Drying kinetics and selected physico - chemical properties of fresh cranberries preserved with microwave – vacuum process

[EN] A one stage drying process for dried cranberry production, employing a vacuum microwave technique, is proposed. The process consists of a specific sequence of microwave energy dosage at a given vacuum level. During the 60 minute process, three sub-stages can be identified: osmotic dehydration, intensive water evaporation and stabilization. Mass transfer, as well as quality changes during the process, has been described, and the final product quality compared to purchased control. The proposed method of dried cranberry production resulted in a microbiologically stable product (aw=0.62) of a decent sensory quality, with an antioxidant potential three times higher than traditional products.This work was performed in the frame of the multiannual programme (IO 2015-2020, PW 1.4.), financed by the Polish Ministry of Agriculture and Rural Development.Piecko, J.; Konopacka, D.; Mieszczakowska-Frąc, M.; Kruczyńska, D.; Celejewska, K. (2018). Drying kinetics and selected physico - chemical properties of fresh cranberries preserved with microwave – vacuum process. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1927-1934. https://doi.org/10.4995/IDS2018.2018.8365OCS1927193

Silica-polymer composites as the novel antibiotic delivery systems for bone tissue infection

Bone tissue inflammation, osteomyelitis, is commonly caused by bacterial invasion and requires prolonged antibiotic therapy for weeks or months. Thus, the aim of this study was to develop novel silica-polymer local bone antibiotic delivery systems characterized by a sustained release of ciprofloxacin (CIP) which remain active against Staphylococcus aureus for a few weeks, and do not have a toxic effect towards human osteoblasts. Four formulations composed of ethylcellulose (EC), polydimethylsiloxane (PDMS), freeze-dried CIP, and CIP-adsorbed mesoporous silica materials (MCM-41-CIP) were prepared via solvent-evaporation blending method. All obtained composites were characterized in terms of molecular structure, morphological, and structural properties by using Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX), and X-ray diffraction (XRD), thermal stability by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and in vitro antibiotic release. The antibacterial activity against Staphylococcus aureus (ATCC 6538) as well as the in vitro cytocompatibility to human osteoblasts of obtained composites were also examined. Physicochemical results confirmed the presence of particular components (FTIR), formation of continuous polymer phase onto the surface of freeze-dried CIP or MCM-41-CIP (SEM/EDX), and semi-crystalline (composites containing freeze-dried CIP) or amorphous (composites containing MCM-41-CIP) structure (XRD). TGA and DSC analysis indicated the high thermal stability of CIP adsorbed onto the MCM-41, and higher after MCM-41-CIP coating with polymer blend. The release study revealed the significant reduction in initial burst of CIP for the composites which contained MCM-41-CIP instead of freeze-dried CIP. These composites were also characterized by the 30-day activity against S. aureus and the highest cytocompatibility to human osteoblasts in vitro

MECHANICAL HARVESTING OF PLUMS FOR PROCESSING WITH A CONTINUOUSLY MOVING COMBINE HARVESTER

A B S T R A C T Eleven plum cultivars (Prunus domestica L.) for processing grafted on semidwarf rootstock 'Wangenheim Prune' and vigorous rootstock 'Myrobalan' were densely planted (1000, 1250, 1666, 2500 trees ha -1 ) and trained to central leader spindle tree. A new training system was applied to obtain trees suitable for mechanical harvesting. The leader was not headed after planting and summer training procedures were performed in May/June. From the third year onwards, renewal pruning was carried out after fruit harvesting. The new training and pruning systems resulted in very fast tree growth, abundant branching, fruit bud formation on young wood and early bearing. The plum trees appeared to be suitable for hand and mechanical harvesting within 3 years from planting. The self propelled straddle combine harvester was able to harvest 2-3 tons of plums per hour compared to 30 kg with hand picking. Harvesting effectiveness was 90-95%. The quality of mechanically harvested plums was a little worse than of those hand picked, but fruits were suitable for processing. The 'Common Prune' and the prune type small plums were the most suitable fruit for mechanical harvesting

The Effect of Hybrid Drying (Convective-Microwave-Ultrasound) on the Bioactive Properties of Osmo-Treated Sour Cherries

The aim of the study was to assess the usefulness of hybrid drying methods (convective-microwave and convective-microwave-ultrasound) for sour cherry fruit preservation compared to convective drying. As the raw material, three sour cherry cultivars varying in quality characteristics (‘Łutówka’, ‘Debreceni Bötermo’, ‘Nefris’) were used. Before drying, fruits were subjected to osmotic treatment. Three different drying methods were examined: 1) convective (C), 2) hybrid with microwaves (C-MV) and 3) hybrid with microwaves and ultrasound (C-MV-US). As the quality indicators of the investigated processes, the changes in chemical composition, including alterations in the main groups of bioactive components, as well as in the antioxidant potential were monitored at each production stage. It was found that, when compared to convective drying, the use of the hybrid techniques allowed the drying time to be reduced from 9 to just 3 hours. Furthermore, employing hybrid drying eliminated the problems associated with the dehydration barrier observed during convective drying of the cultivar ‘Debreceni Bötermo’. Regrettably, although the ultrasound used as the additional source of energy in the hybrid method slightly improved water evaporation, in general no significant effect on the retention of phenolic compounds was found. Irrespectively of the drying method, the effect of the cultivar proved to be crucial to the quality of the final product. Under the same processing conditions, ‘Nefris’ turned out to be the most promising cultivar for producing ready-to-eat fruit snacks of high nutritional value

Quality Potential Of Some New Pear Cultivars – How To Obtain Fruit Of The Best Sensory Characteristics?

The eating quality of nine new pear cultivars grown in Poland was investigated in 2008-2011. Fruits of two summer cultivars: ‘Alfa’ and ‘Radana’, as well as late season varieties: ‘Hortensia’, ‘Dicolor’, ‘Concorde’, ‘Uta’, ‘Xenia’, ‘Erika’ and ‘Verdi’ were compared to fruits of ‘Clapp’s Favorite’ and ‘Conference’, which were taken as cultivars of reference. Fruits of all cultivars were harvested from the Experimental Orchard of the Research Institute of Horticulture at the commercial maturity stage and stored at +2.5 °C or -0.5 °C in a normal atmosphere (NA) or at -0.5 °C in a controlled atmosphere (CA) (0.7% CO2 : 2% O2) for 6 to 16 weeks. At the end of storage, the fruits of each cultivar were subjected to an individual ripening schedule at 18 °C (up to 14 days), which generated samples of diversified quality attributes. Based on instrumental analyses and descriptive sensory assessment the quality attributes of each cultivar were examined. The gathered data on the dynamics of quality attribute changes during the ripening stage confirm that each new cultivar needs an individual strategy during storage and ripening in order to maximise their specific sensory attributes to increase potential market value. The obtained data leads to the conclusion that ‘Xenia’ and ‘Concorde’ fruits have the biggest chance to fulfil consumer expectations, as they were appreciated more than the reference ‘Conference’ cultivar. Among the others also ‘Hortensia’, ‘Verdi’ and ‘Dicolor’ were scored higher than ‘Conference’, but their advantages were not so evident

Suitability Of Plum And Prune Cultivars, Grown In A High Density Planting System, For Mechanical Harvesting With A Canopy Contact, Straddle Harvester

The relation of hand-harvesting cost in plum and prune production to the total costs amounts to 25-40%. Mechanical harvesting makes it possible to cut drastically both the harvesting and total costs. To test the suitability of plum and prune species to be mechanically harvested, an experimental grove (area 0.8 ha) was established in 2008. Three plum cultivars and one prune cultivar grafted on semi-dwarf and vigorous rootstocks were planted at high density (1250; 1666; 2500 trees·ha−1). During the span of full yielding (2012-2014), fruits were harvested mechanically with a canopy contact, straddle harvester in continuous motion, designed at the Institute of Horticulture in Skierniewice, to harvest tart cherry, and later adapted to harvesting plums and prunes. Trees grafted on semi-dwarf rootstock (‘Wangenheim Prune’) appeared to be more suitable for mechanical harvesting than strong-growing trees grafted on Prunus cerasifera clone ‘Myrobalan’. Cumulative yield per ha (years 2012-2014) was the highest at the highest planting density. Trees grafted on the semi-dwarf rootstock had a higher productivity index than trees grafted on the vigorous rootstock. There was no significant difference in fruit quality related to planting distance. Mechanical harvesting was nearly 40 times more efficient than hand picking. The efficiency of mechanical harvest was from 85% to 90%. Over 5% of fruits were lost on the ground and from 1 to 5% of fruits were left on the tree. Up to 18% of the plums and no more than 10% of the prunes harvested mechanically showed some damage. They can be fully acceptable for processing, for up to 10 days, providing the potential deterioration processes are inhibited by cold storage. The large-fruited cultivars seem to be more susceptible to bruising than the small-fruited ones. For the latter, the share of marketable quality fruits within the mechanically harvested crop amounted to about 80%, which could be a good prognostic justifying further trials on the prune harvester

Quality Of Cloudy Plum Juice Produced From Fresh Fruit Of Prunus Domestica L. – The Effect Of Cultivar And Enzyme Treatment

The quality of cloudy juices produced from two plum cultivars varied in chemical characteristics and native polyphenol oxidase (PPO) activity, and was studied in relation to specific pectinolytic activity of enzyme preparations used for fresh fruit maceration before pressing. Process effectiveness expressed as juice yield, turbidity and the rate of transfer of anthocyanins and polyphenols were determined for five different enzyme preparations, whose activity was also analysed. Juice yields obtained after 1 hour mash maceration (50 ºC, 100 g·t−1) were between 86.6 and 95.4%. The anthocyanins content of the obtained juices strongly depended on the cultivar and ranged from 26 to 50 mg·L−1 for ‘Promis’, and from 269 to 289 mg·L−1 for ‘Čačanska Najbolja’, which could be related to the differences in the measured PPO activity (175.4 and 79.8 nkat·g−1, respectively). The type of enzyme preparation strongly affected the degradation rate of anthocyanins during juice processing. Peonidin-3-rutinoside proved to be the most stable during plum juice production in contrast to cyanidin-3-glucoside. Irrespectively of the cultivar, the juice prepared with the mixture of Rohapect PTE + Rohament PL (2 : 1) showed the highest turbidity among the investigated combinations. The results suggest that for the production of cloudy plum juice use of a preparation with low pectin methyl esterase and polygalacturonase activities and high pectin lyase activity could be recommended

Quality Of Cloudy Plum Juice Produced From Fresh Fruit Of Prunus Domestica L. – The Effect Of Cultivar And Enzyme Treatment

The quality of cloudy juices produced from two plum cultivars varied in chemical characteristics and native polyphenol oxidase (PPO) activity, and was studied in relation to specific pectinolytic activity of enzyme preparations used for fresh fruit maceration before pressing. Process effectiveness expressed as juice yield, turbidity and the rate of transfer of anthocyanins and polyphenols were determined for five different enzyme preparations, whose activity was also analysed. Juice yields obtained after 1 hour mash maceration (50 ºC, 100 g·t−1) were between 86.6 and 95.4%. The anthocyanins content of the obtained juices strongly depended on the cultivar and ranged from 26 to 50 mg·L−1 for ‘Promis’, and from 269 to 289 mg·L−1 for ‘Čačanska Najbolja’, which could be related to the differences in the measured PPO activity (175.4 and 79.8 nkat·g−1, respectively). The type of enzyme preparation strongly affected the degradation rate of anthocyanins during juice processing. Peonidin-3-rutinoside proved to be the most stable during plum juice production in contrast to cyanidin-3-glucoside. Irrespectively of the cultivar, the juice prepared with the mixture of Rohapect PTE + Rohament PL (2 : 1) showed the highest turbidity among the investigated combinations. The results suggest that for the production of cloudy plum juice use of a preparation with low pectin methyl esterase and polygalacturonase activities and high pectin lyase activity could be recommended