Agricultural products, starch and related products and pastry had the highest substandard rates last year among 32 types of foods, a report on the city's food safety has revealed.
However, almost 99 percent of 207,107 food samples tested passed safety checks last year, up 0.3 percentage points from 2016, according to the Shanghai Food and Drug Administration report.
Excessive microbes, food additives, pesticide and veterinary drug residues were blamed for nearly 90 percent of substandard foods last year.
The remaining substandard items had excessive amounts of non-edible substances, heavy metals, hormones, antibiotics, ethoxyquine (a preservative), and problems with their labels.
Some vegetables, poultry, meat, fish and shrimp were found to contain excessive pesticide and veterinary drug residues, while excessive bacteria was found in salad, cooked meat, fresh beverages and uncooked aquatic products, the administration said. Excessive bacteria was also detected in boxed lunches and tableware.
Some aquatic products were found to contain malachite green dye, a synthetic dye. Sea crabs, particularly portunid crabs, were found to be contaminated with the heavy metal cadmium, while some fried noodle products were found to excessive residue of aluminum, according to the report. Exposure to a large amount of cadmium can lead to poisoning, while excessive amounts of aluminum damages brain and nerve cells if consumed, according to doctors.
Some imported foods were detected with banned animal derived products, unreported genetically modified ingredients, food additives that don't meet Chinese standards, excessive pesticide and veterinary drug residues, substandard microbes, incorrect labels, broken packaging, or were expired, had mildew and rot and lacked production dates.
Last year, authorities received 130,699 food-related complaints, tip-offs and consultation inquiries, up 22 percent from a year earlier. Whistleblowers behind 1,037 cases received 779,100 yuan (US9,862) in total.
Complaints and tip-offs about dining venues accounted for 40 percent, mainly about discomfort after meals, poor hygiene conditions, unclean cuisine and unlicensed operations.
About 35 percent of eateries in the city that were graded had a smiley face, with 3.1 percent crying faces. A smiling face means good food safety while a crying face indicates the opposite.
No serious food safety incidents were reported last year. Three mass food poisoning cases involving 142 people were recorded, but none involved fatalities, according to the report.
In one case, all nine outlets of LIST, a popular Hong Kong-style dim sum and dessert restaurant in Shanghai, were temporarily suspended after 71 diners became sick after meals at four branches of the restaurant in July. Salmonella was found in the food and the restaurant was found making cold pastries beyond the limits of its license.
In total, 37,256 food manufacturing and operation businesses had their licenses revoked and more than 6,700 illegal food safety cases were uncovered with 224 million yuan in fines or confiscated, according to the report.
Fake food products, the use of expired materials and smuggling and selling overseas beef containing lean meat powder were detected last year, according to the administration. The cases included the Farine bakery flour scandal and illegally adding poppy seeds to crayfish, malatang (a Sichuan-style meat and vegetable soup) and beef soup.
Some criminals were using the Internet selling counterfeit or substandard food, and there was a rise of cross regional food safety cases, officials said.
The top three food-related concerns of residents were food poisoning, bad food and pesticide residues in vegetables, the administration said. Food safety satisfaction score among residents was 76.1 last year, up 3.8 points from 2016.
The city's food authorities have taken a number of measures to curb food safety irregularities by establishing a system tracking the origin of produce, a tip-off reward system, a blacklist, and installing real-time surveillance cameras at food processing venues.