Effect of pH-shifting method on solubility and emulsifying properties of soy protein concentrate

Yıl 2019, Cilt: 23 Sayı: 2, 159 - 166, 18.06.2019

Gülçin Yıldız

https://doi.org/10.29050/harranziraat.427438

Cited By: 7

Öz

The purpose
of the current study was to investigate the influence of pH shifting process on
soy protein concentrate to improve its functional properties. In this work, pH
of the soy protein concentrate was adjusted to pH 2, 3, 4, 10, 11, and 12 prior
to neutral pH (pH 7). pH-shifting process effectively improved the solubility
of soy protein concentrate, whereas the modification of the samples with the
acidic conditions was less pronounced. The alkaline pH values (pH 10, 11, and
12) showed higher solubility compared to the acidic pH values (pH 2, 3, and 4).
With the pH 12 treatment, approximately 30 times higher solubility was
achieved. Among the treatments, the pH 12- treated samples showed the improved
emulsifying properties with the highest emulsifying activity and stability
indexes. All pH treated samples (pH 2, 3, 4, 10, 11, 12) showed less turbidity
with smaller particle sizes where the untreated samples showed most turbid
structure with the biggest particle size.

Anahtar Kelimeler

pH-shifting, Solubility, Soy protein concentrate, Emulsifying properties, Particle size

PH-değişim metodunun soya protein konsantresinin çözünürlüğü ve emülsiyon özellikleri üzerine etkisi

Öz

Bu
çalışmanın amacı, pH değişiminin soya protein konsantresinin fonksiyonel
özelliğini artırmaya yönelik etkisini araştırmaktır. Bu çalışmada, soya protein
konsantresinin pH değeri, nötr pH (pH 7)’dan önce sırasıyla pH 2, 3, 4, 5, 10,
11, ve 12’ye ayarlanmıştır. pH-değişim işlemi, soya protein konsantresinin
çözünürlüğünü etkili bir şekilde artırırken, bu artış asidik koşullar altında
muamele edilen numunelerde daha az gözlenmiştir. Alkalin pH değerleri (pH 10,
11 ve 12), asidik pH değerlerine (pH 2, 3 ve 4) kıyasla daha yüksek çözünürlük
göstermiştir. pH 12 ile muamele edilen örneklerde yaklaşık 30 kat daha fazla
çözunürlük elde edilmiştir. Örnekler
arasında, pH 12 ile muamele edilen numuneler en yuksek emülsiyon aktivite ve
stabilite değerlerini göstermişlerdir. Farklı pH değerleriyle muamele edilen
örneklerin hepsi, asidik veya alkalin olmasına bakılmaksızın, kontrol
örneklerine kıyasla daha küçük parçacık boyutu ve daha az bir bulanıklık
sergilemişlerdir.

Anahtar Kelimeler

pH değişim, Çözünürlük, Soya protein konsantresi, Emülsiyon özellikleri, Parçacık boyutu

Kaynakça

• Bolontrade, A. J., Scilingo, A. A., & Anon, M.C. (2013). Amaranth proteins foaming properties: Adsorption kinetics and foam formation—Part 1. Colloids and Surfaces B: Biointerfaces, 105, 319–327.
• Bradford, M.M. (1976). A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry, 72, 248-254.
• Campbell, M.F., Kraut, C.W., Yackel, W.C., & Yang, H.S. (1985). Soy Protein Concentrate, in New Protein Foods. Altschul and Wilke Eds. Vol. 5, p 301.
• Choi, J.Y., & Kim, J. (2005). Fish protein recovered using pH shifting method and its physicochemical properties. Journal of Ocean University of China, 4(3), 224-228.
• Elizalde, B.E., Bartholomai, G.B., & Pilosof, A.M.R. (1996). The effect of pH on the relationship between hydrophilic/lipophilic characteristics and emulsification properties of soy proteins. LWT-Food Science and Technology, 29, 334–339.
• Goto, Y. (1989). Conformational states of ß-lactamase: Molten-globule states at acidic and alkaline pH with high salt. Biochemistry, 28(3), 945-952.
• Goto, Y., Calciano, L. J., & Fink, A. L. (1990). Acid-induced folding of proteins. Proceedings of National Academy of Sciences of the United States, 87, 573–577.
• Hu, H., Wu, J., Li-Chan, E.C.Y., Zhu, L., Zhang, F., Xu, X., Fan, G., Wang, L., Huang, X., & Pan, S. (2013). Effects of ultrasound on structural and physical properties of soy protein isolate (SPI) dispersions. Food Hydrocolloids, 30 (2), 647-655.
• Jambrak, A., Mason, T., Lelas, V., Herceg, Z., & Herceg, I. (2008). Effect of ultrasound treatment on solubility and foaming properties of whey protein suspensions. Journal of Food Engineering, 86 (2), 281–287.
• Jiang, J., Chen, j., & Xiong, Y.L. (2009). Structural and emulsifying properties of soy protein isolate subjected to acid and alkaline pH-shifting processes. Journal of Agricultural and Food Chemistry, 57 (16), 7576–7583.
• Jiang, J., Xiong, Y.L., & Chen, J. (2010). pH shifting alters solubility characteristics and thermal stability of soy protein isolate and its globulin fractions in different pH, salt concentration, and temperature conditions. Journal of Agricultural and Food Chemistry, 58 (13), 8035–8042.
• Jiang, J., Xiong, Y.L., & Chen, J. (2011). Role of ß-conglycinin and glycinin subunits in the pH-shifting-induced structural and physicochemical changes of soy protein isolate. Journal of Food Science, 76 (2), 293–302.
• Jiang, J., Zhu, B., Liu, Y., & Xiong, Y. (2014). Interfacial structural role of pH-shifting processed pea protein in the oxidative stability of Oil/Water emulsions. Journal of Agricultural and Food Chemistry, 62(7), 1683-1691.
• Kristinsson, H.G., & Hultin, H.O. (2003). Changes in conformation and subunit assembly of cod myosin at low and high pH and after subsequent refolding. Journal of Agricultural Food Chemistry, 51, 7187–7196.
• Kristinsson, H. G., & Hultin, H.O. (2004). Changes in trout hemoglobin conformations and solubility after exposure to acid and alkali pH. Journal of Agricultural Food Chemistry, 52, 3633–3643.
• Lee, H., Yildiz, G., Dos Santos, L.C., Jiang, S., Andrade, J., Engeseth, N.C., & Feng, H. (2016). Soy protein nano-aggregates with improved functional properties prepared by sequential pH treatment and ultrasonication. Food Hydrocolloids, 55, 200–209.
• Li, Y., Chen, Z., & Mo, H. (2007). Effects of pulsed electric fields on physicochemical properties of soybean protein isolates. LWT-Food Science and Technology, 40, 1167-1175.
• Liang, Y., & Kristinsson, H. G. (2007). Structural and foaming properties of egg albumen subjected to different pH-treatments in the presence of calcium ions. Food Research International, 40, 668–678.
• Manassero, C.A., Vaudagna, S.R., Anon, M.C., & Speroni, F. (2015). High hydrostatic pressure improves protein solubility and dispersion stability of mineral-added soybean protein isolate. Food Hydrocolloids, 43, 629-635.
• Molina, E., Papadopoulou, A., & Ledward, D.A. (2001). Emulsifying properties of high pressure treated soy protein isolate and 7S and 11S globulins. Food Hydrocolloids, 15, 263–269.
• Palazolo, G., Sorgentini, D., & Wagner, J. (2005). Coalescence and flocculation in o/w emulsions of native and denatured whey soy proteins in comparison with soy protein isolates. Food Hydrocolloids, 19(3), 595-604.
• Pearce, K.N., & Kinsella, J.E. (1979). Emulsifying properties of proteins: evaluation of a turbidimetric technique. Journal of Agricultural and Food Chemistry, 26, 716–723.
• Puppo, M.C., Speroni, F., Chapleau, N., De Lamballerie-Anton, M., Anon, M.C., & Anton, M. (2005). Effect of high-pressure treatment on emulsifying properties of soybean proteins. Food Hydrocolloids, 19, 289–296.
• Santiago, L., Gonzalez, R., Remondetto, G., & Bonaldo, A. (1998). Emulsifying ability of proteins evaluated by response surface methodology. Food Science and Technology-Lebensmittel-Wissenschaft & Technologie, 31(3), 259-264.
• Tsumura, K., Saito, T., Tsuge, K., Ashida, H., Kugimiya, W., & Inouye, K. (2005). Functional properties of soy protein hydrolysates obtained by selective proteolysis. LWT-Food Science and Technology, 38, 255-261.
• Yildiz, G., Andrade, J., Engeseth, N.C., & Feng, H. (2017). Functionalizing soy protein nano-aggregates with pH-shifting and mano-thermo-sonication. Journal of Colloid and Interface Science, 505, 836-846.
• Zhang, Q., Tu, Z., Xiao, H., Wang, H., Huang, X., Liu, G., Liu, C., Shi, Y., Fan, L., & Lin, D. (2014). Influence of ultrasonic treatment on the structure and emulsifying properties of peanut protein isolate. Food and Bioproducts Processing, 92, 30–37.
• Zhang, Q., Tu, Z., Wang, H., Huang, X., Fan, Z.L., Bao, H., & Xiao, H. (2015). Functional properties and structure changes of soybean protein isolate after subcritical water treatment. Journal of Food Science and Technology, 52, 3412-3421.