Neither bacteria nor yeast can live in honey. In addition, honey also contains 0. 1%-0.4% bacteriostatic agent. Therefore, mature honey is not easy to deteriorate if it is kept for a long time. However, if it is not ripe honey or inferior products mixed with water, it will ferment and foam after a period of time, turn sour and be inedible.
Liquor. Liquor with an alcohol content of more than 10%, that is, liquor with an alcohol content of more than 10 degrees, has its own disinfection function. Under sealed conditions, microorganisms are not easy to invade and reproduce, so they will never deteriorate. However, this does not mean that the longer the wine is stored, the better. After five years, the taste of ordinary aromatic liquor will be weakened and the flavor will be weakened. Maotai-flavor aged wine is good wine, but whether Luzhou-flavor wine stored for many years is good wine is still inconclusive.
Vinegar. Vinegar has antibacterial and bactericidal effects, and can be used for food preservation and preservation, such as acid soaking. Vinegar has a long shelf life, but it is also affected by technology and raw materials. Brew mature vinegar with better technology, seal it in a jar and put it underground. The longer the year, the more mellow the taste.
Solid sugar. Solid sugar includes commonly used white sugar, soft sugar, rock sugar and single crystal rock sugar. Solid sugar has low water content and strong osmotic pressure, and is not easy to be polluted, which is not conducive to the growth of microorganisms. Sugar is also often used to preserve food, such as candied fruit and preserved fruit. However, sugar absorbs moisture easily. If it is improperly placed and its properties change, it will be contaminated by microorganisms.
Salt. The main component of salt is sodium chloride, and its chemical properties are very stable. Like sugar, edible salt is often used to preserve food and is a natural preservative. However, iodized salt, which we often eat, will reduce the iodine content if it is kept away from light and high temperature for too long, but the quality of the salt will not change. (Associate Professor, Department of Food Science, Chongqing University)
Jie Zheng)