作者： CUIGUAI调味研发团队出版：广东优味香精有限公司最后更新： 九月 10, 2026WhatsApp与Telegram： +86 189 2926 7983电子邮箱：info@cuiguai.comWatermelon flavor is one of the most requested profiles in beverage development, and also one of the most frequently failed. The reason is rarely the sweetness, the color, or the mouthfeel. It is the rind. Consumers describe the defect in different words - "green", "cucumber-like", "vegetal", "peel-like", "grassy", or simply "that's not watermelon" - but the chemistry behind it is one family of volatile compounds that watermelon shares with cucumber. This article explains exactly where that rind character comes from, how to measure it, and how beverage brands, R&D teams, and procurement managers can formulate, mask, and source their way around it.Quick answer: The "rind" taste in watermelon beverages is caused mainly by nine-carbon (C9) unsaturated aldehydes and alcohols - above all (Z,Z)-3,6-nonadien-1-ol, the so-called "cucumber alcohol" - which are concentrated in the white rind and in over-ripe flesh, and which survive pressing, concentration, and finished-drink processing. The practical fix combines raw-material control, analytical screening for C9 green markers, and balanced flavor formulation with sweet, juicy top notes plus proven masking technology. Beverage manufacturers who source a watermelon flavor concentrate from a specialist flavor house get this balance engineered in, instead of discovering the rind note after the first production batch.
西瓜风味开发：解决西瓜皮异味问题翠拐味
What Is the "Rind" Taste, and Why Does It Ruin Watermelon Drinks?
The rind taste is a green, cucumber-like, slightly bitter, and faintly astringent aroma-taste complex. It is perceived both orthonasally (the "peel" smell when the glass is raised) and retronasally (the lingering green note at the back of the mouth after swallowing). In finished beverages it usually appears in one of three ways:
As an immediate top note:这种饮料闻起来像切好的黄瓜或未完全成熟的西瓜，而不是甜甜的西瓜肉。
As an aftertaste:the green, slightly bitter note builds after swallowing and lingers for several seconds, which consumers often describe as "peel" or "rind".
As a processing artifact:完全可接受的原型在巴氏灭菌、热灌装或三个月保质期后会呈现出绿色、蜡状的特征，因为热量和氧气会加速 C9 氧化产物的形成和释放。
Watermelon (Citrullus lanatus) flavor is built on a surprisingly small set of odor-active molecules. Research on mini-watermelon aroma (Tripodi et al., 2020, Journal of the Science of Food and Agriculture) found that C6 and C9 aldehydes and alcohols were the most represented compounds and characterized the fruity-green balance of the fruit. The signature "fresh watermelon" note is largely carried by (Z)-6-nonenal, a C9 aldehyde with a clean, watery melon odor, supported by:
(E,Z)-2,6-nonadienal- intense cucumber-like, green odor; part of the same biosynthetic family as the rind note.
(E)-2-nonenal- green, waxy, slightly citrus; at high levels it tips toward stale or cardboard-like.
beta-ionone- floral, violet-like note derived from carotenoid degradation, giving watermelon its perfumed sweetness.
Linalool, citronellol, and geranylacetone- floral-fruity accents that add juiciness.
Short-chain esters and C6 aldehydes(hexanal, (E)-2-hexenal) - fresh-cut, grassy undertones.
A well-balanced watermelon flavor keeps the sweet, juicy, floral-fruity elements dominant, using only a controlled dose of the green C9 compounds to deliver "freshly cut" character. The moment that ratio tips toward the green side, the profile reads as rind.
Nine-carbon aldehyde and alcohol compounds dominated both flesh and rind，但果皮缺乏赋予果肉复杂果香的萜烯、酯和内酯的多样性。
果皮的主要香气化合物超过其气味阈值，包括 17 aldehydes and six unsaturated nine-carbon alcoholsassociated with "fresh, green, cucumber-like aromas".
The same paper found the rind rich in citrulline (61.4 mg/100 g) and arginine (53.8 mg/100 g) - valuable for functional positioning, but irrelevant to flavor quality. For a beverage brand, the practical conclusion is blunt: the closer a concentrate or juice base gets to the rind, the more cucumber-like green character it contributes, and the less "watermelon" it tastes.
绿色 C9 家族：黄瓜醇及其亲属
外皮故事中最重要的化合物是 (Z,Z)-3,6-nonadien-1-ol, sometimes called cucumber alcohol. Identified in cucumber and watermelon decades ago, it has a characteristic green, cucumber, melon-rind odor and an extremely low odor threshold - in the low parts-per-billion range - which means even trace carryover into a beverage is perceptible. PubChem (National Library of Medicine) lists 3,6-nonadien-1-ol (C9H16O) as a flavoring agent and fragrance ingredient, and its GC-MS fingerprints are standard reference data in flavor labs. Related green markers include:
(Z)-6-nonen-1-ol- watery, melon-green; the alcohol analogue of the key flesh aldehyde.
cis-3-hexenol and hexanal- the classic grassy/leafy C6 pair from the lipoxygenase pathway.
(E)-2-nonenal- green, waxy, and at higher levels stale.
These compounds are produced mainly through the lipoxygenase (LOX) pathway from linoleic and linolenic acids. Crushing, pressing, homogenizing, and heating all activate or rebalance this pathway, which is why rind character so often appears - or intensifies - during processing rather than in the raw fruit.
西瓜挥发性化合物：GC-MS 分析风味品质
商业饮料中的果皮异味
原料：成熟度、品种和果皮内含物
The first source of rind character is the fruit itself. Over-ripe or internally bruised watermelon releases more C9 aldehydes and alcohols as cell walls break down and lipoxygenase acts on free fatty acids. Some varieties bred for high sugar also carry stronger green backgrounds. The most common industrial mistake is pressing whole or partially peeled melons: even a small proportion of white rind in the press feed measurably shifts the volatile profile toward the cucumber-alcohol family and can introduce cucurbitacin-type bitterness from the rind's triterpenoid content.
加工：压力、酶和热
Juice extraction pressure matters. High-pressure screw pressing squeezes the rind and the white flesh layer more aggressively than gentle belt pressing, pulling rind tissue, and its volatiles, into the juice. Enzyme-assisted maceration - sometimes used to boost yield - can liberate additional C9 alcohols from glycoside or lipid precursors. Thermal processing then changes the balance again: pasteurization degrades some fresh green aldehydes while creating others, and the final bottled product's green note is the sum of all these shifts. This is why the same flavor concentrate can taste clean in a cold-fill prototype and "rindy" in a hot-fill production run.
专注品质：闻起来绿色的捷径
A third source sits squarely in the supply chain. Watermelon is a difficult profile to build because the "watery sweet" character comes from subtle interactions rather than one hero molecule. Some lower-cost concentrates lean heavily on cheap C9 green alcohols and aldehydes (cucumber alcohol, nonadienal, hexenol) to fake freshness, then add high-dose sugar to cover the result. In a zero- or low-sugar RTD, that cover is gone and the green note is exposed. Brands that buy on price alone often discover they have purchased a cucumber flavor with a watermelon label.
果皮风味在不同饮料形式中的表现如何
The same green marker load reads completely differently across beverage formats, because the matrix changes both the release of volatiles and the consumer's expectation. Understanding the format is the first step in deciding how aggressively to suppress the rind family.
Clear still flavored water:最暴露的格式。没有糖块，没有碳酸化，也没有云彩可以隐藏。果皮的香气立即出现在鼻子上，几乎不可能用矩阵效应来掩盖。这些产品需要所有类别中最低的绿色标志限值。
Sweetened still drinks and lemonades:8-12% 的糖通过跨模式甜味抑制青味，柠檬水中的柑橘增添了一种竞争性的新鲜味道。然而，零糖版本的失败正是含糖版本成功的地方，这就是 OISE 方法很重要的原因。
Myth 1: "The rind taste comes from the seeds."种子对果汁中绿色挥发物的贡献很小。白色的外皮和苍白的内果肉层是C9绿色家族的载体。
Myth 2: "More flavor covers the rind note."Raising total flavor dosage raises the green markers in lockstep if they are part of the concentrate's skeleton. The fix is rebalancing the concentrate, not dosing it harder.
Myth 3: "Only cheap concentrates have rind problems."高品质天然西瓜浓缩汁可以携带来自果皮的挥发物，因为压榨和浓缩不会区分果肉和果皮组织。问题在于原材料和加工的功能，而不仅仅是价格等级。
Myth 4: "Sugar-free drinks just taste less sweet, so they taste greener."Partially true, but the mechanism matters: aroma-induced sweetness enhancement with watermelon's own VOCs can restore perceived sweetness in zero-sugar systems, directly suppressing the relative greenness.
Myth 5: "A trained panel is overkill for this."Untrained consumers detect the rind note only as a vague "off" impression, while trained panels score green/cucumber attributes precisely enough to track process changes and shelf-life drift. That precision is what makes the masking work measurable.
These myths matter commercially because they send R&D teams chasing the wrong fixes - higher dosage, different sweeteners, or supplier changes - when the actual lever is the C9 green balance of the flavor system itself.
Triangle or paired-preference tests对照市场基准，确认果皮味确实受到抑制，而不仅仅是减少。
Spec limits on the key green markers - for example, a maximum area ratio of (Z,Z)-3,6-nonadien-1-ol relative to beta-ionone - give procurement an objective acceptance criterion that survives supplier changes. A flavor house that cannot document this data is not ready to supply watermelon at commercial scale.
西瓜风味的感官评价：掩盖果皮的味道
抑制果皮味的配方策略
1. Rebalance the profile toward "juicy sweet"
The most reliable fix is architectural: build the flavor so the green C9 family is present but subordinated. Boost the fruity-floral elements that define ripe flesh - beta-ionone for perfumed sweetness, linalool and citronellol for floral juiciness, low levels of fruity esters for candy-like ripeness - and cap the C9 green compounds at barely-perceptible levels. The goal is a profile where "fresh cut" is implied by the juicy sweet character, not delivered by raw green aldehydes.
2. 掩蔽和跨模态调制
When a base cannot be cleaned up (for example, when natural watermelon juice concentrate with rind-derived volatiles is a label requirement), targeted masking is the next line of defense. Masking works through several mechanisms - competitive receptor binding, cross-modal aroma distraction, chemical complexation, and temporal modulation - and the right system depends on the exact off-note chemistry. A detailed methodology for identifying and neutralizing off-notes in food and beverage products is covered in our technical guide How to Fix Off-Notes in Food Products (Flavor Masking Solutions Guide).For rind notes specifically, sweet-associated aromas (vanilla, caramel, peach lactones) create cross-modal distraction that makes the same green intensity taste less aggressive, while carefully dosed citrus peel oils add a "fresh" dimension that reframes the greenness as intentional.
3.香气诱导的甜味增强
A 2025 study in Foods (Dai et al.) showed that seven volatile odor compounds naturally present in watermelon juice - ethyl acetate, ethyl propionate, octanal, (E,E)-2,4-hexadienal, (E)-2-octenal, methyl heptenone, and geranyl acetone - significantly increased the perceived sweetness of a 2.5% fructose solution, with the effect mediated through the sweet taste receptor T1R2. This is directly actionable: enriching a watermelon flavor with these specific VOCs lets formulators raise perceived sweetness and juiciness without adding sugar, which in turn suppresses the relative perception of green and rind notes in low-sugar and zero-sugar beverages.
The beverage matrix modulates how green the same flavor reads. Higher perceived sweetness suppresses greenness; typical watermelon RTDs run 8-12 Brix-equivalent sweetness. Acidity around pH 3.5-4.0 sharpens the profile and makes the drink taste fresher, but excessive acid can accentuate astringent green notes - so the sugar-acid balance must be tuned together. Carbonation helps by adding a clean, tingling freshness that distracts from residual greenness. Classic pairings do real work: lime (in watermelon-lime drinks), mint, or even a deliberate cucumber-lime framing repositions the green note as intentional "garden freshness" instead of a defect.
Beverage brands often assume that "natural" automatically means cleaner and more authentic, and that "nature-identical" means synthetic and therefore suspect. For watermelon, the reality is subtler. Natural watermelon flavor built exclusively from natural-source isolates can carry rind-derived C9 volatiles if the starting materials are pressed whole fruit, because those compounds are part of the fruit's own chemistry. A nature-identical watermelon flavor, built from purified aroma chemicals such as (Z)-6-nonenal, beta-ionone, and linalool, can actually be engineered to contain almost no cucumber-alcohol at all, because every input is specified at the molecular level.The practical guidance for procurement is to stop asking "natural or nature-identical?" as a binary quality question and instead ask three questions:
What is the green-marker profile?请求相对于果香花标记（β-紫罗兰酮、芳樟醇）的 (Z,Z)-3,6-nonadien-1-ol、(E,Z)-2,6-nonadienal 和己醛的 GC-MS 数据。
What does the sensory data say?询问关于绿色/黄瓜与多汁/甜味的描述性小组分数，以了解预期的形式和剂量。
What does the label need?If the target market requires "natural flavor" or WONF (with other natural flavors) positioning, choose a natural system with documented rind control; if the label allows "flavor" or "nature-identical", the formulator has a wider palette.
A GC-MS marker report显示绿色 C9 家族相对于 β-紫罗兰酮和果味酯的控制水平。
Dosage and use-level data适合您的目标应用（不含汽、碳酸、热灌装或高度酒精）。
Stability data根据您的 pH 值、巴氏灭菌方式和保质期目标。
Descriptive sensory panel results, not just "tastes like watermelon" claims.
Batch-to-batch consistency specifications，包括写入 COA 的绿色标记限制。
CUIGUAI's watermelon flavor concentrate is formulated with exactly this balance - juicy, floral-sweet watermelon character with the C9 green family held below perceptual annoyance - and is supplied with full analytical and stability documentation for beverage applications.
应用示例：味道干净的西瓜 RTD
250 mL 透明西瓜 RTD 的代表性起始配方（与您自己的供应商和流程进行验证和调整）：
Sucrose or sweetener system:9-10% 白利糖度当量（或零糖赤藓糖醇/甜叶菊混合物）。
Rind off-notes are not only a sensory nuisance; they are a measurable commercial risk. A watermelon beverage that consumers describe as "green" or "cucumber-like" pays three hidden costs. First, repeat purchase suffers: in soft-drink categories, a single disappointing first sip can cut repeat purchase intent by a wide margin, and the defect is exactly the kind that consumers remember by name. Second, rework and write-offs hit the P&L directly - a production run that fails sensory sign-off is reprocessed or destroyed at full cost, and reformulating a launched product costs far more than getting the flavor right before scale-up. Third, the brand's positioning takes damage: "watermelon" is a summer-occasion flavor associated with refreshment, and a green, bitter drink undermines the entire product promise.The cheapest moment to control the rind note is at supplier selection, because the green-marker balance of a concentrate is fixed at formulation. The second-cheapest moment is at prototype validation, where sensory and GC screening costs a few hours of lab time. The most expensive moments are every one after launch. For procurement teams, this argues for writing green-marker limits and panel scores into the flavor specification and the supplier's COA, exactly as you would specify Brix, acidity, or microbiological counts. A flavor house that refuses or cannot document these parameters is, in effect, asking you to accept the risk it has not measured.From a total-cost perspective, a premium watermelon flavor concentrate with documented rind control typically costs a few percent more per kilogram than a commodity alternative - but it is used at the same or lower dosage, eliminates sensory failure risk, and protects the consumer experience that drives the category. In our experience supporting beverage brands across Asia, Europe, and the Americas, that trade is almost always the right one.
结语
The rind taste in watermelon beverages is not a mystery and not inevitable. It is the C9 green family - led by (Z,Z)-3,6-nonadien-1-ol - leaking from rind, over-ripe fruit, aggressive processing, or poorly balanced concentrates into the finished drink. The winning approach is fourfold: control the raw material, screen every concentrate and finished batch for green markers with SPME-GC-MS, formulate with sweet juicy character and proven masking, and source from a flavor manufacturer that documents all of it. Done right, a watermelon beverage tastes the way the fruit smells on a hot day - sweet, watery, floral, and unmistakably watermelon.
