{"title":"Light wavelengths that induce oxidation of oxymyoglobin in meat","authors":"","doi":"10.1016/j.meatsci.2024.109664","DOIUrl":null,"url":null,"abstract":"<div><p>Light wavelengths that induce meat discoloration and the photoreceptors in the meat were studied. We investigated the effects of the light wavelength on the oxidation rate of myoglobin (Mb) by exposing Mb extracts or model solutions containing Mb to light at specific wavelengths with a bandwidth of 5 nm using a fluorescence spectrophotometer. The wavelengths examined comprised 385, 415, 445, 460, 490, 525, 555, 580, 605, 630,660, and 750 nm. In the Mb extracts, Mb oxidation was induced through exposure to the light at 445 and 580–605 nm; Mb was insensitive to light at 445 nm. Mitochondria, containing cytochrome <em>a</em> and cytochrome <em>a</em>3 with absorption peaks at 448 and 600 nm, and riboflavin with fluorescence at 450 nm were studied as 445 nm receptors. Mitochondria significantly oxidized Mb via cytochrome <em>c</em> oxidation through complex IV activity; however, no 445 nm-specific photo sensitivity effects were observed. In contrast, riboflavin increased the Mb oxidation rate induced via exposure to the light at 450 nm in a concentration-dependent manner (minimum concentration: 38.4 μg L<sup>−1</sup>). While native mitochondria did not show 445 nm-specific photosensitivity effects on Mb, supernatants of heated mitochondria conferred 445 nm-wavelength sensitivity to Mb. Riboflavin concentration in this supernatant was 182 ± 60 μg L<sup>−1</sup>. The Mb photosensitivity spectrum with 473 μg L<sup>−1</sup> riboflavin had two peaks at 445 nm and 580 nm, which were similar to those of Mb extract. These results suggest that mitochondrial damage affects the meat discoloration through the release of cytochrome <em>c</em> and riboflavin.</p></div>","PeriodicalId":389,"journal":{"name":"Meat Science","volume":null,"pages":null},"PeriodicalIF":7.1000,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Meat Science","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0309174024002419","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Agricultural and Biological Sciences","Score":null,"Total":0}
引用次数: 0
Abstract
Light wavelengths that induce meat discoloration and the photoreceptors in the meat were studied. We investigated the effects of the light wavelength on the oxidation rate of myoglobin (Mb) by exposing Mb extracts or model solutions containing Mb to light at specific wavelengths with a bandwidth of 5 nm using a fluorescence spectrophotometer. The wavelengths examined comprised 385, 415, 445, 460, 490, 525, 555, 580, 605, 630,660, and 750 nm. In the Mb extracts, Mb oxidation was induced through exposure to the light at 445 and 580–605 nm; Mb was insensitive to light at 445 nm. Mitochondria, containing cytochrome a and cytochrome a3 with absorption peaks at 448 and 600 nm, and riboflavin with fluorescence at 450 nm were studied as 445 nm receptors. Mitochondria significantly oxidized Mb via cytochrome c oxidation through complex IV activity; however, no 445 nm-specific photo sensitivity effects were observed. In contrast, riboflavin increased the Mb oxidation rate induced via exposure to the light at 450 nm in a concentration-dependent manner (minimum concentration: 38.4 μg L−1). While native mitochondria did not show 445 nm-specific photosensitivity effects on Mb, supernatants of heated mitochondria conferred 445 nm-wavelength sensitivity to Mb. Riboflavin concentration in this supernatant was 182 ± 60 μg L−1. The Mb photosensitivity spectrum with 473 μg L−1 riboflavin had two peaks at 445 nm and 580 nm, which were similar to those of Mb extract. These results suggest that mitochondrial damage affects the meat discoloration through the release of cytochrome c and riboflavin.
期刊介绍:
The aim of Meat Science is to serve as a suitable platform for the dissemination of interdisciplinary and international knowledge on all factors influencing the properties of meat. While the journal primarily focuses on the flesh of mammals, contributions related to poultry will be considered if they enhance the overall understanding of the relationship between muscle nature and meat quality post mortem. Additionally, papers on large birds (e.g., emus, ostriches) as well as wild-captured mammals and crocodiles will be welcomed.