Nastaran Akbari1, Jafar Mohammadzadeh Milani1, Pourya Biparva2. 1. Department of Food Science and Technology, Sari Agricultural Sciences and Natural Resources University, Sari, Iran. 2. Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.
Abstract
BACKGROUND: Potato protein hydrolysates (PPHs) were preparedwith Alcalase on intact potato protein isolates (PPI), with differenthydrolysis times (0.5-4 h), and functional and conformational properties of resultant hydrolysates were investigated. RESULTS: The degree of hydrolysis changed during incubation. Peptide bond cleavage increased and hydrolysis progressed rapidly. Gel electrophoresis showed that, by increasing the hydrolysis time, peptides with an apparent molecular weight below 20 kDa increased. It also revealed that, among potato protein components, patatin was more sensitive to Alcalase® hydrolysis than protease inhibitors. Enzymatic hydrolysis significantly enhanced the solubility and foam capacity of PPHs, but impaired foam stability (P < 0.05). Limited enzymatic hydrolysates (0.5PPH) at the interface improved the emulsion activity and stability index. These emulsions also had the smallest z-average and polydispersity index and showed the highest zeta potential. Fourier-transform infrared spectrometry (FTIR) analysis indicated extensive disruption of hydrogen bonds in PPHs, besides augmentation of α-helices and β-turns, and a decline in the β-sheets in the secondary structure of the PPHs was shown. CONCLUSION: Potato protein isolate, especially 0.5PPH, has good functional and conformational properties. Overall, our results provide new insights into the use of potato protein hydrolysates as a functional food component in the food industry.
BACKGROUND:Potato protein hydrolysates (PPHs) were preparedwith Alcalase on intact potato protein isolates (PPI), with differenthydrolysis times (0.5-4 h), and functional and conformational properties of resultant hydrolysates were investigated. RESULTS: The degree of hydrolysis changed during incubation. Peptide bond cleavage increased and hydrolysis progressed rapidly. Gel electrophoresis showed that, by increasing the hydrolysis time, peptides with an apparent molecular weight below 20 kDa increased. It also revealed that, among potato protein components, patatin was more sensitive to Alcalase® hydrolysis than protease inhibitors. Enzymatic hydrolysis significantly enhanced the solubility and foam capacity of PPHs, but impaired foam stability (P < 0.05). Limited enzymatic hydrolysates (0.5PPH) at the interface improved the emulsion activity and stability index. These emulsions also had the smallest z-average and polydispersity index and showed the highest zeta potential. Fourier-transform infrared spectrometry (FTIR) analysis indicated extensive disruption of hydrogen bonds in PPHs, besides augmentation of α-helices and β-turns, and a decline in the β-sheets in the secondary structure of the PPHs was shown. CONCLUSION:Potato protein isolate, especially 0.5PPH, has good functional and conformational properties. Overall, our results provide new insights into the use of potato protein hydrolysates as a functional food component in the food industry.