Publications by authors named "Noreen E Mahoney"

Article Synopsis
  • * Out of 19 almond samples tainted with aflatoxins, 17 oil samples also had detectable levels of these toxins, indicating a direct correlation between the almond’s aflatoxin content and that found in the oil, though not with oil's oxidation levels.
  • * The study found that certain adsorbents, specifically Fuller's earth and bentonite, effectively removed 96% and 86% of aflatoxins from the oil, respectively, highlighting the potential of using mineral clay adsorbents in the refining process
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Abstract: Blanching of almonds was examined for reducing the aflatoxin content of contaminated nuts. Almonds with intact pellicles were spiked with aflatoxin B1 (AFB1) and blanched at 85°C. Following blanching, almond kernels and pellicles contained 20 and 19% of the spiked AFB1, respectively.

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Two natural compounds (quercetin and curcumin) were tested as sensitizing or protecting agents for Navel Orangeworm (NOW) larvae under x-ray sterilization, with the aim to reduce required doses and thus facilitate the substitution of x-ray for radioisotopes. The compounds were added to NOW diet at concentrations between 0 and 1.0 mmol kg and subsequent reared male larvae were subjected to x-ray irradiation (90 keV, 9 mA) to doses up to 15 Gy.

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Background: Pulsed light (PL) is a new potential technology to degrade aflatoxin. The objective of this study was to investigate the degradation characters of aflatoxin B (AFB ) and B (AFB ) treated under PL irradiation. A kinetic degradation study of AFB and AFB in solid medium was performed under PL irradiation at different initial concentrations of AFB (229.

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Fungal-contaminated tissues are known to produce volatile profiles that are different from uncontaminated tissues. Fungi require certain water activity levels before growth can occur. For nonxerophilic fungi, a water activity of 0.

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Contamination by aflatoxin, a toxic metabolite produced by Aspergillus fungi ubiquitous in California almond and pistachio orchards, results in millions of dollars of lost product annually. Current detection of aflatoxin relies on destructive, expensive, and time-intensive laboratory-based methods. To explore an alternative method for the detection of general fungal growth, volatile emission profiles of almonds at varying humidities were sampled using both static SPME and dynamic needle-trap SPE followed by benchtop and portable GC-MS analysis.

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Background: Pulsed light (PL) technology has been proven effective in food disinfection. However, increasing the light intensity or treatment time could swiftly increase the temperature of the food product. Using the thermal effect in an appropriate way may achieve a simultaneous disinfection and drying effect.

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Semiochemicals play a central role in communication between plants and insects, such as signaling the location of a suitable host. Fungi on host plants can also play an influential role in communicating certain plant vulnerabilities to an insect. The spiroketal conophthorin is an important semiochemical produced by developing fungal spores.

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Navel orangeworm (NOW) damage to almond is correlated with increased incidence of aflatoxin contamination caused by Aspergillus flavus. However, no reports demonstrate a causative relationship between NOW feeding and A. flavus infection.

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The spiroketal (E)-conophthorin has recently been reported as a semiochemical of the navel orangeworm moth, a major insect pest of California pistachios and almonds. Conophthorin and the isomeric spiroketal chalcogran are most commonly known as semiochemicals of several scolytid beetles. Conophthorin is both an insect- and plant-produced semiochemical widely recognized as a nonhost plant volatile from the bark of several angiosperm species.

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Aflatoxigenic aspergilli inflict major economic damage to the tree nut industry of California, with the highest negative impact to almonds. Aspergilli and fungi in general are known to emit volatiles in varying quantity and composition dependent upon their growth media. The goal of the study was to determine the volatile emission of whole and blanched almonds that had been picked out and labeled as inedible by processors.

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The phenolic antioxidants, gallic acid, vanillic acid, protocatechuic acid, 4-hydroxybenzoic acid, catechin, caffeic acid, and chlorogenic acid were studied for their effects on ochratoxin A (OTA) production and fungal growth of ochratoxigenic Aspergilli. Of the 12 strains tested, which included A. alliaceus, A.

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Article Synopsis
  • Researchers isolated bacteria from California almond orchards to test their ability to combat the fungus Aspergillus flavus, which produces harmful aflatoxins.
  • They identified 171 bacterial strains from almond flowers and nuts that inhibited the growth of A. flavus and its precursor, norsolorinic acid (NOR).
  • A selection of 20 bacterial isolates was found to significantly prevent fungal growth, suggesting these bacteria could serve as potential biological control agents against aflatoxin-producing fungi in almonds.*
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The yeast Saccharomyces cerevisiae was used in a high-throughput bioassay to identify phenolic agents for control of the aflatoxigenic fungus Aspergillus flavus. Veratraldehyde, 1, cinnamic acid, 5, and the respective benzoic acid derivatives vanillin, 2, vanillic acid, 3, and vanillylacetone, 4, and cinnamic acid derivatives o-coumaric acid, 6, m-coumaric acid, 7, and p-coumaric acid, 8, showed significant antifungal activities (from highest to lowest, 2, 5 > 1 > 6, 7 > 4 > 3, 8) in the yeast system, with caffeic acid, 9, having little to no effect. Antifungal activity levels against A.

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California exports tree nuts to countries where they face stringent standards for aflatoxin contamination. Trade concerns have stimulated efforts to eliminate aflatoxins and Aspergillus flavus from almonds, pistachios and walnuts. Incidence of fungi on tree nuts and associations among fungi on tree nuts were studied.

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Ochratoxin A is a toxic and carcinogenic fungal secondary metabolite; its presence in foods is increasingly regulated. Various fungi are known to produce ochratoxins, but it is not known which species produce ochratoxins consistently and which species cause ochratoxin contamination of various crops. We isolated fungi in the Aspergillus ochraceus group (section Circumdati) and Aspergillus alliaceus from tree nut orchards, nuts, and figs in California.

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