It's a gourmet recipe for an indictment: take chicken anus, duck feathers and fox hair. Process it into counterfeit cooking oil. Distribute widely.

Even in China, a country frequently racked by food safety scandals, this has been a bad week. On Wednesday, a court in eastern China's Jiangsu province sentenced 16 men to prison for processing and selling 5,000 tons of recycled cooking oil made from a melange of discarded animal parts.

But the stomach-churning case was far from unique: that same day, 43 defendants were convicted in three other food safety cases in the province, most for selling meat products made from animal waste. Three days prior, more than 30 passengers on an Air China jet ran for the toilets after eating expired beef pastries. And on Friday, an inquiry found that almost all of the beef jerky in south-eastern Fujian province is actually chemically-treated pork.

Chinese consumers have grown used to reports of fake eggs, poisonous baby milk, exploding watermelons and glow-in-the-dark pork, a result of rampant profit-seeking and lax regulatory oversight in the country's food industry. In May, a gang in Zhejiang province was prosecuted for passing off rat, mink and fox meat as mutton; that same month, authorities caught a company in Hunan province making counterfeit jellyfish slices out of calcium chloride and sodium benzoate.

On Wednesday, the Lianyungang intermediate people's court in Jiangsu province convicted 16 men from a local food company, Kangrun, of illegally processing and selling "poisonous, harmful" cooking oil to 117 businesses in 2011-12, netting 600m yuan (£6.1m) in revenue. Wang Chengkui, the firm's legal representative, was jailed for life; his co-defendants face up to 15 years in prison.

"The Kangrun company can make 'edible oil' out of chicken feather oil, duck feather oil, pig hair oil, even fox hair oil," reported Xinhua, China's official newswire. The company also used "discarded inedible materials such as skins and buttocks of chickens and ducks as well as pig offal," the newswire's English edition added.

Three days before that verdict was announced, more than 30 passengers on an Air China flight from the north-western region Xinjiang to Beijing fell ill after eating an in-flight meal of expired beef-filled snacks. According to state media, a woman called Zhang discovered two dates printed on her meal's wrapper, the most recent of which was four days in the past.

Although Zhang alerted flight staff, they refused to make an announcement, as the other passengers were already eating. Half an hour later, passengers began queuing at the toilets. Most were queasy; many had diarrhoea; some vomited. China Air refused to acknowledge the issue until passenger accounts went viral online, then attributed the incident to a packaging mix-up.

On Friday, a reporter in south-east China's Fujian province revealed that most of the province's beef jerky is made from pork, processed into a beef-like substance using beef extract and illegal chemicals.

"Right now, almost all of the beef jerky on the market in Fujian is fake," Yao Yuancheng, general manager of local Longhai Yuancheng Food Company, told the reporter, whose findings were reprinted by Xinhua. Pork-based beef jerky costs £4.80 a kilo to produce, he said; real jerky costs three times as much.

It takes a grand irony to get Chinese web-users riled but they were treated to an easy target last weekend, when China's president, Xi Jinping, confronted New Zealand prime minister, John Key, about his country's food safety record.

The catalyst was Fonterra, a New Zealand firm that supplies 90% of China's milk-powder imports, recalling its products last month after a botulism scare. "Xi stressed that food safety concerns people's health and urged New Zealand to take tough measures to ensure food quality," Xinhua reported.

Before long, hundreds of users on Sina Weibo, the country's top microblog, had posted Xi's comment aside emoticons of laughing smiley faces and downward-pointing thumbs. "If Xi is demanding that New Zealand pay attention to its food safety, is there anything that [the government] won't say or do?" wrote one. Others were more forthright. "First, take care of our own food safety problems," wrote user Yi Muyi. "Then talk."