Mustafa Öğütcü

Characterization of Hazelnut Oil Oleogels Prepared with Sunflower and Carnauba Waxes

In this study, hazelnut oil oleogels prepared with sunflower wax and carnauba wax were analyzed and compared with a commercial shortening. Oil binding capacities of sunflower wax oleogels were higher than 99%, while carnauba wax had a maximum value of 97.6% for 10% addition level. At 3% addition level of carnauba wax, no gel developed. The crystal formation time of sunflower wax was shorter. Although the highest (8.5%) solid fat content was observed in the 10% carnauba wax containing oleogel (HC10) sample, it was 30.4% in the commercial shortening sample at 20°C. The peak melting temperature of commercial shortening was 52.3°C, and among all organogels, sunflower wax oleogel at 3% addition level had the closest value (58.4°C). The melting enthalpies of the oleogels ranged from 4.3 to 20.3 J/g, while it was 10.9 J/g for the commercial shortening sample. The firmness and stickiness values in the oleogel samples were lower than that of commercial shortening sample. On the other hand, there was no significant change of firmness and stickiness during storage, indicating good stability (p ≤ 0.001). Especially the sunflower wax oleogels were very homogenous and smooth in structure. The polarized light microscopy pictures revealed needle-like crystals for sunflower wax and aggregate-like crystals for carnauba wax oleogels. The x-ray diffraction measurements of the crystals showed the β´ types of the polymorphic structures. Furthermore, the oleogels were very stable against oxidation during the storage period. Hazelnut oil organogels prepared with sunflower wax can be good source material for shortening or margarine-like products.

Oleogels as spreadable fat and butter alternatives: sensory description and consumer perception

Table spreads are one of the fundamental ingredients of human diets. Generally, butter and margarine are the most preferred spread products among others. Moreover, these products have some disadvantages such as high saturated fatty acids contents and the presence of trans fatty acids. In this study, virgin olive oil and hazelnut oil oleogels were prepared with beeswax and sunflower wax, while the hazelnut oil oleogels were aromatized with diacetyl. For the reason stated above, the first purpose of this study was to test the sensory properties and consumer acceptance of virgin olive oil when prepared as a spreadable fat in oleogel form. The second purpose was to determine how the hazelnut oil oleogels would be received as a butter alternative by the sensory and consumer tests as well. The results revealed that both types of oleogels are structurally and thermally suitable as alternative products. For the first time in the literature, these oleogels were described by a panel with thirteen sensory definition terms (hardness, spreadability, liquefaction, grassy, milky, rancid, fatty, sweet, salty, waxy, grittiness, cooling and mouth coating). Hedonic attributes (appearance, odor, flavor, spreadability) tested by the consumers proved that these oleogel products have potential as spread and/or butter alternatives. In the consumer survey study, one of the striking results indicated that more than 50% of the consumers would buy or try once, then decide to buy the oleogel products. In conclusion, these oleogels can be used as spreads or butter alternatives.