Ortuño J, Serrano R, Bañón S
Department of Food Science and Technology and Nutrition, Faculty of Veterinary Science,University of Murcia,Campus Espinardo,30071 Murcia,Spain.
Animal. 2016 Aug;10(8):1391-401. doi: 10.1017/S1751731116000392. Epub 2016 Mar 4.
The objective of the present study was to determine the inhibitory effect of dietary rosemary diterpenes on the formation of the volatile organic compounds (VOCs) responsible for rancid flavour in raw lamb meat. The lamb diet was supplemented during the fattening stage with two levels (200 and 400 mg/kg feed) of a dietary rosemary extract (DRE) containing carnosic acid and carnosol (1 : 1, w/w). The formation of VOCs (determined by headspace solid-phase microextraction at 40°C and MS) and odour deterioration (assessed by quantitative descriptive analysis) were monitored in meat fillets (longissimus dorsi-lumborum muscle) packed in a 70/30 O2/CO2 protective atmosphere and kept at 2°C for up to 14 days. The raw meat odour deteriorated under pro-oxidizing conditions due to the development of an incipient rancidity caused by the formation of volatiles from lipid oxidation. A total of 46 volatile compounds were determined in lamb headspace: 18 aldehydes, seven alcohols, seven organic acids, six ketones, four furan compounds, two benzene compounds, one ester and one terpenoid. The use of DRE contributed to inhibit VOC formation and rancidity. Heptanal, octanal, nonanal and 2-pentyl-furan were the only VOCs affected (P0.75; P<0.001), although similar values were obtained for the coefficients of a large number of carbonyl, alcohols and furan compounds, among other volatiles, which can be considered molecular markers of rancidity in raw lamb meat. Principal component analysis confirmed that the differences in the VOC profile make it possible to identify whether or not samples have been reinforced with dietary rosemary diterpenes. Thus, VOC profiling can be regarded as a useful tool for assessing the dietary treatments used in sheep to improve the oxidative stability of lamb meat.
本研究的目的是确定日粮迷迭香二萜对生羊肉中导致酸败风味的挥发性有机化合物（VOCs）形成的抑制作用。在育肥阶段，给羔羊日粮添加两种水平（200和400 mg/kg饲料）的含有鼠尾草酸和鼠尾草酚（1:1，w/w）的日粮迷迭香提取物（DRE）。在包装于70/30 O2/CO2保护气氛中并在2°C下保存长达14天的肉片中（背最长肌-腰大肌）监测VOCs的形成（通过在40°C下顶空固相微萃取和质谱法测定）和气味劣化（通过定量描述分析评估）。由于脂质氧化形成挥发性物质导致初期酸败的发展，生肉气味在促氧化条件下恶化。在羔羊顶空中共测定了46种挥发性化合物：18种醛、7种醇、7种有机酸、6种酮、4种呋喃化合物、2种苯化合物、1种酯和1种萜类化合物。使用DRE有助于抑制VOC的形成和酸败。庚醛、辛醛、壬醛和2-戊基呋喃是仅受影响的VOCs（P0.75；P<0.001），尽管大量羰基、醇和呋喃化合物以及其他挥发性物质的系数也获得了相似的值，这些可被视为生羊肉酸败的分子标志物。主成分分析证实，VOC谱的差异使得能够识别样品是否用日粮迷迭香二萜强化。因此，VOC谱分析可被视为评估绵羊日粮处理以改善羊肉氧化稳定性的有用工具。
