The use of ozone to extend the shelf-life and maintain quality of fresh produce

Fresh produce has been recognised as a healthy food, thus there is increasing consumer demand for fresh fruit and vegetables. The shelf-life of fresh produce, however, is relatively short and is limited by microbial contamination or visual, textural and nutritional quality loss. There are many methods to reduce/eliminate microorganisms present in food and ozone treatment is one of them. The use of ozone by the fresh produce industry is a good alternative to chemical treatments, e.g. the use of chlorine. The effectiveness of ozone as an antimicrobial agent has previously been reviewed and has been updated here, with the latest findings. The main focus of this review is on the effects of ozone on the fresh produce quality, defined by maintenance of texture, visual quality, taste and aroma, and nutritional content. Furthermore, ozone has been found to be efficient in reducing pesticide residues from the produce. The treatments that have the ability to reduce microbial contamination of the product without having an adverse effect on its visual, textural and nutritional quality can be recommended and subsequently incorporated into the supply chain. A good understanding of all the benefits and limitations related to the use of ozone is needed, and relevant information has been reviewed in this paper

Thermal Conditions Within Pens Fitted With Differing Zone-Heating Options and Resulting Performance of Newly Weaned Pigs in a Wean-to-Finish Facility

Research was conducted to assess the effects of the type of zone heater and floor mat used in a wean-to-finish building on the thermal environment created for newly weaned pigs and resulting pig performance. Gas-fired brooder heaters were compared to electric heat lamps and farm-cut wood sheathing was compared to commercial [unheated] rubber floor mats. No consistent differences in air temperature near the heating zone were found between either of the treatments. However, black-globe temperatures in pens having gas-fired heaters and/or wood mats were consistently warmer than in their comparison pens. Temperature deviations during the 26-day study period were similar statistically for both air and black-globe temperatures (about ±2.5°F) for all treatments, as were the temperature deviations from pen to pen for all treatment combinations (±1.7°F or less). Pig health was affected by an outbreak of porcine reproductive and respiratory syndrome (PRRSV). Performance of the disease-challenged pigs was similar for the two heating systems. However, pigs in pens having wood sheathing on the floor below the zone heater consumed more feed on a daily basis than those resting on rubber mats. This evidence supports statistically significant (P\u3c0.05) advantages for the wood mats in pig weight (+3%) and average daily gain (+6%) over the 26-day study period. Feed-to-gain ratios over this same time period were similar for all treatments. The fact that there was greater radiant heating (as indicated by warmer black-globe temperatures) with gas-fired heaters in this study suggests that extra adjustments in heater height and gas pressure may have been needed to obtain equivalent heating effects, and that additional information on placement and adjustment of zone heaters also would be useful to producers. The data collected in this study and associated experience of farm management imply that producers can develop an similarly stable thermal environment for nursery pigs using either electric heat lamps or gas-fired brooder heaters. The improved heating effect and pig performance observed in this study with floor mats made from wood sheathing have positive practical implications. Sheets of wood sheathing are readily available from many local lumber suppliers and hardware stores and can be purchased at a fraction of the price of commercial rubber mats. A small amount of labor is required to quarter the sheets, and we don’t recommend re-using the wood mats. But, the results of this study suggest that wood sheathing should be investigated further as a floor-mat option

The Creative Economy in Maine: Measurement & Analysis

The Creative Economy is today a large and important part of Maine’s economy. The data in this study show that both the arts & culture and technology sectors of the Creative Economy are large and growing. Arts & culture industries have exhibited particularly strong employment growth at a time when major parts of our technology industries have seen significant employment declines. Although concentrated in urban areas, arts & culture industries flourish throughout Maine, and it is outside urban counties that this economy particularly blooms during the summer

Volatile organic compounds associated with neonectria ditissima infection in apples (Malus pumila cv Gala)

Postharvest diseases in apples during long term storage result in loss and waste. This is mainly caused by fungal pathogens. Fungal contamination and rot can change some of the volatile organic compounds (VOC) emitted by apple fruits. In this study, disease free Gala apples were inoculated with Neonectria ditissima. The aim was to identify VOCs associated with N. ditissima infection in gala apples. The inoculated apples were placed in 5L glass flask, sealed, and incubated at 20oC for one hour after which a charcoal filtered airflow of 1 L/min was maintained for one hour through the Volatile Capture Trap (VCT) with volatile emissions captured on a porapak-Q absorbent filter. Captured volatiles were eluted using 1 mL of dichloromethane (DCM) into a standard Agilent 1.5 mL HPLC vial. Eluted volatiles were analysed using Gas Chromatography coupled with Mass Spectrometry (GC/MS). Volatiles were capture in three replicates for both inoculated and healthy control groups at 2 days, 8 days, 14 days, 21 days, 28 days, 35 days, and 42 days post-inoculation. The N. ditissima discriminatory volatile were identified/discriminated qualitatively based on the unique volatile compounds detected and quantitatively based on variation in peak area of certain combinations of volatile compounds. Some of the discriminatory volatiles such as dodecyl hexanoate, 9-decen-1-yl hexanoate, hexyl butanoate and pentyl acetate were detected in the early stages of the infection. Styrene, terpinene-4-ol, ethyl hexanoate, ethyl butanoate, ethyl pentanoate and 2-methylpentyl formate constituted the main VOCs emitted during apple fruit decay. Other compounds such as alpha Farnesene and hexyl acetate were common to both healthy and inoculated apples but the peak areas in the healthy apples were well above the peak areas in the inoculated apples. However, these compounds expressed a decline in peak area over time. Apples are stored commercially in sealed stores for months making visual observation for early detection of disease almost impossible. Disease of stored apples are most times only detected at advanced stages when it has become nearly impossible to prevent losses. These discriminatory volatile metabolites detected at early stages of infection are important for early non-visual detection of N. ditissima in stored apples. Further research is recommended to the use of these compounds in early detection of the disease caused by N. ditissima

Direct electron attachment to fast hydrogen in 10^-9 contrast 10^18 Wcm^-2 intense laser solid target interaction

The interaction of an ultra-short (10^18 Wcm^-2) laser pulse with a solid target is not generally known to produce and accelerate negative ions. The transient accelerating electrostatic-fields are so strong that they ionize any atom or negative ion at the target surface. In spite of what may appear to be unfavourable conditions, here it is reported that H- ions extending up to 80 keV are measured from such an interaction. The H- ion flux is about 0.1 % that of the H+ ions at 20 keV. These measurements employ a recently developed temporally-gated Thomson parabola ion spectrometry diagnostic which significantly improves signal-to-noise ratios. Electrons that co-propagate with the fast protons cause a two-step charge-reduction reaction. The gas phase three-body attachment of electrons to fast neutral hydrogen atoms accounts for the measured H- yield. It is intriguing that such a fundamental gas-phase reaction, involving the attachment of an electron to a hydrogen atom, has not been observed in laboratory experiments previously. Laser-produced plasma offers an alternative environment to the conventional charged particle beam experiments, in which such atomic physics processes can be investigated

Recombination of Protons Accelerated by a High Intensity High Contrast Laser

Short pulse, high contrast, intense laser pulses incident onto a solid target are not known to generate fast neutral atoms. Experiments carried out to study the recombination of accelerated protons show a 200 times higher neutralization than expected. Fast neutral atoms can contribute to 80% of the fast particles at 10 keV, falling rapidly for higher energy. Conventional charge transfer and electron-ion recombination in a high density plasma plume near the target is unable to explain the neutralization. We present a model based on the copropagation of electrons and ions wherein recombination far away from the target surface accounts for the experimental measurements. A novel experimental verification of the model is also presented. This study provides insights into the closely linked dynamics of ions and electrons by which neutral atom formation is enhanced

Influence of continuous exposure to gaseous ozone on the quality of red bell peppers, cucumbers and zucchini

The effect of continuous exposure to ozone on quality changes during the storage of red bell peppers, cucumbers and zucchini was investigated. Peppers were stored at 14 °C and were exposed to ozone at 0.1 and 0.3 μmol mol−1, while cucumbers and zucchini were stored at 12 and 8 °C, respectively, and exposed to ozone at 0.1 μmol mol−1. The content of fructose (2.75 g/100 g FW) and glucose (2.00 g/100 g FW) in red bell peppers exposed to ozone at 0.1 μmol mol−1 was increased by 8 and 7%, respectively, when compared to controls. Continuous exposure to ozone at 0.3 μmol mol−1, on the other hand, had no effect on fructose (2.52 g/100 g FW) and glucose (1.88 g/100 g FW) content. The content of vitamin C was significantly enhanced in red bell peppers exposed to ozone at 0.1 and 0.3 μmol mol−1 after 7 d of storage, however, this effect was not maintained. After 14 d, vitamin C content in peppers exposed to ozone at 0.1 μmol mol−1 was not significantly different from the control, whereas it was reduced at 0.3 μmol mol−1. Total phenolics content was increased in peppers exposed to ozone at 0.1 μmol mol−1, but was unaffected at 0.3 μmol mol−1. Continuous exposure of red bell peppers to ozone at 0.1 and 0.3 μmol mol−1 had no significant effect on weight loss, texture and colour. In cucumbers and zucchini, continuous exposure to ozone at 0.1 μmol mol−1 reduced weight loss by more than 40% and improved texture maintenance, while having no significant effect on their biochemistry. The findings from this study suggest that continuous exposure to ozone at 0.1 μmol mol−1 is a promising method for shelf-life extension of cucumbers and zucchini. Even though in red bell peppers continuously exposed to ozone at 0.1 μmol mol−1 sugars and phenolics content was increased, further work is still needed to better understand the exact mechanism of ozone action and its potential for the industrial use

CKI isoforms α and ε regulate Star–PAP target messages by controlling Star–PAP poly(A) polymerase activity and phosphoinositide stimulation

Star–PAP is a non-canonical, nuclear poly(A) polymerase (PAP) that is regulated by the lipid signaling molecule phosphatidylinositol 4,5 bisphosphate (PI4,5P2), and is required for the expression of a select set of mRNAs. It was previously reported that a PI4,5P2 sensitive CKI isoform, CKIα associates with and phosphorylates Star–PAP in its catalytic domain. Here, we show that the oxidative stress-induced by tBHQ treatment stimulates the CKI mediated phosphorylation of Star–PAP, which is critical for both its polyadenylation activity and stimulation by PI4,5P2. CKI activity was required for the expression and efficient 3′-end processing of its target mRNAs in vivo as well as the polyadenylation activity of Star–PAP in vitro. Specific CKI activity inhibitors (IC261 and CKI7) block in vivo Star–PAP activity, but the knockdown of CKIα did not equivalently inhibit the expression of Star–PAP targets. We show that in addition to CKIα, Star–PAP associates with another CKI isoform, CKIε in the Star–PAP complex that phosphorylates Star–PAP and complements the loss of CKIα. Knockdown of both CKI isoforms (α and ε) resulted in the loss of expression and the 3′-end processing of Star–PAP targets similar to the CKI activity inhibitors. Our results demonstrate that CKI isoforms α and ε modulate Star–PAP activity and regulates Star–PAP target messages

Morphological, pathological and phylogenetic analyses identify a diverse group of Colletotrichum spp. causing leaf, pod, and flower diseases on the orphan legume African yam bean

African yam bean (AYB; Sphenostylis stenocarpa Hochst. Ex A. Rich.) is an underutilized legume indigenous to Africa. The crop has great potential as it can enhance food security and its chemical composition offers nutritional and medicinal opportunities. However, the low grain yield caused by fungal diseases, including pod blight and leaf tip dieback, deters farmers from large-scale cultivation. The causal agents of pod and leaf tip dieback on AYB are largely uncharacterized. To determine the prevalence of fungal diseases affecting leaves, pods, and flowers of AYB, a survey was conducted in 2018 and 2019 in major AYB-growing areas in Nigeria. Leaf tip dieback, flower bud rot, and pod blight were the most common symptoms. Morphological and molecular assays were conducted to identify the causal agents of the observed diseases. In all the samples examined, fungi from eight genera were isolated from leaves and pods showing disease symptoms. However, Koch’s postulates were fulfilled only for fungi belonging to the Colletotrichum genus. Fungi from the other seven genera did not produce disease symptoms in healthy AYB tissues. Several Colletotrichum isolates were characterized by sequencing the ITS, glyceraldehyde-3-phosphate dehydrogenase, calmodulin, and ApMAT loci. A combined phylogenetic analysis revealed four Colletotrichum species: C. siamense, C. theobromicola, and C. fructicola, which were recovered from the diseased leaves, and C. truncatum, which was recovered from diseased pods and buds. Our results are useful to gear efforts to develop integrated management strategies to control diseases affecting AYB in Nigeria and other parts of Africa. The availability of such strategies may stimulate greater cultivation of AYB to contribute to diet diversification, which has been repeatedly advocated by a range of stakeholders to increase food security and the prosperity of smallholder farmers

Multiscale análisis of heavy metal contents in Spanish agricultural topsoils

This study characterized and mapped the spatial variability patterns of seven topsoil heavy metals (Cr, Ni, Pb, Cu, Zn, Hg and Cd) within the Ebro river basin (9.3 million ha) by Multivariate Factorial Kriging. The variograms and cross-variograms of heavy metal concentrations showed the presence of multiscale variation that was modeled using three variogram models with ranges of 20 km (short-range), 100 km (medium-range) and 225 km (long-range). Our results indicate that the heavy metal concentration is influenced by bedrock composition and dynamics at all the spatial scales, while human activities have a notorious effect only at the short- and medium- range scale of variation. Sources of Cu, Pb and Zn (and secondary Cd) are associated with agricultural practices (at the short-range scale of variation), whereas Hg variation at the short- and medium-range scale of variation is related to atmospheric deposition