Tekin-Cakmak Zeynep Hazal, Atik Ilker, Karasu Salih
Faculty of Chemical and Metallurgical Engineering, Department of Food Engineering, Davutpasa Campus, Yildiz Technical University, Istanbul 34349, Turkey.
Food Technology Program, Afyon Vocational School, Afyon Kocatepe University, Afyonkarahisar 03200, Turkey.
Foods. 2021 Nov 10;10(11):2759. doi: 10.3390/foods10112759.
The cold-pressed pumpkin seed oil by-product (POB) was evaluated for its application as a natural fat substitute and stabilizer in the reduced-fat salad dressings. For this aim, the samples were prepared by combining the xanthan gum (0.2-0.4 g/100 g), POB (1.0-5.0 g/100 g), egg yolk powder (3 g/100 g), and sunflower oil (10-30 g/100 g) in 17 different formulations. The optimization was carried out using response surface methodology (RSM) and full factorial central composite design (CCD). Results showed that all samples presented the shear-thinning (or pseudoplastic) flow behavior with 3.75-16.11 Pa·s and 0.18-0.30, K and n values, respectively. The flow behavior rheological data were fitted to a power-law model (R > 0.99). The samples with high POB and low oil content showed similar K and n values compared to high oil content samples. Additionally, the dynamic rheological properties and three interval thixotropic test (3-ITT) were determined. The G' value was larger than G″ in all frequency ranges, indicating viscoelastic solid characteristics in all samples. The optimum formulation was determined as 0.384% XG, 10% oil, and 3.04% POB. The samples prepared with the optimum formulation (POBLF-SD) were compared to low-fat (LF-SD), and high-fat (HF-SD) control salad dressing samples based on the rheological properties, emulsion stability, oxidative stability, zeta potential, and particle size. The oxidation kinetic parameters namely, IP, E, ΔS, and ΔG showed that the oxidative stability of salad dressing samples could be improved by enriched by POB. The results of the present study demonstrated that POB could be considerably utilized as a natural fat substitute and stabilizer in salad dressing type emulsions.
对冷榨南瓜籽油副产品（POB）作为低脂沙拉酱中的天然脂肪替代品和稳定剂的应用进行了评估。为此，通过将黄原胶（0.2 - 0.4 g/100 g）、POB（1.0 - 5.0 g/100 g）、蛋黄粉（3 g/100 g）和向日葵油（10 - 30 g/100 g）以17种不同配方组合来制备样品。使用响应面法（RSM）和全因子中心复合设计（CCD）进行优化。结果表明，所有样品均呈现剪切变稀（或假塑性）流动行为，K值和n值分别为3.75 - 16.11 Pa·s和0.18 - 0.30。流动行为流变学数据符合幂律模型（R > 0.99）。与高油含量样品相比，高POB和低油含量的样品显示出相似的K值和n值。此外，还测定了动态流变学特性和三区间触变测试（3 - ITT）。在所有频率范围内，G'值均大于G″，表明所有样品均具有粘弹性固体特性。确定最佳配方为0.384% XG、10%油和3.04% POB。基于流变学特性、乳液稳定性、氧化稳定性、zeta电位和粒径，将用最佳配方制备的样品（POBLF - SD）与低脂（LF - SD）和高脂（HF - SD）对照沙拉酱样品进行比较。氧化动力学参数，即IP、E、ΔS和ΔG表明，通过添加POB可以提高沙拉酱样品的氧化稳定性。本研究结果表明，POB可大量用作沙拉酱型乳液中的天然脂肪替代品和稳定剂。
