###### Abstract  
Cold-pressed hempo oils are characterized by an intense color, which is undesirable when used directly. Therefore, research was undertaken on removing chlorophyll and carotenoids effectively. This publication presents the results of tests that verified the adsorption properties of seven bleaching earths (BE1-BE7) in two doses (2.5% and 5.0%) in the low-temperature bleaching process of hempo oils. These oils were obtained by cold and hot pressing of the seeds of three varieties of hemp (_Camabis sativa_ L.): Finola, Earlina 8 FC, and Secuieni Jubileu. The color change and the content of carotenoid and chlorophyll pigments in the bleached oils were verified using the colorimetric method (CIE-Lab). The BEs used had different abilities to reduce the content of natural dyes connected with oil decolorization. The conducted research allowed us to characterize the influence of BEs on the organoleptic properties of the tested oils. Hemp oil obtained from the Secuieni Jubileu CP and HP hemp variety should be bleached with unmodified magnesium bentonite at 2.5%. Unmodified attapuligite clay is not recommended for this variety, as it strongly adsorbs carotenoids from the oil.  
h emo; bleaching earth; Finola; Earlina 8 FC; Secuieni Jubileu; low-temperature bleaching; CIE-Lab; natural dyes +
Footnote †: journal:  
The European Union has no separate regulations containing quality standards for niche oils [17].  
The color of vegetable oils is determined by the carotenoid and chlorophyll pigments [18]. Excess chlorophyll pigments are responsible for faster oil oxidation, bitter taste, and dark green color [19]. Therefore, removing chlorophyll pigments by bleaching will positively affect the sensory properties and extend the shelf life of vegetable oils. This process involves the adsorption of undesirable substances by bleaching earth [20], silica gel [21] and activated carbon [22]. Bleaching earths are mineral clays of aluminum silicates, such as bentonite, attapulgite, or sepiolite [23; 24; 25]. Bleaching earths are activated chemically or physically to increase their sorption surface. Bentonite bleaching earths have good adsorption properties for dyes and other undesirable substances, so they are often used for purifying vegetable oils [26].  
An example of a niche oil is oil obtained by pressing hemp seeds (_Camabis sativa_ L.). Unrefined hemp oil is a rich source of vitamins, mineral salts, and phytosterols. This oil contains approximately 80% of polyunsaturated fatty acids, especially \(\alpha\)-linolenic acid (18:3; n-3) and linoleic acid (18:2; n-6). The ratio of n-6 to n-3 acids is 3:1, positively affecting health-promoting properties [27].  
Niche oils are produced on a small scale and are not refined. Their organoleptic parameters (i.e., color and taste) are intense, which limits their use. Of the four oil refining processes, bleaching is the process that is easy to apply in small-scale oil production. Therefore, verification of the effectiveness of the patented method (PL 232781 [28]) was conducted for this study. The type of absorbent is crucial; therefore, attapulgite clay, magnesium bentonite, and ketolite were used for the study because these BEs are dedicated to oil refining. The types of bleaching earths were selected based on consultation with their manufacturers. The test materials consisted of three vegetable oils pressed from selective hempseed varieties (Finola, Earlina 8 FC, Secuieni Jubileu). The literature continues to present research results on hemp oils from the selected varieties on an industrial scale. Therefore, this study aimed to check the effect of the low-temperature bleaching process on the content of natural pigments in hemp oils. It was achieved by verifying the following research hypothesis: Among the bleaching earth variants selected for the study, it is possible to find an adsorbent that will remove a significant amount of chlorophylls but leave carotenoids in the oil'.