重组疏棉状嗜热丝孢菌脂肪酶对面包烘焙品质的影响

为探究重组疏棉状嗜热丝孢菌脂肪酶(Recombinant Thermomyces lanuginosus Lipase Produced by Pichia pastoris,PTL)在面包体系中的使用效果,试验以面包比容、组织结构以及面包芯白度为指标得出其最佳用量。进一步研究比较PTL、商业脂肪酶Lipopan F BG(以下简称FBG)、化学改良剂双乙酰酒石酸单(双)甘油酯(Diacetyl Tartaric Acid Ester of Mono(di)Glycerides,DATEM)对面包烘焙品质的影响,对面团面筋网络结构及面包芯风味物质分别采用扫描电镜(Scanning Electron Microscope,SEM)和顶空固相微萃取-气相色谱-质谱联用法(Head-Space Solid Phase Micro-Extraction Coupled with Gas Chromatography-Mass Spectrometer,HS-SPME-GC-MS)进行分析。结果表明,PTL在面包中的最佳用量为10~20 mg/kg,过量PTL造成不良影响。PTL在增大面包比容、强化面筋结构和提高感官整体接受度等方面仅次于FBG,优于DATEM。面包配方中加入15 mg/kg PTL能明显增大面包比容(9.8%),降低面包硬度,气味和组织结构的感官得分最佳(6.48分和6.82分)。综上,适量PTL能有效改善面包的烘焙品质且具有不同于商业酶的独特优势。

Effect of Recombinant Thermomyces lanuginosus Lipase on Bread Baking Quality

In this study,optimal dosage of recombinant Thermomyces lanuginosus lipase produced by Pichia pastoris(PTL)based on the specific volume,crumb texture and luminosity was determined in bread making. Furtherly baking quality of bread respectively with addition of PTL,that of commercial lipase lipopan FBG(FBG)and chemical modifier diacetyl tartaric acid ester of mono(di)glycerides(DATEM)were compared,and the gluten network and flavor components were analyzed by scanning electron microscope(SEM)and head-space solid phase micro-extraction coupled with gas chromatography-mass spectrometer(HS-SPME-GC-MS). The results showed that the optimal dosage of PTL was 10~20 mg/kg,and the excessive PTL would have negative effects. PTL performed only second to FBG and better than DATEM on improving the specific volume,gluten strength and overall sensory acceptance of the bread. The addition of 15 mg/kg PTL increased the special volume of bread by 9.8% and reduce the hardness,also it made the bread achieve the maximum score in smell(6.48)and crumb texture(6.82). The results indicated that appropriate addition of PTL could effectively improve the baking quality of bread and had the specific advantages different from commercial lipase.