Oxyresveratrol as an antibrowning agent for cloudy apple juices and fresh-cut apples.
Antibrowning activities of Morus alba L. twig extracts, oxyresveratrol, and mulberroside A isolated from mulberry twig on cloudy apple juices and fresh-cut apple slices were evaluated by monitoring the change of a* value, total color difference (DeltaE), and visual observation. It was found, similar to 4-hexylresorcinol, that oxyresveratrol could effectively inhibit browning in cloudy apple juices at a concentration as low as 0.01% and that mulberry twig extract also showed remarkable antibrowning effects on cloudy apple juices. However, for fresh-cut apple slices, mulberry twig extract and oxyresveratrol needed to be used in combination at least with ascorbic acid to exhibit their antibrowning effects. Apple slice samples treated by dipping in a solution containing 0.001 M oxyresveratrol, 0.5 M isoascorbic acid, 0.05 M calcium chloride, and 0.025 M acetylcysteine did not undergo any substantial browning reaction for 28 days at 4 degrees C. However mulberroside A did not show antibrowning effects on cloudy apple juices although it is also a good mushroom tyrosinase inhibitor.
Li
Haitao
H
Department of Botany, The University of Hong Kong, Hong Kong, People's Republic of China.
Cheng
Ka-Wing
KW
Cho
Chi-Hin
CH
He
Zhendan
Z
Wang
Mingfu
M
D001628:Beverages; D004187:Disaccharides / Q000494:pharmacology; D005638:Fruit / Q000737:chemistry / Q000187:drug effects*; D015416:Maillard Reaction / Q000187:drug effects*; D027845:Malus / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D013267:Stilbenes / Q000494:pharmacology*
D004187:Disaccharides; D010936:Plant Extracts; D013267:Stilbenes; C420606:mulberroside A; C034912:puag-haad