Comparative characterization and correlation between lipids and volatile organic compounds in NingXiang and Berkshire-Ningxiang pork

Lipids and volatile organic compounds (VOCs) are essential contributors to meat flavor. However, no studies to date have comprehensively explored the lipids and VOCs in raw pork from Ningxiang (NX) pigs and their hybrid breed Berkshire × Ningxiang (BN) pigs. This study aimed to identify the lipids and VOCs and reveal the crucial lipids for characteristic flavor formation. Samples were collected from the longissimus dorsi muscle of six NX and BN 8-month-old pigs each. The intramuscular fat (IMF) content of NX pork was 5.43%, almost twice that of BN pork (<i>p</i> &lt; .01). Total 187 significantly different lipids were identified between NX and BN pork (variable importance in projection scores &gt; 1, <i>p</i> &lt; .05). Further analysis suggested 38 lipids were potential markers. Out of 66 identified VOCs, 16 key VOCs were screened both in NX and BN pork. Furtherly, hexanal-D, 2-methylbutanal, 3-methylbutanal, 1-penten-3-one, 1-octen-3-ol, and ethyl acetate-D were found to be key differential VOCs. Comparing with NX pork, BN pork significantly improved pungent odor. Correlation between the lipid markers and key VOCs demonstrated that phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), phosphatidylcholine (PC), and triglyceride (TG) were identified as key differentiating compounds for characteristic flavor. Our findings provided a novel understanding of pork identification and a basis for improving the flavor quality of NX and BN pork.

脂质与挥发性有机化合物（Volatile Organic Compounds，VOCs）是肉类风味形成的关键贡献因子。截至目前，尚无研究对宁乡猪（Ningxiang pigs，NX）及其杂交品种巴克夏×宁乡猪（Berkshire×Ningxiang pigs，BN）的生鲜猪肉中脂质与挥发性有机化合物展开全面探究。本研究旨在鉴定两类猪肉中的脂质与挥发性有机化合物，并揭示参与特征风味形成的关键脂质组分。本研究采集了6头8月龄宁乡猪以及6头8月龄巴克夏×宁乡杂交猪的背最长肌样本。宁乡猪猪肉的肌内脂肪（intramuscular fat，IMF）含量为5.43%，几乎是巴克夏×宁乡杂交猪猪肉的两倍（p < 0.01）。经鉴定，两类猪肉中共存在187种差异显著脂质（投影变量重要性评分>1，p < 0.05）。进一步分析显示，其中38种脂质可作为潜在生物标记物。在鉴定出的66种挥发性有机化合物中，两类猪肉共筛选出16种关键挥发性有机化合物。进一步研究发现，己醛-D、2-甲基丁醛、3-甲基丁醛、1-戊烯-3-酮、1-辛烯-3-醇以及乙酸乙酯-D为关键差异挥发性有机化合物。与宁乡猪猪肉相比，巴克夏×宁乡杂交猪猪肉的刺激性气味更为显著。脂质标记物与关键挥发性有机化合物的相关性分析结果显示，磷脂酰乙醇胺（phosphatidylethanolamine，PE）、磷脂酰丝氨酸（phosphatidylserine，PS）、磷脂酰肌醇（phosphatidylinositol，PI）、磷脂酰胆碱（phosphatidylcholine，PC）以及甘油三酯（triglyceride，TG）可作为参与特征风味形成的关键差异组分。本研究结果为猪肉品种鉴定提供了全新视角，同时为提升宁乡猪与巴克夏×宁乡杂交猪猪肉的风味品质奠定了理论基础。