# The Effect of Edible Coatings on Selected Physicochemical Properties of Cassava Chips
## 3 Results
### Moisture Loss and Fat Absorption
Figure 2: Fat absorption during cassava chip frying at different temperatures and times: The first column indicates the control sample (C), the second column indicates that pectin (P) was used, and the third column indicates that whey protein (WP) was used. Different letters indicate statistical differences (\(p<0.05\)) for the same frying time at different temperatures. In general, the analyses indicated that the cassava chip samples that were treated for a longer time in both the control and the whey protein coatings obtained higher percentages of oil and lower moisture contents (Figures 1 and 2). These results were similar to those reported by [PERSON] et al. (2017) in the immersion frying of tilapia slices and by [PERSON] et al. (2017) during the atmospheric frying of sweet potato slices coated with carboxymethyl cellulose (CMC), where longer processing times meant heat-treated matrices absorbed more oil. The edible coating containing 1% pectin retained the most moisture in the fried samples. In other words, the use of an edible coating retains moisture in fried foods. The coating can form barriers that prevent moisture loss and reduce fat absorption ([PERSON] et al., 2018). The net formed by the pectin edible coating prevented moisture from escaping, thus retaining a higher moisture content in coated samples than in uncoated ones (control) ([PERSON] et al., 2018). Table 4 shows the influence of the coating type and frying time and temperature on the oil absorption of the cassava chips. All factors had an influence on the oil absorption of the chips, which was corroborated by the multifactorial ANOVA analysis of variance. For the coating type, significant statistical differences (p < 0.05) were observed for oil absorption. The same behavior occurred for frying time and temperature, observing differences between chips coated with pectin and whey protein and the control. When analyzing the oil absorption at 60 s, no statistical differences were observed in the whey protein coated chips, but differences were observed in the pectin-coated chips at 180 \({}^{\circ}\)C and in the control at 140 \({}^{\circ}\)C (_p_ < 0.05) (Table 3). At 120 s, the most representative differences were evidenced in the control at all process temperatures; this was also observed at 180 s in the pectin-coated chips, the control, and the whey protein-coated chips at different temperatures. When analyzing coating type, the control and whey protein-coated chips presented 321% more oil content on average at 180 \({}^{\circ}\)C and 180 s than the pectin-coated chips (Figure 2). On the other hand, [PERSON] et al. (2018) investigated the influence of the use of edible coatings from three different hydrocolloids (pectin, whey protein, and soy protein isolate) during the frying of a pre-fried and frozen cassava product. They demonstrated that whey protein showed the best results with respect to fat absorption, with a 27% reduction for the mashed cassava product. The uncoated cassava chips contained the highest oil content, 52.36%. Like the coated cassava chips with a 1% pectin concentration, the oil content of the cassava chips was reduced to 22.31%. The cassava chips treated with a 3% pectin concentration solution had the best or lowest lipid content, 11.75%, where the reduction was up to 40% for the lipid content. This possibly occurred because, during water evaporation, the vapor pressure of water increases the moisture transfer, increasing the porosity of the coating and oil ingress. In addition, high temperatures modify the structure of the material, causing damage to the coating during frying. Also, [PERSON] and [PERSON] (2018) stated that chicken strips coated with 10% denatured whey protein isolate (DWPI) resulted in a surprising 30.68% reduction in fat absorption, as compared to a non-whey protein coating. The DWPI solution possibly dehydrated during the frying process to form a film on the outer surface of the coated chicken strips.