LAUSR

BACKGROUND In this study, the effects of seed weight (4, 8, and 12 g), extraction temperature (30, 60, and 90 °C) and pH (4, 7, and 10) on the yield of mucilage extraction from fenugreek seeds and its chemical properties, were investigated using response surface methodology. RESULTS The optimum condition for mucilage extraction was seed weight of 8.30 g, the temperature of 86.10 °C and pH 6.90. The results showed that the dry weight of extracted mucilage increased with increase and decrease of extraction temperature and pH, respectively at high seed weight. Increasing temperature and pH, increased the extraction yield and their effect was more considerable at low seed weight. The maximum carbohydrate content of mucilage was achieved at average levels of variables. The protein, flavonoid and total phenolic contents of extracted mucilage increased with increasing the temperature. Both flavonoid and total phenolic contents were maximum at neutral pH but, they were maximum at moderate and low levels of seed weight, respectively. Maximum antioxidant activity was obtained at the highest extraction temperature, seed weight of 8 g and neutral pH. The study of rheological properties indicated that extracted mucilage solution showed mainly elastic and shear thinning behavior. CONCLUSION The FTIR spectra of extracted mucilage exhibited the existence of polysaccharides and protein chains in fenugreek seeds mucilage. The XRD corroborated the presence of crystals in mucilage structure. The H NMR spectra confirmed the polysaccharides and protein composition of extracted mucilage. The maximum mucilage mass loss was observed at 190-350 °C in TGA. This article is protected by copyright. All rights reserved.