為何馬令霜不能減糖? Why you can't reduce sugar in meringues?

最近公私都很忙, 所以很久沒寫blog了.

本來也不打算今天寫, 但剛剛看到一篇科研報告, 忍不住快快手寫一篇.

下個星期需要做個presentation, 今早就上網找資料, 居然無意中見到這份報告.

Effct of sugar, citric acid and egg white type on the microstructural and mechanical properties of meringues (糖, 檸檬酸和蛋白種類對馬令的微觀結構和力學性能的影響)
 Journal of Food Engineering, Volume 108, Issue 3, February 2012, Pages 453-462

• Abstract

  Meringues are characterized by a predominant air phase and their overall quality is intimately related with microstructure. The formation of meringues microstructure relies on the capacity of egg white (EW) proteins to form voluminous and stable foams and it is ultimately related with the chemical properties of proteins and with the addition of ingredients such as sugars, salts, acids and surfactants.

  The study aimed at assessing the influence of sugar/EW ratio, citric acid and EW type on the microstructural and mechanical properties of meringues. Meringues prepared with different sugar/EW, citric acid level and different EW type were subjected to microstructural analysis by X-ray microtomography and to mechanical assessment by compression tests.

  Results demonstrate the ability of X-ray microtomography to reconstruct the 3D microstructure of meringues allowing the measurement of porosity, size, shape and distribution of pores. Citric acid, sugar concentration and EW type play a fundamental role on meringues microstructural parameters and mechanical properties. Low sugar/EW ratios as well as increasing citric acid levels increase the air phase and result in a softer texture of meringues. Moreover, low sugar/EW ratios and increasing citric acid in the meringue result in a reduction of pore size and also influence the shape of pores. Meringues microstructural and mechanical properties are affected by the EW quality: fresh and pasteurized EWs and EWs stored at refrigerated temperatures scored the highest structural and mechanical performances, while powdered and frozen EWs and albumens from old eggs showed the worst results. Not only the balance among ingredients but also the choice of raw materials can strongly affect the final quality of meringues.

以我的中文程度不可能把完整翻譯給你們, 只能約略總括一下他們的研究結果:

1. 低糖和蛋白比例和增加檸檬酸水平會令馬令空氣份量增加, 導致較軟的質地的馬令, 馬令內的氣孔也會較細, 氣孔形狀也會受影響.  
2. 儲存於雪櫃內的新鮮和或經巴士殺箘的蛋白較急凍蛋白和不新鮮的蛋白好.

其實這些平常有做蛋糕甜品的人都知道, 只是人家用高科技器材來研究罷了.

聲名 : 這報告和我做的完全沒關連, 只是踫巧見到.