黑莓原花青素超声波辅助提取优化及抗氧化性研究

论文采用响应曲面法研究了超声波辅助提取时温度、时间、料液比、超声波功率及其交互作用对黑莓原花青素提取效果的影响,同时研究了黑莓原花青素对二苯代苦味酰自由基(DPPH)、·OH及·O2-的清除效果.用SAS软件确定了黑莓原花青素超声波提取的工艺参数为:提取温度为70.9℃,料液比为1∶9.14,时间为30.5 min,超声波功率为526.9 W.黑莓原花青素对DPPH、·O2-及·OH 3种自由基具有显著的清除效果,且明显优于茶多酚,当浓度为3.0 μg/mL时,对DPPH、·O2-及·OH 3种自由基的最大清除率分别可达到82.54%、79.90%和65.90%,且黑莓原花青素对3种自由基的清除效果与其浓度之间存在明显的量效关系.     

Identification and characterization of Pichia membranifaciens Hmp-1 isolated from spoilage blackberry wine

The pellicle-forming yeast could cause the quality deterioration of wine. In this study, a pellicle-forming strain Hmp-1 was isolated from the spoilage blackberry wine, and identified as Pichia membranifaciens based on the morphology and partial nucleotide sequence of 26S rDNA. The effects of fermentation conditions (ethanol, sulfur dioxide, sugar, and temperature) on the growth of P. membranifaciens strain Hmp-1 and Saccharomyces cerevisiae strain FM-S-115 (a strain used for the blackberry wine fermentation) were investigated, respectively. The results indicated that Hmp-1 had lower resistance to these factors compared to FM-S-115, and the growth of Hmp-1 was completely inhibited by 10% (v/v) or 50 mg L^–1 SO₂ during the fermentation of blackberry wine. These results suggested that Hmp-1 could effectively be controlled by increasing ethanol or SO₂ concentration during the fermentation and storage of blackberry wine. Furthermore, the analysis based on gas chromatography-mass spectrometry (GC-MS) showed that Hmp-1 remarkably decreased kinds of volatile compounds in blackberry wine, especially aldehydes and esters. In addition, some poisonous compounds were detected in the blackberry wine fermented by FM-S-115 and Hmp-1. These results suggested that Hmp-1 was a major cause leading to the quality deterioration of blackberry wine.     

黑莓松散型胚性愈伤组织的诱导

为了诱导出黑莓松散型胚性愈伤组织,试验采用黑莓试管苗叶片、叶柄和茎段为外植体,在含有不同2,4-D及分裂素的MS培养基上进行愈伤组织的初步诱导,从中筛选出松散型愈伤组织的最佳培养基配方;再将诱导出的黑莓松散型愈伤组织转移到含有不同激素种类和浓度的MS培养基上进行松散型胚性愈伤组织的诱导,从中筛选出最佳培养基配方。结果表明,在1/8 MS+3 mg/L 2,4-D+100 mg/L Vc+10 g/L蔗糖的培养基上可以诱导出松散的黑莓愈伤组织;先在MS+2 mg/L 2,4-D+1 mg/L KT+100 mg/L Vc+30 g/L蔗糖的培养基上进行胚性愈伤的诱导继代2~3次,然后转移到MS+0.5 mg/L 2,4-D+2 mg/L KT+100 mg/L Vc+30 g/L蔗糖的培养基上继续培养并继代3~5次后即可诱导出黑莓的松散型胚性愈伤组织。试验结果将为采用黑莓体细胞诱变育种研究奠定基础。     

黑莓组织培养的研究

通过系统的比较筛选,研究建立黑莓‘三冠王’品种的适宜组培快繁体系,即叶芽诱导时KT与NAA配比较好,且KT:NAA=10:1;壮苗培养时GA3浓度为2.0mg/L时为适宜黑莓壮苗浓度;生根适宜培养基为1/2MS+0.1mg/LIBA+0.1mg/LNAA,成活率达93%～99%,为黑莓工厂化育苗和应用提供理论基础。     

双酶水解制备黑莓澄清汁的工艺优化

为提高黑莓汁的出汁率和澄清度,保持黑莓特有的营养成分,选用黑莓为试验材料,采用果胶酶和果浆复合酶进行处理,探讨两酶联合使用对黑莓汁的澄清效果。以出汁率为指标,通过响应面分析,对其酶解工艺进行优化。结论：结果表明：加酶量（0.05%～0.15%）对黑莓出汁率的影响极显著（P＜0.01）,酶解温度（40～50℃）和酶解时间（2.0～3.0 h）影响不显著（P＞0.05）;最佳酶解工艺条件为：果胶酶与果浆复合酶酶活比为1︰1,加酶量0.13%、酶解温度42.6℃、酶解时间2.5 h。在此条件下,出汁率为79.5