Study on the influence of the hottest irradiation

Study on the effect of irradiation and storage conditions on food VC content (Part I)

Abstract: 60Co γ The function of X-ray irradiation accelerates the destruction of VC in food and reduces the content of VC; The higher the storage temperature and the longer the storage time, the greater the influence of irradiation on the VC content of food; Some foods do not show the effect of VC content on the day of irradiation, but are affected by storage temperature and storage time during storage, and finally show the effect of irradiation on food VC content

key words: irradiated food VC

food irradiation storage technology is an important aspect of radiation processing applications. It is produced by using radionuclides 60Co or 137Cs γ X-rays and electron beams produced by accelerators irradiate food to inhibit germination, delay ripening, promote material transformation, kill insects and bacteria, prevent mildew, etc., so as to achieve the purpose of preserving fresh or improving product quality. Food irradiation preservation and processing has many advantages, such as energy saving, simplicity, high efficiency, enterprises' casually lowering the quality requirements of products in order to blindly reduce prices, safety and reliability, and many advantages that conventional technologies do not have. It has been widely used at home and abroad, and is forming a new radiation processing industry

in 1943, Dr. octor of Massachusetts Institute of technology first irradiated hamburgers with rays for food preservation. After that, the international casserole "neicaizheng" style began to study the irradiation preservation and processing of food. So far, 224 kinds of irradiated foods have been approved by 38 countries in the world. At present, the development and commercial application of food irradiation storage in China are at the forefront of the world. At the "10th International Conference on radiation processing" held in the United States in May 1997, the radiation processing I used was rated as the fastest-growing country in the world

the research on the influence of irradiation on food nutritional components is one of the important contents of food irradiation technology research, but there are relatively few special studies and reports in this field at home and abroad, and the conclusions are not systematic and therefore inconsistent. Some people believe that irradiation will reduce the content of food VC, some people believe that irradiation will not affect the content of food VC, while others believe that irradiation will increase the content of food VC

this paper aims to provide scientific basis for the rational development and utilization of food irradiation by studying the influence of irradiation on the VC content of food and the law of storage temperature on the VC content of irradiated food

1. Materials and methods

1.1 materials

citrus and apple are selected as the representatives of fruit food, and garlic and onion are selected as the representatives of vegetable food. All test materials were selected from high-quality agricultural products in Zhengzhou farmers' market

1.2 experimental design and methods

the experimental design is carried out according to three levels: irradiation dose, storage temperature and storage time. 1) The radiation dose is designed according to the common radiation dose range of fruits and vegetables, namely OkGy (control), 2kGy, 4kgy and 6kgy; 2) The storage temperature is set as low temperature (4 ℃), normal temperature (17 ℃ -21 ℃) and high temperature (30 ℃); 3) The storage time is set to 0d, 10d and 20d

each treated sample is 500g, with three repetitions. The determination of VC content is carried out for one group of repetitions, and the other two repetitions are used as standby. In the experimental design, the VC content of 112 samples was determined, but because 12 samples of citrus, apple and onion stored at high temperature rotted and deteriorated after 20 days of storage, the VC content of 0 samples introduced by the relevant person in charge of China Zhongwang was actually determined

1.3 irradiation treatment

the isotope Institute of Henan Academy of Sciences No. I 60Co γ The irradiation device performs irradiation treatment

1.4 determination of VC content

the determination of VC content is carried out by the agricultural product quality supervision, inspection and testing center of the Ministry of agriculture in accordance with gb/t (national standard)

2, results and analysis

2.1 effect of irradiation on VC content in food

test results, 60Co γ X-ray irradiation can significantly reduce the VC content of food, and shows a strong regularity

in citrus, garlic, apple and onion, the VC content of the irradiation group was significantly lower than that of the control group (Table 1). Compared with the control group, the average content of VC in the irradiation group was 24.58% in citrus, 13.83% in garlic, 20.12% in apple and 16.17% in onion

it can be seen from table 2 that on the day of irradiation, except that citrus obviously showed a downward trend in VC content with the increase of irradiation dose, the law of the performance of the other three test materials was not obvious. The reason why the VC content of the irradiation group of the four tested materials was significantly lower than that of the control group was that the effect of irradiation on the VC content of food was fully manifested due to the influence of storage temperature and storage time during storage (described later)

Table 1 60Co γ Effect of irradiation on VC content in food

material irradiation dose (kGy) storage time (d) average value of VC content (mg/100g) number of data sources of average value of VC content (

citrus 0 28.28 6

21.33 18

garlic 0 6.94 7

5.98 21

Apple 0 3.43 6

2.74 18

onion 0 6.06 6

5.08 18

note: 1 Average value of VC content "From the average data of VC content on the day of irradiation and in different storage periods.

2. Data: during the last determination of citrus, apple and onion high-temperature storage, there was no measured value of VC content due to the decay of the test material. The data of garlic control group was 7, and the other controls were 6; the irradiation group included three irradiation doses, so the data of garlic irradiation group was 21, and the irradiation group of the other three test materials was 18