Determination of The Physical, Physio-Chemical and Chemical Properties of Gilaburu Fruits (Viburnum opulus) Dried by Convectional Drying Technique

Our country has many species in fruit and vegetable cultivation. One of them is Gilaburu fruit (Viburnum Opulus), which has spread to different regions, especially in Kayseri. Longer preservation of products in fruits and vegetables; Drying process has been applied since ancient times to prevent deterioration caused by microbial and/or biochemical changes. One of them and the most common one is convectional drying in other words drying in a drying chamber under controlled hot air stream. In this study, Gilaburu fruits were obtained from a local producer in Kayseri. Drying processes were carried out in a convectional oven at 60, 70 and 80℃ in three repetitions. The effects of different drying conditions on the drying characteristics of Gilaburu fruits were examined. Drying time for Gilaburu fruits decreased with increasing temperature. As a color parameter total color change with respective to fresh fruit (ΔΕ) was investigated. The results indicated that it remained almost identical with temperature change. Similar trend was observed for rehydration rate. Titration acidity and pH values showed compatible changes. With temperature increase, titration acidity increased, as pH decreased. As textural properties, skin-hardness and elasticity of dried fruits were measured. As hardness increased, elasticity decreased with temperature elevation. Total phenolic content and antioxidant activity of dried samples were also examined. The results showed that there were increases in both of them with an increase in temperature.

DRYING, COLOUR AND REHYDRATION CHARACTERISTICS OF ORANGE SLICES UNDER INFRARED RADIATION HEATING

The effect of different infrared (IR) powers on drying of orange slices was investigated in infrared dryer. The orange slices dried at 62, 74 and 88 W infrared powers and constant slice thickness of 6 mm. Results showed that drying, colour and rehydration characteristics of orange slices were greatly influenced by infrared power. The drying data were fitted with five mathematical models available in the literature. Based on the statistical tests applied to make an assessment, the model of Midilli and Kucuk was found to satisfactorily explain drying kinetics of orange slices for all drying conditions. The Fick’s diffusion model was used to calculate the effective moisture diffusivity (Deff) of orange slices. The value of Deff varied from 1.59×10-10 to 2.49×10-10 m2/s. It was found that the effective moisture diffusivities increased with increasing IR power. Activation energy was estimated by a modified Arrhenius type equation as 2.11 kW/kg. As the infrared power increased, the rehydration ratio was found to be reduced. Furthermore, with increase of infrared power, the values of a and DE increased, whereas the values of L, b and C decreased.

Hop Leaves as an Alternative Source of Health-Active Compounds: Effect of Genotype and Drying Conditions

In hop cultivation, one-third of the crop is a valuable product (hop cones), and two-thirds is unexploited biomass, consisting mainly of leaves and stems, which, in a circular economy approach, can be recovered and, once stabilized, supplied to industrial sectors, such as cosmetics, pharmaceuticals and phytotherapy, with high added value. In this regard, this study aimed to investigate the effects of two different drying methods: oven drying (OD) at 45 °C and freeze-drying (FD), on the overall nutraceutical profile (i.e., total phenols, total flavans and total thiols), pigment content (i.e., carotenoids and chlorophylls) and the antioxidant potential of leaves from five different Humulus lupulus varieties grown in central Italy. Moreover, attenuated total reflectance infrared (ATR-FTIR) spectroscopy was applied to dried leaf powders to study the influence of both the variety and treatment on their molecular fingerprints. The spectral data were then analyzed by principal component analysis (PCA), which was able to group the samples mainly based on the applied treatment. Considering the overall phytochemical profile, FD appeared to be the most suitable drying method, while OD provided higher carotenoid retention, depending on the genotype considered. Finally, unsupervised chemometric tools (i.e., PCA and hierarchical clustering) revealed that the two main clusters contained subclusters based on the drying treatment applied; these subgroups were related to the susceptibility of the variety to the drying conditions studied.

Evaluation of Coatings to Improve the Durability and Water-Barrier Properties of Corrugated Cardboard

Recently, corrugated cardboard furniture gained interest from the market, yet is limited to indoor application. With an aim toward outdoor usage, water-barrier improvement of such products must be achieved. In this work, three commercially available coating grades (i.e., polymeric, mineral-filled polymeric, and hybrid silica sol-gel products) were spray-coated on corrugated cardboard using a facile, yet readily transferable, process. The investigation assessed the coating performance from the different drying conditions and natural UV-vis weathering effects, characterising their water absorption, hydrophobicity, coating morphology, and colour change. Results show a reduction in water absorption values (up to −98%) for both the polymeric coatings; instead, the hybrid sol-gel coating showed contact angles up to almost 150°. Generally, the SEM micrographs displayed some surface defects as well as good thickness homogeneity. A perceivable colour change occurred for each sample (CIEDE2000 up to 6.41), mainly occurring in the 0–100 h time range. This work provides promising results for the outdoor application of corrugated cardboard furniture.