Cellulose in Secondary Xylem of Cactaceae: Crystalline Composition and Anatomical Distribution

Protocol to analyse the structural composition by fluorescence microscopy and different conventional and fluorescence staining methods

The protocol shows the effectiveness of using safranin-fast green stain for fluorescence microscopy. This staining technique has been used in conventional microscopy to perform anatomical characterizations of plants. However, this protocol describes the procedure for using samples stained with safranin-fast green in conjunction with fluorescence microscopy. The strength of the protocol lies in the fact that the samples are permanent and allows for effective differentiation of lignified and cellulosic walls unlike conventional fluorescence microscopy stains such as Congo red-acridine orange, calcofluor, and autofluorescence. The protocol for making fluorescence intensity measurements is also standardized, allowing the data to be used for statistical analysis and inference about the chemical composition of plant cell walls.

Combined effect of ultrasound and vacuum impregnation for the modification of apple tissue enriched with aloe vera juice

The aim of the work was to investigate how ultrasonic (US) treatment impacts on the physical and chemical properties of vacuum-impregnated apples. Apple slices were subjected to vacuum impregnation (VI) in an Aloe vera juice solution without additional treatments, serving as the reference material. Alternatively, ultrasound (US) treatments, at frequencies of 25 or 45 kHz, and durations of 10, 20, or 30 min, were employed as a pre-treatments before the VI process. The use of US processing enabled a significant increase in the efficiency of VI, without influencing in a significant way the color of the VI samples. The VI process led to a reduction in the content of bioactive compounds, in particular vitamin C and TPC decreased by 34 and 32 %, respectively. The use of US as a pre-treatment, in particular at 45 kHz for 20 or 30 min, led to a better preservation of these compounds (unchanged values for vitamin C and decrease by 23-26 % for TPC in comparison to the fresh samples). Through cluster analysis encompassing all assessed properties, it was evident that US treatment was beneficial for the processing, however the application of appropriate parameters of US treatment (frequency and time) had an impact on achieving similar quality to VI samples. The ultrasound treatment before vacuum impregnation may be suitable, however, the specific processing parameters should be defined for the obtained high quality of the final product.