|Yoruk, R. - IFAS, UF, FOOD SCIENCE DE|
|Rolle, R. - AGRO-INDUSTRIES/FAO/UN|
|Marshall, M. - IFAS, UF, FOOD TOXICOLOGY|
Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 24, 2003
Publication Date: June 1, 2003
Citation: YORUK, R., HOGSETTE JR, J.A., ROLLE, R.S., MARSHALL, M.R. APPLE POLYPHENOL OXIDASE INHIBITOR(S) FROM COMMON HOUSE FLY. JOURNAL OF FOOD SCIENCE. 2003. v.68. p.1942-1947. Interpretive Summary: Enzymatic browning associated with polyphenol oxidase (PPO) causes millions of dollars in annual losses to the fruit, vegetable and seafood (crustaceans) industries. The catalytic action of PPO is usually a limiting factor in the handling and technological processing of many fruits and vegetables. Few preservatives are available to the food processing industry and one group, the sulfites, may be harmful to asthma sufferers. Because PPO is known to exist in insects, scientists at the USDA Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL, worked with scientists at the University of Florida, Department of Food Sciences and Human Nutrition, to determine the existence of PPO inhibitor(s) in the house fly, Musca domestica. Crude inhibitor(s) was isolated that inhibited the activity of apple PPO up to 90% at pH values greater than 5.0. The highest degree of PPO inhibition was found in isolates from third-instar larvae and 3- to 5-day-old pupae. The PPO inhibitor(s) is most stable at pH 5.0 and quite stable to heating, thawing, and irradiation. This discovery may be useful to the fruit, vegetable, and seafood industries as an alternative mathod for combating enzymatic browning.
Technical Abstract: A new apple polyphenol oxidase (PPO) inhibitor(s) from house fly (Musca domestica L.) was discovered. Crude inhibitor(s) isolated by buffer extraction, heat treatment and dialysis from house fly pupae inhibited the activity of apple PPO up to 90% at pH values above 5.0. Inhibition was strictly pH dependent. Inhibitor(s) was further characterized by employing heat, freezing and thawing, irradiation, pH adjustment and ultrafiltration studies. The potential PPO inhibitor(s) was quite stable to heating at 100 C for 1h, repeated freezing and thawing, and irradiation. Inhibitor(s) was most stable at pH around 5.0 and least stable at alkaline pH. PPO inhibition profile of house fly during its metamorphosis was also evaluated.