Dutch food and cosmetics giant Unilever said Thursday that its first quarter sales soared 11.9 percent to 12.14 billion euros ($16 billion), lifted mostly by emerging market demand. \"Emerging markets, now 56 percent of the business, have again delivered strong growth,\" said chief executive Paul Polman in a statement. Sales in those markets grew by 11.9 percent, while developed ones posted an expansion of 4.2 percent. Polman warned that the \"external macro-economic environment remains difficult and higher input cost headwinds persist,\" but the group said it was maintaining its targets of an improved profit margin for 2012.