Consumers are looking to quercetin, a flavonoid found in fruits, vegetables and plants, for healthier skin.    According to Spate, the New York City-based research firm that analyzes millions of online consumer signals to identify the next big trend, there are an average of 99,500 searches every month in the US for quercetin, which is “high-volume” relative to other supplement product searches. It has grown over 55.5% in searches since last year.    Quercetin has anti...