The purpose of this study was to investigate the changes of oxidative attributes, protein DJ-1 expression, oxidized form (oxDJ-1), and cellular localization in RFN and PSE pork meat during the post-mortem aging. The longissimus thoracis of RFN and PSE groups were collected and classified by determination of pH, color and purge loss and then aged for 1, 3 and 7 d at 4 °C postmortem. Results showed that the content of DJ-1 and oxDJ-1 was continuously increased during 7 d of postmortem aging. A relatively higher protein DJ-1, oxDJ-1, oxygen reactive species and disulfide bond contents were found in PSE meat in comparison to RFN meat. Immunostaining showed that protein DJ-1 was located in cytoplasm, membrane and some nucleus of muscle cells. DJ-1 was shown to correlate with meat quality and oxidative attributes, suggesting a regulatory role in resisting oxidative stress and meat quality formation during post-mortem aging.

In this paper, the potential effect of nitric oxide (NO) on improving the fresh meat quality of pork was primarily investigated by treatment of longissimus thoracis (LT) with 0, 20, 40, 60, 80 μL/L NO gas within 6 h post-slaughter. After the NO treatments were completed, the pork chops were vacuum-packaged and stored at 4 °C for 1, 4, and 7 d. Compared with the control group, NO treatment enhanced ultimate pH and a* value, and decreased the total bacterial count. The meat treated with 40 and 60 μL/L NO presented higher water holding capacity (WHC), lower shear force and meat hardness with more unconsolidated muscle cell structure. Though 80 μL/L NO treatment achieved better color and microbial attributes, it had a negative effect on WHC and tenderness. Our data suggest that NO treatment is able to improve pork meat quality in a dose-dependent manner.

This study compared the quality, oxidation, and microstructure of high-market-share PSE-like chicken meat (PSE) after domestic cooking with those of normal chicken meat (NOR). Cooking techniques included steaming (ST), boiling (BO), roasting (RO), and microwaving (MV) at 60, 70, and 80 °C. The results indicated that PSE-induced chicken breasts were of poor quality, with significantly higher cooking loss rates (NOR: 22.1% vs. PSE: 26.2%) and shear force (NOR: 50.4 N vs. PSE: 69.2 N) than normal chicken meat. In addition, PSE-like chicken meat showed higher oxidative sensitivity and more severe muscle fiber structure damage. Among the four cooking techniques, RO increased meat toughness (NOR: 78.5 N vs. PSE: 98.3 N) and intensified excessive protein oxidation and aggregation in PSE chicken breast most significantly, manifested by the increased malondialdehyde (NOR: 0.46 vs. PSE: 0.57, mg kg-1 meat) and carbonyl (NOR: 11.2 vs. PSE: 13.4, nmol mg-1 protein), reduced tryptophan and thiols (NOR: 41.3 vs. PSE: 33.7, nmol mg-1 protein), and prominent protein cross-linking such as Schiff bases and disulfide bonds during heat treatment (p < 0.05). BO was the second most destructive technique, while MV caused the least impact (p > 0.05). Principal component analysis indicated a correlation between oxidative damage and meat quality, which was attributed to variations of the PSE and normal samples by BO, RO, and ST treatments. Thus, MV is suggested to be a promising and effective cooking method in reducing the differences in quality and oxidation attributes between PSE and normal chicken meat.

烹饪是人们食用肉制品必备的操作流程,适当的烹饪可改善肉类的风味、质地和色泽,提高食物营养价值.由于烹饪加工中传热方式、介质以及烹饪过程中时间和温度的差异,会造成肉类品质、营养特性发生不同程度的变化.肉类品质的变化主要体现在烹饪损失、嫩度、色泽和风味等方面,而对营养特性的影响主要是营养成分如蛋白质、脂类、维生素和矿物质的结构和含量的更改,适当添加天然抗氧化剂可一定程度上对营养成分起保护作用.所以,不同原材料应根据其自身的特性选择合适的烹饪加工方式,这不仅能保护其营养成分,同时能减少烹饪加工中的烹饪损失,提高熟制品的色泽、风味和烹饪效率.

为探究不同腌制方式对腊番鸭品质的影响,分别以干腌、湿腌、先干腌后湿腌和先湿腌后干腌4种腌制方式进行腊番鸭的制作.测定不同腌制方式所得成品的嫩度、保水性、感官评定等品质指标,以及pH值、聚丙烯酰胺凝胶电泳(SDS-PAGE)、硫代巴比妥酸含量(TBARS)、肌纤维小片化指数(MFI)等理化指标,并通过气相色谱-质谱联用(GC-MS/MS)测定腊番鸭的挥发性风味物质.试验结果表明:先干腌后湿腌的方式改善了腊番鸭的感官品质,提高了嫩度和出品率,促进了脂肪氧化和肌原纤维蛋白水解,增加了挥发性风味物质的种类,增进了腊番鸭的风味.