山苍子精油对青贮玉米的霉菌抑制及品质影响研究

The study of Litsea cubeba essential oil on mildew inhibition and quality effects of silage corn

山苍子精油(Litsea cubeba essential oil)是木姜子植物自然产生的复杂的挥发性混合物,具有抗菌、杀虫、抗病毒等特性。为筛选适合青贮玉米储藏的霉菌抑制剂,本试验对不同种霉菌的山苍子精油最低抑制浓度及其效果进行探讨。在玉米中添加0.20%山苍子精油及0.15%丙酸进行青贮,以未加添加剂的青贮玉米为对照,开袋取样后对青贮玉米营养成分进行分析。结果表明:山苍子精油对青贮玉米的镰刀菌、黄曲霉、杂色曲霉、青霉、根霉的最小抑制浓度分别为0.14%、0.20%、0.20%、0.16%和0.12%。通过GC-MS对山苍子精油成分进行定量,其中柠檬醛占比最大,分别为(Z)-柠檬醛占20.66%,(E)-柠檬醛占21.67%。45 d后,未加添加剂对照组的青贮玉米粗蛋白质、脂肪酸和氨基酸对比初始值(0 d)降低了3%、42%和17%,添加0.20%山苍子精油处理可以减少2%、31%和9%的含量损失,是0.15%丙酸处理含量损失的0.17倍、0.20倍和0.38倍。山苍子精油可抑制霉菌生长,显著降低青贮玉米的营养损失。因此,将山苍子精油用做天然生物防霉剂,可以起到抑制青贮玉米霉菌生长和稳定品质双重作用。

Litsea cubeba essential oil is a complex volatile mixture produced naturally by zingiberaceae,which has antibacterial,insecticidal and antiviral properties. In order to screen the mold inhibitors suitable for silage corn storage,the minimum inhibitory concentration of Litsea cubeba essential oil of different mold and its effect were studied. Adding 0.20% Litsea cubeba essential oil and 0.15% propionic acid to silage corn,and taking silage corn without additives as control,the nutritional composition of silage corn was analyzed after bag sampling. The results showed that the minimum inhibitory concentrations of Litsea cubeba essential oil on Fusarium,Aspergillus flavus,Aspergillus variegans,Penicillium and Rhizopus were 0.14%,0.20%,0.20%,0.16%and 0.12%,respectively. The contents of essential oil from Litsea cubeba were quantified by GC-MS,and citral accounted for 20.66%(Z)-citral,21.67%(E)-citral,respectively. After 45 days,the initial values of crude protein,fatty acid and amino acid of silage corn in the control group without additives decreased by 3%,42% and17%. Adding 0.20% Litsea cubeba essential oil could reduce the content loss by 2%,31% and 9%,which were0.17,0.20 and 0.38 folds of that of 0.15% propionic acid treatment. Litsea cubeba essential oil inhibited mold growth and significantly reduced nutrient loss of silage corn. Therefore,the essential oil of Litsea cubeba as a natural biological mildew inhibitor could inhibit the growth of silage corn mold and stabilize its quality.