滇东北地区铁核桃种群优良单株的选择

为研究大理漾泡、紫皮核桃仁营养元素及风味物质的差异，以两种核桃仁为原料，分别测定其氨基酸、脂肪酸、基本营养素、矿物质元素含量，采用气相色谱质谱联用法（GC-MS）检测两种核桃仁之间的挥发性成分。结果表明，紫皮核桃仁总氨基酸、必需氨基酸和鲜味氨基酸含量分别高于漾泡核桃仁，差异均有统计学意义（P<0.05）；两种核桃仁中均检出3种饱和脂肪酸，其中漾泡核桃仁的棕榈酸含量（4.17%）高于紫皮（2.69%）；均检出5种不饱和脂肪酸，其中，紫皮核桃仁的油酸、花生一烯酸和亚麻酸含量均高于漾泡核桃仁（P<0.05），棕榈一烯酸和亚油酸含量低于漾泡核桃仁，差异均有统计学意义（P<0.05）；紫皮核桃仁脂肪、蛋白质、碳水化合物含量均高于漾泡核桃（P<0.05）；共检出9种矿物质元素，紫皮核桃中P、Zn、Fe、Cu、Na、K元素含量高于漾泡核桃（P<0.05）；从漾泡、紫皮核桃仁中分别鉴定出30种、33种挥发性风味物质，其中醇类、醛类、酮类化合物是紫皮核桃的主要风味物质，而漾泡核桃的主要风味物质是醇类和烯烃类化合物（19.948%、3.819%）。两种核桃中醇类化合物峰面积占比最高，对气味贡献较大，尤其己醇峰面积占比最高，可赋予核桃淡青的嫩枝叶气息以及酒香、果香和脂肪气息。以上结果表明两种核桃都具有较高的营养价值，紫皮核桃略胜一筹。

Superior tree selection from Juglans siggillata L. populations in Northeastern Yunnan

The aim of study was to analyze the differences in nutritional elements and flavor substances between the Dali Yangpao and purple walnut kernels, two kinds of walnut kernels were used as raw materials, the content of amino acids, fatty acids, essential nutrients and mineral elements were determined separately, and the volatile components between the two walnut kernels were detected by gas chromatography mass spectrometry (GC-MS). The results showed that compared to those of the Yangpao walnut kernels, the purple walnut kernels had a higher content of total amino acid, essential amino acid, and umami amino acid (P<0.05). Three kinds of saturated fatty acids were detected in both walnut kernels, the palmitic acid content of Yangpao walnut kernels (4.17%) was higher than that of purple walnut kernels (2.69%). Five kinds of unsaturated fatty acids were detected in both walnut kernels, compared to those of the Yangpao walnut kernels, the purple walnut kernels had a higher content of oleic acid, arachidonic acid, and linolenic acid, but purple walnut kernels had a lower content of palmitoleic acid and linoleic acid (P<0.05). Compared to those of the Yangpao walnut kernels, the purple walnut kernels had a higher content of fat, protein, and carbohydrate (P<0.05). A total of 9 mineral elements were detected in both walnut kernels, and the P, Zn, Fe, Cu, Na, and K elements content of Yangpao walnut kernels was higher than those of purple walnut kernels (P<0.05). 30 and 33 volatile flavor compounds were identified from Yangpao and purple walnut kernels, respectively. Alcohols, aldehydes, and ketones were the main flavor substances of purple walnut, while Yangpao walnut's main flavor substances were alcohols and olefin compounds (19.948%, 3.819%). The peak area of alcohol compounds, especially hexanol, accounted for the highest proportion in Yangpao and purple walnut kernels, respectively. The above results indicate that purple walnut kernels have higher nutritional value and flavor substances.