茶和红酒中的涩味来自什么物质？其作用机理是什么？
What compounds cause astringency in tea and red wine, and what is the mechanism?
涩味主要来自多酚类（尤其是茶多酚中的儿茶素与红酒中的单宁）。这些分子富含酚羟基，能与口腔唾液中的蛋白质（尤其富含脯氨酸蛋白）通过氢键和疏水作用结合并沉淀，使黏膜收敛、产生干涩感。涩感是触觉而非基本味觉。
Astringency comes mainly from polyphenols—catechins in tea polyphenols and tannins in red wine. Their many phenolic hydroxyls bind and precipitate salivary proteins (especially proline-rich proteins) via hydrogen bonding and hydrophobic interactions, making oral mucosa feel contracted and dry. Astringency is a tactile rather than a basic taste sensation.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《食品化学》(王璋) 呈味与涩味章；Nature 食品化学研究
Nature Food, polyphenol studies; ACS Journal of Agricultural and Food Chemistry
#多酚 #单宁 #涩味 #儿茶素
辣椒的辣味来自什么化学物质？它为什么让人感觉热？
What chemical causes the heat of chili peppers, and why does it feel hot?
辣椒的辣味主要来自辣椒素类（如辣椒素 capsaicin），它们作用于口腔与皮肤上的 TRPV1 受体（瞬态受体电位香草酸亚型 1）。该受体本用于感知高温与酸性刺激，被激活后向大脑发送灼热信号，因此辣是一种痛觉/热觉而非真正味觉。
The pungency of chilies comes mainly from capsaicinoids such as capsaicin, which act on the TRPV1 receptor (transient receptor potential vanilloid type 1) in the mouth and skin. This receptor normally senses high temperature and acidity; its activation sends a burning signal to the brain, so spiciness is a pain/heat sensation rather than a true taste.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Knotkova, Pappagallo, Szallasi,《Capsaicin (TRPV1 Agonist) Therapy for Pain Relief》,The Clinical Journal of Pain,2008 (DOI: 10.1097/ajp.0b013e318158ed9e)
Knotkova, Pappagallo, Szallasi, 'Capsaicin (TRPV1 Agonist) Therapy for Pain Relief', The Clinical Journal of Pain, 2008, DOI: 10.1097/ajp.0b013e318158ed9e
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1097/ajp.0b013e318158ed9e
#辣椒素 #TRPV1 #辣味 #痛觉
焦糖化反应与美拉德反应有什么不同？
How does caramelization differ from the Maillard reaction?
焦糖化是糖类在约 160 ℃ 以上自身受热脱水、裂解与聚合的非酶褐变，不需氨基酸参与，产生焦糖色素与苦味、坚果香。美拉德反应则需要还原糖与氨基化合物共同作用。两者都生成棕色物质，但原料与机理不同，常在高温烹饪中同时发生。
Caramelization is the non-enzymatic browning of sugars alone when heated above about 160 ℃, involving dehydration, fragmentation, and polymerization without amino compounds, yielding caramel color and bitter, nutty notes. The Maillard reaction requires both reducing sugars and amino compounds. Both give brown products but differ in reactants and mechanism and often co-occur in high-heat cooking.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《食品化学》(王璋) 褐变章；美国化学会(ACS)农业食品化学
ACS Journal of Agricultural and Food Chemistry, browning reactions; Food Chemistry
#焦糖化 #非酶褐变 #糖类 #焦糖色素
为什么许多水果和酒的香气来自酯类？酯是如何形成的？
Why do many fruits and wines owe their aroma to esters, and how do esters form?
酯由羧酸与醇在酶或酸催化下发生酯化反应生成，具有花果般挥发性香气。在水果成熟和葡萄酒发酵中，酵母与酯合成酶将脂肪酸与醇组装成乙酸乙酯、异戊酸乙酯等，构成特征香气。酯的水解则会减弱或改变风味。
Esters form by esterification of carboxylic acids with alcohols under enzyme or acid catalysis and carry fruity, floral volatile aromas. During fruit ripening and wine fermentation, yeasts and ester synthases assemble fatty acids with alcohols into compounds like ethyl acetate and ethyl isovalerate that define characteristic scents. Hydrolysis of esters weakens or alters the flavor.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《食品化学》(王璋) 香气成分章；美国化学会(ACS)农业食品化学
ACS Journal of Agricultural and Food Chemistry, volatile esters; Food Chemistry
#酯 #酯化 #果香 #发酵香气
味精（谷氨酸钠）为什么能带来鲜味？鲜味的化学本质是什么？
Why does monosodium glutamate (MSG) produce umami, and what is the chemical nature of umami?
鲜味是甜、酸、苦、咸之外的第五种基本味觉，主要由谷氨酸等 L-型氨基酸的钠盐激活舌上的鲜味受体（如 mGluR4 与 T1R1/T1R3）产生。MSG 溶于水解离出谷氨酸根，与受体结合并协同呈味核苷酸（如肌苷酸）显著增强鲜味。它广泛存在于天然高汤与发酵食品中。
Umami is a fifth basic taste alongside sweet, sour, bitter, and salty, produced mainly when L-amino acids such as glutamate activate umami receptors on the tongue (e.g., mGluR4 and T1R1/T1R3). MSG dissociates in water to glutamate, which binds these receptors and, with synergistic nucleotides like inosinate, strongly enhances savoriness. It occurs naturally in stocks and fermented foods.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《食品化学》(王璋) 呈味物质章；Nature 味觉受体研究
Nature, umami receptor studies; ACS Journal of Agricultural and Food Chemistry
#味精 #鲜味 #谷氨酸 #味觉受体
乳酸发酵在食品中有什么作用？它和酒精发酵有何不同？
What role does lactic-acid fermentation play in food, and how does it differ from alcoholic fermentation?
乳酸菌将糖类无氧转化为乳酸，降低 pH 抑制腐败菌并赋予酸奶、泡菜酸味与质地。与酒精发酵（酵母将糖转为乙醇和 CO₂）不同，乳酸发酵不产生气体，产物为单一有机酸，因而更适合腌制与乳制品。两者都是 NAD⁺ 再生的无氧产能途径。
Lactic-acid bacteria convert sugars anaerobically to lactic acid, lowering pH to inhibit spoilage microbes and giving yogurt and kimchi their sour taste and texture. Unlike alcoholic fermentation (yeast converting sugar to ethanol and CO₂), lactic fermentation produces no gas and yields a single organic acid, suiting pickling and dairy. Both regenerate NAD⁺ as anaerobic energy pathways.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《食品化学》(王璋) 发酵章；美国化学会(ACS)农业食品化学
ACS Journal of Agricultural and Food Chemistry; Food Microbiology
#乳酸发酵 #乳酸菌 #无氧 #酸奶