Original title: Is it safe to pack leftovers directly in plastic bags?

At present, thrift has become a consensus among people, and more and more citizens take leftovers home after dining out. The reporter visited the catering market in the provincial capital and found that the most common packaging utensils are translucent sealed boxes, plastic bags, and white foam lunch boxes. Are these packaging utensils safe? How can citizens distinguish them? What are the precautions when packing? The reporter interviewed these questions.

Identification of lunch boxes

The good ones are translucent and tough

The bad ones are brittle or colored

"We provide customers with free environmentally friendly lunch boxes for packaging." Manager Li of Jinan Sunshine Home Cooking Restaurant said that through the packaging service, the amount of leftovers in the restaurant has been significantly reduced, "The amount of swill during the Chinese New Year has dropped by about two-thirds."

The reporter visited and found that some large and medium-sized restaurants in the provincial capital mostly provide translucent sealed packaging boxes. In Xindi Restaurant, a special lunch box is used for customers to pack. This lunch box is in the shape of a bowl, and the material looks relatively transparent, feels tough and has strong sealing. Manager Zhang of the restaurant said that this lunch box is safe and environmentally friendly, and can be directly put into the microwave for heating. In a hotel on Luoyuan Street, the take-out boxes used are very similar to those of Xindi Restaurant, but they are rectangular in shape.

The reporter took some sealed take-out boxes and observed them carefully, and found that some of the boxes had the words "+110¡æ-20¡æ" and "No. 5 PP" on the bottom. What material are these take-out boxes made of? Is it safe and non-toxic? Zhu Qingzeng, a professor at the School of Chemistry and Chemical Engineering of Shandong University, told reporters that the packaging lunch boxes made of PP (polypropylene) are non-toxic and high-temperature resistant, and can be used as microwave heating bowls. Lunch boxes made of pure PP resin materials are safer, but if the lunch boxes are products processed from recycled inferior materials, they contain plasticizers, release agents and other additives and impurities, etc., which will be dissolved if they encounter highly oily foods, which are harmful to the human body. Consumers can simply judge like this: good PP materials are translucent and tough, while inferior ones are opaque, brittle or colored.

In addition, there is a thinner transparent lunch box on the market that is made of PS (polystyrene) material and is often used to hold sushi. Zhu Qingzeng said that PS resin material itself is non-toxic, and high-quality PS material lunch boxes are safe, but they are not resistant to high temperatures. Foaming agents, release agents, etc. may remain in the lunch box made of foamed PS material (a white lunch box), which poses a safety hazard.

Plastic bag identification

Transparent and soft ones are of good quality

Colorful and crisp ones are of poor quality

In addition to lunch boxes, another common packaging tool in the provincial capital catering market is plastic bags, which are especially common in some small restaurants.

The reporter consulted the national mandatory standards for plastic shopping bags issued in 2008 and learned that plastic bags for food need to be marked with the "QS" logo and the words "for food" and "for food only". In addition, regular plastic bags will have information such as specifications, strength, and manufacturers printed on the bag. However, this is not the case with packaging bags on the market. The reporter found in several restaurants on Furong Street that the plastic bags used for packaging in the stores were thick and thin, but most of them were translucent and there were no labels on the bags. At the Laodongmen Wholesale Market, when the reporter said he wanted to buy "bags that can be used to hold food", several stall owners took out piles of plastic bags without any labels on them, and the price of each hundred plastic bags ranged from 1 to 3 yuan.

"I always feel uneasy using plastic bags." Some citizens said that they also noticed that the plastic bags for packaging looked irregular, and even if they were used, they were worried that toxic substances might be produced when hot food was used.

Zhu Qingzeng introduced that plastic bags can be made of PE (polyethylene) and PVC (polyvinyl chloride) resin materials. If the food plastic bags used in the market are made of PVC or recycled plastic, there will be great safety hazards, because these plastic bags contain a large amount of plasticizers, etc., which are not safe to contact with food.

How to identify inferior plastic bags? Zhu Qingzeng said that high-quality plastic bags are usually transparent, soft and tough, and plastic bags made of PE resin materials can be used with confidence. Citizens can compare PE plastic wrap. The better the transparency and toughness, and the better the quality of the plastic bags without odor, the better. Plastic bags with color, brittleness, and low strength should not be in contact with food as much as possible.

Experts suggest

It is best to choose meat dishes

Discard vegetable salad

Is it safe to pack in environmentally friendly and safe lunch boxes? In this regard, experts said that there are also particularities in packing. Not all leftovers are suitable for packing. After packing them home, you should also pay attention to the way of eating, otherwise it is easy to cause physical discomfort. Zhao Jinshan, director of the Food and Nutrition Institute of the Shandong Provincial Center for Disease Control and Prevention, said that when packing leftovers, you should pay attention to the choice of containers. Some high-oil and high-temperature foods cannot be packed in plastic lunch boxes, because plastic products are easy to decompose carcinogens in a high-oil and high-temperature environment. For fried foods with little soup, it is recommended to use paper lunch boxes to pack.

"It is better to pack meat dishes, but it is not recommended to pack vegetables, especially cold dishes." Du Huizhen, director of the Nutrition Department of Qianfoshan Hospital, said that vegetables, especially cold dishes, are prone to produce nitrosamines, nitrites and other substances after bacterial growth. These substances are carcinogenic and have adverse effects on the body. If meat products are reheated, some vinegar can be added to reduce the loss of minerals. Reporter Zhao Li Intern Li Xinwei

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