Effects of Photoperiod Regime on Meat Quality, Oxidative Stability, and Metabolites of Postmortem Broiler Fillet (M. Pectoralis major) Muscles

Abstract

The objective of this study was to evaluate the effects of photoperiod on meat quality, oxidative stability, and metabolites of broiler fillet (M. Pectoralis major) muscles. A total of 432 broilers was split among 4 photoperiod treatments [hours light(L):dark(D)]: 20L:4D, 18L:6D, 16L:8D, and 12L:12D. At 42 days, a total of 48 broilers (12 broilers/treatment) was randomly selected and harvested. At 1 day postmortem, fillet muscles were dissected and displayed for 7 days. No considerable impacts of photoperiods on general carcass and meat quality attributes, such as carcass weight, yield, pH, water-holding capacity, and shear force, were found (p > 0.05). However, color and oxidative stability were influenced by the photoperiod, where muscles from 20L:4D appeared lighter and more discolored, coupled with higher lipid oxidation (p < 0.05) and protein denaturation (p = 0.058) compared to 12L:12D. The UPLC–MS metabolomics identified that 20 metabolites were different between the 20L:4D and 12L:12D groups, and 15 were tentatively identified. In general, lower aromatic amino acids/dipeptides, and higher oxidized glutathione and guanine/methylated guanosine were observed in 20L:4D. These results suggest that a photoperiod would result in no considerable impact on initial meat quality, but extended photoperiods might negatively impact oxidative stability through an alteration of the muscle metabolites.

Functional/physicochemical properties and oxidative stability of ground meat from broilers reared under different photoperiods

“…A previous study has corroborated the relationship between storage duration and loss of sulfhydryl groups in chicken meat ( Khan et al., 1963 ). Tuell et al. (2020) found an interaction in thiol contents of intact M. Pectoralis major muscles from day 1 to day 7 of aerobic display, where a detectable loss of thiol groups was observed in the 20L:4D group only ( P < 0.05), whereas thiol contents of shorter photoperiod groups were unaffected ( P > 0.05).…”

“…These differences may arise from the meat having been ground, as this could mitigate the previously mentioned more open muscle structure associated with protein denaturing conditions. Alternatively, the parallel study by Tuell et al. (2020) observed a trend ( P = 0.07) of greater moisture loss in 20L:4D carcasses during carcass chilling compared with shorter photoperiod groups, whereas no measures of WHC in the intact M. Pectoralis major muscles were affected ( P > 0.05).…”

“…(2010) demonstrated that the breast muscle ( M. Pectoralis major ) from broilers reared under a 23L:1D lighting schedule had reduced percent meat protein and increased lipid oxidation compared to 12L:12D. The finding of increased lipid oxidation with longer photoperiod in M. Pectoralis major muscles was corroborated by our parallel study published by Tuell et al. (2020) .…”

“…These results indicate that using a 12L:12D photoperiod regime can improve lipid stability. Although its mechanisms were not tested in this study, it could be related to the decrease of MDA contents in both live broiler serum ( Guob et al., 2010 ) and fillet muscles ( Li et al., 2010 , Tuell et al., 2020 ) associated with shorter photoperiod regimes. This hypothesis is supported by the findings of longer photoperiod promoting the release of free radicals with lowering immune function ( Abbas et al., 2008 , Guob et al., 2010 ).…”

Impact of Pre-Mortem Factors on Meat Quality: An Update

“…This special issue of Foods, "Impact of Pre-Mortem Factors on Meat Quality" (ISSN 2304-8158), aims to compile the recent literature with a focus on pre-mortem factors, muscle metabolism, and meat quality. It includes nine research articles about various types of meat (beef [4], lamb [5], pork [6], chicken [7][8][9], goat [10,11] and fish [12]) as well as one review article about beef quality [13]. These articles, while their aims are different, provide an accurate representation of the current frontier of meat science and the direction in which it is heading.…”