The effect of gaseous ozone exposure on the quality of persimmon picked at 2 different harvest dates was evaluated. Fruit from both harvests were continuously exposed to 0.15 ppm (vol/vol) of ozone for 30 d at 15 °C, 90% relative humidity (RH). Then, fruit were submitted to astringency removal treatment (24 h at 20 °C, 98% CO2) and stored for 7 d at 20 °C (90% RH) in order to simulate shelf‐life period. The most important disorder was flesh softening, which took place when fruit were transferred from 15 °C to shelf‐life conditions. In the 2nd harvest, where the fruit were harvested with lower firmness, ozone maintained firmness over commercial limits even after 30 d at 15 °C plus shelf‐life. Ozone‐treated fruit showed the highest values of weight loss, coinciding with the maximum electrolyte leakage (EL) percentage. Ozone did not affect color index (CI), ethanol, total soluble solids (TSS), or pH. Unremarkable differences in acetaldehyde were observed between fruit submitted to ozone treatment and control fruit. No phytotoxic injuries in tissues were observed in ozone‐treated fruit.

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A B S T R A C T : An unusually complete sequence of pelitic rocks ranging from diagenetic to greenschist-facies metamorphic grades occurs in southern Sierra Espuña, Spain. Prograde and retrograde reactions have been studied by X-ray diffraction and electron microscopy (SEM, TEM and AEM). The prograde reaction series, with reactions facilitated by tectonic stress, includes: (1) R4 interstratified illite-smectite in the diagenetic Malaguide Complex that preserves the variable orientation of original smectite packets, and has 1Md polytypism; (2) chemically heterogeneous illite and Na-K dioctahedral white micas that progressively evolve toward chemical and textural equilibrium in the anchizonal Intermediate Units; and (3) thick, defect-free packets of phengite, paragonite and clinochlore which have a typical metamorphic texture, in the Alpujarride Complex. Two superimposed retrograde episodes produced: (a) sudoite at near-peak metamorphic conditions and (b) dioctahedral smectite during low-temperature retrograde diagenesis.

Devonian and Carboniferous metasedimentary sequences in the southernmost sector of the Iberian Massif, part of the Hercynian Orogen in southwestern Portugal, contain shales and slates of low but variable metamorphic grade. These rocks have been studied by optical microscopy and XRD to obtain basic data on their clay mineralogy and crystal-chemical parameters (IC, the index of "crystallinity", b and d 001 ). Electron-microscopy techniques (SEM, HRTEM and AEM) have been used to characterize the textural relationships and chemical evolution of the minerals, mainly the phyllosilicates. A good correlation has been found between the data determined by XRD methods and by electron microscopy. The main mineral association is quartz + dioctahedral K-rich mica + feldspars, but Na-K intermediate mica, paragonite, kaolinite and chlorite also are present, although discontinuously. The thickness of crystallites measured directly from lattice-fringe images is related to the IC, providing information on the evolution of the metamorphism through the sequences, with decreasing IC from southwest to northeast. The IC values for both the Brejeira and Mira formations correspond to diagenesis and anchizone, the Mértola and Phyllite-Quartzite formations, to high anchizone-epizone, and the Pulo do Lobo Formation presents values typical of epizonal conditions. Despite this pattern of evolution, however, the changes in metamorphic grade are not progressive, and the abrupt changes found between the characteristic values of each stratigraphic formation are interpreted as being associated with thrust surfaces. Textural data provide a clear contrast between the samples of different grade, with the lowest-grade samples showing a bedding-parallel microfabric and stacks of phyllosilicates. The most strongly metamorphosed pelites, on the other hand, present a crenulation-cleavage microfabric and a recrystallized matrix. As grade of metamorphism increases, crystal thickness increases and defects decrease in the phyllosilicates, although chlorite shows a higher density of strain-related defects than mica. There is wide scatter in the chemical data for both dioctahedral micas and chlorites, but some chemical characteristics can still be discerned. XRD and AEM reveal a tendency for the micas to be more similar to muscovite and less to illite with increasing metamorphic grade, although both compositions are present in all samples. The extent of phengitic substitution is extremely low, indicating low-pressure conditions. The formation of chlorite and its composition are mainly controlled by the host-rock composition.