Posted 12 Dec 2010 14:55
1. Determination of acidity can determine the degree of maturity of fruits and vegetables such as: If the determination of organic acids contained in the grape than in the malic acid tartaric acid, the description is not yet ripe grapes, ripe grapes because a lot of tartaric acid. Different types of fruits and vegetables, due to acid maturity, growing conditions vary, generally the higher the maturity, the lower the acid content. In the ripening process, such as tomatoes, total acidity from the green mature stage finished 0.94% down Dao maturity of 0.64%, while the increase in sugar content of sugar and acid Bizeng Da, has good taste, it is determined by the acidity of the raw materials can be judged maturity. 2. To determine the freshness of foods such as: fresh milk, the lactic acid levels in the high, that milk is rotten; fruits of free product in galacturonic acids, that are rotten fruits of the contamination. 3. Acidity indicators reflect the quality of food the amount of organic acids in food directly affects the food flavor, color, stability, and the level of quality. Determination of acid on the microbial fermentation process has a certain significance. Such as: wine and alcohol production, on the wort, fermentation broth, wine, music and so the acidity has certain requirements. Fermentation products in the wine, beer and soy sauce, vinegar and other acids is also an important indicator of quality. In addition, the acid in the maintenance of acid-base balance of **** fluids plays a significant role. Each of us on the fluid pH, there are certain requirements, the body fluid pH value is 7.3-7.4, if the body fluid pH value is too large, it is necessary cramps, is too small then the acid poisoning will occur. The acidity of food is usually the total acidity (titratable acidity), the effective acidity, volatile acidity, said. The total acidity of the food is the total of all acids, including the dissociation of the acid concentration and the dissociation of the acid concentration is not, to the titration with standard alkali, and the main representative of the sample said the percentage content of acid. Acidity refers to the effective state of the sample was ion hydrogen ion concentration (strictly speaking, is the activity) were measured using pH meter, with pH values says. Volatile acidity refers to the portion of food in the volatile organic acids. Such as acetic acid, formic acid and so on, via direct and indirect determination.