Impact of Carnauba Wax–Structured Olive Oil Oleogels Enriched with Thyme Essential Oil on the Physicochemical, Rheological, and Textural Properties of Biscuits

Öz

This study investigated the effects of using olive oil-based oleogels as an alternative to traditional solid fats in biscuit formulations on their physicochemical, rheological and textural properties. The fat content in the biscuit formulations was standardised to 24 per cent, and all production conditions were kept constant to ensure comparability between samples. The oleogels developed were characterised using oscillatory rheological measurements; the textural properties of the biscuit doughs were determined by Texture Profile Analysis (TPA); and the relationships between the variables were evaluated using Principal Component Analysis (PCA). Furthermore, the baked biscuits were evaluated using Principal Component Analysis (PCA) in terms of physicochemical and textural change parameters, such as water activity (aw) and moisture content, over a 14-day storage period. In the rheological analyses, it was determined that the storage modulus (G′) was higher than the loss modulus (G″) across the entire frequency range under investigation, thereby demonstrating that solid-like viscoelastic behaviour predominated in all structured systems. An increase in CW concentration systematically raised the values of G′, G″ and complex viscosity, leading to the formation of denser, mechanically stronger and more deformation-resistant lipid networks. In all samples, the decrease in complex viscosity with increasing angular frequency demonstrated the shear-thinning behaviour characteristic of structured lipid systems. TPA results revealed that all textural parameters examined were significantly influenced by the formulation. The CW10K05 sample stood out with the highest values for hardness, gumminess and chewability, whilst VOO-based samples exhibited the lowest structural strength. PCA results, the first two principal components explained 87.8 per cent of the total variance. PC1 explained 70.1 per cent of the total variance and was found to be primarily related to hardness, gumminess, chewability, cohesion and resilience, whilst PC2 explained 17.7 per cent of the variance and was mainly related to the flexibility parameter. During storage, water activity increased from a range of approximately 0.12–0.159 on day 1 to a range of 0.411–0.438 on day 14, indicating a significant gain in moisture. Changes in moisture content were also observed, depending on the formulation. Although the hardness of the biscuits generally decreased with storage, CW10K05 retained the highest hardness value on day 14. The brittleness values, which initially differed between formulations, became statistically similar by the end of storage. Whilst oleogels formulated with CW improve dough strength and product texture, the control of moisture transfer during storage is of critical importance for maintaining product quality.

Anahtar Kelimeler

• Oleogel
• Olive oil
• Trans fat
• Carnauba wax
• Biscuit

Destekleyen Kurum

Afyon Kocatepe University Scientific Research Coordination Office

Proje Numarası

24.FEN.BİL.04.

Etik Beyan

There is no need to obtain permission from the ethics committee for this study.

Teşekkür

This article is produced as part of a project supported by the Afyon Kocatepe University Scientific Research Coordination Office (No: BAP 24 FEN BİL 04). We thank the Afyon Kocatepe University Scientific Research Projects Coordination Unit for their support. The authors also thank the Yıldız Technical University Food Engineering Department (Dr. Assistant Professor Muhammed Özgölet and Asma Ali) for providing technical support in the realization of this study, and Mehmet Şahin (Agric. Eng M Sci.), Bahri Dağdaş International Agricultural Research Institute - Konya) for his assistance in statistical and chemometric analyses.

Karnauba Mumu ile Yapılandırılmış Zeytinyağı Bazlı Oleojellere Kekik Uçucu Yağı İlavesinin Bisküvilerin Fizikokimyasal, Reolojik ve Tekstürel Özellikleri Üzerine Etkisi

Öz

Bu çalışma, geleneksel katı yağlara alternatif olarak zeytinyağı bazlı oleojellerin bisküvi formülasyonlarında kullanımının fizikokimyasal, reolojik ve tekstürel özellikler üzerindeki etkilerini incelemiştir. Bisküvi formülasyonlarında yağ oranı %24 olacak şekilde standardizasyon sağlanmış ve örnekler arasındaki karşılaştırılabilirliği korumak amacıyla tüm üretim koşulları sabit tutulmuştur. Geliştirilen oleojeller osilasyonlu reolojik ölçümlerle karakterize edilmiş, bisküvi hamurlarının tekstürel özellikleri Tekstür Profil Analizi (TPA) ile belirlenmiş ve değişkenler arasındaki ilişkiler Temel Bileşenler Analizi (PCA) kullanılarak değerlendirilmiştir. Ayrıca pişirilmiş bisküvilerin temel bileşenler analizi (PCA) ile 14 günlük depolama süresindeki su aktivitesi (aw) ve nem içeriği gibi fizikokimyasal ve tekstürel değişim parametreleri açısından değerlendirilmiştir. Reolojik analizlerde, incelenen frekans aralığının tamamında depolama modülünün (G′) kayıp modülünden (G″) yüksek olduğu belirlenmiş ve böylece tüm yapılandırılmış sistemlerde katı benzeri viskoelastik davranışın baskın olduğu ortaya konulmuştur. CW konsantrasyonundaki artış G′, G″ ve kompleks viskozite değerlerini sistematik olarak yükselterek daha yoğun, mekanik olarak daha güçlü ve deformasyona daha dirençli lipid ağlarının oluşmasını sağlamıştır. Tüm örneklerde açısal frekans arttıkça kompleks viskozitenin azalması, yapılandırılmış lipid sistemlerine özgü kayma incelmesi davranışını göstermiştir. TPA sonuçları, incelenen tüm tekstürel parametrelerin formülasyondan anlamlı düzeyde etkilendiğini ortaya koymuştur. CW10K05 örneği en yüksek sertlik, sakızımsılık ve çiğnenebilirlik değerleriyle öne çıkarken, VOO bazlı örnekler en düşük yapısal dayanımı göstermiştir. PCA sonuçlarında ilk iki temel bileşen toplam varyansın %87,8’ini açıklamıştır. PC1 toplam varyansın %70,1’ini açıklayarak başlıca sertlik, sakızımsılık, çiğnenebilirlik, kohezyon ve rezilyans ile ilişkili bulunurken, PC2 %17,7’lik varyansı açıklamış ve esas olarak esneklik parametresiyle ilişkili olmuştur. Depolama süresince su aktivitesi 1. günde yaklaşık 0,12–0,159 aralığından 14. günde 0,411–0,438 aralığına yükselerek belirgin nem kazanımını göstermiştir. Nem içeriğinde de formülasyona bağlı değişimler belirlenmiştir. Bisküvilerin sertliği depolama ile genel olarak azalmasına rağmen CW10K05, 14. günde en yüksek sertlik değerini korumuştur. Başlangıçta formülasyonlar arasında farklılık gösteren kırılganlık değerleri depolama sonunda istatistiksel olarak benzer hale gelmiştir. CW ile yapılandırılmış oleojeller hamur dayanımı ve ürün dokusunu iyileştirmekle birlikte, depolama sırasında nem transferinin kontrolü ürün kalitesinin korunması açısından kritik öneme sahiptir.

Anahtar Kelimeler

• Oleojel
• Zeytinyağı
• Trans yağ
• Karnauba mumu
• Bisküvi

Destekleyen Kurum

Afyon Kocatepe University Scientific Research Coordination Office

Proje Numarası

24.FEN.BİL.04.

Etik Beyan

There is no need to obtain permission from the ethics committee for this study.

Teşekkür

This article is produced as part of a project supported by the Afyon Kocatepe University Scientific Research Coordination Office (No: BAP 24 FEN BİL 04). We thank the Afyon Kocatepe University Scientific Research Projects Coordination Unit for their support. The authors also thank the Yıldız Technical University Food Engineering Department (Dr. Assistant Professor Muhammed Özgölet and Asma Ali) for providing technical support in the realization of this study, and Mehmet Şahin (Agric. Eng M Sci.), Bahri Dağdaş International Agricultural Research Institute - Konya) for his assistance in statistical and chemometric analyses.

Kaynakça

1. Alizadeh, L., Abdolmaleki, K., Nayebzadeh, K. and Bahmaei, M. (2019). Characterization of sodium-caseinate/hydroxypropyl-methylcellulose concentrated emulsions: Effect of mixing ratio, concentration and wax addition. International Journal of Biological Macromolecules, 128: 796–803.
2. Berry, S. E., Bruce, J. H., Steenson, S., Stanner, S., Buttriss, J. L., Spiro, A. et al. (2019). Interesterified fats: What are they and why are they used? A briefing report from the Roundtable on Interesterified Fats in Foods. Nutrition Bulletin, 44(4): 363–380.
3. Brykczynski, H., Hetzer, B. and Flöter, E. (2022). An attempt to relate oleogel properties to wax-ester chemical structures. Gels, 8(9): 579.
4. Chen, H., Zhou, P., Song, C., Jin, G. and Wei, L. (2022). An approach to manufacturing heat-stable and bloom-resistant chocolate by the combination of oleogel and sweeteners. Journal of Food Engineering, 330, 111064.
5. Contreras‐Ramírez, J. I., Acosta‐Gurrola, E., Rosas‐Flores, W., Gallegos‐Infante, J. A. and Toro‐Vázquez, J. F. (2023). Microstructuring process in oleogels formulated with vegetable oils and monoglycerides: A comparison of non‐isothermal nucleation kinetics by spectrophotometric and DSC analysis. Journal of the American Oil Chemists' Society, 100(6): 449-458.
6. Contreras-Ramírez, J. I., Patel, A. R., Gallegos-Infante, J. A., Toro-Vázquez, J. F., Pérez-Martínez, J. D., Rosas-Flores, W. and González-Laredo, R. F. (2022). Organogel-based emulsified systems, food applications, microstructural and rheological features—A review. Biointerface Research in Applied Chemistry, 12(2): 1601–1627.
7. Demirkesen, I. and Mert, B. (2020). Recent developments of oleogel utilizations in bakery products. Critical Reviews in Food Science and Nutrition, 60(14): 2460-2479.
8. Doan, C. D., Tavernier, I., Sintang, M. D. B., Danthine, S., Van de Walle, D., Rimaux, T. and Dewettinck, K. (2017). Crystallization and gelation behavior of low-and high melting waxes in rice bran oil: a case-study on berry wax and sunflower wax. Food Biophysics, 12(1): 97-108.

9. Du, L., Jiang, Q., Li, S., Zhou, Q., Tan, Y. and Meng, Z. (2021). Microstructure evolution and partial coalescence in the whipping process of oleofoams stabilized by monoglycerides. Food Hydrocolloids, 112: 106245.
10. Erenler, S., Bilgin, O., Balkan, A., Göçmen, D. B. and Başer, İ. (2024). Investigation of grain yield and biscuit quality capacities of soft bread wheat (Triticum aestivum L.) advanced lines. Journal of Tekirdag Agricultural Faculty, 21(3): 807–815.
11. Holey, S. A., Sekhar, K. P. C., Mishra, S. S., Kanjilal, S. and Nayak, R. R. (2021). Effect of oil unsaturation and wax composition on stability, properties and food applicability of oleogels. Journal of the American Oil Chemists’ Society, 98(10): 1189–1203.
12. Hwang, H. S., Singh, M. and Lee, S. (2016). Properties of cookies made with natural-wax/vegetable-oil organogels. Journal of Food Science, 81(5): C1045–C1054.
13. Jang, A., Bae, W., Hwang, H. S., Lee, H. G. and Lee, S. (2015). Evaluation of canola-oil oleogels with candelilla wax as an alternative to shortening in baked goods. Food Chemistry, 187: 525–529.
14. Li, S., Zhu, L., Li, X., Wu, G., Liu, T., Qi, X. et al. (2022). Determination of characteristic evaluation indexes for novel cookies prepared with wax oleogels. Journal of the Science of Food and Agriculture, 102: 5544–5553.
15. Mattice, K. D. and Marangoni, A. G. (2017). New insights into wax-crystal networks in oleogels. In: Edible Oil Structuring: Concepts, Methods and Applications, Ed(s): Patel, A. R., Royal Society of Chemistry, U. K.
16. Mert, B. and Demirkesen, I. (2016). Evaluation of highly unsaturated oleogels as shortening replacer in a short dough product. LWT – Food Science and Technology, 68: 477–484.
17. Noonim, P., Rajasekaran, B. and Venkatachalam, K. (2022). Structural characterization and peroxidation stability of palm oil-based oleogel made with different concentrations of carnauba wax and processed with ultrasonication. Gels, 8(12): 763.
18. Pang, M., Kang, S., Liu, L., Ma, T., Zheng, Z. and Cao, L. (2023). Physicochemical properties and cookie-making performance of wax-based rice-bran-oil oleogels as fat replacers. Gels, 9(1): 13.
19. Patel, A. R. and Dewettinck, K. (2015). Comparative evaluation of structured oil systems: Shellac oleogel, HPMC oleogel, and HIPE gel. European Journal of Lipid Science and Technology, 117: 1772–1781.
20. Patel, A. R., Cludts, N., Bin Sintang, M. D., Lesaffer, A. and Dewettinck, K. (2014). Edible oleogels based on water-soluble food polymers: Preparation, characterization and potential application. Food Function, 5(11): 2833–2841.
21. Piekarska, K., Sikora, M., Owczarek, M., Jóźwik-Pruska, J. and Wiśniewska-Wrona, M. (2023). Chitin and chitosan as polymers of the future: Obtaining, modification, life-cycle assessment and main application directions. Polymers, 15(4): 793.
22. Pinto, T. C., Martins, A. J., Pastrana, L., Pereira, M. C. and Cerqueira, M. A. (2021). Oleogel-based systems for the delivery of bioactive compounds in foods. Gels, 7(3): 86.
23. Roche, H. M. (2005). Fatty acids and the metabolic syndrome. Proceedings of the Nutrition Society, 64(1): 23–29.
24. Romani, S., Rocculi, P., Tappi, S. and Dalla Rosa, M. (2016). Moisture adsorption behaviour of biscuit during storage investigated by using a new Dynamic Dewpoint method. Food chemistry, 195: 97-103.
25. Silva, P. M., Martins, A. J., Fasolin, L. H. and Vicente, A. A. (2021). Modulation and characterization of wax-based olive-oil organogels for food-industry applications. Gels, 7(1): 12.
26. Wang, X., Wang, S., Nan, Y. and Liu, G. (2021). Production of margarines rich in unsaturated fatty acids using oxidative-stable vitamin C-loaded oleogel. Journal of Oleo Science, 70(8): 1059–1068.
27. Wettlaufer, T. and Flöter, E. (2022). Wax-based oleogels and their application in sponge cakes. Food Function, 13: 9419–9433.
28. World Health Organization (2018). WHO plan to eliminate industrially produced trans-fatty acids from the global food supply. https://www.who.int/news/item/14-05-2018-who-plan-to-eliminate-industrially-produced-trans-fatty-acids-from-global-food-supply (Accessed Date: 13.12.2025).
29. Yılmaz, E., Keskin Uslu, E. and Öz, C. (2021). Oleogels of some plant waxes: Characterization and comparison with sunflower-wax oleogel. Journal of the American Oil Chemists’ Society, 98(6): 643–655.
30. Żarnowski, A., Jankowski, M. and Gujski, M. (2022). Public awareness of diet-related diseases and dietary risk factors: A 2022 nationwide cross-sectional survey among adults in Poland. Nutrients, 14(16): 3285.
31. Zhang, R. F., Zhang, T., Hu, M. Y., Xue, Y. and Xue, C. H. (2021). Effects of oleogels prepared with fish oil and beeswax on the gelation behaviour of protein recovered from Alaska pollock. LWT – Food Science and Technology, 137: 110423.