Tracking antioxidant properties and color changes in low-sugar bilberry jam as effect of processing, storage and pectin concentration

<p>Abstract</p> <p>Background</p> <p>Recently, an increased interest in the identification of valuable possibilities for preserving the antioxidant properties of products obtained by thermal processing of fruits rich in bioactive compounds can be noticed. In this regard, an extensive analysis is necessary in terms of thermal processed products behavior in relation to various factors. The purpose of the present study was to assess the effect which processing and storage at 20°C has on the antioxidant properties and color quality of low-sugar bilberry jam with different low-methoxyl pectin (LMP) concentrations.</p> <p>Results</p> <p>For all measured parameters, it should be noted that thermal processing induced significant alterations reported to the values registered for fresh fruit. Most important losses due to thermal processing were recorded for total monomeric anthocyanins (TMA) (81-84%), followed by L-ascorbic acid (L-AsAc) content (53-58%), total phenolics (TP) content (42-51%) and FRAP (ferric reducing antioxidant power) values (36-47%). Moreover, depreciation of the investigated compounds occurred during storage at 20°C. Jam storage for 7 months resulted in severe losses in TMA content in the range 58-72% from the value recorded one day after processing. This coincided with marked increases in polymeric color percent of these products after 7 months of storage. Also, bilberry jam storage for 7 months resulted in a decrease in L-AsAc content of 40-53% from the value recorded one day after processing, 41-57% in TP content and 33-46% from the value recorded one day after processing for FRAP values. By decreasing of LMP concentration in the jam recipe from 1 to 0.3% there has been an increase in losses of investigated compounds.</p> <p>Conclusion</p> <p>Overall, the results indicated that bilberry jams can also represent a good source of antioxidant compounds, although compared to the fruit, important losses seem to occur. Practical application of this work is that this kind of information will be very useful in optimizing the jam processing technology and storage conditions, in order to improve the quality of these products.</p

Isogentisin (1,3-dihydroxy-7-methoxyxanthone)

The crystal structure of isogentisin, C14H10O5, a natural product isolated from Gentiana lutea, has been determined. The phenolic ring system is essentially planar and the displacement of the methoxy substituent from the mean molecular plane is very small. The structure is stabilized by a one-dimensional chain of intermolecular hydrogen bonds

Highly oxygenated guaianolides from Anthemis cretica subsp. cretica

Two new guaianolides, i.e. anthemolide B and 8-O-angeloyl-9-O-acetylanethemolide B, in addition to 12 known closely related guaianolides were identified in the aerial parts of the flowering plant Anthemis cretica subsp. cretica. (C) 1998 Published by Elsevier Science Ltd. All rights reserved

Essential oil of achillea corabensis (heimerl) micevski

The essential oil of Achillea corabensis (Heimerl) Micevski collected from a natural location as well as from plants cultivated in the Sirinic valley of Sara mountain was analyzed. In the oil of collected plants 41 compounds were identified, while in the oil from the cultivated plants 36 compounds were identified. In the oil obtained from plants harvested in the wild the monoterpene fraction represented 88.0% of the whole oil, whereas the sesquiterpene fraction represented 5.9% and other compounds 3.1% of the total oil composition. In the oil of cultivated plants, the monoterpene fraction represented 74.6%, the sesquiterpene fraction 10.2% and other compounds 3.5% of the oil composition. In both cases the most abundant compounds were sabinene (33% and 25%) and p-cymene (29–4% and 17%). © 1997, Taylor & Francis Group, LLC. All rights reserved