# Evaluation of Hazelnut Cake Flour for Use as a Milk Powder Replacer in Ice Cream
## 3 Results and Discussion
### Physicochemical Properties of Ice cream mixtures  
The chemical composition results for the ice cream mixtures are detailed in Table 2. It can be observed that samples with higher levels of SMP replacement had elevated (\(p<0.05\)) values for total fat content, between 11.22 and 12.19%, compared to the control sample (10.89%). The increase in the ice creams' fat content due to hazelnut addition confirms the results reported by [PERSON] et al. [42]. Furthermore, [PERSON] [23] showed that the incorporation of hazelnut milk into kefir results in a higher fat content. This was expected since the determined fat content in HPCF was much higher (27.91% d.m.) than those declared for the SMP (maximum 1.5%). According to [PERSON] et al. [43], fat is a predominant component in analyzed hazelnuts and it is known that a certain amount of fat remains in press cake during the cold pressing [10]. The total solids content remained unchanged, but the MSNF, protein, and carbohydrate content significantly (\(p<0.05\)) decreased as the HPCF concentration increased. The total solid content of the samples was found to be about 38% which complies with the data available in the literature [1]. Total solids content is an important factor for achieving the desired consistency properties of ice cream [44]. A protein content of about 4% is usually found in ice cream samples [45; 46]. [PERSON] et al. [44] stated that ice cream's protein and carbohydrate content were 4.27% and 19.19%, respectively. It can be seen that the replacement of SMP with HPCF leads to an increase in titratable acidity, from 0.146% for the control sample to 0.169% for the sample with total replacement. Additionally, results showed that the pH values of samples ranged between 6.658 (control sample) and 6.599 (HN4) and these values are consistent with the pH values of ice cream samples reported by other authors [46; 47; 48]. Such a trend, i.e., decreasing the pH value with an increase in HPCF concentration, may be attributed to chemical structure and acid compounds in hazelnuts [42], referring to a high content of monounsaturated fatty acids [43; 49]. Similar results were observed in a study where hazelnut milk was incorporated into ice cream as a cow milk replacer [42] and in a study where hazelnut flour and skin were added to vanilla ice cream [47]. On the other hand, [PERSON] et al. [50] fortified yoghurt with hazelnut skin and observed that such fortification caused an increase in pH values. [PERSON] [23] explained the rise in pH value in kefir samples where cow milk was partially replaced with hazelnut milk as the consequence of the increased buffering capacity and limited availability of lactose and other compounds important for microorganism growth. The maximum \(\mathrm{a_{w}}\) value was measured in sample HN4 (0.957) and the minimum in the control sample (0.945), which implies that SMP replacement contributes to higher \(\mathrm{a_{w}}\) values. The replacement of SMP with HPCF leads to a lower protein content and a higher fat content, which is less effective at binding water compared to proteins. This substitution also alters the protein profile, and plant-based proteins do not possess the same functional attributes as milk proteins [51]. This can ultimately result in greater availability of free water within the ice cream mixture. Similarly, in our previous research, it was noted that the substitution of skim milk powder with hemp press cake at a level of 50% increased the \(\mathrm{a_{w}}\) values, from 0.946 to 0.950 [52].