加热温度对新疆马脂理化性质、脂肪酸及挥发性风味化合物的影响

Effects of Heating Temperature on Physicochemical Properties,Fatty Acids and Volatile Flavor Compounds of Fat from Horses Raised in Xinjiang

以新疆马脂为研究对象,通过测定过氧化值(measuring peroxide value,POV)、茴香胺值(p-anisidine value,p-AV)、酸价(acid value,AV)及色度值,并采用气相色谱、顶空气相色谱-质谱联用、感官评价及相对气味活度值(relative odor activity value,ROAV),分析加热温度100、120、140、160、180、200℃条件下的马脂基本理化指标、脂肪酸及其挥发性化合物的变化规律。结果表明:加热温度高于160℃时,AV值从160℃的1.62 mg/g(KOH计)急剧增加;POV先增加后降低,在160℃时达到最大值0.124 g/100 g;p-AV在温度上升到160℃后几乎不变;马脂的多不饱和脂肪酸含量随温度升高从20.87%降低到14.54%,其中亚油酸含量高达13.59%~20.06%;马脂在100、120、140、160、180、200℃分别鉴定出49、50、45、47、56、51种风味物质,主要为醛类、醇类、酮类、呋喃类、酸类和酯类,结合主成分分析及ROAV计算最终确定11种关键风味化合物,感官评定表明不同加热温度的马脂在肉味和清香味等特征风味属性上具有显著差异(P<0.05),相关研究结果可为新疆马脂的品质控制及风味改良提供理论依据。

This study analyzed the changes in the physicochemical indexes,fatty acids and volatile compounds of the leaf fat of horses raised in Xinjiang after heating treatment at different temperatures of 100,120,140,160,180 and 200℃.The peroxide value(POV),p-anisidine value(p-AV),acid value(AV)and chromaticity values were measured,and the fatty acid composition and volatile compounds were determined using gas chromatography(GC)and headspace gas chromatography mass spectrometry(HS/GC-MS),respectively,sensory evaluation was performed and relative odor activity(ROAV)values were calculated.Results showed that the AV of horse fat heated at 160℃was 1.62 mg/g,and it sharply increased when the heating temperature exceeded 160℃while the p-AV remained stable.With increasing heating temperature,the POV increased signifi cantly and then decreased,reaching a maximum value of 0.124 g/100 g at 160℃.The percentage of polyunsaturated fatty acids in horse fat decreased from 20.87%to 14.54%with increasing temperature,13.59%–20.06%of which was linoleic acid.In addition,49,50,45,47,56 and 51 volatile substances were identified after heating at 100,120,140,160,180 and 200℃,respectively,with the major ones being aldehydes,alcohols,ketones,furans,acids and esters.Totally 11 key flavor compounds were eventually determined by principal component analysis(PCA)combined with ROAV values.Sensory evaluation showed that horse fat heated at different temperatures had significant differences in characteristic flavor properties such as fatty aroma and delicate fragrance(P<0.05).The results from this study can provide a theoretical basis for the quality control and flavor improvement of horse fat.