Page 1. ORIGINAL PAPER Polyphenol metabolism of developing apple skin of a scab resistant and a s... more Page 1. ORIGINAL PAPER Polyphenol metabolism of developing apple skin of a scab resistant and a susceptible apple cultivar Ana Slatnar Maja Mikulic Petkovsek Heidi Halbwirth Franci Stampar Karl Stich Robert Veberic ...
Pear (Pyrus sp.) is a major fruit crop of temperate regions with increasing extent of cultivation... more Pear (Pyrus sp.) is a major fruit crop of temperate regions with increasing extent of cultivation. Pear flavonoids contribute to its fruit color, pathogen defense, and are health beneficial ingredients of the fruits. Comparative Southern analyses with apple (Malus x domestica) cDNAs showed comparable genomic organization of flavonoid genes of both related genera. A homology-based cloning approach was used to
Antioxidant activity and polyphenols were quantified in vapour-extracted juice of nine Austrian, ... more Antioxidant activity and polyphenols were quantified in vapour-extracted juice of nine Austrian, partially endemic varieties of sweet cherry (Prunus avium): cv. 'Spätbraune von Purbach', cv. 'Early Rivers', cv. 'Joiser Einsiedekirsche', cv. 'Große Schwarze Knorpelkirsche' and four unidentified local varieties. Additionally the effect of storage was evaluated for six of the varieties. A variety showing the highest antioxidant capacity (9.64 μmol Trolox equivalents per mL), total polyphenols (2747 mg/L) and total cyanidins (1085 mg/L) was suitable for mechanical harvest and its juice did not show any losses of antioxidant capacity and total anthocyanin concentration during storage. The juice of cv. 'Große Schwarze Knorpelkirsche' had also high concentrations of total anthocyanins (873 mg/L), but showed substantial losses through storage. The local Austrian sweet cherry varieties from the Pannonian climate zone are particularly suitable for the production of processed products like cherry juice with high content of anthocyanins and polyphenols.
The effect of processing steps on the colour stability and the anthocyanin content of nectars mad... more The effect of processing steps on the colour stability and the anthocyanin content of nectars made from strawberry puree was investigated, including (i) the use of frozen strawberries, (ii) processing temperature (10°C vs. 20°C), (iii) sieving, (iv) pH reduction and (v) storage temperature (20°C vs. 4°C). The use of frozen strawberries significantly improved the colour stability of the nectar even
Pear (Pyrus sp.) is a major fruit crop of temperate regions with increasing extent of cultivation... more Pear (Pyrus sp.) is a major fruit crop of temperate regions with increasing extent of cultivation. Pear flavonoids contribute to its fruit color, pathogen defense, and are health beneficial ingredients of the fruits. Comparative Southern analyses with apple (Malus x domestica) cDNAs showed comparable genomic organization of flavonoid genes of both related genera. A homology-based cloning approach was used to
Page 1. ORIGINAL PAPER Polyphenol metabolism of developing apple skin of a scab resistant and a s... more Page 1. ORIGINAL PAPER Polyphenol metabolism of developing apple skin of a scab resistant and a susceptible apple cultivar Ana Slatnar Maja Mikulic Petkovsek Heidi Halbwirth Franci Stampar Karl Stich Robert Veberic ...
We have investigated the consequences of blocking anthocyanin biosynthesis by silencing a key enz... more We have investigated the consequences of blocking anthocyanin biosynthesis by silencing a key enzyme, anthocyanidin synthase, in transgenic plants of a red-leaved apple cultivar. This is complementary to a previous study of induction of anthocyanin biosynthesis by overexpressing a heterologous transcription factor. Analysis of these opposite phenotypes allows one to study anthocyanin functions in apple and to test the influence of the genetic manipulation on other, related metabolites. As expected, anthocyanin biosynthesis was almost completely blocked and this was accompanied by a shift in the profile of flavonoids and related polyphenols. Most interestingly, a rise in epicatechin was found. A severe reduction of viability by necrotic leaf lesions was also observed, suggesting an essential function of anthocyanins in apple.
Page 1. ORIGINAL PAPER Polyphenol metabolism of developing apple skin of a scab resistant and a s... more Page 1. ORIGINAL PAPER Polyphenol metabolism of developing apple skin of a scab resistant and a susceptible apple cultivar Ana Slatnar Maja Mikulic Petkovsek Heidi Halbwirth Franci Stampar Karl Stich Robert Veberic ...
Pear (Pyrus sp.) is a major fruit crop of temperate regions with increasing extent of cultivation... more Pear (Pyrus sp.) is a major fruit crop of temperate regions with increasing extent of cultivation. Pear flavonoids contribute to its fruit color, pathogen defense, and are health beneficial ingredients of the fruits. Comparative Southern analyses with apple (Malus x domestica) cDNAs showed comparable genomic organization of flavonoid genes of both related genera. A homology-based cloning approach was used to
Antioxidant activity and polyphenols were quantified in vapour-extracted juice of nine Austrian, ... more Antioxidant activity and polyphenols were quantified in vapour-extracted juice of nine Austrian, partially endemic varieties of sweet cherry (Prunus avium): cv. 'Spätbraune von Purbach', cv. 'Early Rivers', cv. 'Joiser Einsiedekirsche', cv. 'Große Schwarze Knorpelkirsche' and four unidentified local varieties. Additionally the effect of storage was evaluated for six of the varieties. A variety showing the highest antioxidant capacity (9.64 μmol Trolox equivalents per mL), total polyphenols (2747 mg/L) and total cyanidins (1085 mg/L) was suitable for mechanical harvest and its juice did not show any losses of antioxidant capacity and total anthocyanin concentration during storage. The juice of cv. 'Große Schwarze Knorpelkirsche' had also high concentrations of total anthocyanins (873 mg/L), but showed substantial losses through storage. The local Austrian sweet cherry varieties from the Pannonian climate zone are particularly suitable for the production of processed products like cherry juice with high content of anthocyanins and polyphenols.
The effect of processing steps on the colour stability and the anthocyanin content of nectars mad... more The effect of processing steps on the colour stability and the anthocyanin content of nectars made from strawberry puree was investigated, including (i) the use of frozen strawberries, (ii) processing temperature (10°C vs. 20°C), (iii) sieving, (iv) pH reduction and (v) storage temperature (20°C vs. 4°C). The use of frozen strawberries significantly improved the colour stability of the nectar even
Pear (Pyrus sp.) is a major fruit crop of temperate regions with increasing extent of cultivation... more Pear (Pyrus sp.) is a major fruit crop of temperate regions with increasing extent of cultivation. Pear flavonoids contribute to its fruit color, pathogen defense, and are health beneficial ingredients of the fruits. Comparative Southern analyses with apple (Malus x domestica) cDNAs showed comparable genomic organization of flavonoid genes of both related genera. A homology-based cloning approach was used to
Page 1. ORIGINAL PAPER Polyphenol metabolism of developing apple skin of a scab resistant and a s... more Page 1. ORIGINAL PAPER Polyphenol metabolism of developing apple skin of a scab resistant and a susceptible apple cultivar Ana Slatnar Maja Mikulic Petkovsek Heidi Halbwirth Franci Stampar Karl Stich Robert Veberic ...
We have investigated the consequences of blocking anthocyanin biosynthesis by silencing a key enz... more We have investigated the consequences of blocking anthocyanin biosynthesis by silencing a key enzyme, anthocyanidin synthase, in transgenic plants of a red-leaved apple cultivar. This is complementary to a previous study of induction of anthocyanin biosynthesis by overexpressing a heterologous transcription factor. Analysis of these opposite phenotypes allows one to study anthocyanin functions in apple and to test the influence of the genetic manipulation on other, related metabolites. As expected, anthocyanin biosynthesis was almost completely blocked and this was accompanied by a shift in the profile of flavonoids and related polyphenols. Most interestingly, a rise in epicatechin was found. A severe reduction of viability by necrotic leaf lesions was also observed, suggesting an essential function of anthocyanins in apple.
Uploads
Papers by Karl Stich