Showing papers by "Attila Kiss published in 2019"

Changes of free fatty acid composition and number of lactic acid bacteria in three functional goat and sheep milk products fortified with inulin or fish oil

Abstract: Inulin and fish oil rich in omega-3 fatty acid were applied to yoghurt, kefir, and smearcase made from goat and sheep milk, and their impact on fatty acid composition was investigated at 8°C throug...

Production of cinnamyl alcohol glycosides by biotransformation in roseroot callus cells

Abstract: Cinnamyl alcohol glycosides (CAGs) are the signature compounds of all roseroot preparations. The rapid growth in the market of roseroot-based products and the increasing demand for its raw material is causing serious threat for wild growing roseroot populations worldwide, which promotes the extensive studies to come up with alternative production resources. In this study the biotransformation of several precursors for the production of CAGs (rosin, rosavin, rosarin) in in vitro roseroot callus culture has been surveyed. Phenylalanine, trans-cinnamic acid, cinnamaldehyde and cinnamyl alcohol; the proposed precursors of CAGs, were added one by one to roseroot liquid callus cultures in 2 mM concentration. Samples were harvested and analysed by HPLC after 24, 48 and 96 h along with controls. All of the studied compounds, except phenylalanine, promoted the formation of CAGs. It was found that the closer the position of precursors to the final product in the biosynthesis pathway the more effective was the biotransformation into the final CAGs, both in terms of time and final product quantities. Addition of 2 mM trans-cinnamic acid and Cinnamyl alcohol resulted in 80-fold increase after 24 h and 130-fold increase after 96 h in callus samples, respectively. Rosin was the only compound which was released into the medium from the callus cells during the experiment and only in the cinnamyl alcohol-fed callus cells. These results revealed the potential of the precursors of the cinnamyl alcohol glycosides to be subject of biotransformation by roseroot callus cultures in order to produce the pharmaceutically important compounds. Biotransformation of precursors in Rhodiola rosea callus culture has proved to be a feasible approach to sustainably enhance the content of active constituents in vitro.

Supplementation of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes) Extract Enhanced the Medicinal Values and Prebiotic Index of Hungarian Acacia Honey.

Abstract: Acacia honey, as a favored delicacy, was supplemented with extracts of distinctive Ganoderma lucidum (lingzhi or reishi) variants to enhance its biological value and lay the foundations for prospective functional food application. Health promoting effects of G. lucidum have already been documented and its prebiotic features have been verified. In spite of promising studies and its unambiguous nutritional value, G. lucidum mushroom has not gained extensive use in the food industry so far. Special honey-based foodstuffs fortified with G. lucidum extract were developed as novel food prototypes, and screened for their enhanced total phenolic content (TPC), antioxidant (FRAP), and antiradical activity (DPPH). The obtained variants were also investigated for the possibly increased prebiotic index by means of an in vitro digestion procedure. A concentration dependent positive correlation was observed for all the studied parameters in case of the investigated prototypes. Supplementation of acacia honey with 0.5% reishi mushroom extract significantly increased the TPC, the antioxidant activity, and the radical scavenging power. A statistically significant improvement in the prebiotic index was also observed for the developed prototypes when compared with pure acacia honey. The evidence gained from the conducted studies fully supports the conception of combining honey and reishi extract to obtain a functional food product of high biological potential.

In vivo and in vitro model studies on noodles prepared with antioxidant-rich pseudocereals

Abstract: Pseudocereals are recently positioned at the forefront of interest, as they are eminent sources of several beneficial bioactive components, such as flavonoids. Noodles of specific composition comprising buckwheat and amaranth have been involved in this research. The aim of presented study was to provide authentic tools in order to estimate the actual behaviour of polyphenols of the special noodles throughout the digestion process. In vitro and in vivo digestion models studies were performed with wheat flour noodles fortified with antioxidant rich pseudocereals. Five noodle variants were prepared with supplementation of different flours of amaranth and buckwheat with wheat flour ranging from 5 to 30%. To reveal the effect of human consumption on polyphenols uptake and real biological impacts, in vitro and in vivo experiments were carried out. Different assays were applied to monitor the release of antioxidants in each gastrointestinal phase. Fortification didn’t change the cooking quality of noodles, but slightly affected the colour and improved the total polyphenol content (597–920 mg GAE/kg), and the antioxidant capacity (3.47–7.23 mM Fe2+/kg) of the noodles. It was established that total polyphenol content and antioxidant capacity exhibited continuous increase in the whole gastrointestinal tracts, due to their gradual release from food matrix. Most pronounced antioxidant capacity was observed in noodles with 30% buckwheat fortification. In vivo model-experiments confirmed the presence of polyphenols in plasma as well, thus their absorption might be accomplished. Therefore, the biological values of these samples were enhanced during digestion. Supplementation prepared pseudocereal resulted in products with improved nutritional properties.