| Sacha Inchi is a a kind of excellent oil plant of euphorbiaceae perennial woody vines, which are widely distributed in southwest in China. Nuts contain fat(43~47%),protein(25~30%), total sugar(3~4%) and a variety of minerals, vitamins and other ingredients. So far, Sacha Inchi seed has just been used to produce oil due to high content of unsaturated fatty acids and unique physical and chemical indicator. Defatted nut contains plenty of protein, as high as 60%, While it is underutilized. Therefore the current urgent solution is how to realize its high effective utilization. In this work,physicochemical, functionality, and immune activity in vitro of defatted nut were comprehensive studied. The main results are as per following:(1) The basic ingredients of defatted Sacha Inchi and the optimal extraction conditions of albu minDefatted Sacha Inchi contain 59.1% protein and 20% fat, Four components were separated from the protein, The content of these fractions were as follows:albumin(43.7%),globulin(22.3%), prolamine(3.0%)),glutelin(31.9%).Comparing two kinds of pretreatment of enzymatic hydrolysis and ultrasound,It is clearly indicated that ultrasonic can be improve the extraction yield of albumin significantly. The acting conditions are: power 1000 W, time: 15 min. Using the response surface test, the conditions for best protein yield are: solid-to-liquid M1: 27(g/m L), acting temperature: 41℃, acting time: 5 h. The yield of albumin was 53.6%.(2)The physical and chemical properties of AlbuminAnalysis on a mino acids composition of albumin showed that albumin had good nutritional quality(TEAA/TAA>40%); Compared with other protein, albumin contains higher tyrosine, methionine, tryptophan and threonine, The branched chain a mino acids of albumin(19%) slightly lower than the whey protein23%, albumin is a good source of sulfur-containing a mino acids( 3.7%); The protein fractions showed an excellent balance of a mino acids except for a lacking of methionine and cystine; Compared with soybean protein, AAS of albumin was higher than that of soybean protein, PER is slightly lower than that of soybean protein, and SRCAA was significantly lower than soybean protein due to the the unusually high content of albumin tryptophan(43mg/g). Only PER and SRCAAwere significantly lower than that of whey protein,the rest indicators were higher than the whey protein. Albumin is a promising resource of vegetable proteins with high nutritional values.SDS-PAGE analysis showed that three bands at Mr 27.53, 24.55, 9.0k Da; The p I of albumin is 10.0; FTIR and DSC analysis both indicated that the endothermic peak of albumin was 100±1℃, So, albumin has good thermal stability. CD analysis shows that the denaturation temperature of albumin solution is 60~70℃, shows that moisture content will affect the thermal stability of albumin;The analysis of FTIR spectra of the amide I band showed that albumin contain more β-folding and β-angle structure, the contents of which were 37.2%, 38.21%, the α-helix was relatively small, containing 24.6%, the secondary structure of albumin is highly ordered.Surface hydrophobicity analysis showed that the albumin under the condition of p I=10 has the relative min-inedx of H0, and H0 has no significant difference from 15℃ to65℃, there was a sharp rise after 65 ℃; Salt addition could enhance the surface hydrophobicity of albumin.(3) The results of the functional properties of albuminAlbumin possessed a better sensory acceptability, foaming and solubility properties compared with SPI, while a relatively low in water holding, fat absorption and emulsifying capacity, foaming ability(342%) is 3.4 times of the soybean protein. Albumin solubility is better than Sacha Inchi protein which was obtained from alkali acid sinking method and spray drying process,and there are no significant differences in foaming properities compared with the total protein, But the holding water,fat absorption and emulsification is far less than the total protein.At room temperature, albumin emulsification maximum value is 12.21 m L/g, only one-third of total protein, which limited its functionality potential.(4)The results of cell experiment on immune activitySpleen lymphocyte immune activity in vitro analysis indicated that albumin at a concentration ranging from 5 to 320 μg/m L resulted in a significant increase of lymphocyte proliferation, and had synergistic effect with Con A and LPS from10 to 40 μg/m L, it also can promote the lymphocyte secretion of TNF-α(p < 0.05), but the activation of IL-2secretion was not obvious; albumin could enhance the mouse peritoneal macrophage phagocytic function at a concentration ranging from 5 to 80 μg/m L, significantly inhibit the H2O2 production of LPS-stimulated macrophage and enhance the activities of acidphosphatase in serum at the same dosage of 5 to 160 μg/m L, At the same time significantly increase the secretion of NO under LPS-stimulated with a dose dependent effect, but albumin inhibited the activation of macrophage at a the dosage of 320μg/m. Albumin could increased the activities of phagocytosis, the killing tumor cell at a concentration ranging at a special concentration, demonstrating good immune activity, promising to be developed into an immunoregulation food by further studies. |
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