The Studies On Comprehensive Processing Of Cold-pressed Sesame Products

The cold-pressed sesame products include cold-pressed sesame oil, mixed sesame oil which was used for separation and purification of sesamin, and sesame meal which was used for preparation of alcohol leached sesame protein concentrates. The sesame protein concentrates was then modified by physical methods.The moisture and volatile matter content, insoluble impurities content, acid value, peroxide value of cold-pressed sesame oil were all better than1st grade fragrant sesame oil. The content of sesamin was3.82mg/g and the content of VE was659.66mg/kg in cold-pressed sesame oil, which were all higher than1st grade fragrant sesame oil. There were86.31%unsaturated fatty acids and no trans fatty acids in cold-pressed sesame oil, so it was more healthy.The optimized processing conditions of adsorption and desorption of macroporous adsorption resin DA-201for sesamin from mixed sesame oil were found to be:the concentration of sesamin was about3.0mg/mL, adsorption flow rate was3.0BV/h, the elution solvent was8.0BV of95%(v/v) ethanol and desorption flow rate was3.0BV/h. Under these conditions, the concentration of sesamin in desorption product increased nearly12-fold and the recovery ratio of sesamin was85.21%. The desorption product was then crystallized. The final sesamin product had a purity of sesamin up to89.49%and a recovery ratio of sesamin up to62.06%. The impurity was sesamolin determined by HPLC-MS.Preparation of sesame protein concentrates using aqueous alcohol from sesame meal. The effects of alcohol concentration, ratio of liquid to solid, extraction temperature and time on the protein content were investigated. By single factor and response surface methodology experiment design, the optimized processing conditions were found to be:alcohol concentration64%(v/v), ratio of liquid to solid4.8:1(v/g), extraction temperature49℃and time54min. Under these conditions, the protein content, products’ yield and NSI of sesame protein concentrates was66.68%,86.30%and3.43%respectively.Firstly examined the effects of three physical modification methods including heating, microwave and ultrasound treatment on the functional properties of sesame protein concentrates, and the results showed ultrasound treatment was the best method. The optimized processing conditions were then found by single factor and orthogonal tests of L9(34) to be:ultrasound power400W, modification time3.0min, protein concentration9%(w/v) and pH10. Under these conditions, the NSI of sesame protein concentrates increased from3.43%to46.25%, and the oil binding capacity increased from0.61g/g to2.80g/g, the emulsifying capacity increased from0.15to0.23, the emulsifying stability increased from19.10min to38.63min, the foaming capacity increased from30.78%to47.23%, the foaming stability increased from38.89%to57.84%.