食用大豆油老化影响.pdf

Application Report Ageing of cooking oils Application report: AR203e Industry section: Food technology Author: CR Date: 09/1995 Method: Drop Volume Tensiometer – DVT10 Keywords: Dynamic interfacial tension, drop volume tensiometry, defoamer, soybean based cooking oil The effects of ageing on the properties of soybean based cooking oils An Example of the Application of Dynamic Tensiometry to Problems that Cannot Be Solved by Static Tensiometry Background One of the large challenges in food science technology is the development of cooking oils with extended usable lifetimes. Extended lifetime oils decrease: (1) the necessity for hot-oil cooker downtime, (2) the overall quantity of oil used per item cooked, and (3) the amount of used oil that subsequently needs disposal. The advantages are economic as well as environmental. After cooking oil has been used for a period of time, a stable froth (or foam) begins to develop on the surface of the oil during the cooking process. Soon thereafter, controlling this surface layer becomes a problem. The esthetics of cooked food, which has passed through a layer of foam during removal from the cooker, also becomes a consideration. It then becomes time to shut down the cooker and change the oil. However, if foaming can be prevented, then the oil would be useable over a longer period. The foam is primarily stabilized bubbles of steam which result from the vapor ization of water that is either contained within the food being cooked or, in the case of frozen foods, attached to the food in the form of ice. The foam is stabilized