## 3 Results and Discussion
### Characteristics of Puffed Chips
#### 3.3.2 Acrylamide Contamination of Puffed Chips  
The highest level of acrylamide was observed for chips fried in a medium with bees wax at a concentration of 5 g/L of oil. Products fried in rapeseed oil without additives and with 2.5 g of rice bran wax per liter of oil were contaminated at the same level by this toxic substance. For products such as romaine, according to Commission Regulation (EU) 2017/2158 of 20 November 2017, the level of AA should not exceed 750 ug/kg. An acrylamide content of 57-97 ug/kg indicates a low and acceptable level of acrylamide (Figure 4).  
The effect of waxes on the acrylamide development has not been studied yet. In our previous studies, we found that rice bran wax and beeswax may increase the formation of this compound. Many scientists have reported that one of the factors influencing the formation of AA is acrylic acid which is a product of triacylglycerols degradation. According to this theory, as a result of hydrolysis glycerol molecule being released, which undergoes chemical changes such as dehydration, leads to the development of acrolein and then oxidation. Acrylic acid with ammonia from protein degradation forms AA [36; 37]. Factors influencing the development of this substance are the heating medium, time, water activity of the fried product, pH and concentration of amino acids, and reducing sugars [37]. [PERSON] et al. [37] reported that increased acidity of oil, with an AV above 0.5, may decrease acrylamide formation. The addition of waxes in this study increased this parameter. However, the AV of the lipid fraction the first day after frying was the highest for BW0.5 with a value of 0.3 and it did not decrease the formation of AA. The mobility of acrylamide precursors is affected by the physical state of water adsorbed during thermal processing. In this context, the final AA content is expected to be influenced also by the moisture content (value of the monolayer) [38; 39]. However, in this study, samples fried in RO had the highest value of water activity and the lowest concentration of AA. The study of [PERSON] et al. [40] showed that higher heat transfer of frying medium may cause an increase in acrylamide development on the surface of products. Studies on the effect of oil oxidation on acrylamide development during frying have not confirmed such influence, even though  
Figure 4: The acrylamide (AA) content of puffed chips. a, b—indicates homogeneous groups determined by [PERSON]’s test (_p_-value \(<\) 0.05).  
Figure 3: Oil uptake of puffed chips. a, b, c—indicates homogeneous groups determined by [PERSON]’s test (_p_-value \(<\) 0.05).  
this process increases the level of AA precursors, carbonyl compounds. However, waxes are a mixture of monoesters and other substances. Refined rice bran wax consists of 99% monoesters and the remaining substances (resinous matter) are aliphatic aldehydes, fatty alcohols, and free fatty acids [41]. In the case of beeswax, the composition is more heterogenous, it contains 35% of monoesters, 17% di- and tresters, 14% hydrocarbons, 12% hydroxy mono- and polyesters, 12% free acids, and other substances [42]. This raises a theory that carbonyl compounds present in waxes, especially in beeswax, may play a role as precursors for AA development; however, this statement needs further investigation.