Wine and Viticulture Department, California Polytechnic State University, San Luis Obispo, One Grand Ave., San Luis Obispo, CA 93407, USA.
Jonata Winery, P.O. Box 191, Buellton, CA 93427, USA.
Molecules. 2022 Feb 14;27(4):1270. doi: 10.3390/molecules27041270.
Microwave technology (MW) was applied to musts and stems over three consecutive vintages in Cabernet Sauvignon, Merlot and Syrah wines from California (USA). Stems were added to musts at a rate of 50 and 100% (50% Stems and 100% Stems), either as untreated or after MW (50% MW Stems and 100% MW Stems). Stem additions lowered ethanol (up to 1.15% / reduction), but increased pH (up to 0.16 units) and the tannin content of the wines. In 2016, tannins increased by 103% (100% Stems), and 124% (100% MW Stems). In 2017, tannins increased by 39% in stem-added Merlot wines and by 63% (100% Stems) and 85% (100% MW Stems) in Syrah wines. In 2018, tannins in Syrah wines increased by 250% (100% MW Stems) and by 743% (100% Stems). Wines made with 50% Stems exhibited intermediate tannin contents. Must MW increased flavonols (up to 278% in Syrah wines), monoglucosylated, acylated and anthocyanin-derived pigments. Stem additions reduced wine color and polymeric pigment formation in Syrah. Must MW decreased the perception of coarseness and herbaceous flavors in Merlot, whereas stem additions increased herbaceous aromas in Syrah. Despite higher tannin contents in stem-added wines, no concomitant increases in astringency were observed.
微波技术（MW）在加利福尼亚州（美国）的赤霞珠、梅洛和西拉葡萄酒的葡萄醪和葡萄梗上连续三个年份应用。将葡萄梗以 50%和 100%（50%葡萄梗和 100%葡萄梗）的比例添加到葡萄醪中，要么未处理，要么经过 MW（50%MW 葡萄梗和 100%MW 葡萄梗）。葡萄梗的添加降低了乙醇（最多 1.15%/减少），但增加了葡萄酒的 pH 值（最多 0.16 个单位）和单宁含量。在 2016 年，单宁增加了 103%（100%葡萄梗）和 124%（100%MW 葡萄梗）。在 2017 年，添加葡萄梗的梅洛葡萄酒中的单宁增加了 39%，西拉葡萄酒中的单宁增加了 63%（100%葡萄梗）和 85%（100%MW 葡萄梗）。在 2018 年，西拉葡萄酒中的单宁增加了 250%（100%MW 葡萄梗）和 743%（100%葡萄梗）。用 50%葡萄梗制成的葡萄酒表现出中等的单宁含量。葡萄醪 MW 增加了类黄酮（在西拉葡萄酒中增加了 278%）、单葡萄糖基化、酰化和花色苷衍生的色素。葡萄梗的添加减少了西拉葡萄酒的颜色和聚合色素的形成。MW 降低了梅洛葡萄酒的粗糙感和草本风味的感知，而葡萄梗的添加增加了西拉葡萄酒的草本香气。尽管添加葡萄梗的葡萄酒中的单宁含量较高，但没有观察到涩味的相应增加。
