Domain: Engineering — Food and Bioprocess Engineering
Target concept: Lycopene Determination (Acetone Extraction - Spectrophotometric Method)

Video generation prompt: Weigh 5 grams of tomato homogenate into a beaker, add 10 mL of acetone for extraction. After filtration, transfer the filtrate into a cuvette and measure the absorbance at 503 nm using a spectrophotometer.

Evaluation guide:
(i) Target concept: Visual verification of lycopene extraction and quantification via standardized spectrophotometric workflow.
Minimum mechanism: Tomato homogenate must contain lycopene; acetone must solubilize it; filtration must remove insoluble matrix; filtrate must retain lycopene in solution; cuvette must hold clarified extract; spectrophotometer must be configured to 503 nm to detect lycopene-specific absorbance.
(ii)Storyline: Frame 1: Hand places dark red tomato homogenate into beaker (visible mass, no spillage). Frame 2: Clear acetone poured from labeled container into same beaker (liquid level rises, mixing begins). Frame 3: Mixture poured through funnel/filter into receiving flask (red liquid flows downward, no splashing). Frame 4: Orange-red filtrate drawn into pipette and dispensed into cuvette (full, bubble-free fill to calibration line). Frame 5: Cuvette inserted into spectrophotometer compartment; display lights up showing “503 nm” and a positive absorbance value, simultaneously visible and stable for ≥1 second. All steps occur from fixed frontal bench-level viewpoint; no camera movement; all critical actions fully visible and unoccluded.

Manual:
Experimental Procedure
1. Weigh 5 g tomato homogenate into a beaker.
2. Add 10 mL acetone to the beaker.
3. Filter the mixture.
4. Transfer filtrate into a cuvette.
5. Insert cuvette into spectrophotometer and measure absorbance at 503 nm.
Observation of Experimental Phenomena
- Tomato homogenate is dark red and semi-viscous.
- Acetone is colorless and highly mobile.
- Filtrate is transparent with distinct orange-red color.
- Spectrophotometer displays a positive absorbance value at 503 nm.
Summary of Experimental Principles
Lycopene is lipid-soluble and extracted by acetone; its concentration is quantified via absorbance at 503 nm using Beer-Lambert law.

Prompt Grounding rubric:
level_1: No visible weighing of tomato homogenate, no beaker, no acetone container, no funnel/filter setup, no cuvette, and no spectrophotometer appear in frame; or these items appear only in a scene unrelated to preparing and reading a lycopene extract (e.g., unrelated glassware being rinsed, or a pouring demo with no connection to weighing, extraction, filtration, or absorbance measurement).
level_2: A beaker or a cuvette appears along with some pouring action, but the five-stage procedure is clearly incomplete: the homogenate is never shown being weighed before it goes into the beaker, or acetone is never added to that beaker, or there is no funnel-and-filter-paper step, or the filtrate is never moved into a cuvette, or the cuvette never appears inside a spectrophotometer; several of these stages are missing or shown out of order.
level_3: All five stages appear in the correct order (homogenate weighed into a beaker, acetone added to that same beaker, the mixture filtered, the filtrate moved into a cuvette, and the cuvette placed into a spectrophotometer), but at least one piece of equipment is the wrong type or shape for its role (e.g., an Erlenmeyer flask stands in for the beaker, or the cuvette appears as a round test tube instead of a rectangular cell), or a shown quantity is clearly inconsistent with the stated amounts (e.g., the acetone poured looks like a single capful rather than roughly 10 mL).
level_4: All five stages appear in order using correctly shaped, recognizable equipment: a cylindrical graduated beaker for the homogenate and acetone, a funnel-and-filter-paper setup feeding a separate receiving flask, a rectangular cuvette for the filtrate, and a bench spectrophotometer with a sample compartment; each transfer is spatially correct (filtrate runs from the funnel into the receiving flask rather than missing it; the cuvette sits fully seated inside the compartment rather than resting beside it); no piece of equipment switches to the wrong type partway through the sequence.
level_5: Everything described for score 4 holds, and in addition the same individual beaker, the same cuvette, and the same spectrophotometer model are recognizable (same size, color, and markings) from their first appearance to their last; no unexplained extra glassware or object appears mid-sequence that wasn't part of the five stages; every hand action is aimed unambiguously at its target: homogenate goes into the beaker rather than beside it, the pipette dispenses filtrate into the cuvette rather than over its rim.

Scientific and Causal Correctness rubric:
level_1: No scientifically plausible extraction is shown: the tomato homogenate looks brown, black, or dry rather than the moist dark-red paste that contains lycopene; the acetone appears colored or thick rather than clear and thin; the filtrate that reaches the cuvette is cloudy or entirely colorless; the cuvette holds air or a solid rather than liquid; the spectrophotometer display stays blank or shows a reading unconnected to the preceding steps (e.g., a wavelength nowhere near 503 nm with no filtrate ever loaded).
level_2: One expected feature is present (e.g., the homogenate is a plausible dark red) but the causal chain breaks elsewhere: the filtrate stays colorless or cloudy despite coming from a red homogenate, or a cuvette is inserted into the spectrophotometer but no absorbance value ever appears, or acetone is added with no visible color change or mixing beginning, or the filtration step appears without any prior acetone addition, leaving the red filtrate with no visible origin.
level_3: The filtrate that reaches the cuvette is transparent and shows a genuine orange-red tint, visibly lighter and clearer than the thick, darker homogenate it came from, consistent with the pigment being diluted into about 10 mL of acetone and cleared of solid matter by filtration; the spectrophotometer shows some positive absorbance reading while the cuvette sits inside it; however, either the filtrate's color reads closer to pale yellow than orange-red, or the reading appears before the cuvette is actually seated, or there is no visible sign that the instrument is set to 503 nm.
level_4: The filtrate is clearly transparent, with no cloudiness or particles, and shows a distinct orange-red hue that reads as a diluted lycopene solution, visibly different from both the opaque dark-red homogenate and from a colorless liquid; the display shows a non-zero absorbance value together with a visible 503 nm wavelength indication (digital readout, dial position, or an illuminated 503 nm setting); the sequence of color changes stays causally consistent throughout (red homogenate, acetone added, mixture filtered, clear orange-red filtrate collected, cuvette filled, reading taken), with no unexplained fading, darkening, or precipitate forming along the way.
level_5: Everything described for score 4 holds, and in addition the 503 nm wavelength indication and the positive absorbance value are shown together only while the cuvette is fully seated in the compartment, never appearing before insertion or lingering after removal; the filtrate shows no implausible secondary tint (no green, blue, or brown cast) and does not turn cloudy or separate into layers between the transfer step and the reading step; the color progression stays coherent with a diluted lycopene-in-acetone solution rather than drifting back toward the appearance of the original homogenate.

Spatiotemporal Consistency rubric:
level_1: Severe breaks make the five-stage sequence physically incoherent: the beaker teleports instantaneously from the bench into the hand with no motion in between; the beaker already holds the acetone-homogenate mixture the first time it appears, with no weighing motion shown at all beforehand; the filtrate is shown running backward, up out of the receiving flask and into the funnel; the filter paper appears torn apart in one shot and fully intact again in the next; the cuvette's apparent size changes by roughly half between the pipetting shot and the measurement shot; or the bench lighting's direction changes abruptly between consecutive shots with no light source shown moving.
level_2: Multiple moderate mismatches interrupt the workflow: the beaker enters frame already containing the homogenate, skipping the weighing step; the acetone bottle's label is never turned toward camera even though the story calls for a labeled container; the filtrate appears to reach a bubble-free fill in the cuvette before any pipetting motion is actually shown; the spectrophotometer's compartment is shown opening and closing without the cuvette's insertion itself ever appearing on screen; the brightness on the bench changes noticeably between the extraction and filtration shots with no visible cause.
level_3: The beaker, funnel stand, cuvette, and spectrophotometer keep a steady size and stay lit from one consistent direction across the sequence; the homogenate is weighed, the acetone is poured, the filtration flows downward into the receiving flask, and the filtrate is transferred and measured without any stage being skipped; still, one minor continuity slip remains: for example, the liquid level in the beaker changes between the filtration and transfer shots in a way the visible pour doesn't fully account for, or the compartment door is shown open while the experimenter's hand partly hides the cuvette going in, leaving the exact moment of seating ambiguous.
level_4: Every hand action (weighing, pouring, filtering, pipetting, and inserting the cuvette) reads as one continuous, physically ordinary motion with no unnatural jump or floating limb; the beaker, filter stand, and spectrophotometer each stay in the same bench position across the whole sequence, and the lighting direction and camera framing hold steady from the first weighing shot to the final reading; the moment the filtrate leaves the funnel matches the moment it appears entering the cuvette, and no hand blocks the exact instant the cuvette seats in the compartment.
level_5: Everything described for score 4 holds, and in addition each stage-to-stage transition plays out as a complete, uninterrupted motion rather than skipping partway through: the pour, the downward filtration flow, the pipetting, and the cuvette insertion each show a full start-to-finish action; the acetone's clear thin liquid and the homogenate's thicker, particulate paste both keep a texture and appearance consistent with their respective materials throughout; the wavelength indication and absorbance value on the spectrophotometer display stay clearly readable to an ordinary viewer for as long as the cuvette remains seated, never turning into an illegible blur or getting cut off mid-shot.