Abstract: Total phenolic content, total antioxidant activity of Myrobalan plum ( Prunus cerasifera Ehrh.) and anthocyanin content in peel were analyzed in this article. In addition, ultra‐performance liquid chromatography with photodiode array detection and electrospray ionization tandem mass spectrometry were used to determine anthocyanin composition of this fruit. The range of total phenolic content of the tested samples was 1.34 to 6.11 g/kg fresh weight (FW), and anthocyanin content in fruit peel of Myrobalan plum was from 1.93 to 19.86 g/kg peel. Ferric reducing antioxidant power values varied from 11.20 to 44.83 μmol Trolox equivalent/g FW. Four main kinds of anthocyanins in purple Myrobalan plum were detected while 6 kinds in red ones. Practical Application: The article showed the anthocyanin composition, phenolic content, and antioxidant activities of wild Myrobalan plum. The purple Myrobalan plum could be developed as a resource of fruit drinks because of its high antioxidant activity and the peel could be used as the resource to extract natural pigments.
The edible mushroom Agaricus bisporus is more prone to senescence than most other vegetables. However, the senescence of A. bisporus before harvesting is often ignored. In this study the changes in reactive oxygen species (ROS) production and antioxidant enzyme activity of A. bisporus harvested at four different stages of maturity were investigated.The firmness of A. bisporus decreased from 6.22 to 5.12 N. Respiration rate increased from 540.65 to 609.82 mg CO2 kg⁻¹ fresh weight (FW) h⁻¹. Browning degree increased from 0.42 to 0.71, showing a positive correlation with polyphenol oxidase activity. For ROS production, superoxide radical production rate increased from 0.51 to 1.16 nmol g⁻¹ FW s⁻¹. Hydrogen peroxide content increased from 0.81 to 1.39 nmol g⁻¹ FW and then decreased rapidly to 0.68 nmol g⁻¹ FW. Malondialdehyde content increased from 1.58 to 2.64 nmol g⁻¹ FW. For antioxidant enzymes, superoxide dismutase and peroxidase activities decreased significantly at stage 4, whereas a significant increase in catalase activity was found at stages 3 and 4.The balance between ROS and antioxidants was destroyed at stage 4, causing extensive senescence of mushroom tissues. Thus A. bisporus should be harvested at stage 3.
The Dendrobium genus includes some important medicinal and famous ornamental plant species over the world.Some species in this genus demonstrated the characteristics of crassulasean acid mechanism plant.Three species i.e.,Dendrobium primulinum,D.nobile and D.chrysotoxum were selected as the experiment objects to study their photosynthesis and growth status in greenhouse during the winter season by means of measuring the gas exchange in combination with determining the chlorophyll fluorescence kinetics.The results showed that D.primulinum exhibited typical traits of CAM plants,when its apparent photosynthetic rate was still minus value before 11:00 am while the electron transport rate was relatively high,which resembled the stage III tendency of diurnal fluctuation of CAM plants.With low apparent photosynthetic rate,D.nobile and D.chrysotoxum were adaptive to shade environment with weaker solar radiation.Comparatively speaking,D.chrysotoxum manifested more typical C3 plant characteristics.The 16℃ temperature in the early morning posed a chilling stress to D.primulinum to certain extent,meanwhile D.nobile and D.chrysotoxum were not negatively effected,showing that the later two species were more adaptive to low temperature.
Abstract Infrared (IR) drying is an effective method for the preservation and processing of carmine radish ( Raphanus sativus L.). This study aimed to investigate the effects of different IR radiation intensities (2125, 2780, and 3358 W/m 2 ) on the drying properties and flavor components of carmine radish slices. As the IR radiation intensity and the drying temperature increased, the total drying time, the moisture content, and the dehydration rate reduced continuously, while the hardness of carmine radish slices decreased and then increased. Drying at a radiation intensity of 2780 and 3358 W/m 2 reduced 50% and 70% of the drying time compared to that of 2125 W/m 2 , respectively. Flavor components of carmine radish showed apparent changes during the IR drying process with a radiation intensity of 2125 W/m 2 . IR drying at a lower intensity was beneficial to the retention of volatile flavor components. The retention of volatile substances at an intensity of 2125 W/m 2 for 15 min was 1.97 and 1.68 times that for 30 min and control samples, respectively. Consequently, to retain good processing quality and flavor properties of carmine radish slices, the optimal drying parameter of IR within this study was an IR radiation intensity of 2125 W/m 2 for about 15 min.
Summary The formation of sexual fruiting bodies and production of polyketides are believed to be the most important strategies for fungal survival in environmental insults. In Neurospora crassa , the backbone gene of polyketide synthase gene cluster 6 (pks‐6 ), which is expressed at lower level under vegetative growth, is highly expressed during perithecia development. Intriguingly, deletion of pks‐6 does not affect perithecia maturation. How the expression of pks‐6 correlates with fungal sexual development remains to be established. Here, we showed that overexpression of pks‐6 results in an enhanced production of an insecticidal furocoumarin (neurosporin A). Deletion of pks‐6 , however, abolished neurosporin A biosynthesis. Moreover, the content of neurosporin A negatively associates with the food preference of fungivores, where the pks‐6 knockout strain is more prone to be grazed by collembolans Sinella curviseta . Additionally, during vegetative growth, confrontation with Drosophila melanogaster also results in an enhanced expression of pks‐6 and production of neurosporin A. Thus, high expression of pks‐6 positively interrelates with the chemo‐resistance of N. crassa to arthropod predation. Our findings suggest that pks‐6 confers the production of insecticidal neurosporin A counteracting the feeding attack by arthropods during sexual development of N. crassa .
Linalool oxide,linalool,β-ionone,dihydro-β-ionone, α-ionone,geraniol,ocimene,etc.were examined by dynamic headspace collection and TCT-GC/MS analysis from 4 Osmanthus fragrance cultivars in Hangzhou Manlong Guiyu Park,comparing with the surrounding air(CK).The results of comparing the volatile compounds in this 4 cultivars showed that there were some differences not only in their relative contents but also in the component's content.There are more content of linalool and ionone in Osmanthus fragrans'Fo Ding Zhu',but no geraniol can be detected.Osmanthus fragrans'Yu Linglong'contains more ionone and cis-linalool oxide.More linalool,ocimene and ionone were detected in Osmanthus fragrans'Xiaoye Jin'.Osmanthus fragrans'Zhusha Dan'contains more content of linalool,linalool oxide and trans-geraniol.
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