Domain: Healthcare — Nutrition & Dietetics
Target concept: Natural Antimicrobial (Tea Polyphenols)

Video generation prompt: At 25°C, two transparent glasses are placed side by side on a table. The glass on the left contains an appropriate amount of freshly squeezed grape juice, while the glass on the right contains an equal volume of the same grape juice. A sufficient amount of 0.15% tea polyphenol sodium solution is added to the glass on the right. The two glasses are continuously photographed for several days with the camera focused on the grape juice in both glasses.

Evaluation guide:
(i) Target concept: Tea polyphenols inhibit spoilage-related visual degradation (cloudiness and browning) in grape juice via antimicrobial and antioxidant mechanisms.
Minimum mechanism: Grape juice must be susceptible to endogenous enzymatic oxidation and/or microbial spoilage under ambient conditions; tea polyphenol sodium must be bioactive at the given concentration; spoilage must manifest as objectively observable, macroscopic optical changes (transparency loss, hue shift) without requiring magnification or chemical assay.
(ii)Storyline: Frame 1: Static wide shot showing two identical transparent glasses side-by-side on a tabletop, both filled with grape juice at equal volume. Frame 2: Close-up action showing tea polyphenol sodium solution delivered only to the right glass (e.g., dropper tip contacts the right glass rim). Frame 3–10: Sustained static shot capturing progressive divergence: the left glass's liquid becomes increasingly cloudy and browner; the right glass's liquid remains uniformly transparent and vividly purple-red. Perspective: fixed frontal viewpoint, full glass height in frame, no occlusion, consistent lighting. Visibility constraints: all critical states (clarity, color, liquid-glass interface) must be optically resolvable at native resolution without enhancement. Note on elapsed time: the 'several days' in the prompt describes the real-world timescale of spoilage, not something the short clip must depict literally (no calendar or day-counter is required); judge the sequence as a compressed progression toward the final contrast between the two glasses, scoring on the visible states shown across frames 1 through 10 rather than on whether the clip conveys that days have passed.

Manual:
Experimental Procedure
1. Place two identical transparent glasses side-by-side on a flat, well-lit tabletop.
2. Pour freshly squeezed grape juice into both glasses until volumes are visually equal.
3. Add 0.15% tea polyphenol sodium solution exclusively to the right glass.
4. Maintain fixed frontal camera focus on both glasses for continuous observation.
Observation of Experimental Phenomena
Over time, the left glass (untreated grape juice) develops visible cloudiness and progressive browning; the right glass (tea polyphenol–treated) remains clear and retains its original purple-red color.
Summary of Experimental Principles
Tea polyphenols act as natural antimicrobials and antioxidants, inhibiting microbial growth and oxidative browning in fruit juices.

Prompt Grounding rubric:
level_1: Fewer than two transparent glasses appear in the shot, or neither glass contains any liquid, or the liquid shown is clearly not grape juice (e.g., it is colorless or an unrelated food or drink), or the two glasses are never placed together on a common tabletop.
level_2: Two transparent glasses containing liquid are shown on a surface, but they are positioned far apart or on different surfaces rather than together; or only one glass contains grape juice while the other is empty; or the liquid in one or both glasses is a color inconsistent with grape juice (e.g., clear, orange, or bright red); or no dropper, pipette, or other dispensing implement ever appears near either glass.
level_3: Two transparent glasses stand next to each other on the same tabletop; both contain grape juice of matching purple-red color and roughly equal volume; a dispensing action occurs at some point, but it is unclear which glass received the tea polyphenol sodium solution (e.g., both glasses look identical afterward, or the dispenser's target is ambiguous).
level_4: Beyond level 3, the tea polyphenol sodium solution is visibly delivered only to the right-hand glass (e.g., a dropper or pipette tip touches or hovers only over the right glass's rim while dispensing), and the left-hand glass is never touched by the dispenser.
level_5: Further, the dispenser's path never crosses toward the left glass at any point, the dispensed solution is visually distinguishable as a discrete addition (e.g., a clear liquid entering from a labeled vial or measured dropper) rather than blending in as an indistinguishable part of the juice, and there is no ambiguity anywhere in the sequence about which glass received the additive.

Scientific and Causal Correctness rubric:
level_1: The two glasses look the same throughout the entire sequence, with no visible difference in clarity or color developing between them; or it is the right (tea-polyphenol-treated) glass that develops cloudiness or browning while the left one stays clear; or both glasses spoil to the same degree at the same time; or a color or clarity change appears before the solution is ever added.
level_2: A difference between the two glasses does appear, but its direction is inconsistent with an antimicrobial effect from the added solution (for example the right glass shows cloudiness, sediment, or browning appearing earlier or more severely than in the left glass), or what appears is a change not typical of juice spoilage, such as sudden solid formation, bubbling, or the liquid separating into layers.
level_3: By the end of the sequence, the left (untreated) glass has visibly turned cloudy or developed a uniform brownish tint compared to its starting appearance, while the right (treated) glass still looks clear and keeps its original color; the exact timing of when this divergence began is not evaluated, only the final contrast; no other unrelated change (e.g., foaming, crystal formation) appears in either glass.
level_4: Beyond level 3, the contrast is sustained rather than momentary: the right glass keeps its transparency and purple-red color for the full sequence with no partial clouding, while the left glass's cloudiness and browning increase steadily and never clear up or reverse; no stray particles appear in the right glass and no unexplained layering or condensation mismatch appears in either glass.
level_5: Further, the contrast between the two glasses is unmistakable: the right glass shows no haze and no shift away from its original hue anywhere in the liquid column; the left glass's cloudiness and browning are even throughout the liquid rather than patchy, with no odd green, yellow, or grey tint appearing; no glare, reflection, or blur hides the difference between the two glasses at any point; and the contrast is visible across the entire height of the liquid in both glasses, not only near the surface or the bottom.

Spatiotemporal Consistency rubric:
level_1: One of the two glasses disappears from the shot or appears in a new spot with no visible motion explaining the change; the liquid's height in either glass jumps up or down between frames with no pouring or spilling shown; the camera suddenly cuts to a different angle or spins; the room's lighting swings between much darker and much brighter with no visible cause; or either glass cracks, shatters, or vanishes outright.
level_2: The camera's framing shifts sideways or up and down between shots; the spacing between the two glasses widens or narrows over the sequence; the liquid surface in either glass flickers or ripples with no draft or disturbance shown; the shadows the glasses cast move even though the lighting looks unchanged; or background elements pop in and out of view.
level_3: The camera holds one fixed frontal angle; both glasses stay fully in frame and motionless on the tabletop for the whole sequence; the liquid surfaces in both glasses stay calm and undisturbed after the solution is added (no ripples or waves); the lighting stays even across both glasses without sudden shifts; and neither glass nor liquid shows any tearing, warping, or gap in its shape.
level_4: Beyond level 3, the tabletop's texture and color stay consistent throughout, the two glasses keep the exact same spacing and framing relative to each other and the camera, no jitter or shake affects either glass between frames, and the curve of each liquid surface and the visible thickness of the glass walls look the same from frame to frame.
level_5: Further, the dispensing motion (the solution entering the right glass) plays out smoothly with no stutter, freeze-frame, or jump cut, the liquid surfaces show no visible shimmer or vibration once they settle after the addition, the image stays in consistent focus with no hunting or breathing of the lens, and the edges of the liquid and glass never appear to slide, shear, or stretch out of place between frames.