Effect of Palm Oil-Carnauba Wax Oleogel That Processed with Ultrasonication on the Physicochemical Properties of Salted Duck Egg White Fortified Instant Noodles

Abstract

The present study permutes edible palm oil (PO) into oleogel by incorporating carnauba wax (CW) at two different concentrations (5 g/100 g and 10 g/100 g, w/w) and processing using ultrasonication. The prepared oleogels (OG1: PO-CW (5 g/100 g); OG2: PO-CW (10 g/100 g); and OGU1: PO-CW (5 g/100 g) with ultrasonication, and OGU2: PO-CW (10 g/100 g) with ultrasonication) were compared with PO (control) to deep fry salted duck egg white (SDEW) fortified instant noodles. The impact of different frying mediums on the physicochemical properties of SDEW noodles was investigated. SDEW instant noodles that were fried using OGU and OG samples had a higher L* and b* but lower a* values than those that were fried in PO (p < 0.05). Among the oleogel-fried samples, noodles that were fried in OGU2 and OG2 effectively lowered the oil uptake and showed better cooking properties than OGU1- and OG1-fried noodles, respectively (p < 0.05). Textural attributes such as higher hardness, firmness, chewiness, tensile strength and elasticity, and lower stickiness were noticed in the samples that were fried in OGU, followed by OG and PO (p < 0.05). Scanning electron microstructure revealed a uniform and smoother surface of noodles fried in OGU and OG, whereas the PO-fried sample showed an uneven and rough surface with more bulges. Noodles were tested for fatty acid compositions, and the results found that oleogel-fried noodles retained more unsaturated fatty acids than the control (p < 0.05). During storage of the frying medium after frying the noodles, OGU and OG had higher oxidative stability with lower TBARS, PV, p-AnV, and Totox values than PO at room temperature for 12 days. Overall, using oleogel as frying media improved the physicochemical and nutritional properties of SDEW noodles. This finding could be beneficial for food industries to produce healthy fried food products for consumers.

Keywords: Chaiya; carnauba wax; instant noodles; microstructure; oleogel; palm oil; physicochemical properties; salted duck egg white; storage stability; ultrasonication.

Figure 1

Color characteristics (L* (A), a* (B), b* (C) and ΔE* (D)) of palm oil, palm oil–carnauba wax oleogel and palm oil–carnauba wax oleogel with ultrasonication treatments. Note: PO represents palm oil; OG1 represents palm oil–carnauba wax (5 g/100 g); OG2 represents palm oil–carnauba wax (10 g/100 g); OGU1 represents palm oil–carnauba wax (5 g/100 g) homogenized with ultrasonication; and OGU2 represents palm oil–carnauba wax (10 g/100 g) homogenized with ultrasonication. The different alphabets (a–e) in the figures indicate significant differences.

Figure 2

Cooking properties (oil uptake (A), cooking yield (B) and optimum cooking time (C)) of palm oil, palm oil–carnauba wax oleogel and palm oil–carnauba wax oleogel with ultrasonication treatments. Note: PO represents palm oil; OG1 represents palm oil–carnauba wax (5 g/100 g); OG2 represents palm oil–carnauba wax (10 g/100 g); OGU1 represents palm oil–carnauba wax (5 g/100 g) homogenized with ultrasonication; and OGU2 represents palm oil–carnauba wax (10 g/100 g) homogenized with ultrasonication. The different alphabets (a–e, bc) in the figures indicate significant differences.

Figure 3

Textural profile (hardness (A), firmness (B), chewiness (C), stickiness (D), tensile strength (E) and elasticity (F)) of palm oil, palm oil–carnauba wax oleogel and palm oil–carnauba wax oleogel with ultrasonication treatments. Note: PO represents palm oil; OG1 represents palm oil–carnauba wax (5 g/100 g); OG2 represents palm oil–carnauba wax (10 g/100 g); OGU1 represents palm oil–carnauba wax (5 g/100 g) homogenized with ultrasonication; and OGU2 represents palm oil–carnauba wax (10 g/100 g) homogenized with ultrasonication. The different alphabets (a–e, ab) in the figures indicate significant differences.

Figure 4

Microstructural observation of the surface of SDEW instant noodles that are fried using palm oil, palm oil–carnauba wax oleogel and palm oil–carnauba wax oleogel with ultrasonication treatments. Note: PO represents palm oil; OG1 represents palm oil–carnauba wax (5 g/100 g); OG2 represents palm oil–carnauba wax (10 g/100 g); OGU1 represents palm oil–carnauba wax (5 g/100 g) homogenized with ultrasonication; and OGU2 represents palm oil–carnauba wax (10 g/100 g) homogenized with ultrasonication.

Figure 5

Fatty acid profile (A–I) of the surface of SDEW instant noodles that are fried using palm oil, palm oil–carnauba wax oleogel and palm oil–carnauba wax oleogel with ultrasonication treatments. Note: PO represents palm oil; OG1 represents palm oil–carnauba wax (5 g/100 g); OG2 represents palm oil–carnauba wax (10 g/100 g); OGU1 represents palm oil–carnauba wax (5 g/100 g) homogenized with ultrasonication; and OGU2 represents palm oil–carnauba wax (10 g/100 g) homogenized with ultrasonication. The different alphabets (a–e, ab, cd) in the figures indicate significant differences.

Figure 6

Cumulative level of saturated and polyunsaturated fatty acid content in the surface of SDEW instant noodles that are fried using palm oil, palm oil–carnauba wax oleogel and palm oil–carnauba wax oleogel with ultrasonication treatments. Note: PO represents palm oil; OG1 represents palm oil–carnauba wax (5 g/100 g); OG2 represents palm oil–carnauba wax (10 g/100 g); OGU1 represents palm oil–carnauba wax (5 g/100 g) homogenized with ultrasonication; and OGU2 represents palm oil–carnauba wax (10 g/100 g) homogenized with ultrasonication. The different alphabets (a–c, bc) in the figures indicate significant differences.

Figure 7

Changes in lipid oxidation (peroxide value (A), TBARS (B), p-AnV (C) and totox value (D)) during storage at ambient temperature in the different frying mediums that fried SDEW instant noodles. Note: PO represents palm oil; OG1 represents palm oil–carnauba wax (5 g/100 g); OG2 represents palm oil–carnauba wax (10 g/100 g); OGU1 represents palm oil–carnauba wax (5 g/100 g) homogenized with ultrasonication; and OGU2 represents palm oil–carnauba wax (10 g/100 g) homogenized with ultrasonication. The different alphabets (a–e) in the figures indicate significant differences.

Figure 8

Pictorial reference of the preparation of the palm oil–carnauba wax oleogels and the ultrasonication assisted oleogels.