Edible oil deterioration level determination device, edible oil deterioration level determination system, edible oil deterioration level determination method, edible oil deterioration level determination program, edible oil deterioration level learning device, learned model for use in edible oil deterioration level determination, and edible oil exchange system

An edible oil deterioration level determination device configured for determining a deterioration level of edible oil used for deep-fry cooking performed to cook a deep-fried food, the edible oil deterioration level determination device comprising:

• an air bubble image extraction section configured to extract an air bubble image, which is an image of a portion of air bubbles formed due to the deep-fry cooking, from an oil surface image which is an image of a surface of the edible oil during the deep-fry cooking;
• a feature parameter calculation section configured to calculate a feature parameter, the feature parameter being a parameter characterizing deterioration of the edible oil, from the air bubble image extracted by the air bubble image extraction section, and the feature parameter including one or more feature parameters selected from an area ratio of the air bubble image relative to a total area of the oil surface image, a cumulative value of the area ratio of the air bubble image relative to the total area of the oil surface image, the number of air bubbles, disappearance speed of air bubbles, presence or absence of a stream of air bubbles, and difference between a color of the edible oil and a color of a region of the deep-fried food;
• a deterioration indicator estimation section configured to estimate a deterioration indicator of the edible oil based on the feature parameter calculated by the feature parameter calculation section;
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• a deterioration level determination section configured to determine the deterioration level of the edible oil based on the deterioration indicator estimated by the deterioration indicator estimation section.