Dinner last night included trail mix. We weren't on our way to Tinker's Knob in the High Sierra, but with the Fourth of July weekend about to commence we wanted to start acclimating ourselves for any hikes we might take, and trail mix is as crucial to a successful outing as sturdy shoes and sunscreen.

I'm sure food scientists have given trail mix plenty of thought when it comes to the best formula to provide hikers with the most helpful blend of nutrients. At least, I trust they have. What's important to me is the taste, as well as the obvious standards a well-conceived trail mix should meet: It's got to be light and it can't need refrigeration, reconstituting or cooking. The package should be easy to open and close, and withstand knocking around in the backpack. And the mix should consist of foods that chipmunks and other wildlife would enjoy without doing them harm, since you're bound to spill some as you shake it into your hand or mouth.

Beyond that, a good trail mix should be colorful and diverse in flavor and texture. It shouldn't be too dry; you don't want to drink all your water washing it down. It helps if it looks wholesome - nuts, seeds, dried fruit. And sweetness is crucial, providing incentive to get to the top of the peak, and reward when you are there. M&M's are always good.

The trail mix we had last night is new to the market - Emerald Tropical Blend Trail Mix, one of three mixes being introduced by Diamond Foods Inc. of Stockton. From its durable and resealable foil packet to the balance and freshness of its contents, this mix is a winner, and we look forward to trying the others in the lineup. (A six-ounce package of Tropical Blend costs about $2.70 and soon should be available at most Safeway, Raley's, Save Mart, Walgreens and Longs stores, if it isn't already.)

We were especially impressed by the whole cashews in the blend. Often, trail mix contains so many broken bits of nuts and other ingredients it looks as if it tumbled out of the pack and rolled down the slope. The dried mango, dried pineapple and ribbons of shaved coconut brought color, fruitiness and moist chewiness to the blend, while glazed walnuts contributed the all-important sweetness. Small clusters of granola were a curiosity, and I could have lived without the banana chips, though they did add contrasting crunch. Nutritionally, the product is sound, with a quarter-cup portion providing 130 calories, 8 percent of the daily value of dietary fiber, 10 percent of the daily value of saturated fat and just 2 percent of the daily value of sodium. There are no trans fats.

We enjoyed it on its own, but if you plan to toss yourself a salad at the end of the trail it also will complement and brighten that.