蒸氣膨發之研究：膨發多澱粉食品之熱機械性質

A Study of Vapor-Induced Puffing Mechanism: Thermal Characterization of Puffed Starch-Rich Materials

吳柏青(Po-Ching Wu) ； Henry G. Schwartzberg

《農業機械學刊》 3卷3期 (1994/09) Pp. 65-81

https://doi.org/10.30062/JAM.199409.0006

摘要

在膨發過程中，孔洞週圍物質因溫度升高而由玻璃狀態(Glassy State)轉移至橡皮狀態(Rubbery State)或熔解(Melting)。由於孔洞內外之壓力差而使孔洞週圍之物質流動，進而造成孔同的膨脹。本試驗研究採用熱分析儀(DSC)量測玉米澱粉(Corn Starch)及爆玉米碎粒(Popcorn Grits)之熱相變化，並量測各類膨發食品包括爆玉米、膨發米、膨發玉米、與其他膨發穀類之膨發體積及孔洞大小。試驗結果顯示熱分析儀之加熱速度與樣品之水分含量顯著地影響相化溫度。然而，在膨發過程中溫度與含水率都會影響孔同的膨脹和凝結固定。在過高含水率狀態下，孔洞大小及其偏差量有顯著的增加。如此顯示，在膨發過程中孔洞間壁(Pore Wall)被破壞，且孔洞會相互接合成一較大孔洞。因此，開放性的孔洞(Open Pores)數量隨著含水率增加而增多。

關鍵字

膨發 ； 熱機械性質 ； 相變化 ； 多孔食品

並列摘要

The transitions from a glassy state to a rubbery state or actual melting would permit pressure-driven flows that could provide large degree of pore expansion during puffing. Phase transitions of corn starch and popcorn grits were determined by Differential Scanning Calorimetry. The transition temperatures were strongly dependent on the DSC heating rates and moisture contents. Both temperature and moisture content affect cell expansion and setting during puffing. At excessively high moisture content, size of cells and extent of variation in cell size markedly increase, indicating that wall between cells have ruptured extensively and allow cells to coalesce. Therefore, the amount of open pores increases with increasing moisture content.

並列關鍵字

Puffing ； Thermal mechanical property ； Phasse transition ； Porous food