Crown Fruit Seeds For The Quality Of Its Oils And Fats And Protein Resource Use

Shinyleaf yellowhorn (Xanthoceras sorbifolia Bunge) is a unique medicinal and oil woody plant, which is widely distributed in northern districts of China. Shinyleaf yellowhorn also is multi-purpose plant and has extremely high developing value. It can be used in ornament, ecology, food, environment, medicine, wood, and biological energy industry. In this dissertation, shinyleaf yellowhorn seed were studied further. The quality of shinyleaf yellowhorn kernel(the curly embryo in the seed), oil extraction technology, protein extraction and its function, edible safety of kernel oil and oil antioxidant activity were discussed respectively. This systematical research was expected to provide theoretical basis and technology parameters for the development and deep-processing of Shinyleaf yellowhorn.The dissertation study contents and results are following:1. The quality of shinyleaf yellowhorn seed and kernel which come from different district were studied.The analysis result of quality showed that there was no difference in seed's (from seven districts) shape and color, but there is small difference in seed size. There was significant difference (p< 0.01) in those indexes of weight/1000 seeds, weight/lL seeds, kernel/shell ratio, water content of kernel and ash content of kernel.There also have variances in quality index of shinyleaf yellowhorn kernel. The average content of oil and protein in kernel was 60% and 25.64% respectively, and there is significant difference in this two indexes(p< 0.01). The oil fatty acid was composed with oleic acid, linoleic acid, erucic acid, 11-eicosenoic acid, palmitic acid,15-Tetracosenoic acid, stearic acid, and so on. The acid value and peroxide value of cold pressing oil was 0.601 mgKOH/g and 0.16meq/kg, the iodine value was 121.4g/100g, so shinyleaf yellowhorn kernel oil was a very good resource for edible and functional oil.The average content of amino acid in kernel protein was 188.61 mg/g. Kernel protein contains seventeen amino acids in crude protein of shinyleaf yellowhorn kernel, and including seven essential amino acids (its average content is 53.80 mg/g, and of total amino acids 28.53%). There also has great significant difference of amino acid content in kernel protein from seven districts(p< 0.01), especially in seven essential amino acids. The biggest difference exists in methionine content (CV=85.92%), and the bigger difference was exist in tyrosine and serine content (CV=31.16%, CV=30.43%) respectively.There has significant difference in nutritional and mineral element content of N, K, Mg, P, Fe, Zn, Mn, Ba(p< 0.01). The biggest difference exists in the content of barium and the coefficient of variance (CV) was 61.59%. There also has significant difference in the contents of VE, VB1,VB2. The biggest difference exists in the content of VB1(CV=68.0%), and followed by VE(CV=44.1%) and VB2(CV=40.62%).In a word, the seed and kernel quality which associated with the nutrition was influenced greatly by the soil and environmental factors. There was great difference in seed and kernel from different district. The best quality of kernel relatively for shinyleaf yellowhorn was from ZHI Dan, SHAAN Xi.2. The technology conditions of cold pressing, aqueous enzymatic extraction, microwave and ultrasonic assistant extraction were determined respectively using shinyleaf yellowhorn kernel powder as material.(1) The cold pressing conditions were:pressure was (5.5±0.2) Mpa, ratio of kernel to husk was 9:1(g/g), pressing time was 8h. Under this condition, the oil yield was 40.44% and extraction ratio was 63.2%.(2) The optimal conditions of microwave assistant extraction by orthogonal experiments were as follows:material/solvent ratio was 1:16(g/mL), extracting time 20min, temperature 75℃, microwave power 100 W, the optimal solvent was ligarine (60～90℃). Under this condition, the oil yield was 53.27% and extraction ratio was 81.95%.(3) With ligarine (60～90℃) as optimal solvent, through quadratic regression orthogonal rotational test, the optimal technology parameters of ultrasonic assistant extraction should be: solid/liquid ratio 1:10(g/mL), extract temperature 60℃, extraction time 35min, ultrasonic frequency 60 kHz. Under this condition, the oil yield was 60.18%, extraction ratio was 92.47%. The mathemat regression model (Y= 51.12500+0.91792X,-0.88042X2+1.26542X3-0.69292 X4-0.89010X12-0.50635 X22-0.53385X32-0.62385X42-0.68313X2X4) was established using response surface analysis, which was able to predict the oil extraction rate of shinyleaf yellowhorn kernel accurately. The order of factors that influence the oil extraction rate within the experimental ranges was as follows:extraction time> solid/liquid ratio>extraction temperature>ultrasoriic frequency.(4) Through single factor and orthogonal tests, the optimal parameters of shinyleaf yellowhorn kernel oil with aqueous enzymatic method were as follows:solid/liquid ratio is 1:6(g/mL), temperature 45℃, dosage of alkaline protease (pH7.0) 3.0%, dosage of cellulose (pH4.5) 1.0%, enzymatic hydrolysis time 8h (4h receptively). Under this condition, the oil yield was 52.78%, extraction ratio was 81.2%. Among the above four technologies, the quality of cold pressing oilis best, but oil and protein could be obtained by aqueous enzymatic method, the extraction ratio was biggest with ultrasonic assistant extraction, and there was short time, low cost of oil extraction using microwave assistant method.The oxidative stability of shinyleaf yellowhorn kernel oil was best. When the oil was added into combined anti-oxidants (0.02%TBHQ+0.01%Vc), it could be storied about 30 months at room temperature.3. Using Alkali-Solution and Acid-Isolation method, the optimal extraction parameters of shinyleaf yellowhorn kernel protein were as following:liquid/solid ratio 11:1 (mL/g), pH 11, extracting time 73 min, extracting temperature 49℃, protein yield was 84.66%. The mathematic model (Y= 82.64+3.98 X,+3.56 X2+3.04 X3+5.11 X2X3-4.40 X12-6.63 X22-5.89 X32-6.79 x42) was obtained through the method of response surface analysis, and it could predict the yield of protein exactly.The shinyleaf yellowhorn kernel was an excellent protein resource. The complete range of essential amino acid is involved in shinyleaf yellowhorn kernel protein; 75 score was get according to WHO method with great nutritious value. The protein isoelectric point was 4.6. The protein has good functional properties, such as oil absorption capacity, water absorption capacity, oil emulsification capacity and stability. It can be used as food additives and emulsifier in food industry, and has broad application prospects.4. The edible security of cold pressing oil from shinyleaf yellowhorn kernel was evaluated through acute toxicity, genetic toxicity tests, and 30 days feeding test. The results of acute toxicity test indicated that kernel oil was non-toxicity. The three genetic toxicity tests were all negative. The 30 days feeding of sub acute toxicity test of shinyleaf yellowhorn kernel oil showed that SD rats had no obvious poisoning and death symptoms. Compared with the negative control group, there was no significant difference of TP, AST, ALB, ALT, BUN, GLU of SD rats'blood biochemical parameters, and CHO, TG were within the normal reference range. But CRE values of SD rats were higher than the reference range in three dose group. The further research may be required to determine the animal testing results.5. In vitro antioxidant activity test of shinyleaf yellowhorn kernel oil indicated that it has good scavenging effect on-OH and-O2-and has strong scavenging effect on DPPH-. Test results also show that the reduction capacity of shinyleaf yellowhorn kernel oil is greater than BHT and TBHQ, and it has good inhibition of Fe2+induced lipoprotein peroxidation PUFA reaction at higher concentration of oil.In vivo antioxidant activity test of shinyleaf yellowhorn kernel oil shows that it has significant anti-oxidation activity. Because it can improve the mice's catalase, superoxide dismutase, and glutathione peroxidase activity significantly of their liver and brain tissue, and it also has a great reduction in malonaldehyde content of these mice's tissues.6. The chemical and physical analysis results show that the shinyleaf yellowhorn kernel oil relative density and freezing point was 0.9144 and-15℃respectively (it was higher than diesel, lower than other pant oil, such as soybean oil). The oil hexadecane value was 37(it was higher than soybean oil, rapeseed oil), residual C was 0.22%(it was lower than other pant oil, such as soybean oil), and the oil thermal value was get to 9488Kcal/kg. The analysis results of fatty acid composition for shinyleaf yellowhorn kernel oil showed that its composition and property was close to diesel by Gas chromatography-Mass spectrometry. So shinyleaf yellowhorn kernel oil was a best biodiesel material in China.7. With alkali as catalyst, using shinyleaf yellowhorn kernel oil as raw materials, the Ultrasonic-assisted optimal synthesis technologies of biodiesel were as follow:the amount of KOH and methanol was 1.2%(w/w) and 30%(v/v) respectively; reacting temperature and time was 50℃and 40min respectively. Under this condition, the conversion rate was 93.7% with once transesterification, and twice transesterification's conversion rate was improved to 96.7%. The mathematic model (Y= 88.00833+3.60000X1+3.10833X2+2.27500X3+3.28333X4-1.43125X22) was obtained through quadratic regression orthogonal rotational combination design. The theoretical predictions value of this regression module was as same as synthesis test, and the conversion rate of shinyleaf yellowhorn kernel oil was as high as its prediction.Using immobilized lipase (Novo435) as catalyst, the optimum synthesizing technology of biodiesel was as follows:the 28 KHz ultrasonic assisting time 60 min, petroleum ether (60～90℃) amount 20mL/10goil, reacting temperature 50℃, the molar ratio of methanol to oil 1.5:1, and lipase amount 10%(by the weight of the oil). Under this condition, the ester conversion was 93.84%through three steps transesterification reaction when total reacting time was 3 h. The Novo435 can be used six times repeatedly.According to the production cost and product separation, the synthesize biodiesel method with immobilized lipase (Novo435c) as catalysis was superior to the method with alkali as catalyst.