scholarly journals Impact of a Brief Postharvest Hot Water Drench Treatment on Decay, Fruit Appearance, and Microbe Populations of California Lemons and Oranges

2003 ◽  
Vol 13 (2) ◽  
pp. 333-338 ◽  
Author(s):  
Joseph L. Smilanick ◽  
David Sorenson ◽  
Monir Mansour ◽  
Jonah Aieyabei ◽  
Pilar Plaza

A brief (15 or 30 seconds) high-volume, low-pressure, hot-water drench at 68, 120, 130, 140, or 145 °F (20.0, 48.9, 54.4, 60.0, or 62.8 °C) was applied over rotating brushes to `Eureka' lemons (Citrus limon) and `Valencia' oranges (Citrus sinensis). The impact of this treatment on populations of surface microbes, injury to the fruit, the incidence of green mold (Penicillium digitatum)or sour rot (Geotrichum citri-aurantii), when inoculated into wounds one day prior to treatment, and temperatures required to kill the spores of these fungi and P. italicum suspended in hot water were determined. Fruit microbial populations were determined immediately after treatment. Decay and injuries were assessed after storage for 3 weeks at 55 °F (12.8 °C). The efficacy of the hot water treatments was compared to immersion of fruit in 3% wt/vol sodium carbonate at 95 °F (35.0 °C) for 30 seconds, a common commercial practice in California. Initial yeast and mold populations, initially log10 6.0 per fruit, were reduced to log10 3.3 on lemons and log10 4.2 on oranges by a 15-second treatment at 145 °F. Green mold control improved with increasing temperature and treatment duration. Green mold incidence was reduced from 97.9% and 98.0% on untreated lemons and oranges, respectively, to 14.5% and 9.4% by 30 seconds treatment with 145 °F water. However, immersion of lemons or oranges in 3% wt/vol sodium carbonate was superior and reduced green mold to 8.0% and 8.9%, respectively. Sour rot incidence on lemons averaged 84.3% after all water treatments, and was not significantly reduced, although arthrospores of G. citriaurantii died at lower water temperatures than spores of P. digitatum and P. italicum in in vitro tests. Sodium carbonate treatment for 30 seconds at 95 °F reduced sour rot to 36.7%. None of the treatments caused visible injuries to the fruit.

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1452
Author(s):  
Raluca-Maria Pârlici ◽  
Aurel Maxim ◽  
Stefania Mirela Mang ◽  
Ippolito Camele ◽  
Lucia Mihalescu ◽  
...  

Organic berry plantations have been gaining popularity among farmers during recent years. Even so, farmers experience serious challenges in disease control management, which is a concern in organic farming. Phragmidiumrubi-idaei (DC) P. Karst is the pathogen responsible for blackberry and raspberry rust disease, one of the most present and active diseases in plantations. The antifungal certified products found on the organic farming market offer the opportunity for an efficient control strategy over plant pathogens in fruit shrub plantations. In this study, 5 natural based products—namely Altosan, Mimox, Canelys, Zitron, and Zeolite—were tested for their fungistatic effect over P. rubi-idaei. The experiments were carried out under laboratory conditions, performing observations over the impact of organic products, used at different concentration levels, on rust conidia germination. Moreover, field experiments were conducted in order to evaluate the efficiency of different treatments for rust control on raspberry (‘Polka’, ‘Veten’ and ‘Heritage’) and blackberry (‘Thorn Free’, ‘Chester’ and ‘Loch Ness’) varieties. Data analysis based on ANOVA tests showed significant differences between the tested variants and the control sample at p < 0.001. Furthermore, LSD test confirmed differences between all substances tested (p < 0.005). The natural products Canelys (formulated with cinnamon) and Zytron (based on citrus extract) have proven the highest inhibitory capacity for conidia germination during in vitro tests registering values of 80.42% and 78.34%, respectively. The same high inhibitory rates against rust pathogen were kept also in the field tests using the same two natural-based products mentioned earlier. In addition, outcomes from this study demonstrated that Zeolite is not recommended for raspberry or blackberry rust control.


2021 ◽  
pp. 096739112110060
Author(s):  
Mouna Werchefani ◽  
Catherine Lacoste ◽  
Hafedh Belguith ◽  
Chedly Bradai

The present work is a comparative study of the impact of Alfa fiber modifications on the Cereplast composites mechanical behavior. Various treatments have been employed, including mechanical, soda, saltwater-retting, hot-water treatments and enzymatic treatment using xylanase. Chemical and morphological analyses were carried out in order to determine the changes of the biochemical composition and the dimensions of fibers. Cereplast composites reinforced with Alfa fibers were fabricated using a twin-screw extrusion followed by an injection molding technique with a fiber load of 20 wt. %. Resulting materials were assessed by means of tensile, flexural and Charpy impact testing. Scanning Electron Microscopy analysis was carried out to investigate the interfacial properties of the composites. The results have shown a significant enhancement of mechanical strengths and rigidities for the xylanase-treated fiber composites, owing to the increase of cellulose content, the enhancement of defibrillation level and the improvement of matrix-fiber adhesion. The data proved that the technology of enzymes can be used as a powerful and eco-friendly approach to modify fiber surfaces and to increase their potential of reinforcement.


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 349 ◽  
Author(s):  
Anita Staroń ◽  
Olga Długosz ◽  
Jolanta Pulit-Prociak ◽  
Marcin Banach

The rapid development of the production of materials containing metal nanoparticles and metal oxides is a potential risk to the environment. The degree of exposure of organisms to nanoparticles increases from year to year, and its effects are not fully known. This is due to the fact that the range of nanoparticle interactions on cells, tissues and the environment requires careful analysis. It is necessary to develop methods for testing the properties of nanomaterials and the mechanisms of their impact on individual cells as well as on entire organisms. The particular need to raise public awareness of the main sources of exposure to nanoparticles should also be highlighted. This paper presents the main sources and possible routes of exposure to metal nanoparticles and metal oxides. Key elements of research on the impact of nanoparticles on organisms, that is, in vitro tests, in vivo tests and methods of detection of nanoparticles in organisms, are presented.


2020 ◽  
Vol 8 (9) ◽  
pp. 1379 ◽  
Author(s):  
Marc-Kevin Zinn ◽  
Laura Schages ◽  
Dirk Bockmühl

Toothbrushes play a central role in oral hygiene and must be considered one of the most common articles of daily use. We analysed the bacterial colonization of used toothbrushes by next generation sequencing (NGS) and by cultivation on different media. Furthermore, we determined the occurrence of antibiotic resistance genes (ARGs) and the impact of different bristle materials on microbial growth and survival. NGS data revealed that Enterobacteriaceae, Micrococcaceae, Actinomycetaceae, and Streptococcaceae comprise major parts of the toothbrush microbiome. The composition of the microbiome differed depending on the period of use or user age. While higher fractions of Actinomycetales, Lactobacillales, and Enterobacterales were found after shorter periods, Micrococcales dominated on both toothbrushes used for more than four weeks and on toothbrushes of older users, while in-vitro tests revealed increasing counts of Micrococcus on all bristle materials as well. Compared to other environments, we found a rather low frequency of ARGs. We determined bacterial counts between 1.42 × 106 and 1.19 × 107 cfu/toothbrush on used toothbrushes and no significant effect of different bristles materials on bacterial survival or growth. Our study illustrates that toothbrushes harbor various microorganisms and that both period of use and user age might affect the microbial composition.


Cosmetics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 70 ◽  
Author(s):  
Maria-Beatrice Coltelli ◽  
Serena Danti ◽  
Luisa Trombi ◽  
Pierfrancesco Morganti ◽  
Giovanna Donnarumma ◽  
...  

The preparation and selection of biobased materials compatible with skin is essential for producing innovative and highly eco-friendly beauty masks. The use of a commercial elastomeric poly(hydroxyalkanoate) and starch was fundamental to select materials for bioplastic films with the necessary resistance in wet conditions, skin compatibility and capacity for a fast release of polysaccharides and similar active and functional molecules. Micrometric calcium carbonate was also used to control the stickiness of film during moulding. Starch release in water was investigated by gravimetric and infrared analyses. The compatibility with skin was investigated via two different in vitro tests based on human keratinocytes and human mesenchymal stromal cells. The materials were highly cytocompatible with skin, enabled immune modulation by keratinocytes and starch release in water up to 49% by weight in 30 min. These outcomes are a good starting point for boosting the production of biobased and biodegradable beauty masks, thus decreasing the impact onto environment of cosmetic products that are currently still mainly produced using petrol-based substrates.


2000 ◽  
Vol 66 (4) ◽  
pp. 1354-1359 ◽  
Author(s):  
Liesbeth Rijnen ◽  
Pascal Courtin ◽  
Jean-Claude Gripon ◽  
Mireille Yvon

ABSTRACT The first step of amino acid degradation in lactococci is a transamination, which requires an α-keto acid as the amino group acceptor. We have previously shown that the level of available α-keto acid in semihard cheese is the first limiting factor for conversion of amino acids to aroma compounds, since aroma formation is greatly enhanced by adding α-ketoglutarate to cheese curd. In this study we introduced a heterologous catabolic glutamate dehydrogenase (GDH) gene into Lactococcus lactis so that this organism could produce α-ketoglutarate from glutamate, which is present at high levels in cheese. Then we evaluated the impact of GDH activity on amino acid conversion in in vitro tests and in a cheese model by using radiolabeled amino acids as tracers. The GDH-producing lactococcal strain degraded amino acids without added α-ketoglutarate to the same extent that the wild-type strain degraded amino acids with added α-ketoglutarate. Interestingly, the GDH-producing lactococcal strain produced a higher proportion of carboxylic acids, which are major aroma compounds. Our results demonstrated that a GDH-producing lactococcal strain could be used instead of adding α-ketoglutarate to improve aroma development in cheese.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1963
Author(s):  
Sangsu Park ◽  
Jeongin Lim ◽  
Kyung Tae Lee ◽  
Myung Sook Oh ◽  
Dae Sik Jang

Butterbur (Petasites japonicus (Siebold & Zucc.) Maxim) leaves are available to consumers in the marketplace, but there is no guarantee that they are safe for human consumption. Previously, we demonstrated that hot water extracts of P. japonicus leaves (KP-1) had anti-inflammatory properties and attenuated memory impairment. However, data regarding KP-1 toxicity are lacking. This study assessed the safety of KP-1 by examining oral and genotoxic effects using in vivo and in vitro tests, respectively. In a single oral dose toxicity and two-week repeated oral dose toxicity study, we observed no toxicologically significant clinical signs or changes in hematology, blood chemistry, and organ weights at any dose during the experiment. Following a thirteen-week repeated oral dose, toxicity, hyperkeratosis, and squamous cell hyperplasia of the limiting ridge in the stomach were observed. The no observable adverse effect level (NOAEL) was found to be 1250 mg/kg/day in male and female rats. However, hyperkeratosis and hyperplasia were not considered to be of toxicological significance when extrapolating the NOAEL to humans because the limiting ridge in the stomach is species-specific to rats. Therefore, in our study, the NOAEL was considered to be 5000 mg/kg/day when the changes in the stomach’s limiting ridge were discounted. Moreover, in vitro bacterial reverse mutations and chromosomal aberrations in Chinese hamster lung (CHL) cells and the in vivo micronucleus in Institute of cancer research (ICR) mice assays showed that KP-1 possessed no mutagenicity. Although additional research is required, these toxicological evaluations suggest that KP-1 could be safe for human consumption.


2019 ◽  
Vol 28 (11) ◽  
pp. 1420-1431 ◽  
Author(s):  
Bin Wang ◽  
Jie Lin ◽  
Qin Zhang ◽  
Xinyuan Zhang ◽  
Hui Yu ◽  
...  

Alpha-calcitonin gene-related peptide (αCGRP) plays a significant pathophysiological role in the regulation of bone metabolism. Our previous research indicated that αCGRP might have a potential application in enhancing osseointegration in vivo. To further uncover the intrinsic mechanism of its networks in bone regeneration, here we investigate the impact of αCGRP on osteogenic differentiation in bone marrow-derived mesenchymal stem cells (BMSCs) from both wild-type and αCGRP-/- mice. Considering the half-life of αCGRP in plasma is only 10 min, we applied αCGRP lentivirus and stably transfected it into BMSCs, followed by transfection identification and cell cycle assay. We further conducted a series of in vitro tests, and the results revealed that biological functions including migratory ability and osteogenicity exhibited positive correlation with BMSCs’ αCGRP expression. Meanwhile, this phenomenon was associated with an enhanced expression of YAP (Yes-associated protein), the key downstream effector of the Hippo pathway. To sum up, our data together with previous in vivo observations is likely to elucidate the intrinsic mechanism of αCGRP in bone remodeling, and αCGRP would appear to be a novel treatment to promote bone wound healing.


2003 ◽  
Vol 15 (3) ◽  
pp. 145-148 ◽  
Author(s):  
Renar João Bender ◽  
Eduardo Seibert ◽  
Jeffrey K. Brecht

With the use of ethylene dibromide for mango disinfestation being ruled out, vapor heat or hot water treatments are the only alternatives for quarantine treatments of mangoes. Physical treatments such as heat treatments have been implicated in higher incidence of physiological disorders and enhancement of ripening processes. Therefore, the objective of the present work was to determine the effects of hot water treatments on ethylene production and on the in vitro activity of ACC oxidase. Cv. Keitt mangoes were immersed for 3 min in hot water at 53 °C or 90 min in water at 46 °C. Immediately after the treatments, some of the mangoes were analyzed for ACC oxidase activity and others were stored to be analyzed after 4 days at 12 °C. There was a significant increase in the ACC oxidase activity just after the hot water treatments. After 4 days, only the mangoes treated for 90 min maintained high ethylene production and ACC oxidase activity. Tissue from the outer layers of the mesocarp had higher enzyme activity compared to tissues from the innermost layers of the mesocarp of heat-treated mangoes.


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