kasvo-, iiris-, verkkokalvo-, DNA- ja kämmentunnistus. Näistä kolmea ensimmäistä käsitellään tutkielmassa tarkemmin. Työssä selvennetään, mitä biometriikka ja biometriset tunnistusjärjestelmät ovat ja tutkitaan, millä tavoin sormenjälkitunnistusta voidaan käyttää älypuhelimissa. Vertailukohteina käytetään Apple iPhone 5s- ja Samsung Galaxy S5 - älypuhelimia. Tutkielma koostuu asiapohjaisen lähdemateriaalin monipuolisesta käsittelystä. Ensimmäisissä luvuissa esitellään biometrisiä tunnistusjärjestelmiä lähdemateriaalien avulla. Luvuissa tutkitaan järjestelemien mahdollisia käyttökohteita, yleistä toimintaperiaatetta sekä ongelmia. Viimeisessä luvussa käsitellään ja pohditaan kattavasti älypuhelimien sormenjälkitunnistusta lähdemateriaaleihin ja tutkielman aiempiin tuloksiin nojaten. Lopputuloksina biometristen tunnistusjärjestelmien todetaan olevan tehokkaita menetelmiä yksityisyyden suojaamiseen. Älypuhelimien sormenjälkitunnistus on tällä hetkellä käytössä olevista keinoista yksi parhaista mahdollisista laitteen suojaukseen. Sillä voidaan nopeuttaa ja helpottaa laitteen käyttöä. Vertailussa huomataan Applen passiivisen lukumenetelmän olevan käyttäjäystävällisempi kuin Samsungin pyyhkäisyyn perustuva lukumenetelmä.

Analyses, persistence an degradation of the synthetic pyrethroid insecticides permethrin and fenvalerate

Studies on persistence and degradation of the synthetic pyrethroid insecticides, permethrin and fenvalerate, were carried out under natural environmental conditions of the Niagara Peninsula. Permethrin and fenvalerate were treated on apple foliage atrat~s of 0.21 kg(AI)!ha and 0.14 kg(AI)/ha, respectively. The initial cis- and trans-permethrin spray deposits were found to be 13.5 ppm and 19.2 ppm, respectively and 38.0 ppm was observed for the fenvalerate treated sample. Twenty-three days and 84 days after spray application, permethrin residues were 4.0 ppm and 2.7 ppm for the cis-isomer, whereas they were 7.9 ppm and 4.7 ppm for the trans-isomer, respectively. Residues of fenvalerate 23 days and 84 days after spray application were 13.4 ppm and 8.0 ppm, respectively. The values of observed half-life of cis-permethrin, trans-permethrin and fenvalerate were found to be 42 days, 46 days and 51 days, respectively. Studies were extended to quantitatively determine some of the major degradation compounds of permethrin and fenvalerate, which were expected to be produced as results of ester cleavage of the parent compounds. A permethrin treated sample, 84 days after initial spray application, showed 0.25 and 0.8 ppm of cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid (C12CA (18), respectively. These two acids were not found as free acids, but found as conjugated compounds. The other expected degradation compounds, 3-phenoxybenzyl alcohol (PBalc (~)),3-phenoxybenz.aldehyde (PBald (38)) and 2- (4-chlorophenyl) isovaleric acid (CPIA (31)) were not detected by the methods employed in this study. The results indicate that these degradation compounds were not present, or, if they were present, their concentrations were too low to detect by the methods used.

Sensitivities of Ontario isolates of Venturia inaequalis to metiram /

The effects of metiram (Polyram 80 DF) on the growth of Venturia inaequalis, cause of apple scab, and the degradation of metiram were examined in culture media. Samples of V. inaequalis conidia were collected from nine orchards in 1998 and six orchards in 1999 and tested for sensitivity. Samples were plated on water agar amended with metiram or mancozeb. Mean EC50 values (effective concentration of fungicide required to inhibit germination of half the conidia) for each population were calculated. The mean EC50 values for metiram ranged from 0.26 - 1.20 ^ig metiram a.i./ml, with differences (Student Newman Keul's Test (SNK), a=0.05) between populations. EC50 values for mancozeb ranged from 0.06 - 0.58 which were also different (SNK, a=0.05). Five of these populations were examined for mycelial growth sensitivity to metiram by testing 30 monoconidial isolates from each population on metiram amended potato dextrose agar. Mean EC50 values for populations were calculated and ranged from 3.44-5.94 |ig metiram/ml, and showed differences (Friedman Test, a=0.05). As the EC50 values obtained are far less than the concentrations applied in the field, results indicate that Ontario populations of V. inaequalis are still sensitive to metiram and mancozeb. The stability of metiram in PDA at 22°C was studied over a 10-day period. The initial concentration of metiram decreased by approximately 50% within the first day, and continued to decline slowly, to approximately 20% of the initial concentration. The factors possibly affecting initial metiram degradation, including agar, heat, and the use of glass or polystyrene Petri dish composition were examined. The effects from the polystyrene in the Petri dish composition were negligible, however more studies must be done to examine metiram degradation during the first 24 hours of preparation.

Custom House Niagara forms, 1833

In 1833 William Clarke, the collector of customs at Niagara, completed and signed four forms for the movement of goods between Niagara and York, and Niagara and Brantford. The forms were issued to the firm of Lewis & Gray, James Armstrong, J.A. Wilks, and William Blackely. The goods being transported included scythes, corn brooms, hide whips, sacks, snuff, shovels, spades and two apple trees.

Role of Exopolysaccharides and Monosaccharides in Erwinia amylovora Resistance to Bacteriophages

Fire blight is a disease caused by the phytopathogenic bacterium Erwinia amylovora, an economically important pathogen in the commercial production of apples and pears. Bacteriophages have been proposed as a commercial biopesticide to relieve the pressures on apple and pear production and provide alternatives to existing biological control options. This work reports on the investigation of host resistance in the development of a phage biopesticide. Exopolysaccharide (EPS) deficient bacterial mutants were generated through recombineering to investigate the role of EPS in bacteriophage adsorption and infection. The mutants that were deficient in amylovoran production were avirulent and resistant to infection by phages of the Podoviridae and some of the Siphoviridae family. Levan deficient bacterial mutants resulted in reduced phage titers in some phages from the Myoviridae family. Exopolysaccharide mimetic monosaccharides were used to demonstrate that levan and amylovoran play an important role in phage attack of E. amylovora.

Web et théorie du document. Utopie des ingénieurs et appétit des entrepreneurs

Cet article illustre la pertinence d’une théorie du document le représentant en trois dimensions complémentaires : forme, texte, médium. Deux exemples sont proposés : l’évolution de la conception du web par son inventeur Tim Berners-Lee qui passe progressivement d’une dimension à l’autre ; le classement des stratégies des principales firmes investissant le web du document, Amazon, Apple, Google et Facebook et privilégiant chaque fois une des dimensions.

Évaluation de suppléments alimentaires pour deux espèces d’acariens prédateurs, Amblyseius swirskii et Neoseiulus cucumeris (Acari: Phytoseiidae) pour l’optimisation du contrôle biologique du thrips des petits fruits (Frankliniella occidentalis) en serriculture

Projet réalisé en cotutelle avec Jacques Brodeur et Les Shipp