Coca-Cola (KO 0.50%) is set to report earnings on Tuesday. Here's what you need to watch for in the company's results.

Earnings expectations
The first issue that must be addressed is whether the cola giant met Wall Street's expectations. Analysts tack earnings for Coke at $0.44 per share this quarter. Coca-Cola booked earnings per share of $0.46 in the same quarter last year, so the company expects deterioration in profit growth. The company reported approximately $11 billion in sales for the first quarter of last year and nearly $47 billion for the full-year 2013.

Sales growth
Carbonated soft drink sales in the U.S. have fizzled out in the past decade, with Coca-Cola and its soda rivals feeling the negative effects. Most recently, Coca-Cola's fourth-quarter 2013 revenue fell 4%. As consumers become increasingly nutrition- and calorie-conscious, Coke and rival PepsiCo (PEP 0.15%) are growing their respective noncarbonated beverage portfolios. Coke has gained traction in this segment. In fact, Coke's volume of tea, juice, packaged water, and sports drinks grew 11%, 5%, 5%, and 2%, respectively, in 2013. Coca-Cola added Dasani water, Minute Maid, PowerAde, and Honest Tea to its noncarbonated beverage offerings in recent years, while PepsiCo holds Aquafina, Naked Juice, and Tropicana brands. 

Continued innovation
The steady decline in soda consumption has also spurred innovation and strategic partnerships in an effort to boost sales. Coke and Keurig Green Mountain (GMCR.DL) recently signed a decade-long agreement to develop and roll out Coke's portfolio of products for use in Green Mountain's upcoming Keurig Cold at-home beverage system. It's unclear if these machines will boost consumption of Coke products, but it certainly legitimizes the at-home market.

Since Coke's announcement, speculation has surfaced that PepsiCo would be tempted to match Coke's move into home beverage systems. PepsiCo CEO Indra Nooyi hinted during her fourth-quarter earnings conference call that her company was "participating with multiple single serve home delivery product tests," but that it was "too premature to commit without having a technology that actually works." Yet PepsiCo announced just last month that it would enter the at-home market with Bevyz, a multidrink beverage maker. The machine is expected to hit stores in May, several months ahead of the Keurig Cold's debut.

Foolish takeaway
When Coca-Cola releases earnings on Tuesday, I'll be watching to see exactly if and how the cola maker achieved first-quarter earnings and sales growth. I'll also be looking for more details from Coke regarding its partnership with Keurig Green Mountain.