This is the 1428th most frequent Japanese word.
新鮮
Fresh.
The word "新鮮" means "fresh" in this context, describing the air's quality as invigorating and pure.
新鮮な空気を吸うと気分が良くなります。
Breathing fresh air makes you feel better.
Here, "新鮮" refers to "fresh" in the sense of being novel and innovative.
彼が出したアイデアはとても新鮮で面白い。
His suggested idea is very fresh and interesting.
In this case, "新鮮" again signifies "fresh" but is about the quality of an ingredient, emphasizing its natural and recently obtained condition.