The oil and fat industry is a branch whose development is rapidly gaining momentum in the food industry of Ukraine. However, it is currently facing new challenges that require solutions at the expense of both increasing production volumes and finding new mechanisms for technological solutions. The purpose of the article is to establish the relationship between the appearance of rancidity in vegetable oils and the composition of the main oxidation products in them - hydroperoxides and aldehydes, that is, to find a way to predict the moment of rancidity of oils using the peroxide number and/or anisidine number. A tasting commission consisting of 10 people was formed to carry out the organoleptic evaluation of vegetable oils for the appearance of bitterness. A sensory panel with a scale of taste variation was developed to study the nuances of bitterness. Oil samples for the experiment were placed in transparent glass (Petri dish). The article examines the possibility of predicting the appearance of rancidity by the main indicators of oil oxidation – peroxide and anisidine numbers. During oxidation at 28°C and access to oxygen, the oils accumulated significant amounts of hydroperoxides (up to 160-180 mmol1/2O/kg), but there was no feeling of rancidity. It has been proven that the moment of deterioration of organoleptic indicators of oils can be predicted based on the kinetics of oil oxidation based on the data of anisidine numbers. The practical value of the research is to contribute to the transformation and improvement of the products of the oil and fat industry, including through awareness of the changes that occur in fats during their extraction, processing and storage | У статті досліджено можливість передбачення появи відчуття згіркнення за основними показниками окисненості олій – пероксидними та анізидиновими числами. Під час окиснення при 28°С та доступі кисню олії накопичували суттєві кількості гідропероксидів (до 160-180 ммоль1/2О/кг), однак не з’являлось відчуття згіркнення. Доведено, що по кінетиці окиснення олій за даними анізідинових чисел можливо передбачення моменту погіршення органолептичних показників олій