Panpipat Worawan, Limsuwanmanee Jutaporn, Cheong Ling-Zhi, Chaijan Manat
Food Technology and Innovation Research Center of Excellence, School of Agricultural Technology and Food Industry, Walailak University, Nakhon Si Thammarat 80160, Thailand.
School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia.
Foods. 2023 Jan 7;12(2):274. doi: 10.3390/foods12020274.
Non-protein nitrogen (NPN) is abundant in stingray () muscle, which also has in vitro antioxidant activity. In this study, NPN from stingray muscle was further investigated for its antioxidant properties in lecithin liposome and oxymyoglobin model systems to validate its protective impact against lipid and myoglobin oxidations during storage for 120 min at various temperatures (4, 25, and 60 °C). NPN solution (10 ppm nitrogen) was added to the lecithin liposome system at different concentrations (0, 0.5, 1, 5, and 10% (/)) to investigate its effects on lipid stability by measuring the conjugated diene (CD), peroxide value (PV), and thiobarbituric acid reactive substances (TBARS) contents. In the oxymyoglobin system, NPN solution (10 ppm nitrogen) was also added at different concentrations (0, 0.5, 1, 5, and 10% (/)) to the oxymyoglobin solution in order to examine its effect on the stability of myoglobin by determining the contents of oxymyoglobin, metmyoglobin, and protein carbonyl. According to the findings, in all NPN concentrations, the system incubated at 4 °C had the lowest levels of lipid oxidation as measured by CD, PV, and TBARS values, and the lowest levels of myoglobin oxidation. At all incubating temperatures, the oxymyoglobin and lipid oxidation of all model systems tended to rise with the lengthening of the incubation duration. With the addition of 5% NPN, however, the lowest CD, PV, TBARS, oxymyoglobin oxidation, metmyoglobin formation, and protein carbonyl content were all observable, and the remarkable result was discovered during incubation at 4 °C. The results indicate that stingray NPN, especially at 5%, can be used to delay lipid and myoglobin oxidation, particularly at 4 °C. In order to prolong the shelf life of products with dark-fleshed fish and red meat, stingray NPN might be used as an alternative antioxidant to delay the oxidation of lipid and myoglobin during cold chain storage.
非蛋白氮（NPN）在黄貂鱼肌肉中含量丰富，其肌肉还具有体外抗氧化活性。在本研究中，进一步研究了黄貂鱼肌肉中的NPN在卵磷脂脂质体和氧合肌红蛋白模型系统中的抗氧化特性，以验证其在不同温度（4、25和60℃）下储存120分钟期间对脂质和肌红蛋白氧化的保护作用。将NPN溶液（10 ppm氮）以不同浓度（0、0.5、1、5和10%（/））添加到卵磷脂脂质体系统中，通过测量共轭二烯（CD）、过氧化值（PV）和硫代巴比妥酸反应性物质（TBARS）含量来研究其对脂质稳定性的影响。在氧合肌红蛋白系统中，也将NPN溶液（10 ppm氮）以不同浓度（0、0.5、1、5和10%（/））添加到氧合肌红蛋白溶液中，通过测定氧合肌红蛋白、高铁肌红蛋白和蛋白质羰基的含量来研究其对肌红蛋白稳定性的影响。根据研究结果，在所有NPN浓度下，通过CD、PV和TBARS值测量，在4℃下孵育的系统脂质氧化水平最低，肌红蛋白氧化水平也最低。在所有孵育温度下，所有模型系统的氧合肌红蛋白和脂质氧化都随着孵育时间的延长而趋于升高。然而，添加5%的NPN时，可观察到最低的CD、PV、TBARS、氧合肌红蛋白氧化、高铁肌红蛋白形成和蛋白质羰基含量，并且在4℃孵育期间发现了显著的结果。结果表明，黄貂鱼NPN，尤其是5%的NPN，可用于延缓脂质和肌红蛋白氧化，特别是在4℃时。为了延长深色鱼肉和红肉产品的保质期，黄貂鱼NPN可作为一种替代抗氧化剂，在冷链储存期间延缓脂质和肌红蛋白的氧化。
