Commodity costs have eaten into quarterly earnings at US-based J&J Snack Foods.

The cookie-to-pretzel maker posted a 15% jump in sales for the three months to 29 December but blamed an "unprecedented escalation" in costs for the slump in profits.

While revenue rose to US$130.9m, operating income tumbled 55% to $2.3m, J&J said.

President and CEO Gerald Shreiber said: "The unprecedented escalation in commodity costs including both wheat and dairy impacted this quarter. Given the current environment and expected lack of substantial relief, this will continue to pressure earnings in the future."