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71.
以蓝靛果为原料,研究鲜汁发酵、熟汁发酵与去渣发酵3 种发酵工艺在发酵过程中对蓝靛果酒乙醇体积分数、活性成分、体外抗氧化活性及香气成分的影响。结果表明,3 种发酵酒乙醇体积分数均先上升后趋于稳定,发酵结束后熟汁发酵蓝靛果酒乙醇体积分数最高,为(12.29±0.08)%;熟汁发酵酒中花青素与总酚质量浓度最高((830.17±8.65)mg/L和(2.41±0.03)g/L),表现出较强的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基和超氧阴离子自由基清除能力((14.25±0.14)mmol/L和(8.93±1.37)mmol/L)。鲜汁发酵酒中黄酮质量浓度最高((470.50±6.15)mg/L),表现出较强的羟自由基清除能力((40.43±3.33)mmol/L);且不同发酵工艺对蓝靛果酒香气成分影响较大,鲜汁和熟汁发酵酒的主体香气均以酯类为主,相对含量分别为60.23%和85.31%;去渣发酵酒以萜烯类和酯类为主体香气,相对含量分别为11.50%和61.96%。经熟汁发酵的蓝靛果酒醇类和酸类物质含量降低,酯类物质含量显著升高,改变了蓝靛果酒香气结构,加速蓝靛果酒的成熟,且产生了月桂酸异戊酯、肉豆蔻酸乙酯、己酸异戊酯等独特呈香物质。熟汁发酵不仅有利于蓝靛果酒功能性成分含量和体外抗氧化能力的提高,还能赋予蓝靛果酒更加浓郁的果香,有利于蓝靛果酒综合品质的提高。 相似文献
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Our aim was to screen for antibacterial bioactive compounds from Lonicera japonica leaves. Staphylococcus aureus and Escherichia coli were used as the indicator bacteria. Bacteriostatic assay-guided extraction and stepwise partitioning of the samples yielded five compounds of interest. Antimicrobial activities of the compounds were determined using a disk diffusion assay. Extracts, fractions, and compounds from L. japonica leaves possessed considerable antibacterial activities against the tested bacterial strains and the most active fraction was attributed to J3B2, which primarily contained 3,5-di-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid. Meanwhile, five bacteriostatic constituents were isolated (3-O-caffeoylquinic acid, secoxyloganin, luteoloside, 3,5-di-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid), among which, secoxyloganin was isolated for the first time from leaves. The antibacterial activity of the compounds was in the order of 3,5-bis-O-caffeoyl quinic acid, 4,5-bis-O-caffeoylquinic acid, luteoloside > 3-O-caffeoylquinic acid > secoxyloganin. Our results suggested that the phenolic compounds might significantly contribute to antibacterial activity and were the most responsible for the bacteriostatic activity of L. japonica leaves. 相似文献
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Mojtaba Delfanian Reza Esmaeilzadeh Kenari Mohammad Ali Sahari 《International Journal of Food Properties》2013,16(12):2813-2824
The antioxidation activities of Eriobotrya japonica (Lindl.) fruit peel and pulp extracts were determined using DPPH, β-carotene, and Rancimat methods. Results showed that ethanol-water extract of peel and ethanol extract of pulp had the highest antioxidant activity. Protective effects of extracts in stabilization of soybean oil were tested and compared to tert-butyl hydroquinone by measuring peroxide values, free fatty acids, thiobarbituric acid, oxidative stability, and conjugated dienes and trienes values during storage (65 days at 25°C). Results showed that the ethanol-water extract of peel at 400 ppm exhibited stronger antioxidant activity, but the highest effect was observed in tert-butyl hydroquinone. 相似文献
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78.
枇杷花系统溶剂提取物抑菌作用研究 总被引:4,自引:0,他引:4
研究枇杷花系统溶剂提取物抑菌的作用。实验以苯甲酸钠为对照组,分别研究了枇杷花石油醚、氯仿、乙酸乙酯、正丁醇、丙酮、95%乙醇和水的提取物对大肠杆菌、金黄色葡萄球菌、白色念珠菌的抑菌效果,并对不同提取物进行薄层色谱分析。结果表明,枇杷花的提取液对细菌、真菌均有抑制作用,并优于对照组。正丁醇、丙酮提取物对金黄色葡萄球菌抑制能力优于其他溶剂;石油醚提取物对大肠杆菌抑制能力优于其他溶剂;石油醚、乙酸乙酯提取物对白色念珠菌抑制能力优于其他溶剂。 相似文献
79.
不同年份对虾白斑综合征病毒基因组差异的微阵列分析 总被引:2,自引:0,他引:2
根据对虾白斑综合征病毒(white spot syndrome virus,WSSV)全基因组序列的分析与应用,设计了190对引物,覆盖全基因组绝大多数可预测的开放读框(ORF).扩增相应基因片段,在尼龙膜上点样,制备成为DNA微阵列.收集了1996年和2002年感染阳性对虾,分别提取纯病毒基因组DNA,用地高辛标记后与DNA微阵列杂交.与1996年病毒株相比较,2002年病毒株缺失了wsv479、wsv482、wsv489和wsv493.运用PCR技术验证了DNA微阵列杂交结果的可靠性. 相似文献
80.
Xiaochen Liu Xiuling Zhang Xueting Zhang Fengfeng Li Yaqin Tian Meiling Du Hengtian Zhao Lingling Shao 《International Journal of Food Science & Technology》2020,55(7):2851-2862
Tomatoes are rich in nutrients, yet they have a short shelf life and are prone to decay due to bacterial invasion. Polysaccharides extracted from Osmunda japonica (Thunb) were briefly characterised. The inhibitory effect of polysaccharides on nine kinds of common spoilage and pathogenic bacteria in tomatoes stored postharvest was studied, and the polysaccharides had broad-spectrum antibacterial and antifungal activities against many tested strains. The minimum inhibitory concentrations (MICs) and the minimum bactericidal (fungicidal) concentrations (MBCs) were determined, and the lowest MBC against Bacillus cereus was 0.15 g L−1. Various concentrations of an O. japonica (Thunb) polysaccharide (OP) solution were sprayed onto ordinary preservation paper, which then distinctly maintained tomato freshness. OP delayed vitamin C (VC) and titratable acid decreases and increased respiratory intensity in a dose-dependent manner, reducing malondialdehyde accumulation. The tomatoes could be stored for 30 day at 25 ± 1 °C. OP has potential as a safe, nontoxic natural plant preservative. 相似文献