发酵条件和青贮时间对黑麦草色素和植物醇含量的影响

本研究旨在探讨青贮时间及青贮时添加乳酸菌对黑麦草化学成分、色素及植物醇含量的影响。试验1:将用塑料袋包装的黑麦草进行为期5周的青贮,测定化学成分及色素含量变化。试验2:将不添加任何添加剂青贮的黑麦草作为对照组,处理组在青贮过程添加乳酸菌,两组黑麦草共青贮60d。结果 :青贮第5周时,黑麦草的pH最低(P <0.05),乳酸、乙酸和丁酸含量最高(P <0.05)。黑麦草在青贮第5周粗蛋白质含量显著提高(P <0.05),而粗脂肪含量在青贮0~2周时随青贮时间的延长显著升高(P <0.05)。黑麦草青贮前,叶绿素a、叶绿素b及叶绿素a+b含量最高,之后随着青贮时间的延长显著降低(P <0.05),但脱镁叶绿素a在青贮前最低,之后随青贮时间的延长显著升高(P <0.05)。乳酸菌组pH较对照组显著降低31.52%(P <0.05),乳酸含量较对照组显著提高438.89%(P <0.05)。青贮后(加或不加乳酸菌)较青贮前粗脂肪含量显著提高46.04%和40.59%(P <0.05),中性洗涤纤维含量显著降低6.42%和5.17%(P <0.05)。黑麦草青贮后的叶绿素a、叶绿素a+b和β-胡萝卜素含量显著降低(P <0.05)。结论 :乳酸菌发酵黑麦草降低了pH,提高了β-胡萝卜素含量。无论何种发酵条件,青贮黑麦草中的叶黄素和叶绿醇含量均保持较好。

Effects of fermentation conditions and silage time on the contents of pigment and phyto in ryegrass

The purpose of this study was to investigate the effects of silage and lactobacillus on the chemical composition,pigment and plant alcohol content of ryegrass.In experiment 1,ryegrass packed in plastic bags was silaged for 5 weeks to measure changes in chemical composition and pigment content.In experiment 2,the ryegrass without any additives was used as the control group,and lactobacillus was added to the treatment group during silage.The two groups were silage for 60 days.Results:at the 5th week of silage,the pH value of ryegrass was the lowest(P<0.05),and the contents of lactic acid,acetic acid and butyric acid were the highest(P<0.05).The content of crude protein in ryegrass increased significantly at the 5th week of silage(P<0.05),while the content of crude fat increased significantly with the extension of silage at 0-2 weeks(P<0.05).The contents of chlorophyll a,chlorophyll b and chlorophyll a+b in ryegrass were the highest before silage,and then decreased significantly with the extension of silage time(P<0.05).However,pheophytin a showed the lowest expression before silage and then increased significantly with the extension of silage time(P<0.05).The pH value of the lactobacillus group was significantly lower than that of the control group(P<0.05),and the lactic acid content was significantly higher than that of the control group(P<0.05).After silage(with or without lactobacillus),crude fat content significantly increased by 46.04%and 40.59%(P<0.05)compared with that before silage,and neutral scrubber fiber content significantly decreased by 6.42%and 5.17%(P<0.05).The contents of chlorophyll a,chlorophyll a+b and beta-carotene in ryegrass silage were significantly reduced(P<0.05).In conclusion:the fermentation of ryegrass by lactic acid bacteria decreased the pH value,increased the content of beta-carotene The content of lutein and phyto in silage ryegrass remained good regardless of the fermentation conditions.