Effects of Various Thermal Treatments on the Physicochemical Properties of Adlay

不同加熱處理對薏仁理化特性之影響

張曙明(Shuh-Ming Chang) ； 張采蓮(Tsai-Lean Chang)

《中央研究院化學研究所集刊》 45期 (1998/03) Pp. 55-65

https://doi.org/10.6522/BICAS.1998.45.5

摘要

本篇係探討薏仁（台中選5）經蒸、煮、高壓加熱及高壓驟降等不同加熱方式處理後對其理化特性所產生之變化。高壓驟降加工後之薏仁內部已膨發成蜂巢狀結構，而其它加工處理後的產品則呈現不同破壞及糊化程度之膠狀物。經不同加工方式處理後，吸水率、膨潤率、糊化程度及消化率（蒸者除外）均因而增加，而溶解率卻反倒減少（高壓驟降處理者例外）。在布氏（Brabender）黏度曲線上，高壓驟降處理產品呈現較高之初黏度而於升溫時一路下降；煮及高壓加熱產品則顯示較低之初黏度，隨升溫而上升，而後趨於穩定；於蒸、浸水後再蒸或浸水後高壓加熱的產品則仍保有黏度尖峰。由蒸及高壓加熱產品之X-射線繞射圓形上仍可看到一些原來生粉之尖峰，唯強度已減弱，而其餘各加工產品均呈現無定型。各種加工處理對薏仁澱粉分子均有降解作用，而以高壓驟降處理者為明顯。

並列摘要

In this paper, brown adlay of Taichung selective 5 was treated under boiling, steaming with or without steeping, autoclaving with or without steeping and explosion-puffing. The physicochemical properties of these processed samples were investigated and compared. The explosion-puffed adlay was highly expanded with a comb-like inner structure while the others formed a gel-like substances with different extent of gelatinization and disintegration during various heat treatments. After each treatment, water absorption index, swelling power, degree of gelatinization and in vitro digestibility (except the steamed one) were increased, while water solubility was decreased except in explosion-puffing. The explosion-puffed sample exhibited higher initial viscosity in Brabender viscoamylogram and showed a decline in viscosity during heating. The boiled and autoclaved samples with lower initial viscosity increased in viscosity during heating and tended to be stable. However, in steamed, steamed or autoclaved with steeping samples, it still retained a viscosity peak. The steamed and autoclaved samples also revealed some x-ray diffraction peaks with decreased intensity while the others showed an amorphous pattern. The degradation of starch molecules did happen during different treatments especially in the explosion-puffing process.