Effects of Molding Techniques on Main Chemical Components of White Peony Tea
To investigate the effects of different molding techniques on the main chemical components of white peony tea,Fu'an Dabai was used as the raw material and the withered leaves with different moisture content(40±1)%,(35±1)%,and(30±1)%were light rolled(QR)or tidied(LT)referring to the traditional white tea processing technology.The main chemical components of tea samples were detected and analyzed by ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry(UPLC-QqQ-MS)and headspace solid-phase microextraction combined with gas chromatography time-of-flight mass spectrometry(HS-SPME-GC-TOF-MS).The results showed that the sensory quality score of white peony tea with different molding techniques decreased with the decrease of moisture content in the withered leaves.At the same moisture content,the QR molding was superior to the LT molding.The total contents of amino acids and catechins of white peony tea after molding(QR,LT)were significantly lower than those in traditional white peony tea(CK)(P<0.05),while the total sugar content and the relative contents of aldehydes were significantly higher than those in traditional white peony tea(P<0.05).Tea soup of white peony tea with high moisture content(40±1)%and gently kneaded withered leaves exhibited better freshness,thickness,and sweetness,along with a noticeable sweet floral aroma.Overall,the white peony tea molded with high-moisture(40±1)%withered leaves had better comprehensive quality.QR could facilitate the formation of sweet flower fragrance,while LT could be more conducive to the development of delicate fragrance flavor,providing a technical reference for improving the flavor and quality of white peony tea through molding techniques.