Hydrothermal Degradation of Fats, Carbohydrates and Proteins in Sunflower Seeds after Treatment with Subcritical Water

• Published in: Chemical and Biochemical Engineering Quarterly Vol. 29; no. 3; pp. 351 - 355
• Main Authors: Ravber, M, Knez, Z, Skerget, M
• Format: Journal Article Paper
• Language: English
• Published: Croatian Association of Chemical Engineers 14.10.2015; Hrvatsko društvo kemijskih inženjera i tehnologa
• Subjects: Carbohydrates; Chemical properties; Composition; Decomposition (Chemistry); Fat; free fatty acids; hydrothermal degradation; Identification and classification; Observations; Proteins; subcritical water; Sunflower seed; Thermal properties
• ISSN: 0352-9568; 1846-5153
• DOI: 10.15255/CABEQ.2015.2193

In this study, the hydrothermal degradation of fats, carbohydrates and proteins in sunflower seeds after treatment with subcritical water was observed. Sunflower seeds were subjected to subcritical water in a wide temperature range (130-240°C) for periods from 5 to 120 minutes. The oil- and water-soluble phases were analysed for products of hydrothermal degradation. Oil stability was investigated by analysing the content of free fatty acids using gas chromatography. The water-soluble phase was analysed for the presence of any formed amino acids, and the amount of carbohydrates remaining after treatment was determined. Total amino acids and carbohydrates were determined using the ninhydrin and phenol/sulphuric acid spectrophotometric methods, respectively. The results show that oils are the most stable macronutrient present in sunflower seeds. Only small amounts of free fatty acids had formed during processing but the amount drastically started to increase at 240°C. Proteins seem to be less stable than oils, whereas carbohydrates have proven to be very susceptible to hydrothermal degradation. Key words: subcritical water, hydrothermal degradation, free fatty acids, carbohydrates, proteins