Fried convenience foods Contains oil, protein and other nutrients, which are oxidized in the presence of oxygen or decomposed by microorganisms or oxidized at high temperatures to produce small-molecule acids, which lead to excessive acid value in foods, appear rancidity phenomenon, and the release of a unique smell, in severe cases will volatilize acrid smell. Therefore, the control of acid value is one of the important measures to prevent rancidity in production.
Food oil choices
1. If the quality of oils and fats used in processed food is poor and the storage environment is not appropriate, it will lead to the oxidation and rancidity of food contents.
2. The antioxidant capacity of different oils is different, mainly because of the different classification and content of antioxidants in oils. When an oil is oxidized, it reacts first with the antioxidants in the oil and then with the oil itself after the antioxidants have been consumed. The higher the amount of unsaturated fat in the oil, the more likely it is to be oxidized.
3.Soybean oil has high unsaturated fat content (more than 85%) and poor antioxidant activity. But palm oil contains half the fatty acid and half the unsaturated fat, as well as natural antioxidants such as tocopherols and tocopherols, therefore, palm oil is commonly used for frying instant noodles. Of course, it is also important to control the standard acid value and peroxide value of the feedstock.
Adjustment of acid value in production process of instant noodle machine
Main influencing factors: oil turnover, frying temperature, production continuity, metal ion pollution, timely separation of oil residue, use of antioxidants, etc. .
1. turnover: in the process of instant noodle machine noodles, with the production of dough, some fat will be taken away, so to continue to add new oil fryer. The amount of time (in hours) required to replenish the oil so that the fat in the frying pan is completely renewed is called the frying oil turnover time (or turnover rate) .
The relationship between the rotation time of frying oil in instant noodles and the increase of acid price: the shorter the rotation time of frying oil, the lower the acid price of oil and the smaller the increase of acid price. On the contrary, the longer the turnover time, the higher the price of fatty acids, the higher the increase of acid prices.
2. Frying temperature of instant noodle machine: in theory, the higher the temperature, the more easily the acid change. Therefore, ZHENGZHOU DONGFANG NAOMU FOOD MACHINERY CO., LTD. high temperature frying should be avoided in the process design, reasonable design instant noodle oil temperature gradient and frying time, in the cooking process as far as possible to avoid high temperature over-frying.
3. productivity and continuity: long-term continuous production of grease has little effect, if the various factors that produce grease precipitation overlap, acidification will accelerate.
4. metal ion pollution: this is mainly a new production line, oil pan equipment need passivation.
5. Separate the oil immediately: this is important. There are several steps that you can take to ensure that the noodles that go into the fryer are intact. Pour as little sauce and condiments as possible, including soy sauce and the various condiments that are added to the noodles, before putting them into the fryer, such as scallions, chocolate powder, etc. . Minimize product contamination.
The problem of food packaging
Poor quality of the outer packaging easy to make air into the inner packaging cause food oxidation, rancidity and so on. The problem of food packaging can be divided into three aspects
1. barrier, such as the poor oxygen resistance of packaging materials, resulting in finished product packaging in the long-term storage process, the outside air slowly infiltrated into the packaging caused by the oxidation of food ingredients. For example, some products with high oil content use poor composite film as external packaging materials, such materials poor resistance to oil, easy to cause composite film layering, resulting in the overall packaging barrier decline.
2. sealing, such as bad heat seal caused by poor sealing, resulting in external air from the heat seal into the package. In addition, some non-high-temperature cooking of the finished product packaging in the high-temperature cooking sterilization link after easy to appear sealing leakage, resulting in a decline in sealing.
3. physical mechanical properties, such as poor toughness of packaging materials, not content puncture or production process and storage process kneading or extrusion, in the process of storage and transportation, pinholes, creases and even broken bags are not found in time, resulting in food contact with a lot of oxygen and oxidation deterioration.