(Reuters) - The U.S. Food and Drug Administration (FDA) said on Tuesday it has issued a warning letter to Amazon.com Inc’s Whole Foods Market for not labeling some products for the presence of food allergens, which led to a series of product recalls. The supermarket chain, which was bought by Amazon in 2017 for $13.7 billion, has recalled more than 30 food products in the last year as the presence of major food allergens was not listed on product labels, the agency said. The products were mainly from the deli and bakery sections of the store, the FDA said. (bit.ly/3nN1fSU) Whole Foods is responsible for investigating and determining the causes of the violations identified and for preventing their recurrence, the FDA said in the letter issued to the company on Dec. 16. The agency said the company should respond within 15 working days from receipt of the letter, listing out in writing the actions it is taking to address the violations. “We are working closely with the FDA to ensure all practices and procedures in our stores meet if not exceed food safety requirements,” Whole Foods said in an emailed statement.