It is also harmful to use leavening agent for alum-free fritters. According to experts, almost all puffed foods (including fried dough sticks and bread) on the market now have excessive aluminum residues. The reason why aluminum exceeds the standard is that enterprises add baking powder (chemical leavening agent) to food in the production process. In order to change the situation of aluminum exceeding the standard, we must choose aluminum-free leavening agent. The cost of aluminum-free leavening agent is 3-4 times higher than that of ordinary chemical leavening agent. Therefore, in order to reduce costs, some unscrupulous traders will inevitably choose low-priced chemical leavening agents, so the phenomenon of aluminum exceeding the standard still exists. Aluminum is not a trace element needed by human body, on the contrary, it is a food pollutant harmful to health. Although aluminum is a low toxic metal element in toxicology, it will not cause acute poisoning. However, aluminum entering cells can combine with many important substances in human body, such as protein, enzymes, adenosine triphosphate and so on. It will affect many biochemical reactions in the body, interfere with the normal metabolism of cells and organs, and lead to some dysfunction and even some diseases. Long-term consumption of puffed food with high aluminum content will interfere with people's thinking, consciousness and memory function, and cause nervous system diseases, which are manifested as memory loss, visual and motor coordination disorder, brain injury and mental decline, and in severe cases, dementia may occur. Excessive intake of aluminum can also replace calcium deposited in bone, inhibit bone formation and cause osteomalacia. In addition, puffed foods with high aluminum content are mostly high-fat and high-calorie foods, which will promote the acidification of body fluids and easily bring obesity, diabetes, hypertension, hyperlipidemia and other rich diseases. At the same time, puffed foods are generally high in salt and monosodium glutamate, which may easily lead to hypertension and cardiovascular diseases in children's adulthood. Consumers are advised to strengthen their awareness of self-care, try not to eat fried dough sticks and puffed food, such as French fries, bread, biscuits, etc., especially in the current market supervision, choose steamed bread and cakes made by natural fermentation. Growing children should eat less puffed food. So as not to affect the normal diet and lead to malnutrition. At the same time, consumers should try to choose to buy puffed food in sealed packages produced by regular manufacturers to minimize the chance of being hurt.